Contributed by David Newton, MD and Edward C. Klatt, MD
Department of Pathology, University of Utah Health Sciences Center
Published on line in June 2000
This 48-year-old man initially developed some muscular weakness at age 26. He had a right cataract excision with lens implantation at age 32. At that time his disease was described as mostly apparent in his speech which was slow and a little undistinguishable. His movements were also slow and deliberate. At age 36 he had motor strength of 4/5 in extremities. At age 46 he had no major difficulties with eating and could carry out all activities of daily living, although he was not able to perform certain tasks such as buttoning his shirt. He had difficulty getting up off the floor and was using a wheelchair occasionally. His neck was weak and he was using a collar to support it. He had slurred speech and marked distal weakness. Motor function testing showed global impairment.
A year later he had more progressive weakness and additionally bulbar dysfunction with difficulty swallowing. His heart function began to substantially worsen. An echocardiogram showed an ejection fraction of 23%, a severely enlarged left ventricle, and mild mitral regurgitation. Holter monitor examination at that time showed a sinus rhythm with borderline first degree AV block and right bundle branch block with a ventricular rate of 69. There were also single premature ventricular complexes. Examination one year later showed an increased number of single premature ventricular complexes and ventricular pairs. Several months later the conduction defects were more prominent with left ventricular conduction defects that suggested alternating right bundle branch block, left bundle branch block, and AV block. He had lost 14 kg over the last three months. He was using a wheelchair. Physical exam showed an asymmetric face, with the inability to purse lips or whistle. The tongue was midline with lateral atrophy. The sternocleidomastoid muscles were weak. There was diffuse muscle atrophy throughout with no particular distribution. Strength was markedly reduced throughout with minor contractions of the wrists and abduction of the thumbs. He required assistance to stand. He developed congestive heart failure and died. An autopsy was performed.