Correction: Nerve Conduction Study of the Distal Branches of the Superficial Radial Nerve

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Correlation of Pain Drawing Patterns with Electrophysiological Findings in Carpal Tunnel Syndrome

OBJECTIVE: To evaluate the association between neuralgic pain distribution and the severity of carpal tunnel syndrome (CTS). METHOD: Pain drawings using computerized pain chart system were collected from 131 patients (213 hands) with CTS. The presence and severity of CTS were determined by means of median motor and sensory nerve conduction studies. The severity was divided into 3 classes on the basis of electrophysiological findings: mild (93 hands), moderate (70 hands) and severe (50 hands). The similarities between pain drawing patterns and median nerve dermatome in the hands were evaluated. The pain distributions of the palmar and dorsal sides of each five fingers, palm and dorsum of hand were also evaluated. RESULTS: There were no significant differences in similarity values of pain distribution among the groups of CTS hands divided by severity: similarity values were 0.22+/-0.14 in mild CTS patients, 0.24+/-0.16 in moderate CTS patients and 0.27+/-0.14 in severe CTS patients. In the CTS patients, the pain drawings showed relatively frequent distributions in the palmar side of 2nd to 4th fingers. CONCLUSION: There was no significant correlation between pain drawing patterns and severity of CTS. The pain drawings of patients with CTS indicate distribution to be most frequent in the palmar side of 2nd to 4th fingers.

Nerve Conduction Study of the Distal Branches of the Superficial Radial Nerve

OBJECTIVE: To acquire normal values of nerve conduction study of the superficial radial sensory nerve (SRN) distal branches to the second web space (2 WEB) and second digit (2 DIG) and compare them with the results of the conventional method. METHOD: Forty-three healthy adult subjects (25 males, 18 females) were included. Nerve conduction study was performed in both hands. Superficial radial sensory responses were obtained with 2 recording montages: 1) antidromic stimulation, recording electrode placed between the 2nd and 3rd metacarpals with stimulation 10 cm proximally on the lateral forearm (2 WEB); 2) orthodromic stimulation, stimulation at the second digit with recording 10 cm proximally at the snuff box (2 DIG). Each stimulation was performed twice, and onset latency, peak latency, and sensory nerve action potential (SNAP) amplitude (baseline-to- peak) were measured. Correlations between the values and body mass index (BMI), sex, and finger circumference were tested statistically. RESULTS: The age of the subjects was 36.0+/-10.4 years (range, 23~64 years), and the BMI was 22.6+/-2.8 kg/m2. The onset latency, peak latency and SNAP amplitude of the 2 WEB response were 1.7+/-0.1 ms, 2.2+/-0.2 ms, and 24.6+/- 8.2 micro V, respectively. The onset latency, peak latency and SNAP amplitude of the 2 DIG response were 1.6+/-0.2 ms, 2.2+/-0.2 ms, and 15.2+/-6.0 micro V, respectively. A statistically significant difference was observed between male and female subjects for both 2 WEB and 2 DIG responses. Weak correlations were found between the nerve conduction values and BMI, sex, and finger circumference. CONCLUSION: Sensory nerve action potentials can be successfully obtained from the distal branches of the superficial radial nerve.

Anatomical Considerations of Lateral and Medial Antebrachial Cutaneous Nerves

OBJECTIVE: To evaluate the anatomic course of the lateral antebrachial cutaneous nerve (LABCN) and medial antebrachial cutaneous nerve (MABCN) in the forearm. METHOD: We dissected 29 upper extremities of 16 cadavers for LABCN and 20 upper extremities of 15 cadavers for the MABCN. We measured the distance (BT_L) between the biceps tendon (BT) and LABCN on the intercondylar line. The BT is the point at which biceps tendon crosses intercondylar line. The distance (L12) between LABCN and the point of 12 cm distal to BT on the line between BT and radial artery at wrist was measured. The distance (ME_M) between MABCN and medial epicondyle on the intercondylar line was measured. M8 and M10 are the distances between MABCN and the points 8 cm and 10 cm distal to BT on the line from BT to mid-point of flexor carpi radialis and palmaris longus at the wrist respectively. RESULTS: BT_L and L12 were 1.4+/-3.7 mm and 4.4+/-3.7 mm respectively. ME_M, M8 and M10 were 28.6+/-6.9 mm, 18.9+/-8.9 mm and 18.3+/-8.2 mm respectively. The thickness of LABCN and MABCN was 19.1+/-4.9 mm and 13.2+/-4.2 mm respectively. CONCLUSION: The LABCN was emerge just lateral to biceps tendon at the elbow and ran down to radial artery. The anatomic course of MABCN was variable at the elbow and forearm.

Vascular Thoracic Outlet Syndrome with Arterial Occlusion: A case report

The diagnosis of thoracic outlet syndrome (TOS) is sometimes confused by its nonspecific symptoms and various etiologies. Moreover, the paths of involving nerves and arteries are highly diverse. We report a 35 year-old man who had numbness and coldness in his left upper extremity with no improvement to medical therapy. The electrophysiologic studies were normal. Radial artery pulse was absent and the thermography revealed markedly reduced temperature below the left mid-forearm. The arteriography showed compression of the left subclavian artery between the clavicle and the 1st rib with aneurysmal change proximal to the compression. Occlusion of the left brachial artery and collateral arteries were also observed. Under the diagnosis of vascular TOS, 1st rib resection was performed and his symptoms were relieved. Vascular TOS may be considered in cases of upper limb paresthesia.