Seizure occurrence during long-term monitoring

Intensive long-term monitoring (LTM) for patients with refractory seizures is common and expensive. Methods to decrease the length of stay would improve patient experience and reduce cost. Therefore, we prospectively analyzed seizure occurrence in 36 patients who had LTM.

Antiepileptic drug (AED) levels and reduction were monitored and seizures were related to these changes. Patients were divided into temporal and extratemporal groups.

Twenty patients had partial seizures of temporal lobe origin. The temporal lobe partial seizures occurred between LTM days 1 and 16. All but 4 of the patients required reduction or discontinuation of a least one AED and had subtherapeutic levels of the tapered medications. In 16 patients with extratemporal partial seizures, seizures occurred between LTM days 1 and 8. Six of these patients required reduction of at least one AED, and 5 of the 6 had subtherapeutic levels of that medication. These differences between length of monitoring and AED reduction in temporal and extratemporal patients were statistically significant. The groups did not differ significantly with respect to number or identity of tapered or nontapered medications or levels of nontapered medications. Reported seizure frequency at home was significantly related to number of seizures recorded in the temporal group only. The only significant predictor of secondarily generalized seizure activity during monitoring was a history of such activity occurring at home.

We conclude that patients with extratemporal partial seizures need little reduction of AED for seizures to be captured in a minimal time period. Patients with temporal lobe seizures, however, required drastic reduction of AEDs to allow capture of seizures in a long time period.