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MRI scans from cases 1 – 6 showing the status of the fornix. The MRI scan for case 1 shows a sagittal view; all other views are coronal. The fornix is present in cases 1, 2, 3 and 6, but is absent bilaterally in cases 4 and 5.
Source publication
A series of twelve cases, all of whom had received surgery for the removal of a colloid cyst in the third ventricle, was examined on a series of memory tests. The only consistent predictor of poor memory performance that could be detected from MRIs was the presence of bilateral interruption of the fornix, which occurred in three of the subjects. Al...
Contexts in source publication
Context 1
... and dizziness about 8 months prior to her surgery. A colloid cyst was identi fi ed and removed via a transcallosal approach in August 1993, when she was 41 years of age. Postoperative recovery was uneventful; she was discharged 6 days after surgery and resumed her work. An MRI 3 years after surgery, at the time of testing, con fi rmed the surgical approach and revealed that the middle one-third of the corpus callosum (~20 mm) was now absent ( Fig. 1). While the fornix appeared intact, there was evidence of a limited zone of pathology con fi ned to the region of the left medial pulvinar. The rest of the thalamus and the mammillary bodies appeared normal. There was evidence of mild ventricular enlargement in the left hemisphere that was con fi ned to the frontal horn and body of the left lateral ventricle (Table 1). Case 2 was a self-employed driver. At the age of 38 years he was admitted to hospital with symptoms of headaches and fainting. A week later a cyst was removed from the third ventricle via a right frontal approach (January 1995). His recovery was uneventful and he has resumed work as a driver. The MRI scans for this study were taken 32 months after surgery and revealed evidence of gliotic changes in the anterior aspect of the frontal horn of the right lateral ventricle, as a result of the surgical approach. The fornix was intact, but the ventricles appeared slightly larger than normal for his age (Fig. 1). All other regions, including the mammillary bodies, appeared normal. Testing occurred 18 months after surgery. Case 3 was a driver who, when aged 46 years, suffered from bouts of dizziness, headaches and nausea. CT scans revealed the presence of a cyst in the third ventricle which was removed via a right frontal approach (April 1994). He made an uneventful recovery and was later able to resume his job as a driver. An MRI scan 28 months after surgery, at the time of testing, revealed evidence of gliotic changes in the right frontal lobe corresponding to the region of approach, but the fornix, thalamus and mammillary bodies all appeared normal (Fig. 1). There was, however, modest ventricular enlargement in the right lateral ventricle associated with the region of surgical approach. The left lateral ventricle and third ventricles appeared normal, although the left hippocampus appeared slightly smaller than the right hippocampus. Case 4 was a banker who suffered symptoms of acute hydrocephalus at the age of 50. He was admitted to hospital and a right ventriculoperitoneal shunt was inserted. He recovered successfully, but 6 months later symptoms of headaches and unsteadiness recurred. An MRI scan indicated a colloid cyst in the third ventricle; this was then removed in September 1995 via a right frontal approach. He made a good physical recovery but signi fi cant and persistent memory problems were noted from that period. A series of MRI scans 3 weeks and then 4 months after surgery revealed moderate bilateral ventricular enlargement but no signs of damage or shrinkage in the thalamus, apart from a small indentation in the left anterior thalamus at the site of the cyst. Both the hippocampus and the mammillary bodies appeared normal. The left and right fornices were, however, both absent (Fig. 1). Apart from frontal damage resulting from the surgical approach, no other pathology could be discerned. Testing occurred 10 months after the colloid cyst surgery. Case 5 was a 27-year-old farmer who suffered from severe headaches and nausea. Following admittance to hospital in Dublin he received a ventriculoperitoneal shunt. Six days later he had surgery (July 1992) for the removal of a third ventricular colloid cyst, the approach being through the right frontal cortex. Five months later he had an epileptic seizure, but had not suffered a seizure during the months preceding the current study. Fifteen months after his original surgery the ventriculoperitoneal shunt was replaced. Following the surgery for a cyst, he returned to work as a labourer. An MRI scan 4 years after surgery, at the time of testing, revealed complete bilateral interruption of the fornix at the anterior aspect of the tract (Fig. 1). There was also moderate, bilateral dilation of the lateral ventricles and the third ventricle. This dilation extended to the right temporal horn, and both hippocampi appeared slightly smaller than normal The thalamus, cingulate cortices and corpus callosum appeared intact, although there was signi fi cant damage in the right frontal cortex at the site of the surgical tract. The mammillary bodies appeared shrunken. Case 6 was a marketing executive. Following a combination of severe headaches and right facial numbness at the age of 24 years, she was admitted to hospital and 3 days later a cyst was removed via a transcallosal approach (December 1995). Recovery was uneventful and she was able to return to her previous work. An MRI scan 10 months after surgery, at the time of testing, revealed the loss of the middle third (20 mm) of the corpus callosum, with restricted damage to the right cingulum. The left lateral ventricle was of normal size but the right lateral ventricle showed mild dilation associated with the surgery. The thalamus and mammillary bodies appeared normal (Fig. 1). Although the fornix was intact, there were signs of thinning of the right fornix. In addition, the right hippocampus appeared slightly smaller than the left. Case 7 was a quali fi ed fi tter who was operated upon in Dublin in September 1988. He had complained of headaches and diplopia in 1984, but a scan at that date showed no colloid cyst. A diagnosis of aqueductal stenosis was con fi rmed and a ventriculoperitoneal shunt was installed, which was later removed. In 1988, at the age of 30 years, he again complained of headaches, and a scan now revealed the colloid cyst. The cyst was removed via a transcallosal approach the following week. Postoperatively he complained of memory impairments. An MRI scan 4 years after surgery showed that the middle third of the corpus callosum was now absent and that there was restricted damage to the adjacent cingulum (Fig. 2). It also showed that the fornix was completely interrupted. The lateral ventricles and the third ventricle appeared normal, as did the thalamus (Fig. 2). Both the mammillary bodies and the hippocampus appeared slightly shrunken. Testing occurred 8 years after his surgery. Case 8 was a retired fi reman. He complained initially ...
Context 2
... and dizziness about 8 months prior to her surgery. A colloid cyst was identi fi ed and removed via a transcallosal approach in August 1993, when she was 41 years of age. Postoperative recovery was uneventful; she was discharged 6 days after surgery and resumed her work. An MRI 3 years after surgery, at the time of testing, con fi rmed the surgical approach and revealed that the middle one-third of the corpus callosum (~20 mm) was now absent ( Fig. 1). While the fornix appeared intact, there was evidence of a limited zone of pathology con fi ned to the region of the left medial pulvinar. The rest of the thalamus and the mammillary bodies appeared normal. There was evidence of mild ventricular enlargement in the left hemisphere that was con fi ned to the frontal horn and body of the left lateral ventricle (Table 1). Case 2 was a self-employed driver. At the age of 38 years he was admitted to hospital with symptoms of headaches and fainting. A week later a cyst was removed from the third ventricle via a right frontal approach (January 1995). His recovery was uneventful and he has resumed work as a driver. The MRI scans for this study were taken 32 months after surgery and revealed evidence of gliotic changes in the anterior aspect of the frontal horn of the right lateral ventricle, as a result of the surgical approach. The fornix was intact, but the ventricles appeared slightly larger than normal for his age (Fig. 1). All other regions, including the mammillary bodies, appeared normal. Testing occurred 18 months after surgery. Case 3 was a driver who, when aged 46 years, suffered from bouts of dizziness, headaches and nausea. CT scans revealed the presence of a cyst in the third ventricle which was removed via a right frontal approach (April 1994). He made an uneventful recovery and was later able to resume his job as a driver. An MRI scan 28 months after surgery, at the time of testing, revealed evidence of gliotic changes in the right frontal lobe corresponding to the region of approach, but the fornix, thalamus and mammillary bodies all appeared normal (Fig. 1). There was, however, modest ventricular enlargement in the right lateral ventricle associated with the region of surgical approach. The left lateral ventricle and third ventricles appeared normal, although the left hippocampus appeared slightly smaller than the right hippocampus. Case 4 was a banker who suffered symptoms of acute hydrocephalus at the age of 50. He was admitted to hospital and a right ventriculoperitoneal shunt was inserted. He recovered successfully, but 6 months later symptoms of headaches and unsteadiness recurred. An MRI scan indicated a colloid cyst in the third ventricle; this was then removed in September 1995 via a right frontal approach. He made a good physical recovery but signi fi cant and persistent memory problems were noted from that period. A series of MRI scans 3 weeks and then 4 months after surgery revealed moderate bilateral ventricular enlargement but no signs of damage or shrinkage in the thalamus, apart from a small indentation in the left anterior thalamus at the site of the cyst. Both the hippocampus and the mammillary bodies appeared normal. The left and right fornices were, however, both absent (Fig. 1). Apart from frontal damage resulting from the surgical approach, no other pathology could be discerned. Testing occurred 10 months after the colloid cyst surgery. Case 5 was a 27-year-old farmer who suffered from severe headaches and nausea. Following admittance to hospital in Dublin he received a ventriculoperitoneal shunt. Six days later he had surgery (July 1992) for the removal of a third ventricular colloid cyst, the approach being through the right frontal cortex. Five months later he had an epileptic seizure, but had not suffered a seizure during the months preceding the current study. Fifteen months after his original surgery the ventriculoperitoneal shunt was replaced. Following the surgery for a cyst, he returned to work as a labourer. An MRI scan 4 years after surgery, at the time of testing, revealed complete bilateral interruption of the fornix at the anterior aspect of the tract (Fig. 1). There was also moderate, bilateral dilation of the lateral ventricles and the third ventricle. This dilation extended to the right temporal horn, and both hippocampi appeared slightly smaller than normal The thalamus, cingulate cortices and corpus callosum appeared intact, although there was signi fi cant damage in the right frontal cortex at the site of the surgical tract. The mammillary bodies appeared shrunken. Case 6 was a marketing executive. Following a combination of severe headaches and right facial numbness at the age of 24 years, she was admitted to hospital and 3 days later a cyst was removed via a transcallosal approach (December 1995). Recovery was uneventful and she was able to return to her previous work. An MRI scan 10 months after surgery, at the time of testing, revealed the loss of the middle third (20 mm) of the corpus callosum, with restricted damage to the right cingulum. The left lateral ventricle was of normal size but the right lateral ventricle showed mild dilation associated with the surgery. The thalamus and mammillary bodies appeared normal (Fig. 1). Although the fornix was intact, there were signs of thinning of the right fornix. In addition, the right hippocampus appeared slightly smaller than the left. Case 7 was a quali fi ed fi tter who was operated upon in Dublin in September 1988. He had complained of headaches and diplopia in 1984, but a scan at that date showed no colloid cyst. A diagnosis of aqueductal stenosis was con fi rmed and a ventriculoperitoneal shunt was installed, which was later removed. In 1988, at the age of 30 years, he again complained of headaches, and a scan now revealed the colloid cyst. The cyst was removed via a transcallosal approach the following week. Postoperatively he complained of memory impairments. An MRI scan 4 years after surgery showed that the middle third of the corpus callosum was now absent and that there was restricted damage to the adjacent cingulum (Fig. 2). It also showed that the fornix was completely interrupted. The lateral ventricles and the third ventricle appeared normal, as did the thalamus (Fig. 2). Both the mammillary bodies and the hippocampus appeared slightly shrunken. Testing occurred 8 years after his surgery. Case 8 was a retired fi reman. He complained initially ...
Context 3
... and dizziness about 8 months prior to her surgery. A colloid cyst was identi fi ed and removed via a transcallosal approach in August 1993, when she was 41 years of age. Postoperative recovery was uneventful; she was discharged 6 days after surgery and resumed her work. An MRI 3 years after surgery, at the time of testing, con fi rmed the surgical approach and revealed that the middle one-third of the corpus callosum (~20 mm) was now absent ( Fig. 1). While the fornix appeared intact, there was evidence of a limited zone of pathology con fi ned to the region of the left medial pulvinar. The rest of the thalamus and the mammillary bodies appeared normal. There was evidence of mild ventricular enlargement in the left hemisphere that was con fi ned to the frontal horn and body of the left lateral ventricle (Table 1). Case 2 was a self-employed driver. At the age of 38 years he was admitted to hospital with symptoms of headaches and fainting. A week later a cyst was removed from the third ventricle via a right frontal approach (January 1995). His recovery was uneventful and he has resumed work as a driver. The MRI scans for this study were taken 32 months after surgery and revealed evidence of gliotic changes in the anterior aspect of the frontal horn of the right lateral ventricle, as a result of the surgical approach. The fornix was intact, but the ventricles appeared slightly larger than normal for his age (Fig. 1). All other regions, including the mammillary bodies, appeared normal. Testing occurred 18 months after surgery. Case 3 was a driver who, when aged 46 years, suffered from bouts of dizziness, headaches and nausea. CT scans revealed the presence of a cyst in the third ventricle which was removed via a right frontal approach (April 1994). He made an uneventful recovery and was later able to resume his job as a driver. An MRI scan 28 months after surgery, at the time of testing, revealed evidence of gliotic changes in the right frontal lobe corresponding to the region of approach, but the fornix, thalamus and mammillary bodies all appeared normal (Fig. 1). There was, however, modest ventricular enlargement in the right lateral ventricle associated with the region of surgical approach. The left lateral ventricle and third ventricles appeared normal, although the left hippocampus appeared slightly smaller than the right hippocampus. Case 4 was a banker who suffered symptoms of acute hydrocephalus at the age of 50. He was admitted to hospital and a right ventriculoperitoneal shunt was inserted. He recovered successfully, but 6 months later symptoms of headaches and unsteadiness recurred. An MRI scan indicated a colloid cyst in the third ventricle; this was then removed in September 1995 via a right frontal approach. He made a good physical recovery but signi fi cant and persistent memory problems were noted from that period. A series of MRI scans 3 weeks and then 4 months after surgery revealed moderate bilateral ventricular enlargement but no signs of damage or shrinkage in the thalamus, apart from a small indentation in the left anterior thalamus at the site of the cyst. Both the hippocampus and the mammillary bodies appeared normal. The left and right fornices were, however, both absent (Fig. 1). Apart from frontal damage resulting from the surgical approach, no other pathology could be discerned. Testing occurred 10 months after the colloid cyst surgery. Case 5 was a 27-year-old farmer who suffered from severe headaches and nausea. Following admittance to hospital in Dublin he received a ventriculoperitoneal shunt. Six days later he had surgery (July 1992) for the removal of a third ventricular colloid cyst, the approach being through the right frontal cortex. Five months later he had an epileptic seizure, but had not suffered a seizure during the months preceding the current study. Fifteen months after his original surgery the ventriculoperitoneal shunt was replaced. Following the surgery for a cyst, he returned to work as a labourer. An MRI scan 4 years after surgery, at the time of testing, revealed complete bilateral interruption of the fornix at the anterior aspect of the tract (Fig. 1). There was also moderate, bilateral dilation of the lateral ventricles and the third ventricle. This dilation extended to the right temporal horn, and both hippocampi appeared slightly smaller than normal The thalamus, cingulate cortices and corpus callosum appeared intact, although there was signi fi cant damage in the right frontal cortex at the site of the surgical tract. The mammillary bodies appeared shrunken. Case 6 was a marketing executive. Following a combination of severe headaches and right facial numbness at the age of 24 years, she was admitted to hospital and 3 days later a cyst was removed via a transcallosal approach (December 1995). Recovery was uneventful and she was able to return to her previous work. An MRI scan 10 months after surgery, at the time of testing, revealed the loss of the middle third (20 mm) of the corpus callosum, with restricted damage to the right cingulum. The left lateral ventricle was of normal size but the right lateral ventricle showed mild dilation associated with the surgery. The thalamus and mammillary bodies appeared normal (Fig. 1). Although the fornix was intact, there were signs of thinning of the right fornix. In addition, the right hippocampus appeared slightly smaller than the left. Case 7 was a quali fi ed fi tter who was operated upon in Dublin in September 1988. He had complained of headaches and diplopia in 1984, but a scan at that date showed no colloid cyst. A diagnosis of aqueductal stenosis was con fi rmed and a ventriculoperitoneal shunt was installed, which was later removed. In 1988, at the age of 30 years, he again complained of headaches, and a scan now revealed the colloid cyst. The cyst was removed via a transcallosal approach the following week. Postoperatively he complained of memory impairments. An MRI scan 4 years after surgery showed that the middle third of the corpus callosum was now absent and that there was restricted damage to the adjacent cingulum (Fig. 2). It also showed that the fornix was completely interrupted. The lateral ventricles and the third ventricle appeared normal, as did the thalamus (Fig. 2). Both the mammillary bodies and the hippocampus appeared slightly shrunken. Testing occurred 8 years after his surgery. Case 8 was a retired fi reman. He complained initially ...
Context 4
... and dizziness about 8 months prior to her surgery. A colloid cyst was identi fi ed and removed via a transcallosal approach in August 1993, when she was 41 years of age. Postoperative recovery was uneventful; she was discharged 6 days after surgery and resumed her work. An MRI 3 years after surgery, at the time of testing, con fi rmed the surgical approach and revealed that the middle one-third of the corpus callosum (~20 mm) was now absent ( Fig. 1). While the fornix appeared intact, there was evidence of a limited zone of pathology con fi ned to the region of the left medial pulvinar. The rest of the thalamus and the mammillary bodies appeared normal. There was evidence of mild ventricular enlargement in the left hemisphere that was con fi ned to the frontal horn and body of the left lateral ventricle (Table 1). Case 2 was a self-employed driver. At the age of 38 years he was admitted to hospital with symptoms of headaches and fainting. A week later a cyst was removed from the third ventricle via a right frontal approach (January 1995). His recovery was uneventful and he has resumed work as a driver. The MRI scans for this study were taken 32 months after surgery and revealed evidence of gliotic changes in the anterior aspect of the frontal horn of the right lateral ventricle, as a result of the surgical approach. The fornix was intact, but the ventricles appeared slightly larger than normal for his age (Fig. 1). All other regions, including the mammillary bodies, appeared normal. Testing occurred 18 months after surgery. Case 3 was a driver who, when aged 46 years, suffered from bouts of dizziness, headaches and nausea. CT scans revealed the presence of a cyst in the third ventricle which was removed via a right frontal approach (April 1994). He made an uneventful recovery and was later able to resume his job as a driver. An MRI scan 28 months after surgery, at the time of testing, revealed evidence of gliotic changes in the right frontal lobe corresponding to the region of approach, but the fornix, thalamus and mammillary bodies all appeared normal (Fig. 1). There was, however, modest ventricular enlargement in the right lateral ventricle associated with the region of surgical approach. The left lateral ventricle and third ventricles appeared normal, although the left hippocampus appeared slightly smaller than the right hippocampus. Case 4 was a banker who suffered symptoms of acute hydrocephalus at the age of 50. He was admitted to hospital and a right ventriculoperitoneal shunt was inserted. He recovered successfully, but 6 months later symptoms of headaches and unsteadiness recurred. An MRI scan indicated a colloid cyst in the third ventricle; this was then removed in September 1995 via a right frontal approach. He made a good physical recovery but signi fi cant and persistent memory problems were noted from that period. A series of MRI scans 3 weeks and then 4 months after surgery revealed moderate bilateral ventricular enlargement but no signs of damage or shrinkage in the thalamus, apart from a small indentation in the left anterior thalamus at the site of the cyst. Both the hippocampus and the mammillary bodies appeared normal. The left and right fornices were, however, both absent (Fig. 1). Apart from frontal damage resulting from the surgical approach, no other pathology could be discerned. Testing occurred 10 months after the colloid cyst surgery. Case 5 was a 27-year-old farmer who suffered from severe headaches and nausea. Following admittance to hospital in Dublin he received a ventriculoperitoneal shunt. Six days later he had surgery (July 1992) for the removal of a third ventricular colloid cyst, the approach being through the right frontal cortex. Five months later he had an epileptic seizure, but had not suffered a seizure during the months preceding the current study. Fifteen months after his original surgery the ventriculoperitoneal shunt was replaced. Following the surgery for a cyst, he returned to work as a labourer. An MRI scan 4 years after surgery, at the time of testing, revealed complete bilateral interruption of the fornix at the anterior aspect of the tract (Fig. 1). There was also moderate, bilateral dilation of the lateral ventricles and the third ventricle. This dilation extended to the right temporal horn, and both hippocampi appeared slightly smaller than normal The thalamus, cingulate cortices and corpus callosum appeared intact, although there was signi fi cant damage in the right frontal cortex at the site of the surgical tract. The mammillary bodies appeared shrunken. Case 6 was a marketing executive. Following a combination of severe headaches and right facial numbness at the age of 24 years, she was admitted to hospital and 3 days later a cyst was removed via a transcallosal approach (December 1995). Recovery was uneventful and she was able to return to her previous work. An MRI scan 10 months after surgery, at the time of testing, revealed the loss of the middle third (20 mm) of the corpus callosum, with restricted damage to the right cingulum. The left lateral ventricle was of normal size but the right lateral ventricle showed mild dilation associated with the surgery. The thalamus and mammillary bodies appeared normal (Fig. 1). Although the fornix was intact, there were signs of thinning of the right fornix. In addition, the right hippocampus appeared slightly smaller than the left. Case 7 was a quali fi ed fi tter who was operated upon in Dublin in September 1988. He had complained of headaches and diplopia in 1984, but a scan at that date showed no colloid cyst. A diagnosis of aqueductal stenosis was con fi rmed and a ventriculoperitoneal shunt was installed, which was later removed. In 1988, at the age of 30 years, he again complained of headaches, and a scan now revealed the colloid cyst. The cyst was removed via a transcallosal approach the following week. Postoperatively he complained of memory impairments. An MRI scan 4 years after surgery showed that the middle third of the corpus callosum was now absent and that there was restricted damage to the adjacent cingulum (Fig. 2). It also showed that the fornix was completely interrupted. The lateral ventricles and the third ventricle appeared normal, as did the thalamus (Fig. 2). Both the mammillary bodies and the hippocampus appeared slightly shrunken. Testing occurred 8 years after his surgery. Case 8 was a retired fi reman. He complained initially ...
Context 5
... and dizziness about 8 months prior to her surgery. A colloid cyst was identi fi ed and removed via a transcallosal approach in August 1993, when she was 41 years of age. Postoperative recovery was uneventful; she was discharged 6 days after surgery and resumed her work. An MRI 3 years after surgery, at the time of testing, con fi rmed the surgical approach and revealed that the middle one-third of the corpus callosum (~20 mm) was now absent ( Fig. 1). While the fornix appeared intact, there was evidence of a limited zone of pathology con fi ned to the region of the left medial pulvinar. The rest of the thalamus and the mammillary bodies appeared normal. There was evidence of mild ventricular enlargement in the left hemisphere that was con fi ned to the frontal horn and body of the left lateral ventricle (Table 1). Case 2 was a self-employed driver. At the age of 38 years he was admitted to hospital with symptoms of headaches and fainting. A week later a cyst was removed from the third ventricle via a right frontal approach (January 1995). His recovery was uneventful and he has resumed work as a driver. The MRI scans for this study were taken 32 months after surgery and revealed evidence of gliotic changes in the anterior aspect of the frontal horn of the right lateral ventricle, as a result of the surgical approach. The fornix was intact, but the ventricles appeared slightly larger than normal for his age (Fig. 1). All other regions, including the mammillary bodies, appeared normal. Testing occurred 18 months after surgery. Case 3 was a driver who, when aged 46 years, suffered from bouts of dizziness, headaches and nausea. CT scans revealed the presence of a cyst in the third ventricle which was removed via a right frontal approach (April 1994). He made an uneventful recovery and was later able to resume his job as a driver. An MRI scan 28 months after surgery, at the time of testing, revealed evidence of gliotic changes in the right frontal lobe corresponding to the region of approach, but the fornix, thalamus and mammillary bodies all appeared normal (Fig. 1). There was, however, modest ventricular enlargement in the right lateral ventricle associated with the region of surgical approach. The left lateral ventricle and third ventricles appeared normal, although the left hippocampus appeared slightly smaller than the right hippocampus. Case 4 was a banker who suffered symptoms of acute hydrocephalus at the age of 50. He was admitted to hospital and a right ventriculoperitoneal shunt was inserted. He recovered successfully, but 6 months later symptoms of headaches and unsteadiness recurred. An MRI scan indicated a colloid cyst in the third ventricle; this was then removed in September 1995 via a right frontal approach. He made a good physical recovery but signi fi cant and persistent memory problems were noted from that period. A series of MRI scans 3 weeks and then 4 months after surgery revealed moderate bilateral ventricular enlargement but no signs of damage or shrinkage in the thalamus, apart from a small indentation in the left anterior thalamus at the site of the cyst. Both the hippocampus and the mammillary bodies appeared normal. The left and right fornices were, however, both absent (Fig. 1). Apart from frontal damage resulting from the surgical approach, no other pathology could be discerned. Testing occurred 10 months after the colloid cyst surgery. Case 5 was a 27-year-old farmer who suffered from severe headaches and nausea. Following admittance to hospital in Dublin he received a ventriculoperitoneal shunt. Six days later he had surgery (July 1992) for the removal of a third ventricular colloid cyst, the approach being through the right frontal cortex. Five months later he had an epileptic seizure, but had not suffered a seizure during the months preceding the current study. Fifteen months after his original surgery the ventriculoperitoneal shunt was replaced. Following the surgery for a cyst, he returned to work as a labourer. An MRI scan 4 years after surgery, at the time of testing, revealed complete bilateral interruption of the fornix at the anterior aspect of the tract (Fig. 1). There was also moderate, bilateral dilation of the lateral ventricles and the third ventricle. This dilation extended to the right temporal horn, and both hippocampi appeared slightly smaller than normal The thalamus, cingulate cortices and corpus callosum appeared intact, although there was signi fi cant damage in the right frontal cortex at the site of the surgical tract. The mammillary bodies appeared shrunken. Case 6 was a marketing executive. Following a combination of severe headaches and right facial numbness at the age of 24 years, she was admitted to hospital and 3 days later a cyst was removed via a transcallosal approach (December 1995). Recovery was uneventful and she was able to return to her previous work. An MRI scan 10 months after surgery, at the time of testing, revealed the loss of the middle third (20 mm) of the corpus callosum, with restricted damage to the right cingulum. The left lateral ventricle was of normal size but the right lateral ventricle showed mild dilation associated with the surgery. The thalamus and mammillary bodies appeared normal (Fig. 1). Although the fornix was intact, there were signs of thinning of the right fornix. In addition, the right hippocampus appeared slightly smaller than the left. Case 7 was a quali fi ed fi tter who was operated upon in Dublin in September 1988. He had complained of headaches and diplopia in 1984, but a scan at that date showed no colloid cyst. A diagnosis of aqueductal stenosis was con fi rmed and a ventriculoperitoneal shunt was installed, which was later removed. In 1988, at the age of 30 years, he again complained of headaches, and a scan now revealed the colloid cyst. The cyst was removed via a transcallosal approach the following week. Postoperatively he complained of memory impairments. An MRI scan 4 years after surgery showed that the middle third of the corpus callosum was now absent and that there was restricted damage to the adjacent cingulum (Fig. 2). It also showed that the fornix was completely interrupted. The lateral ventricles and the third ventricle appeared normal, as did the thalamus (Fig. 2). Both the mammillary bodies and the hippocampus appeared slightly shrunken. Testing occurred 8 years after his surgery. Case 8 was a retired fi reman. He complained initially ...
Context 6
... and dizziness about 8 months prior to her surgery. A colloid cyst was identi fi ed and removed via a transcallosal approach in August 1993, when she was 41 years of age. Postoperative recovery was uneventful; she was discharged 6 days after surgery and resumed her work. An MRI 3 years after surgery, at the time of testing, con fi rmed the surgical approach and revealed that the middle one-third of the corpus callosum (~20 mm) was now absent ( Fig. 1). While the fornix appeared intact, there was evidence of a limited zone of pathology con fi ned to the region of the left medial pulvinar. The rest of the thalamus and the mammillary bodies appeared normal. There was evidence of mild ventricular enlargement in the left hemisphere that was con fi ned to the frontal horn and body of the left lateral ventricle (Table 1). Case 2 was a self-employed driver. At the age of 38 years he was admitted to hospital with symptoms of headaches and fainting. A week later a cyst was removed from the third ventricle via a right frontal approach (January 1995). His recovery was uneventful and he has resumed work as a driver. The MRI scans for this study were taken 32 months after surgery and revealed evidence of gliotic changes in the anterior aspect of the frontal horn of the right lateral ventricle, as a result of the surgical approach. The fornix was intact, but the ventricles appeared slightly larger than normal for his age (Fig. 1). All other regions, including the mammillary bodies, appeared normal. Testing occurred 18 months after surgery. Case 3 was a driver who, when aged 46 years, suffered from bouts of dizziness, headaches and nausea. CT scans revealed the presence of a cyst in the third ventricle which was removed via a right frontal approach (April 1994). He made an uneventful recovery and was later able to resume his job as a driver. An MRI scan 28 months after surgery, at the time of testing, revealed evidence of gliotic changes in the right frontal lobe corresponding to the region of approach, but the fornix, thalamus and mammillary bodies all appeared normal (Fig. 1). There was, however, modest ventricular enlargement in the right lateral ventricle associated with the region of surgical approach. The left lateral ventricle and third ventricles appeared normal, although the left hippocampus appeared slightly smaller than the right hippocampus. Case 4 was a banker who suffered symptoms of acute hydrocephalus at the age of 50. He was admitted to hospital and a right ventriculoperitoneal shunt was inserted. He recovered successfully, but 6 months later symptoms of headaches and unsteadiness recurred. An MRI scan indicated a colloid cyst in the third ventricle; this was then removed in September 1995 via a right frontal approach. He made a good physical recovery but signi fi cant and persistent memory problems were noted from that period. A series of MRI scans 3 weeks and then 4 months after surgery revealed moderate bilateral ventricular enlargement but no signs of damage or shrinkage in the thalamus, apart from a small indentation in the left anterior thalamus at the site of the cyst. Both the hippocampus and the mammillary bodies appeared normal. The left and right fornices were, however, both absent (Fig. 1). Apart from frontal damage resulting from the surgical approach, no other pathology could be discerned. Testing occurred 10 months after the colloid cyst surgery. Case 5 was a 27-year-old farmer who suffered from severe headaches and nausea. Following admittance to hospital in Dublin he received a ventriculoperitoneal shunt. Six days later he had surgery (July 1992) for the removal of a third ventricular colloid cyst, the approach being through the right frontal cortex. Five months later he had an epileptic seizure, but had not suffered a seizure during the months preceding the current study. Fifteen months after his original surgery the ventriculoperitoneal shunt was replaced. Following the surgery for a cyst, he returned to work as a labourer. An MRI scan 4 years after surgery, at the time of testing, revealed complete bilateral interruption of the fornix at the anterior aspect of the tract (Fig. 1). There was also moderate, bilateral dilation of the lateral ventricles and the third ventricle. This dilation extended to the right temporal horn, and both hippocampi appeared slightly smaller than normal The thalamus, cingulate cortices and corpus callosum appeared intact, although there was signi fi cant damage in the right frontal cortex at the site of the surgical tract. The mammillary bodies appeared shrunken. Case 6 was a marketing executive. Following a combination of severe headaches and right facial numbness at the age of 24 years, she was admitted to hospital and 3 days later a cyst was removed via a transcallosal approach (December 1995). Recovery was uneventful and she was able to return to her previous work. An MRI scan 10 months after surgery, at the time of testing, revealed the loss of the middle third (20 mm) of the corpus callosum, with restricted damage to the right cingulum. The left lateral ventricle was of normal size but the right lateral ventricle showed mild dilation associated with the surgery. The thalamus and mammillary bodies appeared normal (Fig. 1). Although the fornix was intact, there were signs of thinning of the right fornix. In addition, the right hippocampus appeared slightly smaller than the left. Case 7 was a quali fi ed fi tter who was operated upon in Dublin in September 1988. He had complained of headaches and diplopia in 1984, but a scan at that date showed no colloid cyst. A diagnosis of aqueductal stenosis was con fi rmed and a ventriculoperitoneal shunt was installed, which was later removed. In 1988, at the age of 30 years, he again complained of headaches, and a scan now revealed the colloid cyst. The cyst was removed via a transcallosal approach the following week. Postoperatively he complained of memory impairments. An MRI scan 4 years after surgery showed that the middle third of the corpus callosum was now absent and that there was restricted damage to the adjacent cingulum (Fig. 2). It also showed that the fornix was completely interrupted. The lateral ventricles and the third ventricle appeared normal, as did the thalamus (Fig. 2). Both the mammillary bodies and the hippocampus appeared slightly shrunken. Testing occurred 8 years after his surgery. Case 8 was a retired fi reman. He complained initially ...
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Citations
... Interestingly, the fornix also carries projections linking hippocampal areas with the prefrontal cortex (PFC; [2,29,32]). Studies in NHPs and humans have revealed that damage to the fornix causes deficits in learning and memory and can produce anterograde amnesia (e.g., [1,9,12,13,18,30,37]). Intriguingly, microstructural integrity of the fornix has been indicated as a predictive biomarker of memory decline [22], while recent clinical trials revealed that deep brain stimulation of the fornix improved cognitive functions in small groups of patients with Alzheimer's disease ( [10]; for a recent review see [19]). ...
The fornix, the limbic system’s white matter tract connecting the extended hippocampal system to subcortical structures of the medial diencephalon, is strongly associated with learning and memory in humans and nonhuman primates (NHPs). Here, we sought to investigate alterations in structural connectivity across key cortical and subcortical regions after fornix transection in NHPs. We collected diffusion-weighted MRI (dMRI) data from three macaque monkeys that underwent bilateral fornix transection during neurosurgery and from four age- and cohort-matched control macaques that underwent surgery to implant a head-post but remained neurologically intact. dMRI data were collected from both groups at two time points, before and after the surgeries, and scans took place at around the same time for the two groups. We used probabilistic tractography and employed the number of tracking streamlines to quantify connectivity across our regions of interest (ROIs), in all dMRI sessions. In the neurologically intact monkeys, we observed high connectivity across certain ROIs, including the CA3 hippocampal subfield with the retrosplenial cortex (RSC), the anterior thalamus with the RSC, and the RSC with the anterior cingulate cortex (ACC). However, we found that, compared to the control group, the fornix-transected monkeys showed marked, significant, connectivity changes including increases between the anterior thalamus and the ACC and between the CA3 and the ACC, as well as decreases between the CA3 and the RSC. Our results highlight cortical and subcortical network changes after fornix transection and identify candidate indirect connectivity routes that may support memory functions after damage and/or neurodegeneration.KeywordsAnterior cingulateHippocampusAnterior thalamusRetrosplenial cortexFornixDiffusion-weighted MRIProbabilistic tractography
... The fornix is the predominant bundle of efferent fibers connecting the hippocampus to other brain structures [2,48] and one of the key regions controlling memory and executive functions [49]. This is the first large-scale GWAS of fornix white Fig. 4 Heritability estimates and genetic overlap with other DTI traits. ...
The fornix is a white matter bundle located in the center of the hippocampaldiencephalic limbic circuit that controls memory and executive functions, yet its genetic architectures and involvement in brain disorders remain largely unknown. We carried out a genome-wide association analysis of 30,832 UK Biobank individuals of the six fornix diffusion magnetic resonance imaging (dMRI) traits. The post-GWAS analysis allowed us to identify causal genetic variants in phenotypes at the single nucleotide polymorphisms (SNP), locus, and gene levels, as well as genetic overlap with brain health-related traits. We further generalized our GWAS in adolescent brain cognitive development (ABCD) cohort. The GWAS identified 63 independent significant variants within 20 genomic loci associated (P < 8.33 × 10⁻⁹) with the six fornix dMRI traits. Geminin coiled-coil domain containing (GMNC) and NUAK family SNF1-like kinase 1 (NUAK1) gene were highlighted, which were found in UKB and replicated in ABCD. The heritability of the six traits ranged from 10% to 27%. Gene mapping strategies identified 213 genes, where 11 were supported by all of four methods. Gene-based analyses revealed pathways relating to cell development and differentiation, with astrocytes found to be significantly enriched. Pleiotropy analyses with eight neurological and psychiatric disorders revealed shared variants, especially with schizophrenia under the conjFDR threshold of 0.05. These findings advance our understanding of the complex genetic architectures of fornix and their relevance in neurological and psychiatric disorders.
... Nevertheless, there was no significant decrease in postoperative complications and postoperative venous infarction became a major challenge with this method. [19][20][21] These side effects prompted neurosurgeons to try more microinvasive approaches through stereotactic techniques; however, a lower rate of GTR (50% of patients) was achieved, with a significant difference from microsurgical approaches. 22,23 Endoscopy Simultaneously, in the early years of the 21st century, with advancements in neuroendoscopic devices, neuroendoscopy decreased the time of surgery and length of hospitalization and 26 Also, endoscopy comes with some challenges and limitations, the most important in our experience being the inability to perform bimanual microdissection. ...
Background:
Both endoscopic and microsurgery trans-cortical resection methods are used for colloid cysts of third ventricle but they are not compared to each other in regard to benefits and pitfalls.
Method:
Data of patients who underwent surgical resection of third ventricle colloid cyst via either endoscopic or microsurgery approach by a single surgeon from 2005 to 2020 were retrospectively collected. After administration of criteria, 140 records were retrieved (60 patients through endoscopic resection and 80 patients by trans-cranial microsurgery approach). Clinical and surgical measures were compared between the two types of surgery after adjustment for confounders.
Results:
Length of hospital stay, postoperative meningitis, and operation time, cyst size, and baseline comorbidities was similar between groups. Gross total resection (GTR) was achieved for all cases in microsurgery group while in endoscopic group it was lower (90% vs 100%; p=0.005). Intraoperative hemorrhage occurred in 14 (23.3%) of endoscopic patients while for microscopic group it was zero (p<0.001). Post-operative shunt was required for two patients (one in endoscopic group and the other in microscopic group). Two patients had tumor recurrence, both being in endoscopic group. No mortality was detected in either group. Multivariate analyses were insignificant for confounding effects of clinical and demographic factors in occurrence of worse surgical outcomes (non-GTR and hemorrhage).
Conclusion:
In our series the rate of intra-operative hemorrhage was higher in endoscopic method and GTR was lower, even after adjustment for other factors. This could be due to technologic shortcomings and limited space for resection maneuvers and complication management.
... This pathway contains many different hippocampal connections including those reaching the mammillary bodies and anterior thalamic nuclei (Poletti and Creswell, 1977;Aggleton, 2012). Fornix damage causes amnesia (e.g., Gaffan and Gaffan, 1991;D'Esposito et al., 1995;McMackin et al., 1995;Aggleton et al., 2000;Vann et al., 2008;Takano et al., 2018;Salvalaggio et al., 2018), often impairing the recall of information more than the recognition of previously experienced information (McMackin et al., 1995;Aggleton et al., 2000;Vann et al., 2008Vann et al., , 2009b; see also Adlam et al., 2009;Jonin et al., 2018). Added evidence from diffusion MRI studies shows that indices of fornix integrity correlate with episodic memory (Rudebeck et al., 2009;Metzler-Baddeley et al., 2011;Hodgetts et al., 2017), including an association with recollective but not familiarity-based recognition (Rudebeck et al., 2009). ...
... This pathway contains many different hippocampal connections including those reaching the mammillary bodies and anterior thalamic nuclei (Poletti and Creswell, 1977;Aggleton, 2012). Fornix damage causes amnesia (e.g., Gaffan and Gaffan, 1991;D'Esposito et al., 1995;McMackin et al., 1995;Aggleton et al., 2000;Vann et al., 2008;Takano et al., 2018;Salvalaggio et al., 2018), often impairing the recall of information more than the recognition of previously experienced information (McMackin et al., 1995;Aggleton et al., 2000;Vann et al., 2008Vann et al., , 2009b; see also Adlam et al., 2009;Jonin et al., 2018). Added evidence from diffusion MRI studies shows that indices of fornix integrity correlate with episodic memory (Rudebeck et al., 2009;Metzler-Baddeley et al., 2011;Hodgetts et al., 2017), including an association with recollective but not familiarity-based recognition (Rudebeck et al., 2009). ...
... recognition, contrasting with a loss of recollection-based recognition (Vann et al., 2009b). Thus, like the fornix findings (e.g., Aggleton et al., 2000;Rudebeck et al., 2009) the mammillothalamic connections appear vital for the recall of episodic information but not for some forms of recognition (Carlesimo et al., 2007). ...
After more than 80 years, Papez serial circuit remains a hugely influential concept,initially for emotion, but in more recent decades, for memory. Here, we show how this. circuit is anatomically and mechanistically naïve as well as outdated. We argue that a, new conceptualisation is necessitated by recent anatomical and functional findings that, emphasize the more equal, working partnerships between the anterior thalamic nuclei, and the hippocampal formation, along with their neocortical interactions in supporting, episodic memory. Furthermore, despite the importance of the anterior thalamic for mnemonic processing, there is growing evidence that these nuclei support multiple aspects of cognition, only some of which are directly associated with hippocampal function. By viewing the anterior thalamic nuclei as a multifunctional hub, a clearer picture emerges of extra-hippocampal regions supporting memory. The reformulation presented here underlines the need to retire Papez serially processing circuit.
... 35 Damage to the fornix, from tumour, trauma or surgical resection, leads to a major deficit in verbal recall, with relative sparing of familiarity memory. 36,37 A role for the hippocampus in short-term or working memory is more controversial. However, contributions to effective learning strategies in visual memory encoding 38 and short-term visual memory for complex objects 39 have been described and the view that the medial temporal lobe exclusively supports long-term episodic memory challenged. ...
Spontaneous recovery of motor and cognitive function occurs in many individuals after stroke. The mechanisms are incompletely understood, but may involve neurotransmitter systems that support neural plasticity, networks that are involved in learning and regions of the brain that are able to flexibly adapt to demand (such as the ‘multiple-demand system').
Forty-two patients with first symptomatic ischaemic stroke were enrolled in a longitudinal cohort study of cognitive function after stroke. High-resolution volumetric, diffusion MRI and neuropsychological assessment were performed at a mean of 70 ± 18 days after stroke. Cognitive assessment was repeated 1 year after stroke, using parallel test versions to avoid learning effects, and change scores were computed for long-term episodic, short-term and working memory. Structural MRI features that predicted change in cognitive scores were identified by a two-stage analysis: a discovery phase used whole-brain approaches in a hypothesis-free unbiased way; and an independent focused phase, where measurements were derived from regions identified in the discovery phase, using targeted volumetric measurements or tractography. Evaluation of the cholinergic basal forebrain, based on a validated atlas-based approach, was included given prior evidence of a role in neural plasticity.
The status of the fornix, cholinergic basal forebrain and a set of hippocampal subfields were found to predict improvement in long-term memory performance. In contrast to prior expectation, the same pattern was found for short-term and working memory, suggesting that these regions are part of a common infrastructure that supports recovery across cognitive domains. Associations between cholinergic basal forebrain volume and cognitive recovery were found primarily in subregions associated with the nucleus basalis of Meynert, suggesting that it is the cholinergic outflow to the neocortex that enables recovery. Support vector regression models derived from baseline measurements of fornix, cholinergic basal forebrain and hippocampal subfields were able to explain 62% of change in long-term episodic and 41% of change in working memory performance over the subsequent 9 months.
The results suggest that the cholinergic system and extended hippocampal network play key roles in cognitive recovery after stroke. Evaluation of these systems early after stroke may inform personalized therapeutic strategies to enhance recovery.
... Patients with colloid cysts are especially vulnerable to neuropsychological deficits mainly due to the close proximity of the cysts to the fornices forming the Papez circuit [9,[15][16][17]. Fornix is a white matter bundle connecting hippocampal formation in the mesial temporal lobe with both diencephalon (mamillary bodies, mammillothalamic tract and anterior thalamic nucleus) and basal forebrain. ...
... This closed-circuit looping along cingulum, entorhinal cortex back to hippocampus constitutes part of the limbic system playing a key role in the encoding of episodic memory [18]. Disturbance in forniceal pathway has been noted to be more significantly associated with memory deficits than mere ventricular enlargement [16,17]. ...
... We noted the QOL of patients who underwent endoscopic surgery to be better than those who had undergone either microsurgery or just a VP shunt. The lowest QOL scores after VP shunt despite ventricular decompression are likely due to the cyst's persistent compression on the fornices or the shunt per se, again ruling out any significant hydrocephalus brunt on QOL in at least elective cases [17,26]. The additional morbidity of traditional microsurgery is probably due to retraction and handling of neural or venous structures in addition to excessive soft tissue dissection [6,9,27,28]. ...
Background
Endoscopy is increasingly being adopted for removing colloid cysts. However, the neuropsychological outcome and quality of life(QOL) have not been studied in detail. This study is to evaluate the efficacy of endoscopic excision on cognitive measures and QOL.
Methods
Patients with colloid cysts larger than 7 mm, undergoing endoscopy were prospectively studied concerning clinico-radiology, cognitive parameters (age & education adjusted), extent of resection and recurrence. A cross-sectional QOL assessment was additionally performed on endoscopic patients in comparison with cases who underwent microsurgery or standalone ventriculo-peritoneal(VP) shunt.
Results
A total of 22 endoscopic patients with a mean age of 34 years and a mean cyst diameter of 19 mm were studied. Gross total resection(GTR) could be achieved in all. Over a mean follow-up of 53.4 months, none had a recurrence, ventriculomegaly, or retreatment. Among neuropsychological parameters, digit span was the most affected before surgery. There was a broad-based improvement in the mean global cognitive score from 40.63(+10.4) at baseline to 50.25(+5.8) after endoscopy with maximum improvement in 'immediate recall.' The change in scores also had a significant inverse correlation with cyst size, with cysts larger than 18 mm, resulting in lower scores following endoscopy(R=-0.9, P=0.01). QOL was significantly influenced by visual & cognitive impairments and was better among endoscopic patients than similar microscopic or VP shunt controls, with a significant difference in social and environmental domains(P=0.02).
Conclusion
Endoscopy is effective in achieving GTR and long-term control, with neuropsychological improvement correlated with cyst size. QOL is influenced by cognitive parameters and is better following endoscopy than after microsurgery or VP shunt.
... Memory deficits are a common complication of all approaches, since there is likely to be some degree of injury to the fornix. [37,38] However, this is much more likely to be transient than permanent. [34] The transcortical approach is likely to result in a greater incidence of post-operative seizures, subdural effusion, hemiparesis, and cognitive and behavioral deficits. ...
... Additionally, the fornix is associated with recollection and recall in MRI studies (Rudebeck et al., 2009;Metzler-Baddeley et al., 2011) and has shown changes in patients with hippocampal lesions (Henson et al., 2016). Interestingly, causal evidence from humans and nonhuman primates further shows that transecting the UF or the fornix impairs cognitive performance in learning and memory tasks (D'Esposito et al., 1995;Aggleton et al., 2000;Gaffan, 2002;Browning and Gaffan, 2008;Tsivilis et al., 2008;Kwok et al., 2015). However, it remains unclear how learning new visuospatial information alters (sub)cortical connectivity, and how, following the loss of subcortical inputs to the cortex, this connectivity is rearranged. ...
... The Experimental group received extensive training on a complex visuospatial task for an average of 17 months to master the rapid learning of new visuospatial information during each testing session. We used a variant of the object-in-place discrimination (OIP) task (Gaffan, 1994) that assesses rapid learning of visuospatial discriminations in nonhuman primates (Murray and Wise, 2010) and humans (Aggleton et al., 2000). The task was adapted so that it required a longer time to learn and attain a consistent learning criterion. ...
... These observations further support the notion that the neurosurgical procedures, the perioperative drug treatments, or the surgical approach of slicing through up to 10 mm of corpus callosum at the midline (but not transecting it) to expose and transect the fornix fibers underneath did not in themselves result in the cognitive deficits observed in the bilateral lesion group or in the brain connectivity changes (described below). Instead, the lack of change in cognitive ability specific to this task in the unilaterally damaged monkey is consistent with findings in humans who have undergone neurosurgery to remove a colloid cyst growing in the fornix or around the third ventricle; a procedure that causes damage to the fornix but typically not a complete transection of the fibers (Aggleton et al., 2000). ...
The frontal cortex and temporal lobes together regulate complex learning and memory capabilities. Here, we collected resting-state functional and diffusion-weighted MRI data before and after male rhesus macaque monkeys received extensive training to learn novel visuospatial discriminations (reward-guided learning). We found functional connectivity changes in orbitofrontal, ventromedial prefrontal, inferotemporal, entorhinal, retrosplenial, and anterior cingulate cortices, the subicular complex, and the dorsal, medial thalamus. These corticocortical and thalamocortical changes in functional connectivity were accompanied by related white matter structural alterations in the uncinate fasciculus, fornix, and ventral prefrontal tract: tracts that connect (sub)cortical networks and are implicated in learning and memory processes in monkeys and humans. After the well-trained monkeys received fornix transection, they were impaired in learning new visuospatial discriminations. In addition, the functional connectivity profile that was observed after the training was altered. These changes were accompanied by white matter changes in the ventral prefrontal tract, although the integrity of the uncinate fasciculus remained unchanged. Our experiments highlight the importance of different communication relayed among corticocortical and thalamocortical circuitry for the ability to learn new visuospatial associations (learning-to-learn) and to make reward-guided decisions.
... It is important to acknowledge that the fornix runs along the cranial part of the septum pellucidum. The fornix is the major tract connecting the hippocampal formation to the mamillary bodies, the diencephalon (consisting amongst others of the hypothalamus and thalamus), and the medial temporal regions [54][55][56][57]. All of these structures are believed to be involved in memory and other important cognitive functions such executive functions. ...
... All of these structures are believed to be involved in memory and other important cognitive functions such executive functions. Lesions to these structures are often associated with temporal lobe and diencephalic amnesia beyond executive function disorder [54,55,57,58]. Some fibers of the limbic system (fornix-hippocampus-mamillary bodies) seem to be linked and connected with the amygdaloid complex and the orbitofrontal cortex both discussed in control of emotions, decision-making, and social cognition [57]. ...
... Some studies show that temporal lobe or diencephalic lesions have a stronger association with anterograde amnesia than damage to the fornix. On the other hand, some recent publications showed convincing data that damage to the forniceal tracts causes memory impairment [55,58,59]. In addition, atrophy of the mamillary bodies, usually occurring due to fornix lesions, was found to be strongly associated with memory impairment [55,59]. ...
In recent years, neuroendoscopic treatment of hydrocephalus and various ventricular pathologies has become increasingly popular. It is considered by many as the first-choice treatment for the majority of these cases. However, neurocognitive complications following ventricular neuroendoscopic procedures may occur leading mostly to amnesia, which might have a grave effect on the patient’s quality of life. Studies assessing neurocognitive complications after ventricular neuroendoscopic procedures are sparse. Therefore, we conducted a systematic review assessing the available literature of neurocognitive complications and outcome after ventricular neuroendoscopy. Of 1216 articles screened, 46 were included in this systematic review. Transient and permanent neurocognitive complications in 2804 ventricular neuroendoscopic procedures occurred in 2.0% (n=55) and 1.04% (n=28) of the patients, respectively. Most complications described are memory impairment, followed by psychiatric symptoms (psychosyndrome), cognitive impairment not further specified, declined executive function, and confusion. However, only in 20% of the series describing neurocognitive complications or outcome (n=40) was neurocognition assessed by a trained neuropsychologist in a systematic manner. While in most of these series only a part of the included patients underwent neuropsychological testing, neurocognitive assessment was seldom done pre- and postoperatively, long-term follow up was rare, and patient’s cohorts were small. A paucity of studies analyzing neurocognitive complications and outcome, through systematic neuropsychological testing, and the correlation with intraoperative lesions of neuronal structures (e.g., fornix) exists in the literature. Therefore, the neurocognitive and emotional morbidity after ventricular neuroendoscopic procedures might be underestimated and warrants further research.
... The colloid cysts of the third ventricle vary in size from small (0.3 cm) to giant (more than 3 cm). 1 This cysts can lead to the substantial fornix damage and development of the anterograde amnesia. 2 The cysts usually arise in its upper third and can also lead to a lethal acute hydrocephalus. 3 Early detection of these cysts leads to an improvement of associated symptoms and has a promising positive prognosis. 4 The central neurocytomas can also be intraventricular. ...
Objectives The defining of the normal parameters of spacious relations and symmetry
of the ventricular system of the brain depending on the gender and age is currently
one of the topical research problems of clinical anatomy. The present research aims to
identify the correlation between the morphometric parameters of the third ventricle of
the brain and the shape of the skull in the middle-aged people.
Design This is a prospective cohort study.
Setting This study was set at the Trinity School of Medicine.
Participants A total of 118 normal computed tomography scans of the head of
people aged from 21 to 86 years (mean age: 48.6 years�17.57) were selected for the
study.
Main Outcome Measures The anteroposterior diameter, transverse diameter, and
height of the third ventricle were measured and compared in dolichocranial, mesocranial,
and brachycranial individuals.
Results The study has shown the presence of a statistically significant difference
between morphometric parameters of the third ventricle of the brain in dolichocranial,
mesocranial, and brachycranial individuals.
Conclusion The morphometric parameters of the third ventricle of the brain, such as
height, anteroposterior diameter, and transverse diameter depend on the individual
anatomic variability of the skull shape and gender.
