Focal seizures due to chronic localized encephalitis

Abstract

OCCASIONAL SPECIMENS of scarred, atrophic brain removed for the relief of focal cerebral seizures at the Montreal Neurological Institute have shown striking perivascular collections of round cells, particularly in less severely damaged areas of these specimens. In the past this perivascular cuffing has been attributed to the effect on the brain of recurring seizures, with recognition, however, that this was a rather unsatisfactory explanation since the great majority of surgical specimens removed from patients with equally frequent focal seizures do not show this change. Histologic studies of surgical specimens from three children recently operated upon for intractable focal seizures suggest that this microscopic picture may indicate the presence of an unsuspected, more or less localized, chronic encephalitis that has smoldered along over a period of years. The clinical and histologic data on these three children will be reported in some detail.The most complete study from the pathologic standpoint was made in the last of the three patients to appear. This case will be discussed first, since it seems to clarify interpretation of the train of events in the other two. M.D.Remooal of the left frontal lobe, carded out six months after the onset of seizures in a fruitless attempt to stop them, proofded an oppoctunity to compare the miczoscopic picture at that time with that shown at autopsy three and a half months later.Birth and early development of this child were normal, and there were no signscant illnesses until April 1955 at 18 months of age, when the parents noted a scratch behind the right ear. The following day swelling in this region was noted and the temperature rose to 104" F. The tempefature subsided the next day after administration of penicillin, but the swelling behind the ear continued to discharge bloody fluid for one week.The child seemed entirely well for two months, but in July he became unusually irritable one day and vomited the followin mornin . That afternoon he seemed dizzy an% soon aifer was noted to stare and salivate; he then developed clonic movements of the right side of the body.persisted for an hour before the convulsion was stopped by administration of chloroform. A similar attack occurred a month later in August 1955, and from then on milder right-sided seizures recurred several times daily. During the next three months his usual quiet, pleasant bebehavior changed and he became somewhat irritable and destructive. During this period his parents felt that his speech was becoming somewhat less clear than it had been.In November the right arm became completely useless and hung limply by his side for three days.From the department of neurology and neurosurgery.

Neuroprotective intervention by interferon-γ blockade prevents CD8+ T cell-mediated dendrite and synapse loss

“…Second, the IFNGR may form a complex with the AMPA receptor subunit GluR1 in neurons, leading to increased excitability and vulnerability to glutamate excitotoxicity (Mizuno et al, 2008). It thus seems plausible that CTL-derived IFN- sensitizes inflamed brain regions to epileptic seizures, which represents the earliest and most prominent manifestation of RE (Rasmussen et al, 1958;Bien et al, 2005). Of note, our present findings offer a potential explanation for the disease-enhancing effects of IFN- in an exploratory trial for MS (Panitch et al, 1987), a disease with prominent dendritic pathology.…”

Surgical Treatment of Patients with Rasmussen Encephalitis

“…A viral etiology has already been suggested by Rasmussen [1] based on the constituents of the immune reaction in the brain, such as lymphocyte infiltration and microglial nodules, but no pathogenic viral agents have been observed in any study subject [7,8]. Circulating autoantibodies, such as GluR3 and munc-18 [9,10], have also been suggested, but follow-up studies confirmed that those antibodies also existed in other diseases.…”

“…Rasmussen encephalitis (RE) is a rare progressive encephalitis that results in intractable seizures, cognitive decline and hemiparesis [1]. The affected hemispheres of RE patients are typically unilateral.…”

“…The pathological changes in RE patients usually consist of reactive astrocytosis, neuronal loss, abundant foci of perivascular mononuclear cells, thickened meninges with lymphocytic infiltration and microglial nodules. During the residual stage, the illness is presented as a diffuse gliosis and spongy degeneration of the cortex [1,6]. …”

Refractory Occipital Lobe Epilepsy Treated by Surgery in a Child with Chronic Encephalitis

“…Intractable focal epilepsy in children associated with progressive hemiparesis and cognitive impairment due to chronic encephalitis was first reported by Rasmussen et al [1]. Most of these patients suffer from epilepsia partialis continua characterized by focal motor seizures (Khozhevnikov’s syndrome), and the epileptic process spreads to involve the whole of one hemisphere.…”