Isolated, chronic, epilepsia partialis continua in an HIV-infected patient

Background: The characteristic clinical feature of epilepsia partialis cont inua (EPC) is chronic focal myoclonus, usually involving the distal part of one extremity. A variety of pathogenetic factors have been implicated in E PC. In children, the most common cause is Rasmussen encephalitis; in adults , it is vascular disease or tumor involving the sensorimotor cortex. Epilep tic seizures are a relatively common manifestation of central nervous syste m involvement in patients infected with human immunodeficiency virus (HIV), but, to our knowledge, isolated, chronic EPC has not been previously repor ted. Objective: To describe a case of typical EPC in a patient infected with HIV . Design and Setting: Case report from an epilepsy center. Patient: A 58-year-old man infected with HIV had continuous myoclonus that involved the right arm and was associated with intermittent motor seizures. The electroencephalographic findings were normal at the onset of the sympt oms, but left central theta rhythm appeared later. Serial magnetic resonanc e imaging scans obtained over a 3-month period showed a progressively incre asing left rolandic T-2-weighted hypersignal. Histologic study of a stereot actic biopsy specimen demonstrated inflammation characterized by perivascul ar mononuclear cell infiltration. The only detectable cause was HIV infecti on. Immunocytochemical tests ruled out JC virus. Neuropsychological testing showed no evidence of cognitive impairment. An electroencephalographic-ele ctromyographic "back-averaging" study showed a reproducible transient left biphasic complex preceding the bursts by about 30 milliseconds on the C3 an d F3 electrodes, thus demonstrating that the myoclonus was of cortical orig in. High-dose corticosteroid (prednisone, 100 mg/d) and anti-HIV-1 therapy led to marked radiological and clinical improvement. Infection with HIV enh ances the risk of seizures, but, to our knowledge, this is the first report ed case of "inflammatory" EPC. Conclusions: The present case suggests that the possibility of central nerv ous system involvement by HIV-1 should be taken into account in the diagnos tic workup of patients with EPC. This case also indicates that treatment ca n be effective.