Focal bilateral motor seizures precipitated by abrupt cessation of chronic lormetazepam abuse and amitriptyline overdose

Abstract

We report the case of an adult psychiatric patient who developed new-onset focal bilateral motor seizures (FBMS) in the context of a severe benzodiazepine withdrawal syndrome. The patient was forced to interrupt chronic lormetazepam abuse and overdosed on amitriptyline (800 mg in an oral solution) before the onset of seizures. Typical signs of amitriptyline intoxication such as sedation and anticholinergic effects were not observed. Video-EEG recordings revealed a stereotypical ictal motor pattern with asymmetric tonic posturing and bilateral clonic movements of the upper limbs, but there were no abnormalities identified by EEG. Seizures recurred multiple times per day but resolved simultaneously when withdrawal symptomatology subsided eight days after onset. Nonepileptic seizures (NES) were considered in the differential diagnosis because of the patient's psychiatric history including preserved awareness during the bilateral convulsions, the absence of postictal confusion, and normal EEG. The present case indicates that FBMS may occur during benzodiazepine withdrawal in patients who overdosed on amitriptyline. The diagnosis may be challenging as FBMS may mimic NES in the absence of abnormal neurophysiologic findings. This may be especially challenging in patients with an underlying psychiatric disease.

Keywords

• Benzodiazepine withdrawal
• Lormetazepam
• Focal seizures