Numbness after Transradial Cardiac Catheterization: the Results from a Nerve Conduction Study of the Superficial Radial Nerve

BACKGROUND AND OBJECTIVES: Numbness on the hand occurs infrequently after a transradial cardiac catheterization (TRC). The symptom resembles that of neuropathy. We, therefore, investigated the prevalence, the predicting factors and the presence of neurological abnormalities of numbness, using a nerve conduction study (NCS). SUBJECTS AND METHODS: From April to December 2013, all patients who underwent a TRC were prospectively enrolled. From among these, the patients who experienced numbness on the ipsilateral hand were instructed to describe their symptoms using a visual analogue scale; subsequently, NCSs were performed on these patients. RESULTS: Of the total 479 patients in the study sample, numbness occurred in nine (1.8%) following the procedure. The NCS was performed for eight out of the nine patients, four (50%) of which had an abnormal NCS result at the superficial radial nerve. A larger sheath and history of myocardial infarction (p=0.14 and 0.08 respectively) tended towards the occurrence of numbness; however, only the use of size 7 French sheaths was an independent predictor for the occurrence of numbness (odds ratio: 5.50, 95% confidence interval: 1.06-28.58, p=0.042). The symptoms disappeared for all patients but one, within four months. CONCLUSION: A transient injury of the superficial radial nerve could be one reason for numbness after a TRC. A large sheath size was an independent predictor of numbness; therefore, large sized sheaths should be used with caution when performing a TRC.

Clinical Features of Wrist Drop Caused by Compressive Radial Neuropathy and Its Anatomical Considerations

OBJECTIVE: Posture-induced radial neuropathy, known as Saturday night palsy, occurs because of compression of the radial nerve. The clinical symptoms of radial neuropathy are similar to stroke or a herniated cervical disk, which makes it difficult to diagnose and sometimes leads to inappropriate evaluations. The purpose of our study was to establish the clinical characteristics and diagnostic assessment of compressive radial neuropathy. METHODS: Retrospectively, we reviewed neurophysiologic studies on 25 patients diagnosed with radial nerve palsy, who experienced wrist drop after maintaining a certain posture for an extended period. The neurologic presentations, clinical prognosis, and electrophysiology of the patients were obtained from medical records. RESULTS: Subjects were 19 males and 6 females. The median age at diagnosis was 46 years. The right arm was affected in 13 patients and the left arm in 12 patients. The condition was induced by sleeping with the arms hanging over the armrest of a chair because of drunkenness, sleeping while bending the arm under the pillow, during drinking, and unknown. The most common clinical presentation was a wrist drop and paresthesia on the dorsum of the 1st to 3rd fingers. Improvement began after a mean of 2.4 weeks. Electrophysiologic evaluation was performed after 2 weeks that revealed delayed nerve conduction velocity in all patients. CONCLUSION: Wrist drop is an entrapment syndrome that has a good prognosis within several weeks. Awareness of its clinical characteristics and diagnostic assessment methods may help clinicians make diagnosis of radial neuropathy and exclude irrelevant evaluations.

Compression of the Superficial Radial Nerve by Schwannoma: A Case Report

PURPOSE: Schwannoma, a benign peripheral nerve tumor, is slow-growing, encapsulated neoplasm that originates from the Schwann cell of the nerve sheath. Schwannoma most frequently involves the major nerve. Schwannoma occurring in the superficial radial nerve rare. This is a report of our experience with schwannoma arising from the superficial radial nerve with neurologic symptom. METHODS: A 55-year-old woman presented with eight-month history of progressive numbness and paresthesia in dorsum of the thumb and index finger. Physical examination revealed a localized mass on the midforearm. Sonographic examination showed an ovoid, heterogenous, hypoechoic lesion, located eccentrically in related to the superficial radial nerve. The lesion was mobile in the transverse but not in the longitudinal axis of the nerve, which was thought to favour schwannoma rather than neurofibroma. At operation, a 20 x 15 mm ovoid, yellowish grey mass was seen arising from the superficial radial nerve. The tumor present as eccentric masses over which the nerve fibers are splayed. Using operating microscope, the tumor was removed, preserving the surrounding nerve. RESULTS: Histology confirmed that the mass was a benign schwannoma. There were no postoperative complications. After two months the patient had no clinically demonstrable sensory deficit. CONCLUSION: An unsusual case of a schwannoma of the superficial radial nerve is presented. In case with neurologic symptom, prompt surgical decompression must be made to prevent further nerve damage and to restore nerve function early.

Superficial Radial Nerve and Cephalic Vein: An Anatomic Study by Cadaver Dissection

OBJECTIVE: To acquire normal anatomy of superficial radial nerve and cephalic vein and identify the optimal site for venipuncture of cephalic vein at wrist to decrease the damage of superficial radial nerve. METHOD: We examined anatomic relationships of the superficial radial nerve, cephalic vein, and styloid process of radius in 14 hands from 10 cadavers. The distances were measured from the styloid process of radius to the point at which the superficial radial nerve pierced fascia, and to the crossing point of superficial radial nerve with cephalic vein. RESULTS: The mean distance from the styloid process of radius to the point at which the superficial radial nerve pierced fascia was 79.9+/-9.84 (60~93) mm and from the styloid process of radius to the crossing point of superficial radial nerve with cephalic vein was 29.5+/-15.24 (13~55) mm. CONCLUSION: The most optimal injection site for venipuncture of cephalic vein at wrist was located 55 mm more proximal area from styloid process.

Clinical observation of superficial radial nerve transplanting to repair musculospiral nerve defection and functional reconstruction of donor site / 中国综合临床

Objective To observe the effect of superficial radial nerve transplanting to repair musculospiral nerve defection and using end-to-side neurorrhaphy to reconstruct the function of the donor site. Methods Thirtyfour cases underwent superficial radial nerve transplanting to repair musculospiral nerve defection and end-to-side neurorrhaphy was performed to reconstruct the function of the donor site. Results All cases were followed-up for 6 to 18 months,the functional recovery of the recipient of musculospiral nerve was excellent in 23 cases and good in 5 cases,with an excellent and good rate of 82. 53 %. Sensory recovery of donator nerve was excellent in 27 cases and good in 5 cases,with an excellent and good rate of 94. 12%. Conclusions Superficial radial nerve transplanting to repair musculospiral nerve defection and functional reconstruction of donor site is a better choice in treating neurologic defect.

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.