Typical absence status in adults: Diagnostic and syndromic considerations

Purpose: To study the electroclinical features of typical absence status (T AS) in adults with syndromes of idiopathic generalized epilepsies (IGEs). Methods: Twenty-one patients with one or more spells of TAS were identified among 136 consecutive adult patients with IGEs. All patients with TAS had comprehensive electroclinical investigations and EEG or video-EEG recorded absences. Results: TAS occurred in 24.4% of 86 patients who had IGEs with typical abs ences alone or in combination with other seizures presisting in adult Life. The prevalence of TAS appeared to be syndrome related, ranging from as hig h as 57.1% in perioral myoclonia with absences and 46.2% in "phantom" absen ces with GTCS to as low as 6.7% in juvenile myoclonic epilepsy. A varying d egree of impairment of cognition was the cardinal clinical symptom shared i n all TAS, but corresponding syndromes of IGE were often betrayed by other symptoms such as eyelid or perioral myoclonia. In phantom absences with GTC S, TAS was more numerous (p less than or equal to 0.05) and more frequently the first overt seizure type (p = 0.006) than in any other IGE. Only in th e syndrome of eyelid myoclonia with absences, TAS was always situation rela ted, mainly as a result of antiepileptic drug discontinuation. Conclusions: The clinical EEG semiology and prevalence of TAS appear to be syndrome related with the highest prevalence in the syndromes of perioral m yoclonia with absences and phantom absences with GTCS (p = 0.0024).