A case series of dengue fever with altered consciousness and electroencephalogram changes in Sri Lanka.

We describe six serology-positive dengue patients presenting sporadically over 8 years, who lapsed into coma and showed generalized irregular slow waves in consecutive electroencephalograms (EEG) in the absence of any structural brain damage. The mean age was 41 years (range 16-65). All had fever, headache and vomiting for 3 days (range 2-4) on admission and developed coma after 24 h. Five patients developed generalized convulsions and two showed generalized paroxysmal spike-wave discharges in the EEG. All regained normal consciousness within 36 h. In two patients, slow waves in the EEG persisted for 6 and 18 months.