Encephalitis and myelitis associated with dengue viral infection. Clinical and neuroimaging features

Objectives: The objective of this study was to identify clinical and neuroimaging features and outcome of patients with encephalitis and myelitis associated with dengue viral infection. Patients and methods: We retrospectively reviewed 225 cases of dengue viral infection. The diagnosis of dengue was confirmed by serology (presence of IgM antibodies). Results: Six patients (3%) had evidence of neurological infection (encephalitis: 5 patients; encephalomyelitis: 1 patient). Age range was 18-35 years (Mean 27 years). Five patients (83%) were women. All patients (100%) had drowsiness, five patients (83%) had fever, four patients (67%) presented with seizures and one patient presented with paraparesis (16%). All patients had elevated CSF cell count (range 25-102; mean 61) with predominant lymphocytes. Five patients (83%) had abnormal CT or MRI scan. Cerebral edema was present in three patients. Other findings included low density signals in right temporal and occipital lobe (1 patient), bi temporal hyperintensities and meningeal enhancement (1 patient), Frontal and subcortical hyperintense lesion (1 patient) and hyperintense lesion on T2 in Pons and cervical and thoracic spinal cord (1 patient). EEG was done in four patients and showed generalized slowing (2 patients), bi temporal spikes (1 patient) and burst suppression pattern (1 patient). Two patients (32%) died and one patient was discharged in bedridden state. Conclusion: The involvement of brain and spinal cord is uncommon in dengue viral infection. Most patient present with seizures. Neuroimaging features are diverse. Prognosis is poor in patients presenting with encephalitis or myelitis.