Prevalence of genuine epilepsy among adult emergency patients with an episode of unconsciousness.
OBJECTIVE
Loss of consciousness (LOC) is caused by a variety of conditions including epileptic, cardiac, psychiatric, and autonomic disorders. We investigated the prevalence of presenting attacks of genuine epilepsy among patients of Emergency Department and Department of Cardiology evaluated for an episode of LOC with or without a convulsion.


METHODS
We retrospectively studied 371 adults presenting to the Emergency Department and Department of Cardiology of our hospital from 1991 to 1999 with a chief complaint of an episode of LOC with or without a convulsion. Ages ranged from 15 to 78 years. Patients were free of severe chronic illnesses, drug abuse, and alcoholism. LOC was considered to represent genuine epilepsy either when the interictal electroencephalogram (EEG) showed epileptiform discharges in the absence of imaging abnormalities, or when both the EEG and imaging studies were unrevealing but one or more previous attacks had occurred and administration of an anticonvulsant prevented subsequent attacks.


RESULTS
Patients included 302 patients without a convulsion, and 69 patients with a convulsion. Of the former, 14 subjects had epileptiform discharges on EEG, and three subjects had no epileptiform discharges but had three or four attacks of LOC that were abolished by anticonvulsant therapy. Of the 69 patients with a convulsion, seven had epileptiform discharges, and 12 had two to five attacks, no epileptiform discharges, and a response to anticonvulsant therapy.


CONCLUSIONS
The prevalence of presenting attacks of genuine epilepsy in 371 adult patients with an episode of LOC was remarkably high (9.7%: 36 subjects).
Shintani
S
S
Department of Neurology, Toride Kyodo General Hospital, Toride City, 302-0022, Ibaraki, Japan. dw4s-sntn@asahi-net.or.jp
Tsuruoka
S
S
Shiigai
T
T
D000328:Adult; D000367:Age Factors; D004569:Electroencephalography; D004636:Emergency Service, Hospital; D004827:Epilepsy / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012737:Sex Factors; D014474:Unconsciousness / Q000209:etiology / Q000503:physiopathology*