Which parameter is more reliable in a cold hand, NCV or latency.

Temperature affects distal sensory & motor latencies & nerve conduction velocity but not necessarily at the same degree. Purpose of this study is to see which one is affected less and thus could be more reliable in cold conditions. A total of 32 healthy individuals with age range of 18-28 years (mean 22.25 +/- 2.2) participated in this study. Skin Temperature was recorded at wrist. Distal median motor & sensory latencies and transcarpal median NCV were recorded before and after immersion in cold water. Statistical analysis was performed using paired t-test with SPSS. All parameters were affected by cold but the effect was less dramatic in transcarpal NCV. Transcarpal median NCV is least affected parameter by cold, so it may be more reliable than sensory & motor latencies at wrist.

Sympathetic skin response (SSR) in erythromelalgia.

BACKGROUND: Erythromelalgia (EM) is characterized by severe pain associated with local redness and hotness in the extremities. When the extremity is lowered, or heat is applied, the pain is intensified and when coldness is applied, or the extremity is elevated the pain is decreased. OBJECTIVE: To evaluate if there is any sympathetic nervous system involvement in erythromelalgia, sympathetic skin response (SSR) test was done. SETTING: This study was conducted during the years 1998-2000 in the Department of Physical medicine and Rehabilitation, Shiraz University of Medical Sciences. METHODS: SSR study was done on 22 patients with erythromelalgia and 22 normal subjects were matched for age and sex for comparison. RESULTS: There is a significant difference between the patients and controls especially in the lower extremity findings (P = 0.000). More than 72.7% of the patients had abnormal SSR. CONCLUSION: It is concluded that sympathetic peripheral fibers (C fibers) are involved in erythromelalgia and it is probably the pathogenesis of the disease.