Isolated Unilateral Third Cranial Nerve Palsy : A Rare Presentation of Dengue Fever

ABSTRACT

We herein report a case of unilateral 3rd cranial nerve palsy in a 15 years old boy. It can be due to numerous aetiologies like infectious, inflammatory, malignant, metabolic or vascular. In our case the nerve palsy was preceded by history of high grade fever of 5 days. Involvement of 3rd cranial nerve started 9 days after fever onset, insidiously, presenting as Ptosis and Diplopia. No history of altered sensorium, limb weakness, diurnal variation. Routine investigation was normal. Integrated Counselling and Testing Centre (ICTC) was negative. Cerebrospinal Fluid (CSF) study revealed viral picture but was negative for neurotropic viral panel. MRI brain was essentially normal except for presence of small Lipoma over prepontine cistern. Antinuclear Antibody (ANA) and Antineutrophil Cytoplasmic Antibodies (ANCA) were negative. Serology for Dengue was sent considering the history of high grade fever associated with blanchable rash. Dengue IgM report came out to be reactive. CSF Dengue IgM also came out to be reactive. Patient was put on short course of oral steroid therapy and cranial nerve palsy improved gradually. Neurological complications of dengue is uncommon. Few cases of Cranial Nerve Involvement associated with Dengue have been reported in the literature, most of them are associated with encephalitis. But in our case Cranial Nerve involvement was not associated with Encephalitis, it was probably due to immune reactions secondary to Dengue, making this case atypical.