ABSTRACT

We investigated the contribution of polysomnography (PSG) to daytime and routine EEG findings with regard to observation of seizures, detection of epileptic foci, and documentation of sleep stages at which culmination of epileptic activity occurs.

The study included 22 patients (9 men, 13 women; mean age 38 years; range 17 to 55 years) with nocturnal seizures. Diagnoses of seizure types according to patient histories were primary generalized in 15 patients (68%) and complex partial in seven patients (32%). The patients were hospitalized for a night to perform 8-hour-PSG recordings. The results were compared with routine and daytime longterm EEG findings for various seizure types.

During PSG, seizures were observed in two patients while epileptic foci were documented in 14 patients (64%). Of these, epileptic foci were on the left in 10 patients (71.4%), on the right in two patients (14.3%), and bilateral in two patients (14.3%). Compared with PSG recordings, repeated routine EEGs and daytime long-term EEGs revealed foci in 11 patients (50%) and 10 patients (45.5%), respectively.

Observation of seizures and documentation of epileptic foci by means of PSG may prove useful in the diagnosis, follow-up, and prognosis of patients with pure nocturnal seizures, and in the selection of appropriate antiepileptic drugs.

Keywords: Brain/physiopathology; electroencephalography;epilepsy/physiopathology; polysomnography;sleep/physiology; sleep, REM; sleep stages