David G. Greathouse

Radiculopathy of the Eighth Cervical Nerve

STUDY DESIGN Residents case problem. BACKGROUND The C8 nerve root is the least commonly encountered of cervical radiculopathies. The purpose of this residents case problem is to provide an unusual presentation of a C8 radiculopathy, without cervical or proximal upper quarter symptoms, diagnosed by a combination of physical examination, electromyography (EMG) and nerve conduction studies (NCSs), and imaging. DIAGNOSIS A 49-year-old, right-hand-dominant male was referred to the EMG/NCS laboratory for a suspected left ulnar neuropathy at the elbow. A physical examination, NCS, and EMG were performed, and a C8 radiculopathy involving both the anterior and posterior primary rami was identified. Following the EMG and NCS evaluation, the patient had enhanced magnetic resonance imaging studies that confirmed a foraminal C7-T1 herniation and associated small central disc protrusion. The patient was then referred to neurosurgery for further consultation and subsequent surgical intervention. The patient underwent a C7-T1 laminectomy, mesial facetectomy, and foraminotomy, and excision of a herniated disk using an operating microscope. The neurosurgeon noted that there was a large disk herniation containing some disk material immediately anterior to the C8 motor root, that impinged directly on the motor root. One month postoperatively, the patient had decreased pain and numbness and tingling in his arm and his hand weakness had improved. DISCUSSION The report illustrates the utility of a combination of physical examination, EMG and NCSs, and imaging in the diagnosis of a C8 radiculopathy in a patient presenting with forearm and hand symptoms but without cervical or upper quarter symptoms. LEVEL OF EVIDENCE Diagnosis, level 4.

Clinical and electrodiagnostic abnormalities of the median nerve in dental assistants.

STUDY DESIGN Descriptive. OBJECTIVES To determine the presence of clinical and electrodiagnostic abnormalities of the median and ulnar nerves in both upper extremities of dental assistants. BACKGROUND A high prevalence of median neuropathies at, or distal to, the wrist have been reported in dentists and dental hygienists. But there is a paucity of literature on the incidence of abnormalities of the median or ulnar nerves in dental assistants. METHODS Thirty-five United States Army dental assistants (24 female, 11 male; age range, 18-41 years) volunteered for the study. Subjects completed a standardized history and physical examination. Nerve conduction status of the median and ulnar nerves of both upper extremities was obtained by performing motor, sensory, and F-wave (central) nerve conduction studies. RESULTS All electrophysiological variables were normal for motor, sensory, and F-wave (central) values when compared to a chart of normal values. Based on comparison studies of median and ulnar motor latencies within the same hand, 9 subjects (26%) involving 14 hands (20%) were found to have electrodiagnostic abnormalities of the median nerve at, or distal to, the wrist. The other 26 dental assistants demonstrated normal comparison studies of the median and ulnar nerves in both upper extremities. CONCLUSIONS In this descriptive study of 35 dental assistants, 9 subjects (26%) were found to have electrodiagnostic abnormalities of the median nerve at, or distal to, the wrist (when compared to the ulnar nerve of the same hand). Ulnar nerve electrophysiological function was within normal limits for all subjects examined.