Paradoxical reaction in tubercular meningitis resulting in involvement of optic radiation.

A 25-year-old woman was diagnosed to have tubercular meningitis (TBM) with a right parietal infarct. She responded well to four-drug anti-tubercular treatment (ATT), systemic steroids and pyridoxine. Steroids were tapered off in one and a half months; she was put on two-drug ATT after two months. Six months after initial diagnosis she presented with sudden, bilateral visual loss. Vision was 3/200 with afferent pupillary defect and un-recordable field in the right eye; vision was 20/60 in the left eye, pupillary reaction was sluggish and the field showed a temporal hemianopia. On reintroduction of systemic corticosteroids vision improved (20/120 in right eye and 20/30 in left eye) within three days; the field defects improved sequentially to a left homonymous hemianopia, then a left homonymous inferior quadrantonopia. A diagnosis of TBM, on treatment, with bilateral optic neuritis, and right optic radiation involvement was made. Since the patient had been off ethambutol for four months, the optic neuritis and optic radiation lesion were attributed to a paradoxical reaction to tubercular allergen, corroborated by prompt recovery in response to corticosteroids. This is the first report of optic radiation involvement in a paradoxical reaction in neuro-tuberculosis in a young adult.