Sensory axonopathy in mild to moderate peripheral arterial disease

The effect of mild to moderate arterial occlusive disease on peripheral nervous system conduction was prospectively investigated in 18 subjects and 18 control subjects, aged 40 to 85 years. Experimental and control subjects underwent a thorough history and physical followed by vascular and electrophysiologic studies. The primary outcome measure was the sensory nerve action potential. Although 33% of the subjects with peripheral arterial disease had experienced paresthesias, the clinical evaluation of sensation was relatively unaffected. Sensory conduction studies revealed 30% absent sural responses and 56% absent superficial peroneal nerve responses in subjects with peripheral arterial disease compared with 3 and 14% absent responses in control subjects, respectively (P = 0.044; 0.025). There were no differences in distal latency or sensory amplitude, although the superficial peroneal amplitude did approach significance (P = 0.06). No significant differences were found in motor distal latency, amplitude, or conduction velocity. Age, leg length, temperature, disease severity, presence of paresthesias, cholesterol levels, and past alcohol or tobacco ingestion did not account for the difference in sensory responses. These results support the presence of a mild sensory axonopathy in subjects with peripheral arterial disease. Electromyographers should be cognizant of absent distal responses from peripheral arterial disease so as not to ascribe the findings to an alternative pathology and should not attribute abnormal motor conduction results to the presence of this degree of peripheral arterial disease.