Acute demyelinating encephalomyelitis after anti-venom therapy in Russell's viper bite

Russell's viper is a commonly encountered venomous snake in India. Morbidity and mortality following envenomation and the treatment thereof are frequent. We report a rarely seen complication after a treated Russell's viper bite.

A 36-year-old male farmer received 30 vials polyvalent anti-snake venom after a viper bite to his right leg. Improvement in initial hematemesis and circulatory shock was followed by acute renal failure managed with regular hemodialysis. He displayed no abnormalities on neurological examination at admission. Fourth day onwards his neurologic status started deteriorating with development of behavioral abnormalities, hemi-spatial neglect of left upper limb, paralysis of left facial nerve, left upper limb, and right lower limb. Acute disseminated encephalomyelitis was confirmed on magnetic resonance imaging (MRI) of brain with typical spectroscopic characteristics. High dose methyl prednisolone was administered and a rapid recovery followed.

Russell's viper bite followed by treatment with antivenom may be complicated by the development of immune complex mediated demyelination and development of acute disseminated encephalomyelitis. MRI spectroscopy helps in early identification of demyelination and in a definite diagnosis. Treatment with corticosteroids was associated with resolution of symptoms in this case.