History

A 75-year-old, right-handed, married, retired dockyard electrical engineer presented in 2005 with a 35-year history of progressive right leg weakness, such that he was finding walking difficult. Over the 10 years before presentation, he had also developed right hand weakness, with loss of feeling in the right ring and little fingers. He had difficulty writing, using cutlery, washing and dressing. Aside from approximately 10 kg of weight loss over several months there were no other symptoms; in particular, there were no bulbar, cognitive or autonomic symptoms and no neck pain.

His past history included atrial fibrillation and supraventricular tachycardia, mitral valve prolapse, left ventricular failure and an atrioseptal defect repaired in 1990. A pacemaker was inserted for supraventricular tachycardia in 1990. Pleural plaques were identified in 1990, thought to be secondary to previous asbestos exposure. His medications at presentation were digoxin, ramipril, verapamil, furosemide, warfarin and amiodarone. He had a normal developmental history and had no difficulties with sports or other physical activities when younger. He did not drink alcohol to excess and was an ex-smoker, with a 10-year pack history. His parents had died of strokes (his mother aged 78 years and father aged 66 years), but there was no other family history.

Examination

He looked well, and was comfortable at rest. There were no cranial nerves abnormalities. There was wasting of the intrinsic hand muscles bilaterally, right biceps and right forearm. The right calf was thinner than the left. There were no fasciculations. Tone was normal. There was weakness of right finger extension, abduction and thumb abduction, but finger flexion and proximal strength were normal. Hip flexion on the right was weak, and he could not lift his leg off the couch. The remaining right leg flexors were weak but the extensors were normal. Strength in the left arm and leg …