Amyotrophic lateral sclerosis in a patient with leprosy peripheral neuropathy.

Peripheral neuropathy leading to sequelae is the most important complication of leprosy. The radial, ulnar, median, common peroneal, and posterior tibial nerves are the most commonly involved peripheral nerves in leprosy. Clinical manifestations of such involvement include anaesthesia, paraesthesia, and paralysis, and commonly found disabilities are clawing of the fingers and weakness of pinch, loss of opposition of the thumb, clawing of toes, and foot drop . At early stages of the disease, only the nerves of the cutaneous lesions are involved and there is loss of sensitivity and autonomic function in those skin areas . Isolated motor symptoms are not usual in leprosy, and paralysis and loss of sensitivity occur simultaneously. However, motor neuropathy could be caused by dapsone, one of the drugs used in the multidrug therapy (MDT), but not typically with increased reflexes and diffuse fasciculations. The neuropathies due to dapsone involve distal axonal degeneration, and the most commonly involved nerves are the ulnars and medians. These neuropathies may be dose related and are usually reversible when the dapsone is discontinued .