Cold Perception Hypoesthesia Seen in Amputees
Small study shows significantly reduced threshold values for cold sensation in distal residual limbs
FRIDAY, May 5 (HealthDay News) -- Distal residual limbs in amputees show significant cold perception hypoesthesia, according to research presented this week at the annual meeting of the American Pain Society in San Antonio, Texas.
R. Norman Harden, M.D., of the Rehabilitation Institute of Chicago, and colleagues used physical exam and thermal quantitative sensory testing (tQST) to compare sensation in amputated versus unaffected extremities in 23 subjects (18 with pain, five without) with a unilateral upper or lower limb amputation.
The researchers found significantly reduced perceptual threshold values for cold sensation and no significant difference in thresholds for warm perception, cold pain or hot pain. They found that 18 of 23 (78.3 percent) of patients showed hypoesthesia on at least one tQST paradigm, with nine showing differences in warm sensation, 11 showing differences in cold pain and 10 showing differences in heat pain thresholds.
"These unexpected results suggest a possible pathological process involving the sensory innervation in skin above the amputation, perhaps preferentially involving small unmylinated afferents," the authors conclude. "This was 'unexpected' as the innervation of these areas comes from 'healthy' nerve far above the amputation site."