Hand posture as localizing sign in adult focal epileptic seizures.
Ferando I, Soss JR, Elder C, et al.
Ann Neurol 2019; 86:793-800.
The aim of this study was to identify specific ictal hand postures (HPs) as localizing signs of the epileptogenic zone (EZ) in patients with frontal or temporal lobe epilepsy.
In this study, we retrospectively analyzed ictal semiology of 489 temporal lobe or frontal lobe seizures recorded over a 6-year period at the Seizure Disorder Center at University of California, Los Angeles in the USA (45 patients) or at the C. Munari Epilepsy Surgery Center at Niguarda Hospital in Milan, Italy (34 patients). Our criterion for EZ localization was at least 2 years of seizure freedom after surgery. We analyzed presence and latency of ictal HP. We then examined whether specific initial HPs are predictive for EZ localization.
We found that ictal hand postures were present in 72.5% of patients with frontal and 54.5% of patients with temporal lobe seizures. We divided hand postures into 6 classes depending on the reciprocal position of the fingers (“fist,” “cup,” “politician’s fist,” “pincer,” “extended hand,” “pointing”). We found a striking correlation between epileptogenic zone localization and ictal hand posture. In particular, fist and pointing hand postures are strongly predictive of frontal lobe epileptogenic zone; cup, politician’s fist, and pincer are strongly predictive of temporal lobe epileptogenic zone.
Our study offers simple ictal signs that appear to clarify differential diagnosis of temporal versus frontal lobe epileptogenic zone localization. These results are meant to be used as a novel complementary tool during presurgical evaluation for epilepsy. At the same time, they give us important insight into the neurophysiology of hand movements.