Assessment of somatosensory indicators of polyneuropathy in patients with eating disorders

The somatosensory functions of small-diameter nerve fibres were tested on the lower and upper extremities in nine patients with anorexia nervosa, ten patients with bulimia nervosa and ten control subjects, by analysing warmth, cold, and pain thresholds. To test large-diameter nerve fibres, the vibration threshold was also measured. Both patient groups had markedly elevated pain thresholds compared with the control subjects. In contrast, warmth and cold thresholds were only suggestively elevated while vibration thresholds were not at all increased in the patients. A distal-proximal pattern of somatosensory deficits, suggestive of peripheral polyneuropathy, was not observed. Hence, a peripheral polyneuropathy affecting small or large afferent fibres as a consequence of an eating disorder seems to be a rare event.