Clinical and Electroencephalographic Correlates in Rasmussen's Encephalitis

Abstract

Summary:Purpose: Rasmussen's encephalitis (RE) is a progressive childhood disease characterized by unilateral brain dysfunction, seizures, and inflammatory histopathology. Converging lines of evidence suggest that an autoimmune process is important in the pathogenesis of RE.Methods: Two patients with pathologically confirmed RE and increased levels of circulating glutamate receptor subunit (GluR3) antibodies were studied prospectively before, during, and after trials of plasmapheresis (PEX) and other immunomodulation. Frequency, duration, and intensity of clinical seizures were directly correlated with the abundance of interictal epileptiform activity on serial EEGs.Rasmussen's encephalitis (RE) is a rare childhood syndrome of unilateral brain dysfunction and focal seizures (1-3). Unihemispheric dysfunction progresses relentlessly in severity and degree over months to decades, culminating in hemiparesis and dementia. Seizures are refractory to antiepileptic drugs (AEDs). Partial corticectomy may temporarily control seizures, but spread of the process to the rest of the hemisphere eventually follows. Functional hemispherectomy is the recommended alternative (3,4). Neuroimaging shows progressive atrophy of the affected hemisphere (33). Neuropathology characteristically shows perivascular lymphocytic cuffing and proliferation of microglial nodules in the cortex of the affected hemisphere, with sparing of the contralateral hemisphere, basal ganglia, and posterior fossa structures (1,6). Converging lines of evidence suggest an autoimmune process is important in the pathogenesis of RE, and that the glutamate receptor subunit, GluR3, may be an important autoantigen (7-9).This report correlates clinical and EEG features of 2 patients with RE who underwent therapeutic plasmaphaAccepted September 27, 1996. Address correspondence and reprint requests to Dr. P. I. Andrews at Division of Neurology, Sydney Children's Hospital, High St., Randwick, Australia, 2031.Results: Serial EEGs in these patients suggest that early in the course of RE interictal epileptiform activity is localized to the affected hemisphere and that disease progression is associated with increasingly frequent bilaterally synchronous and contralateral epileptiform activity.Conclusions: The clinical and EEG parameters of epileptogenesis were transiently diminished by PEX, which suggests that circulating factors induce dose-dependent, reversible epileptogenic effects in some patients with RE. Key Words: Rasmussen's encephalitis-Electroencephalography-Autoimmune4lutamate receptor-False lateralization. resis (PEX), highlighting the progression of EEG abnormalities over time. METHODSTwo previously reported patients (7,9) with pathologically confirmed RE were enrolled sequentially in a series of therapeutic trials of PEX and other immunemodulating therapies, with the approval of the Duke University Medical Center Institutional Review Board and informed consent of the families. Data were collected prospectively. Daily seizure diaries were recorded by the parents. ...

Resetting of brain dynamics: epileptic versus psychogenic nonepileptic seizures

“…(When ES do not reset the established pathology in brain's dynamics, cluster of seizures and/or status epilepticus may result [2]. ) We have called this reversal of dynamics brain resetting at epileptic seizures and we have observed it in focal as well as generalized seizures, within and across patients [3-9]. We also have observed it using other measures of brain dynamics [10].…”

Immunoglobulin-responsive refractory epilepsy – 3 cases with a similar EEG pattern

“…21,22 The EEG in RE evolves over time, initially comprising lateralized epileptiform discharges from the affected hemisphere, and progressing to multifocal contralateral epileptiform discharges later in the disease course -termed ''false lateralisation''. 23,24 Other syndromes sharing this pattern include Sturge-Weber, focal cortical dysplasia, hemiconvulsionhemiplegia-epilepsy-syndrome and PCDH19 related epilepsies. None of these fit our cases.…”

Seizure Prediction and its Applications

“…Figure 1(C) shows the same trend at the level of STL max profiles of individual brain sites. We have called this reversal of dynamics brain resetting at seizures and we have observed it in focal as well as generalized seizures, within and across patients [60–66]. We also have observed it using other measures of brain dynamics [67].…”