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The syndrome of chronic encephalitis with epilepsy (Rasmussen's syndrome) typically occurs in children and is characterized by the development of intractable focal seizures, progressive hemiparesis and intellectual deterioration. The etiology is unknown, and the pathological abnormalities vary from those of active disease, with numerous microglial nodules, with or without neuronophagia, perivascular round cells and glial scarring, to those of remote disease, demonstrated by neuronal loss, gliosis and perivascular round cells but few microglial nodules. We describe five patients presenting with clinical features typical of Rasmussen's syndrome, in whom pathological examination showed a second, previously unsuspected pathology in addition to the changes of chronic encephalitis. Two of the patients had vascular abnormalities bearing some resemblance to cavernous angiomata, one had a tumor, one had tuberous sclerosis, and one the forme fruste of tuberous sclerosis. The coexistence of a second pathology in these patients may provide information about the underlying mechanism of this rare condition.

Chronic encephalitis and epilepsy (Rasmussen's encephalitis) is a rare progressive disorder of uncertain etiology that usually occurs in children, producing focal epilepsy, hemiparesis, and intellectual deterioration. We identified 13 patients in whom seizures developed in adolescence or adulthood with a pathologic picture of chronic encephalitis. The clinical characteristics were more variable than those occurring in children, with the patients falling into three groups: five patients developed seizures in adulthood, but otherwise showed many resemblances to the childhood form; five developed seizures in adolescence, with similar presentation but rather more benign course than in the younger patients; and three presented with clinical features initially suggestive of a tumor. Occipital onset to the seizures appeared to be more common than in the childhood form, and bilateral disease also occurred.

This report is a sequel to our 1958, 1960 and 1968 reports on a series of patients operated upon for focal epilepsy whose surgical specimens unexpectedly showed histological lesions typical of active encephalitis. None of these patients, now 27 in number, exhibited the clinical picture ordinarily associated with encephalitis. With one exception, all showed a severe focal seizure tendency beginning in infancy or childhood, often associated with episodes of epilepsia partialis continua. In addition, all except 2 showed slowly progressive neurological deterioration, usually hemiparesis and mental retardation, which advanced over periods of months or years before the progression became arrested. No infectious agent has yet been identified by standard viral studies carried out in the most recent 14 patients or by investigation for slow viruses in 6 patients operated upon between 1966 and 1971. The clinical course of this condition is outlined and the role, the timing and the results of treatment by craniotomy and cortical excision are discussed.

N. A. Renner, R. K. Redmann, T. Moroney-Rasmussen, H. A. Sansing, P. P. Aye, P. J. Didier, A. A. Lackner and A. G. MacLean (2012) Neuropathology and Applied Neurobiology 38, 162-174 S100β as a novel and accessible indicator for the presence of monocyte-driven encephalitis in AIDS Aims: The pathogenesis of human/simian immunodeficiency virus encephalitis (HIVE/SIVE) remains incompletely understood, but is associated with alterations in the blood-brain barrier. At present, it is not possible to easily determine if an individual has HIVE/SIVE before post mortem examination. Methods: We have examined serum levels of the astroglial protein S100β in SIV-infected macaques and show that it can be used to determine which animals have SIVE. We also checked for correlations with inflammatory markers such as CCL2/MCP-1, IL-6 and C-reactive protein. Results: We found that increased S100β protein in serum correlated with decreased expression of the tight junction protein zonula occludens-1 on brain microvessels. Furthermore, the decrease in zonula occludens-1 expression was spatially related to SIVE lesions and perivascular deposition of plasma fibrinogen. There was no correlation between encephalitis and plasma levels of IL-6, MCP-1/CCL2 or C-reactive protein. Conclusions: Together, these data indicate that SIVE lesions are associated with vascular leakage that can be determined by S100β protein in the periphery. The ability to simply monitor the presence of SIVE will greatly facilitate studies of the neuropathogenesis of AIDS. [ABSTRACT FROM AUTHOR]

It is known that there is disruption of the blood–brain barrier during terminal AIDS encephalitis in both human immunodeficiency virus (HIV)-infected humans and simian immunodeficiency virus (SIV)-infected rhesus macaques. Much, although by no means all, of the neuropathological findings of HIV and SIV infection involves accumulation of monocytes/macrophages that have likely crossed the blood–brain barrier (BBB). There is no convincing, rigorous, demonstration of HIV (or SIV) infecting endothelial cells in vivo. However, this is not to say that HIV infection would not have any effects on the physiology of microvascular brain endothelial cells. Because of the elaborate nature of cerebral microvessels, previous studies of cerebral endothelial cells have been constrained by sectioning artifacts. Examination of freshly isolated cerebral microvessels allows investigation of extended lengths of vessels (>150 μm) without sectioning artifacts. These studies determine the changes in the expression of the tight junction protein zo-1 protein on the endothelial cells of cerebral capillaries at terminal acquired immune deficiency syndrome, demonstrating that there is a decreased expression of zo-1 protein over extended lengths of microvessels. [ABSTRACT FROM AUTHOR]