Electrodiagnostic Methods for Carpal Tunnel Syndrome Combined with Diabetic Polyneuropathy

OBJECTIVE: To find out the most useful method among three electrodiagnostic tests for carpal tunnel syndrome (CTS) in patients with diabetic peripheral polyneuropathy (PPN). METHOD: Eighty-three hands out of seventy-four patients who had diabetic PPN and tingling sensation in their hands were included in this study. They were divided into two groups: Group A, PPN with CTS; Group B, PPN only. Fifty-four hands with CTS in patients without diabetes were included as a control group (Group C). Another forty normal hands were also included as a healthy control group (Group D). Clinical and electrophysiologic information was gathered from those subjects. Sensitivity, specificity and receiver operating characteristic (ROC) curves of the three electrodiagnostic tests, namely, the difference between the median nerve latency to the second lumbrical muscle and the ulnar nerve latency to the second interosseous muscle (L-I difference), ratio of distoproximal latency in median sensory nerve (MW ratio), and difference of distoproximal latency in median sensory nerve (MW difference) to diagnose clinical CTS were obtained. RESULTS: The specificity of L-I difference as a diagnostic test for CTS was highest (87.0%). The area of ROC curve of L-I difference was also highest (0.949) among three different electrodiagnostic tests of CTS with diabetic PPN. CONCLUSION: We suggest that L-I difference as the most useful test with highest specificity for the diagnosis of CTS in the patients with diabetic PPN.

Predictive Value of Sensory Nerve Conduction in Carpal Tunnel Syndrome

OBJECTIVE: Electrodiagnostic test has shown diagnostic sensitivity and specificity in carpal tunnel syndrome(CTS). This study was to evaluate the correlation between clinical outcome of endoscopic carpal tunnel ligament release(ECTR) and the predictive value of sensory nerve conduction. METHODS: From January 1998 to December 2004, 87 patients (44 right hand, 37 left hand, 6 bilateral hands) with CTS who underwent ECTR were followed up in our hospital for an average of 2.4 months. We retrospectively analyzed the results with previous medical records. All patients underwent electrodiagnostic test and ECTR. The patients were divided into three groups according to the electrodiagnostic test results. Group (A) was normal sensory nerve response, Group (B) was slowing sensory response and Group (C) was no sensory response. Improvement of the symptom after ECTR was assessed using a visual analogue scale(VAS) score. RESULTS: Differences between the three groups on the correlation of severity of sensory potential and duration of preoperative symptoms were significant. The mean value of improved VAS scores for the three groups were 6.0+/-0.96 in the Group A, 6.11+/-0.48 in the Group B and 6.14+/-0.53 in the Group C. There was no statistically significant difference between the severity of sensory nerve response and improvement in VAS score after ECTR. Complications included a wound infection, a case of skin necrosis, and two patients with persistent symptoms without any improvement. CONCLUSION: Although electrodiagnostic test has been known to be useful, sensory nerve response is considered not to be a good prognostic value for carpal tunnel syndrome after ECTR.

Brachial Plexopathy Caused by Pancoast Tumor: A case report

Pancoast tumor is a specific lung carcinoma that has symptoms according to the location. It often involves the extrathoracic structure more than parenchyme of lung, that cause shoulder pain. A 61-years old man had been complaining of shoulder pain and limitation of range of motions of shoulder joint. Conservative management of the shoulder pain was not effective with physical therapy and injection therapy and the symptom of right upper extremity radiating pain had been aggravated. We had examination of the eletro-diagnostic test in 17 months after shoulder pain was developed. The findngs of the electrodiagnostic test was suspected as the injury of lower trunk of brachial plexus, so we had checked MRI on brachial view. The pancoast tumor was found in the extrathoracic region that invaded the lower trunk of the brachial plexus. The shoulder pain related with tumor was rare and could cause brachial plexopathy.

Electrodiagnostic Study on Neuropathies in String Players

OBJECTIVE: To determine the frequency, involved nerves and sites of entrapment neuropathy in string players. METHOD: The subjects were 24 string playing musicians and age matched 24 normal controls. Questionnaire, physical examination were taken in the musicians and the electrodiagnostic study was performed in both the musician and the control groups. Electrodiagnostic study included nerve conduction study of median and ulnar nerves. The distal motor latency, segmental motor conduction velocity, distal sensory latency, and amplitude of sensory nerve action potentials were measured. Each parameter of nerve conduction study was compared in two groups and was correlated to the string playing duration. RESULTS: Three musicians (12.5%) were diagnosed as entrapment neuropathy: One, left ulnar neuropathy at the elbow and the wrist and left median neuropathy at the wrist; Two, left ulnar neuropathy at the elbow. Ulnar motor conduction velocity of right forearm segment and left elbow segment were significantly reduced in the musicians compared to those of the controls (P<0.05). The distal sensory latency of left ulnar nerve was significantly prolonged in musicians compared to that of the controls (P<0.05). The string playing duration significantly correlated with the distal motor latency of right median nerve (R=0.632, P<0.05) and the distal sensory latency of left median nerve (R=0.518, P<0.05). CONCLUSIONS: These results suggest that some entrapment neuropathies could be developed due to cumulative trauma in string players. Elbow and wrist segment of left ulnar nerve, forearm segment of right ulnar nerve are possible sites of entrapment neuropathy in string players.

Polyneuropathy by Occupational Exposure to Acrylamide / 대한산업의학회지

Authors report a first Korean case of polyneuropathy in an acrylamide producing factory together with an environmental and epidemiologic survey for the ten workers of the same workplace and 46 workers in the production and manufacturing acrylamide in Ulsan, Korea. The case is 30 years old man who worked in the prcduction of the acrylamide for two years. In August, 1997, he had a weakness of the lower extremity with loss of body weight of 15 Kg which progressed to paresthesia of the limbs, the loss of vibration sense, difficulty in walking, speech disturbance, dysuria, constipation, difficulty in erection and swallowing difficulty. Neurologic examination showed a complete loss of vibration and position sense, and loss of deep tendon reflex in all the limbs. There was a contact dermatitis-like skin lesion on the feet. Electrodiagnostic test showed a generalized polyneuropathy of moderate degree involving motor and sensory component of peripheral and cranial nerves. After 8 months' cessation from exposure and supportive care, his symptoms were completely resolved, but abnormality in electrodiagnostic test and vibrotactile perception threshold still persisted, although much improved than before. There were 11 workers in the same workplace of the case, producing acrylamide by microorganism as a catalyst. Environmental monitoring of the workplace revealed air-borne concentration of the acrylamide to be from 0.05 to 0.23 mg/m(3) by personal sampling and from 7.65 to 11.65 mg/m(3) by area sampling during filter exchanging process, which far exceeds TLV-TWA of 0.03 mg/m(3). However acrylamide was not detected from the plasma of the workers. Symptom questionnaire showed a markedly higher complain of neurologic symptoms, compared to the workers of the other acrylamide producing companies. Electrodiagnostic test showed a several workers are in the lower normal range without definite abnormality. Vibrotactile perception threshold by Vibratron II showed a significantly increased threshold in the workers of the same workplace compared to the other acrylamide workers and significantly decreased test score of color vision compared to normal controls. After improvement of the production process and strict wearing of the protective device, most workers reported the improvement of clinical symptoms, but vibrotactile perception threshold was not improved. These result suggests the need for the effective environmental monitoring together with a periodic biological monitoring. Development of effective screening test is urgently needed to control and assess the skin absorption of acrylamide.