EEG in dengue virus infection with neurological manifestations: A clinical and CT/MRI correlation

Objective: To evaluate electroencephalography (EEG) changes in dengue virus infection and correlate these with clinical, laboratory and CT/MRI changes. Methods: Consecutive patients with dengue virus infection were prospectively evaluated. A detailed history and clinical examination were carried out. Level of consciousness was assessed by Glasgow Coma scale (GCS). Cranial CT scan or MRI or both were carried out. EEG was carried out within 24 h of hospitalization and repeated after 15-30 days. Outcome was defined at 1 month into death, poor, partial and complete recovery. Results: Twenty-four patients aged 5-65 years with dengue virus infection having neurological manifestations were included; of whom six were females. EEG revealed theta to delta slowing in 11 out of 20 patients. Five of these patients had seizures, 12 altered sensorium, 3 hypotension, 9 CSF pleocytosis, 3 moderate to severe liver dysfunction and 2 MRI abnormalities who had Japanese encephalitis virus coinfection. Presence of EEG slowing correlated with altered sensorium and depth of coma but not with outcome. At 1 month, three patients died and 16 had complete, three partial and two poor recovery. Conclusions: EEG revealed non-specific slowing in 55% patients with dengue virus infection, which correlated with level of consciousness but not with CT/MRI abnormalities or clinical recovery. Significance: Dengue virus infection results in non-specific EEG slowing in 55% patients, which may be due to dengue virus encephalitis per se or associated confounding variables such as seizure, metabolic encephalopathy, or structural brain lesion. (c) 2006 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.