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Imaging Findings in Pyogenic Ventriculitis
Abstract and Figures
Pyogenic ventriculitis is an uncommon but often severe intracranial infection.
Case report with illustrative CT and MRI imaging.
A 49-year-old man presented with an intraparenchymal hematoma with extension of blood into the ventricles. The persistence of intraventricular blood necessitated long term placement of an external ventricular drain. On day 23 after admission, a contrast-enhanced CT scan of the brain showed slight hydrocephalus, irregular debris in the dependent part of the occipital horns and periventricular hypodensities. An MRI scan confirmed the characteristic hallmarks of pyogenic ventriculitis on the T2-weighted, Fluid Attenuated Inversion Recovery (FLAIR), and diffusion-weighted and contrast-enhanced T1-weighted images.
Neuroimaging is crucial in clearly depicting pyogenic ventriculitis. A contrast-enhanced CT scan, but especially MR imaging, is an ideal tool to reliably diagnose this life-threatening cerebral infection.
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... The possible mechanisms of infection of the ventricular system include hematogenous spread to the subependyma of the choroid plexus, diffusion by contiguity from a brain abscess or direct implantation secondary to trauma or surgical procedure [4]. Brain imaging techniques can demonstrate intraventricular debris and pus, representing the most common signs of ventriculitis [3][4][5]; other findings may include hydrocephalus and periventricular magnetic resonance abnormalities reflecting inflammatory changes [3]. ...
... The possible mechanisms of infection of the ventricular system include hematogenous spread to the subependyma of the choroid plexus, diffusion by contiguity from a brain abscess or direct implantation secondary to trauma or surgical procedure [4]. Brain imaging techniques can demonstrate intraventricular debris and pus, representing the most common signs of ventriculitis [3][4][5]; other findings may include hydrocephalus and periventricular magnetic resonance abnormalities reflecting inflammatory changes [3]. ...
... CT scan was quite unremarkable and only the diffusion MRI sequences could clearly indicate the presence of purulent material within the ventricles. Recent studies have emphasized the importance of diffusion sequences in the diagnosis of pyogenic ventriculitis [2][3][4]. Indeed, the relatively high viscosity, hypercellularity and binding of water to macromolecules have been suggested as explanations for the restricted water diffusion observed in the purulent material [2]. Conversely, FLAIR sequences are considered useful in detecting periventricular high signal and ependymal enhancement [5]. ...
Pyogenic ventriculitis is a rare and severe cerebral infection characterized by the presence of suppurative fluid in the cerebral ventricles. It is a life-threatening condition and may present with an aspecific neurological picture. Brain imaging techniques usually demonstrate intraventricular debris and pus, but negative imaging along with a misleading clinical picture may delay the diagnosis.
The described patient underwent a number of surgical procedures and eventually developed an unusual clinical picture characterized by psychomotor slowing, facial dyskinesias and myoclonic jerks without complaint of headache and in absence of meningeal irritation signs or focal neurological deficits. Cerebrospinal fluid cultural examination showed methicillin-resistant Staphylococcus aureus and vancomycin treatment lead to a complete recovery. Brain computed tomography scan was normal, while only diffusion magnetic resonance imaging sequences were able to define the presence of purulent material within the brain lateral ventriculi.
The present case underlines the importance of taking into account the diagnosis of pyogenic ventriculitis even when the neurological picture does not match the suspect of a central nervous system infection. Moreover, brain computed tomography scan and standard magnetic resonance imaging sequences may be unable to confirm the diagnosis, whereas diffusion-weighted sequences prove a unique role in diagnosing cerebral pyogenic ventriculitis.
... Neuroimaging is useful for helping to establish the diagnosis of ventriculitis, MRI with gadolinium enhancement and diffusion-weighted imaging being the best image. Ventricular debris (characterized by irregular levels) and periventricular signal abnormalities in MRI that reflects the periventricular inflammatory change observed at this pathology, are the most characteristic findings [4,9,15]. We performed a magnetic resonance to see the extent of the lesion [4,16]. ...
Ventriculitis is one of the most severe intracranial infections and potentially life-threatening. Ventriculo-myelitis, a simultaneous infection of the ventricles and the spinal cord, is a rare condition with few cases published. We present a neonate with a congenital lateral abdominal hernia who underwent surgery. In the immediate postoperative period, she had an acute renal failure and she needed peritoneal dialysis. After that, she was lethargic and presented seizures. Head ultrasonography and magnetic resonance imaging showed images compatible with ventriculo-myelitis and a cerebrospinal fluid culture positive for Pseudomonas aeruginosa was obtained, so she received systemic antimicrobial therapy and, after clinical deterioration, she also needed an external ventricular drainage and treatment with intraventricular gentamicin. Ventriculo-myelitis by Pseudomonas aeruginosa is an aggressive infection of the central nervous system in the newborn. Intraventricular antimicrobial therapy should be considered in patients with ventriculo-myelitis whose infections have responded poorly to systemic antimicrobial therapy alone.
... To summarize, 1) increased signal abnormality on the DW MRI in the occipital/dependent horn of the cerebral ventricles with corresponding dark material was seen on the axial ADC companion image ( Figure 1C) and was indicative of PV [5][6][7], and 2) the increased signal in the sulci on the FLAIR MRI ( Figure 1A) indicated proteinaceous material in the CSF typically seen with meningitis. Although a post-contrast MRI was not performed upon initial presentation, this did not limit the diagnosis of ventriculitis. ...
Patient: Male, 49
Final Diagnosis: Pyogenic ventriculitis and meningitis caused by Streptococcus acidominimus
Symptoms: Confusion • fever • headache
Medication: —
Clinical Procedure: Antibiotics
Specialty: Infectious Diseases
Objective
Rare disease
Background
Streptococcus acidominimus, which belongs to the viridans streptococci group, is rarely considered pathogenic in humans. However, over the past 10 years, this bacterium has been reported to cause serious infections in humans, particularly among the critically ill. This article is the first case report of pyogenic ventriculitis (PV) and meningitis caused by S. acidominimus in North America.
Case Report
A 49-year-old Asian male presented to the emergency department with complaints of a headache, fever greater than 37.8°C (100°F) and confusion, of approximately 3 days duration. He was unable to speak coherently or follow approximately half of the given commands. He appeared ill; an intracranial infection was suspected. Magnetic resonance imaging of the brain showed: 1) infected proteinaceous material and pus-like material throughout the cerebral sulci and in the occipital horns of both lateral ventricles, 2) ependymal signal abnormality of the posterolateral margin of the occipital horn of the left lateral ventricle, and 3) early hydrocephalus suggestive of ventriculitis and meningitis. The blood and cerebrospinal fluid cultures were positive for S. acidominimus. The patient improved with minimal deficits after 6 weeks of IV ceftriaxone without requiring a neurosurgical intervention, such as an intraventricular drain or neuroendoscopic surgery.
Conclusions
PV and meningitis caused by S. acidominimus are rare but potentially fatal intracranial infections. Therefore, despite the risk of generalizing, our case report suggests that PV and meningitis caused by S. acidominimus can be effectively treated with a prompt and prolonged course of IV ceftriaxone without neurosurgical intervention.
Purulent meningitis (PM) is a diffuse acute purulent bacterial infectious disease of the pia mater and arachnoid and subarachnoid spaces [1, 2]. PM is one of the serious intracranial infections that often coexist with purulent encephalitis or brain abscess. Pathogenic bacteria can be found in the cerebrospinal fluid, the most common pathogenic organisms being S. meningitidis, S. pneumoniae, and H. influenzae, followed by S. aureus, Streptococcus, Escherichia coli, S. pyogenes, and P. aeruginosa. S. pneumoniae meningitidis most commonly affects children, but adults can also be infected. S. pneumoniae meningitis occurs in the elderly and in infants and children. B. influenzae meningitis occurs in young children under the age of 6. Escherichia coli is the most common causative agent of neonatal meningitis. Staphylococcus aureus and Pseudomonas aeruginosa meningitis are often secondary to lumbar puncture and neurosurgery. Patients often present with acute infection, symptoms of intracranial hypertension, and focal brain symptoms. In the acute encephalitis stage, patients have fever, headache, vomiting, and elevated blood leukocyte counts. In the brain abscess formation stage, patients have increased intracranial pressure, headache, and optic disc edema. The detection of relevant pathogens in the cerebrospinal fluid is used as a basis for the diagnosis of this disease.
The aim of the study is to explore the experiences in diagnosis and treatment of severe neurosurgical patients with pyogenic ventriculitis caused by gram-negative bacteria (G−). Nineteen patients with pyogenic ventriculitis were reviewed for their treatment. The bacterial testing results of cerebrospinal fluid (CSF), the clinical intervention, and the patients’ prognosis were evaluated. The bacterial smears of ventricular drainage from all the cases were G− bacteria. Head CT and MRI scans confirmed that they were intraventricular empyema. Eighteen cases of CSF bacterial test were positive, including 12 cases of Acinetobacter baumannii positive, 2 of Klebsiella pneumonia positive, 2 of Serratia marcescens positive, 1 of Pseudomonas maltophila positive, and 1 case of Escherichia coli positive. One case of the bacterial culture was negative. All patients were treated by using intraventricular lavage in combination with intravenous and intraventricular antibiotics in accordance with the clinical conditions. After treatment for 2 to 8 weeks, 14 patients were cured (74%) and 5 were died (26%). Eight patients who were cured had received ventriculoperitoneal shunt due to hydrocephalus at 2 to 6 weeks after infection controlled, and none of them had any reinfection. Twelve of the 14 cured cases came to consciousness, but 2 were persistent in vegetative state starting before the infection; they did not show any improving consciousness after infection had been cured. Suppurative ventriculitis in severe neurosurgical patients is mainly infected by G− with a higher mortality. Early diagnosis, especially in identifying pathogen types, timely ventricular irrigation, and ventricular drainage together with intravenous and intraventricular antibiotic treatment, should improve prognosis.
Surgical site infections (SSIs) following cranial surgery remain a serious clinical problem and major causes of morbidity and mortality. Classically, SSIs are divided into extradural and intradural infections. Risk factors can be categorized as patient related or procedure related. Clinical symptoms vary greatly depending on many features, with the most common being fever, local wound inflammation, purulent drainage, headache, mental status change, seizure, and focal neurologic deficits. CT scanning and MRI offer an interesting basis for the diagnosis of cranial and intracranial infections. Inflammatory biomarkers are highly variable in their expression in the postoperative period, with the most useful being C-reactive protein (CRP) and procalcitonin levels. When possible, CSF should be evaluated in patients with suspected intradural infections. The most common causative pathogens are quite similar, dominated by gram-positive skin flora, especially Staphylococcus aureus. Patients with limited infections may be managed with local measures and antimicrobial therapy alone, but these selected cases require careful monitoring and should be considered for surgery if complications arise. Abscess, empyema, and large cranial osteomyelitis require reoperation with cleaning, evacuation of fluids, debridement, removal of foreign material, drainage, and careful wound closure. Strict awareness of hygiene, with careful application of protocols, decreases SSIs. If treated rapidly and vigorously, SSIs may resolve without sequelae, but many neurologic complications may occur, especially in patients with intradural infections.
Pyogenic ventriculitis (pyoventriculitis) is characterized by the existence of suppurative fluid in the cerebral ventricular system. It may result from the rupture of a brain abscess, extension of meningitis into the ventricles, implantation of pathogens following a head injury, or a neurosurgical procedure with or without an implanted device. The typically indolent clinical course of pyoventriculitis sometimes can be rapidly life-threatening. Signs and symptoms are those of meningitis and raised intracranial pressure. Focal neurologic deficits may be present when a brain abscess is associated. Neuroimaging techniques are fundamental in the diagnosis. CT scan and especially MRI usually demonstrate intraventricular debris and pus in the cerebrospinal fluid (CSF). Other findings may include hydrocephalus, periventricular anomalies, and ventricular ependymal enhancement. CSF studies usually show a low glucose level, high protein, and pleocytosis. Isolation of the pathogenic agent and culture are essential in determining the antimicrobial therapy. When ventriculitis is unresponsive to intravenous antibiotics or if neurologic status is considered perilous, intrathecal antibiotic drugs can be administered. Concomitant brain abscess may be drained. Pyogenic ventriculitis is a potentially fatal infection that can lead to severe sequelae.
Often presenting as medical emergencies, nervous system infections can be diagnostically challenging. Knowledgeable utilization of neuroimaging modalities and the understanding of characteristic imaging findings facilitate early diagnosis and treatment. In the first part of this two-part review, we address common and unique diagnostic imaging features of bacterial and parasitic nervous system infections.
Pyogenic ventriculitis is an uncommon manifestation of severe intracranial infection that might be clinically obscure. We hypothesized that determining characteristic imaging features of pyogenic ventriculitis in patients with appropriate risk factors might improve recognition of this severe infection.
Review of the medical records from 1990 to 2000 revealed 17 cases (12 men, five women) that satisfied inclusion criteria of abscess (n = 3) and/or positive cultures or increased white cells and protein in ventricular (n = 12) or cisternal (n = 1) cerebrospinal fluid. In one case, the diagnosis of ventriculitis was based on the combination of bacterial growth in lumbar cerebrospinal fluid and follow-up imaging. Staphylococcus species and Enterobacter species were the most common organisms. Two neuroradiologists independently evaluated imaging studies for hydrocephalus, ventricular debris, periventricular attenuation or signal abnormality, ependymal enhancement, and signs of meningitis or abscess. Sixteen studies in 11 patients were performed after the intravenous administration of contrast material.
Ventricular debris was detected in 16 (94%) of 17 cases and was irregular in 13 (81%) of 16 cases. Hydrocephalus was present in 13 (76%) of 17 cases. Periventricular hyperintense signal was present in most (seven [78%] of nine) cases with MR imaging and was most conspicuous on fluid-attenuated inversion recovery sequences. Ependymal enhancement was detected in seven (64%) of 11 cases in which contrast material was administered. Signs of meningitis (eg, pial or duraarachnoid signal abnormality or enhancement) were present in 13 (76%) of 17 cases. Three cases had imaging signs of abscess.
Ventricular debris was the most frequent sign of ventriculitis in this series. An irregular level was characteristic of debris in ventriculitis. Hydrocephalus and ependymal enhancement were less frequent signs. Detection of ventricular debris might facilitate diagnosis of pyogenic ventriculitis, a potentially fatal infection, and thus permit appropriate therapy.
The purpose of this study was to test if a reduction of external ventricular drains (EVD) related ventriculitis could be achieved by a strict protocol of care and if protocol violation was associated with a higher incidence of EVD-related ventriculitis.
A written protocol for EVD insertion, nursing and surveillance was implemented. A retrospective comparison of EVD-related ventriculitis incidence was performed between control (161 EVD in 131 patients) and study periods (216 EVD in 175 patients). Risk factor analysis was performed in patients in whom an EVD was inserted during the study period including the relationship between protocol compliance and ventriculitis. A score for the number of protocol violations (absence of hair clipping, absence of a tunnelled EVD, absence of shampooing, incorrect dressing change, inappropriate CSF bag or tap samplings and EVD manipulation) was established for each patient.
Incidence of patient-related ventriculitis decreased from 12.2% (1999) down to 5.7% (p<0.05) as well as incidence of EVD-related ventriculitis (9.9% vs 4.6%, p<0.05). During the study period, the only statistically significant risk factors for infection were CSF leak and protocol violations. The mean protocol violation score was 4 times higher in the infected versus the non-infected patients (p<0.0001). Patients with a violation score of 0 or 1 had no infection (EVD duration 2 to 42 days).
EVD can be left safely, as long as needed, provided that meticulous care is taken for EVD insertion and nursing. EVD duration seems to have no effect on infection incidence.
Objective:
The purpose of this study was to describe the features of pyogenic ventriculitis (ventricular empyema, pyocephalus) on diffusion-weighted MR imaging.
Conclusion:
Markedly increased signal intensity of dependent intraventricular fluid on diffusion-weighted MR imaging and an apparent diffusion coefficient that is less than that of normal cerebral white matter indicate restricted water diffusion in purulent fluid and suggest the diagnosis of pyogenic ventriculitis.
Neuroimaging plays a crucial role in the diagnosis and therapeutic decision making in infectious diseases of the nervous system. The review summarizes imaging findings and recent advances in the diagnosis of pyogenic brain abscess, ventriculitis, viral disease including exotic and emergent viruses, and opportunistic disease. For each condition, the ensuing therapeutic steps are presented. In cases of uncomplicated meningitis, cranial computed tomography (CT) appears to be sufficient for clinical management to exclude acute brain edema, hydrocephalus, and pathology of the base of skull. Magnetic resonance imaging (MRI) is superior in depicting complications like sub-/epidural empyema and vasculitic complications notably on FLAIR (fluid-attenuated inversion recovery)-weighted images. The newer technique of diffusion-weighted imaging (DWI) shows early parenchymal complications of meningitis earlier and with more clarity and is of help in differentiation of pyogenic abscess (PA) from ring enhancing lesions of other etiology. Proton magnetic resonance spectroscopy (PMRS) seems to produce specific peak patterns in cases of abscess. The presence of lactate cytosolic amino acids and absence of choline seems to indicate PA. Also in cases of suspected opportunistic infection due to toxoplasma DWI may be of help in the differentiation from lymphoma, showing no restriction of water diffusion. In patients with herpes simplex and more exotic viruses like West Nile and Murray Valley virus DWI allows earlier lesion detection and therapeutic intervention with virustatic drugs.
Objective:
The ability of different MRI sequences to depict characteristic findings suggestive of ventriculitis was compared.
Conclusion:
The study comprised 20 brain MRI studies in 13 patients who had a final diagnosis of ventriculitis. Both diffusion-weighted imaging and FLAIR imaging were equally and highly sensitive for detecting intraventricular debris and pus--the most common MRI finding suggestive of ventriculitis. FLAIR imaging was superior to contrast-enhanced T1-weighted imaging for depicting ventricular wall abnormalities--a less common finding that also is suggestive of ventriculitis.
Robert Department of (neurological) Critical Care Medicine B-2650 Edegem, Belgium e-mail: Philippe
- P G Jorens
P. G. Jorens (&) Á D. Robert Department of (neurological) Critical Care Medicine, Antwerp University Hospital, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem, Belgium e-mail: Philippe.Jorens@uza.be M. H. Voormolen Á P. M. Parizel Department of Radiology, Antwerp University Hospital, University of Antwerp, Edegem, Belgium Neurocrit Care (2009) 11:403–405 DOI 10.1007/s12028-009-9263-3 References
Diffusionweighted imaging of pyogenic ventriculitis
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- G A Tung
- S Mudigonda
- J M Rogg
Pezzulo JA, Tung GA, Mudigonda S, Rogg JM. Diffusionweighted imaging of pyogenic ventriculitis. AJR Am J Roentgenol. 2003;180:71-5.