EEG changes in intrathecal baclofen overdose: a case report and review of the literature

Objective: To review the clinical and EEG manifestations of intrathecal bac lofen overdose. Methods: We identified one patient who had received an overdose of intrathe cal baclofen. Information about the clinical course was obtained by reviewi ng the patient's medical record. EEGs were recorded with the use of the sta ndard 10-20 electrode placement system. Results: The patient received 30 mg baclofen intrathecally. Shortly after t he injection he developed respiratory insufficiency and quadriparesis and l ater became comatose. The first EEG obtained 20 h after the injection showe d very frequent quasiperiodic generalized epileptiform discharges. The pati ent gradually improved clinically and a second EEG obtained 24 h later show ed only intermittent bursts of generalized slow wave activity. A repeat EEG study 1 week later was normal. Conclusions: The EEG in intrathecal baclofen overdose can show quasiperiodi c generalized epileptiform discharges. This does not necessarily indicate t he presence of underlying potential epileptogenicity, and treatment with an antiepileptic medication is not necessary. (C) 1998 Elsevier Science Irela nd Ltd. All rights reserved.