Intensive neuromonitoring for complex partial seizures: focal seizure pattern variability in surgical patients.

Intensive neuromonitoring of seizure surgery candidates, with its associated medication withdrawal, involves increased seizure susceptibility. This can cause a confusing array of seizure patterns. This problem was examined in the candidates for seizure surgery in the Austin Hospital Comprehensive Epilepsy Programme, emphasis being placed on focal seizures. Generalized seizures were very common. Eleven (15%) patients showed multiple focal seizure patterns. Seven patients showed temporal lobe seizures originating from either side separately. Three showed persistent frontal and temporal complex partial seizures. One patient showed 2 separate species of focal epilepsy. Whilst the simplest and most effective way out of this diagnostic problem was close consultation and video review with parent or spouse, this process was ineffective in 6 of 11 patients. In patients with bitemporal lobe epilepsy there was often little to distinguish the fit coming from one side from that coming from the other and often elements of the fit from either side were recognized by the relative. In all patients with frontal and temporal complex partial seizures, elements of the seizure had been seen previously and in only 1 was there any preponderance on neuromonitoring. Therefore it is suspected that the confusing seizure detail seen on intensive neuromonitoring may in fact exist in real life and render the clinical history suspect--a problem which can be avoided only by initial neuromonitoring.