Rheumatoid arthritis with arteritis and neuropathy masking amyotrophic lateral sclerosis

The clinical and pathologic features of amyotrophic lateral sclerosis (ALS) superimposed on rheumatoid arthritis (RA) are described in a 45 yr old woman. Such a combination of collagen disease and motor neuron disease has not been reported so far. Widespread necrotizing arteritis, a well recognized complication of RA, with resultant peripheral neuropathy and myopathy masked the characteristic clinical features of ALS. In view of the protein neuromuscular manifestations of RA, the difficulty in recognizing a coexisting primary neurologic disease is emphasized by this case.