Evaluation of Nerve Block after Phenol and Ethanol Injection

OBJECTIVE :To evaluate the axonal degeneration after nerve block with phenol and ethanol injection into tibial nerve. METHOD: Tibial nerves of thirty Sprague-Dawley rats were exposed. For the developement of neuropathic pain, the method of intraneural injection was performed. Five percent phenol, 90% ethanol or normal saline were injected into the epineurial sheath of tibial nerve at each group. The mechanical and thermal allodynia were evaluated in post- injection 1, 2, 3, and 4 weeks. The mechanical allodynia was evaluated by withdrawal response to 10 stimulations with von Frey hair. Thermal allodynia was tested by withdrawal response to 5 stimulations with acetone. Motor nerve conduction study was performed in post-injection 1, 2, and 4 weeks. RESULTS: In behavioral test, the experimental group exhibited increased withdrawal response to mechanical and cold stim ulation, but there was no significant difference between two groups, phenol and ethanol groups. In motor nerve conduc tion study, compound motor action potential amplitude loss were observed in experimental group, but there was no significant difference between two groups, phenol and ethanol groups. CONCLUSION: These results suggest that axonal degeneration of ethanol is roughly similar to those of phenol block.

The Prevalence and Ergonomic Analysis of Cumulative Trauma Disorders in the Paper Reviewing Workers

OBJECTIVE: To survey the prevalence of cumulative trauma disorders (CTDs) and to analyze the ergonomic factors in the paper reviewing workers. METHOD: Five hundreds and twenty subjects of paper reviewers were collected from 'National Medical Insurance Association' who had been exposed to risky working environment regarding CTDs. The subjects were first screened by occupational medicine specialists and confirmed by physiatrist. The subjects were also examined by serologic test, radiologic imaging, and electro diagnostic study. Ergonomists analyzed the job element to identify the risk factors by baseline checklist of CTDs. RESULTS: Among the workers, 51 (9.8%) of 520 were confirmed to CTDs, the prevalance of myofascial pain syndrome was 22 (43.1%), that of medial epicondylitis was 13 (25.5)%, lateral epicondylitis 8 (15.7%) and others. Pain scale of National Industrial Occupational Safety Health Institute symtoms criteria was highest in the shoulder girdle and the next was in the neck, in the wirst and fingers. The ergonomic risk score was highest 2.56 in the 'verifying' job, and the next 2.20 in 'the 2nd examination' job and 'the 1st examination' job, 1.72 in 'correcting' job. CONCLUSION: The result would be helpful for the prevention and management of CTDs in the paper reviewing workers.

The Proximal and Distal Interphalangeal Flexion Dysfunction, Opposition Palm Ratio and Thumb Index Ratio in the Korean Adults

OBJECTIVE: The purpose of this study was to evaluate the incidence of inability to flex proximal interphalangeal (PIP) and distal interphalangeal (DIP) joint in normal Koreans. The opposition palm ratio and thumb index ratio was also of interest. METHOD: Randomly selected eighty nine normal Korean adults of 48 men and 41 women, with ages 20 to 79 years. The finger flexion was measured using the standard flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) screening tests. Thumb index ratio and opposition palm ratio was also assessed additionally. RESULTS: In the sample population, 2 subjects (2.2%) were unable to bilaterally flex their fifth PIP joints independently. Four subjects (4.4%) were unable to flex one or both of their fourth or fifth DIP joints. These results show far less incidence of FDS dysfunction comparing with 52% of FDS dysfunction rate in Americans. The opposition palm ratio in men were 63.6% and in women 69.9%, indicating lower ratio in men. The thumb index ratio was not different statistically between the men and women. CONCLUSION: These data suggest that the different incidences of FDS and FDP dysfunction should be considered in interpretation. The opposition palm ratio and thumb index ratio might be useful in the hand rehabilitation.

Medial Femoral Cutaneous Nerve(MFCN) and Posterior Femoral Cutaneous Nerve(PFCN) Conduction Study in Korean

Medial femoral cutaneous nerve(MFCN), a sensory branch of the femoral nerve, supplies the skin over the anteromedial aspect of the thigh and knee. Posterior femoral cutaneous nerve(PFCN), comprised of fibers originating from the anterior and posterior divisions of the first three sacral segments, supplies the skin over the posterior aspect of the thigh. Forty nerves of twenty healthy adults, ages from 20 to 58, were tested. The onset and peak latencies of MFCN were 2.3+/-0.2 ms and 2.9+/-0.2 ms respectively. The baseline to peak amplitude was 6.5+/-2.3 V. The onset and peak latencies of PFCN were 2.4+/-0.2 ms and 2.9+/-0.2 ms respectively. The baseline to peak amplitude was 7.1+/-1.7 V.