Postictal paresis in focal epilepsies - Incidence, duration, and causes - A video-EEG monitoring study

Background: Although familiar to every neurologist, postictal paresis ( PP) has only rarely been analyzed systematically. Objective: To describe the frequency and duration of PP in patients undergoing video-EEG monitoring, the semiology characteristics of seizures preceding PP, and the pattern of associated symptoms and signs. Methods: The records of 513 consecutive patients who underwent prolonged video-EEG monitoring during presurgical epilepsy evaluation were reviewed for postictal motor deficit. Three hundred twenty-eight patients fulfilled the inclusion criteria. The videotapes of patients with PP were subsequently analyzed with a careful analysis of ictal motor phenomena at the side of the PP. Results: PP was found in 44 patients (13.4%). PP was always unilateral and always contralateral to the seizure focus and had a median duration of 173.5 seconds ( range 11 seconds to 22 minutes). Of all seizures with PP, 77.8% were accompanied by evident and 9.7% by very slight ictal motor phenomena ipsilateral to the side of PP, whereas 9.7% of the seizures showed no motor signs ( two seizures [2.8%] could not be evaluated for motor phenomena). The most common ictal lateralizing sign was unilateral clonic activity in 55.6% of all seizures. Concomitant dystonic posturing was found in 47.9% and ictal limb immobility in 24.6% of the seizures. PP was of longer duration if ictal clonic activity was present and after tonic-clonic seizures. Conclusions: PP is relatively frequent ( 13.4%), is easy to detect, and has a high lateralizing value. The high incidences of dystonic posturing and of ictal limb immobility in our patients with PP may indicate that an active inhibitory process is involved in its pathogenesis.