Unusual ipsilateral hyperkinetic automatisms in SMA seizures

To describe repetitive movements of the right arm possibly originating from the ipsilateral SMA area in two drug-resistant epileptic patients.

Two epileptic patients (one female, one male, 35 and 36 years old, respectively) were submitted to pre-surgical evaluation including history, neurological examination, long-term video-EEG monitoring, interictal and ictal SPET, MRI and fMRI, neuropsychological assessment. Invasive recordings (stereoelectroencephalography) were also performed.

In both patients ictal semiology was characterized by very stereotyped repetitive right arm movements, i.e. tapping towards the thorax (movement rate of 6-7 Hz and 3-4 Hz for the two subjects, respectively). Seizures in the first patient, whose epilepsy was cryptogenetic, originated from the right pre-SMA area, which was surgically removed. She is seizure free 2 years after the operation. In the second patient, in whom a right pre-frontal post-abscess porencephaly was disclosed, the epileptogenic zone included the lesion and surrounding areas, while the SMA area was involved less consistently.

Even if, according to literature, SMA epilepsy is predominantly characterized by postural manifestations, ipsilateral repetitive movements could be a relevant sign in this kind of epilepsy, as showed in our first patient. The presence of similar semiology in the second patient, might suggest that the symptomatogenic zone involved SMA area.