Tatsuharu Sato's research while affiliated with Nagasaki University Hospital and other places

Background: Cerebellitis is a rare complication of clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS); however, MERS with cerebellitis is associated with a higher risk of neurological sequelae in comparison to MERS alone. Although the disease is difficult to diagnose by conventional MRI in the early disease phase, arterial spin labeling (ASL), a noninvasive MRI perfusion technique using magnetically-labeled arterial blood water protons, is considered promising. Case report: We experienced three cases of MERS with cerebellitis. Diffusion-weighted imaging showed a high-intensity lesion at the splenium of the corpus callosum. ASL showed increased blood flow in the cerebellum in all three cases, despite cerebellar symptoms being inapparent or difficult to notice in the early phase of disease in all cases. Patients received methylprednisolone pulse therapy and intravenous immunoglobulin from the early phase of the disease and recovered without neurological sequelae. Discussion: ASL magnetic response imaging simultaneously showed an area of hyperperfusion in the cerebellum. At the same time, the apparent diffusion coefficient of the splenial lesion was decreased in all three cases. The successful diagnosis of cerebellitis in the acute phase led to early therapeutic intervention, which may be important for this condition. We report the usefulness of ASL and review the relevant literature on MERS with cerebellitis.

The persistent upregulation of type I interferon through nucleic acid sensing contributes greatly to immunopathogenesis of congenital infections such as congenital cytomegalovirus infection as well as genetic defects in any of the elements involved in the endogenous nucleic acid clearance system. Type I interferon is neurotoxic to the developing brain, and proinflammatory responses also affect the central nervous system; therefore, encephalopathy is one of the most devastating clinical features of type I interferonopathies of either infectious or genetic causes.

Background: Tubulinopathies include a wide spectrum of disorders ranging from abnormal ocular movement to severe brain malformations, and typically present as diffuse agyria or perisylvian pachygyria with microcephaly, agenesis of the corpus callosum, and cerebellar hypoplasia. They are caused by the dysfunction of tubulins encoded by tubulin-related genes, and the TUBA1A gene encoding alpha-1A tubulin is most frequently responsible for this clinical entity. Porencephaly is relatively rare among patients with the TUBA1A mutations. Mild case of tubulinopathy associated with porencephaly caused by a novel TUBA1A mutation. Case report: The patient, a 10-month-old girl, presented with gross motor delay at 4 months of age and convulsions at 7 months of age. Brain magnetic resonance imaging showed porencephaly, occipital polymicrogyria, hypoplasia of the corpus callosum, volume loss of the white matter, dysgenesis of anterior limbs of internal capsules, non-separative basal ganglia, cerebellar hypoplasia, and dysplastic brainstem. We identified a novel de novo heterozygous missense mutation in the TUBA1A gene, c.381C > A (p.Asp127Glu), by whole-exome sequencing. Discussion: Microtubules composed of tubulins regulate not only neuronal migration but also cell division or axon guidance. Accordingly, tubulinopathy affects the cortical lamination, brain size, callosal formation, and white matter as seen in the present case. In contrast to the previously reported cases, the present case showed milder cortical dysgenesis with a rare manifestation of porencephaly. The genotype-phenotype correlation is still unclear, and this study expands the phenotypic range of tubulinopathy.

We report a 2-year-old female patient with anoxic-epileptic seizures. Since 6 months of ages, she has had generalized tonic convulsion after crying too hard and holding her breath. It sometimes lasted for one hour. She was brought to a nearby clinic, but she had been followed up with no medication under the diagnosis of breath-holding spells. At 2 years and one month, she was referred to our hospital with increased ictal events in which crying, breath-holding, atonia, asymmetrical tonic convulsion and generalized clonic convulsion occurred in a sequence. Ictal EEG showed a low-voltage pattern followed by rhythmical activity with the right frontal predominance and subsequent intermittent polyspike-and-wave. Treatment with Kanbaku-Taisou-Tou (an herbal medicine) and iron had no effect, but carbamazepine decreased the frequency of occurrence and continuance length of convulsive phases. Combination therapy of carbamazepine and levetiracetam completely suppressed the emergence of convulsive phases. In case of breath-holding spells with long convulsive phase, ictal EEG should be considered. If anoxic-epileptic seizures are demonstrated, anti-epileptic agent(s) should be administrated.

Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) technique that enables visualizing of cerebral blood flow without need of a contrast medium. In recent years, there have been reports from outside Japan related to ASL use in migraine attacks. We report two cases of acute confusional migraine (ACM) in children. At time of confusion, ASL imaging showed reduced blood flow: for the first patient, in both cerebral hemispheres from the occipital lobe through the parietal lobe to the temporal lobe; for the second patient, throughout the left cerebral hemisphere. T1-, T2-, diffusion-weighted images, and fluid attenuation inversion recovery (FLAIR) images indicated normal results. Subsequent ASL re-examinations for both cases showed recovery from reduced blood flow. In our view, ACM can be characterized by a reduction in blood flow not limited to the occipital lobe but across wide regions of the cerebral hemisphere. We consider ASL to be helpful in the difficult differentiation of ACM from other disturbances of consciousness, in addition to enabling repeated examinations without the risks associated with single-photon emission computed tomography (SPECT) concerning radiation exposure or with contrast MRI concerning contrast media use.

To evaluate the diagnostic value of SPECT (single photon emission computed tomography) brain blood flow imaging for patients with non-herpetic acute limbic encephalitis (NHALE). A retrospective review of three patients who had clinical symptoms compatible to NHALE and were positive for anti-N-methyl-d-aspartate-type glutamate receptor (GluRε2) antibody. The patients consisted of a 6-year-old female, a 10-year-old female and a 13-year-old male, all of whom had limbic symptoms and were anti-GluRε2 antibody-positive. In all cases, brain MRI failed to detect any abnormality, but SPECT brain blood flow imaging was able to detect blood flow changes. All three cases showed some abnormality in their brain waves, and one of them also developed epilepsy. SPECT brain blood flow imaging may therefore be helpful for diagnosing NHALE which can lead to the development of either epilepsy or cognitive impairment.

In mouse embryonic stem (mES) cells, ubiquitylation of histone H2A lysine 119 represses a large number of developmental genes and maintains mES cell pluripotency. It has been suggested that a number of H2A ubiquitin ligases as well as deubiquitylases and related peptide fragments contribute to a delicate balance between self-renewal and multi-lineage differentiation in mES cells. Here, we tested whether known H2A ubiquitin ligases and deubiquitylases are involved in mES cell regulation and discovered that Dzip3, the E3 ligase of H2AK119, represses differentiation-inducible genes, as does Ring1B. The two sets of target genes partially overlapped but had different spectra. We found that Dzip3 represses gene expression by orchestrating changes in 3D organization, in addition to regulating ubiquitylation of H2A. Our results shed light on the epigenetic mechanism of transcriptional regulation, which depends on 3D chromatin reorganization to regulate mES cell differentiation.

Objective: To evaluate the long-term effects and tolerability of levetiracetam (LEV) in refractory epilepsy. Methods: LEV was administered to 76 patients whose seizures were inadequately controlled by their current medications. The patients were followed for a minimum of 18 months but less than 2 years. The efficacy of LEV treatment was assessed retrospectively as the proportion of patients who experienced at least a 50% reduction in the frequency of seizures (50% RR), and adverse events were analyzed. Results: The 50% RR in all 76 patients was 42%. The 50% RRs in the 54 patients with localization-related epilepsy and in the 20 patients with generalized epilepsy were 42% and 35%, respectively. The patients who responded most remarkably to the therapy, with at least a 75% reduction in the frequency of seizures, were more often those with localization-related epilepsy. Among adverse events, irritability and hyperactivity/impulsivity were observed more frequently in this study than in previous reports. These events were observed predominantly in patients suffering from autism or attention deficit hyperactivity disorder (AD/HD) as a comorbidity. γ-GTP values were improved in 14 of 17 patients whose values prior to beginning LEV treatment were higher than the normal range. This beneficial effect presumably resulted from a dose reduction or the discontinuation of other hepatotoxic antiepileptic drugs. Conclusions: LEV was useful for the treatment of refractory epilepsy, and long-term efficacy was demonstrated. LEV also appeared to be less hepatotoxic. Behavioral changes should be monitored carefully when LEV is administered to patients with concomitant autism or AD/HD.

Drug-induced hypersensitivity syndrome (DIHS) is a rare but severe multiorgan disorder. The reactivation of human herpesvirus-6 (HHV-6) and other human herpesviruses has been reported to be associated with its pathogenesis. We herein report a case of 14-year-old female who developed DIHS during the treatment with lamotrigine, a novel antiepileptic drug. She initially presented with fever, skin rash, cervical lymphadenopathy, leukocytosis with eosinophilia and atypical lymphocytosis, liver dysfunction and hypogammaglobulinemia. Discontinuation of the drug and administration of prednisolone led to improvement;however, tapering of prednisolone and administration of midazolam and ketamine thereafter triggered clinical deterioration. She subsequently developed hyperthyroidism followed by hypothyroidism. Herpesviral loads were determined in her peripheral blood by real-time PCR during the course of the treatment, and sequential reactivation of Epstein-Barr virus (EBV), HHV-6 and cytomegalovirus was demonstrated. EBV viremia was detected throughout the course, except for a short period when HHV-6 viremia was at the peak. HHV-6 viremia developed after the secondary deterioration. Cytomegalovirus viremia appeared transiently before the hyperthyroidic state reversed and became hypothyroidic. Although this syndrome should be regarded as a systemic reaction induced by a complex interplay among herpesviruses and the immune responses against viral infections and drugs, it remains unknown how such a sequential reactivation is related to the pathogenesis of the condition.

We report for the first time the single photon emission computed tomography (SPECT) findings of a patient with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) associated with Kawasaki disease, which showed hypoperfusion of the bilateral cingulate gyri, thalamus, basal ganglia, brainstem, and cortex of the frontal lobes. These findings indicate that the pathogenesis of MERS is based on cerebral hypoperfusion due to vasculitis or cerebrovascular dehydration.