No abstract

A 56-year-old woman with a 3-year history of hydrocephalus and ventriculo-peritoneal shunt placement, presented with worsening altered level of consciousness for 2 days. Imaging studies showed severe ventriculomegaly involving the lateral and third ventricles with multiple septated cysts noted in the lateral ventricles predominantly near the frontal horns. Histopathologic examination of the excised brain lesion revealed choroid plexus tissue and adjacent cerebral parenchyma with several non-caseating granulomas. Granulomatous inflammation was also identified in mediastinal lymph nodes. By using specific monoclonal antibodies, Propionibacterium acnes (P. acnes) were detected in non-caseating granulomas of both the brain and mediastinal lymph nodes. No acid-fast bacilli or fungal elements were present. To the best of our knowledge, this is the first demonstration of P. acnes in sarcoid granulomas of cerebral tissue, and it reinforces the possible link between P. acnes and sarcoidosis.

The authors report a case of fatal acute encephalopathy following influenza infection, with slightly atypical pathological and imaging findings. A healthy 8-year-old boy with probable recent influenza A/B infection admitted for refractory seizures was placed on phenobarbital coma and later developed hemodynamic instability. Magnetic resonance imaging revealed bilateral cerebral and cerebellar white matter lesions and microhemorrhages. Following his demise, the autopsy revealed a large area of necrosis in the right centrum semiovale with similar lesions in the temporal and cerebellar regions. Microscopically, there was extensive coagulative necrosis, compatible with necrotizing white matter encephalopathy, and neuronal loss suggesting superimposed hypoxic–ischemia. The acute progressive neurologic deterioration was partly reminiscent on acute necrotizing encephalopathy, a condition recently associated with influenza A. In acute necrotizing encephalopathy, typical brain findings are characterized by bilateral thalamic necrosis/petechiae with variable white matter edema. The somewhat atypical findings in our case can relate to superadded cardiovascular collapse and hypoxic–ischemic effects.

We report a new radiological finding in two patients with hepatic encephalopathy. A new susceptibility-weighted (SWI) magnetic resonance imaging sequence revealed multiple bilateral microsusceptibility changes in the corpus callosum and white matter, while the conventional T1 and T2 weighted images were unremarkable. We postulate that the etiology of the microsusceptibility changes may be related to hepatic coagulopathy and other factors, such as impaired cerebral blood flow and brain edema.

Purposeof review: Brain MRI findings of focal cortical dysplasia (FCD) can undergo dramatic changes over time, which may be related to long-term epilepsy or a combination of histopathologic changes that necessitate further investigation.Recent findings:We describe two cases of FCD Type IIb that initially displayed inconspicuous findings on MRI, however progressed to obvious signal changes on subsequent MRI 10-17 years later. Pathologic analysis indicates that the interval changes are likely attributed to reactive astrogliosis and diffuse parenchymal rarefaction. A few case reports and case series showing similar MRI changes have been described in the literature, the majority in pediatric patients. The adult cases we present add to the scientific evidence of these changes occurring in the adult population.Summary:Our observations lead to several clinical suggestions, including closer interval follow up imaging for non-lesional cases, the addition of post-processing imaging methods, earlier surgical intervention, and meticulous surgical planning.