It has been hypothesized that idiopathic carpal tunnel syndrome (CTS) is a manifestation of vitamin B6 deficiency. Some claim that B6 supplementation can alleviate symptoms. Others argue that pain relief occurs because of vitamin B6's anti-nociceptive properties or because B6 supplementation addresses an unrecognized peripheral neuropathy. Few studies on CTS and B6 employed electrodiagnostic te...

The radial nerve is the major nerve serving the extensor compartment of the arm. This article describes the anatomic features, clinical features based on lesion location, electrodiagnostic assessment, prognosis, and treatment of radial neuropathies. Numerous traumatic causes have been reported to result in radial neuropathies, including compression or stretch injury, surgical insult, or trauma....

Basis of the Electroretinogram An electrical potential exists between the cornea and the fundus of the living eye. When the eye is illuminated by a flash of light a small potential is generated in addition to this corneofundal potential, which forms the ERG. This is analogous to the way in which the ECG is recorded above the steady skin potential. The final response is the sum of a number of co...

PURPOSE Cadaveric palmar dissections reveal an ulnar sensory crossover (Berrettini anastomosis) to the third common palmar nerve so frequently that this crossover is considered a normal part of the anatomy. No literature has documented electrophysiologic evidence of the Berrettini anastomosis (BA). Presentation of third digit ulnar sensory crossover waveforms. METHODS Retrospective chart revi...

A 25-year-old man with acute, bilateral facial palsies is presented. He had a lymphocytic meningitis, history of tick bites, and lived in an area endemic for Lyme disease, which was ultimately confirmed by serology. Electrodiagnostic investigation included facial motor nerve study, blink reflex and electromyography of facial muscles, which were indicative of a neurapraxic lesion on the right an...

Brachial plexus injuries represent a complex clinical challenge from both a diagnostic and treatment standpoint. Given the potential etiologic mechanisms of injury, as well as the varied number of anatomic sites vulnerable to such injury, it is essential that a precise diagnostic approach be utilized. From a neurophysiologic perspective, the electrodiagnostic examination has been shown to be th...

Schwannoma is an encapsulated nerve sheath tumor that is distinct from neurofibromatosis. It is defined as the occurrence of multiple schwannomas without any bilateral vestibular schwannomas. A 46-year-old man with multiple schwannomas involving peripheral nerves of the ipsilateral lower extremity presented with neurologic symptoms. Electrodiagnostic studies revealed multiple mononeuropathies i...

Posterior interosseous nerve entrapment is a potential cause of upper extremity muscle weakness and pain. The diagnosis may be difficult to make clinically, and electrodiagnostic tests may not identify the exact site of nerve compression. We report a case of posterior interosseous nerve entrapment in which electrodiagnostic studies suggested radial neuropathy at the level of the spiral groove, ...