This study was designed to determine the cause of upper trunk brachial plexopathy, which is referred to as a "stinger" or a "burner." This injury often has been thought to occur secondary to traction when an athlete sustains a lateral flexion injury of the neck. At the United States Military Academy, a 4-phase study was begun with 261 tackle football players (236 intramural- and 25 varsity-level players) to investigate this injury. Electromyography and nerve root stimulation studies were used to delineate the lesion, which was found in a total of 32 players who continued throughout the study. This study demonstrated that a much more common mechanism of injury resulting in the stinger syndrome is probably compression of the fixed brachial plexus between the shoulder pad and the superior medial scapula when the pad is pushed into the area of Erb's point, where the brachial plexus is most superficial. An orthosis was designed to protect the brachial plexus from the compressive force of the shoulder pad. In preliminary trials, this orthosis had been very effective in decreasing the number of episodes in which stinger injuries occurred.

A nerve conduction method is demonstrated for cranial nerve XII, the hypoglossal nerve. Submandibular surface stimulation is performed while recording over the anterior surface of the tongue. There were 30 normal adult subjects and 60 hypoglossal nerves studied. Evoked response parameters are reported as follows: mean latency 2.2 +/- 0.4 msec, mean amplitude 3.8 +/- 1.6 mV (baseline to peak, best of 5 responses). This nerve conduction method is reliable and should expand the electrophysiological assessment of XII cranial nerve motor function.

No abstract

Mechanisms underlying urethral pressure changes at the external sphincter region after administration of neuropharmacologic agents were investigated with cystosphincterometric studies and electromyography of the external urethral sphincter in adult patients with spinal cord injury and control male subjects. Bethanechol chloride, propantheline or phentolamine were administered to 37 spinal cord injury men and 3 normal controls. After cystectomy 3 additional spinal cord injury patients were subjected to bethanechol studies. The results of these studies suggested that the pressure changes in the external sphincter zone were caused predominantly by the concurrent changes produced in the detrusor and/or the smooth muscle components of the proximal urethra and of the external sphincter zone.

Experiences are presented with bilateral (3 and 9 o'clock incisions) and anteromedian (12 o'clock incision) external urethral sphincterotomy in 84 patients with neuropathic vesicourethral dysfunctions. Hemorrhage and loss of reflexogenic erections have been notably absent in 31 patients who underwent anteromedian sphincterotomy. The rationale is discussed for the preference of anteromedian over bilateral sphincterotomy based on postoperative complications. The postoperative, radiologically aided cystosphincterometric and electromyographic studies during micturition indicated the adequacy of the surgical procedures, satisfying the urodynamic criteria, although dyssynergic myolectric activity of the periurethral striated muscle continued to exist.