Chronic isolated hemifacial spasm as a manifestation of epilepsia partialis continua

The objective of this case study was to describe the clinical and electroencephalography (EEG)/functional magnetic resonance imaging (fMRI) data of a case of isolated hemifacial spasm due to epilepsia partialis continua in a 59-year-old man with abnormal hemifacial movements that disappeared during voluntary tasks, were absent during sleep, and responded to carbamazepine. His neurological examination was normal; EEG revealed right inferior frontal epileptiform discharges. EEG/fMRI demonstrated increased blood oxygenation level-dependent contrast in the right inferior and middle frontal gyri corresponding to the contralateral motor and premotor cortex responsible for facial movements (BA 44, 45, 45, 9), with widespread BOLD signal deactivations suggestive of epileptic network involvement despite a very focal epileptogenic process. We hypothesize that the response of some cases of hemifacial spasm to carbamazepine, a first-line treatment in the pre-botulinum toxin era, may have been due to its antiepileptic effects, rather than to modulation of facial nerve hyperexcitability.