Neurological complications of windsurfing (sailboarding).

This article presents a brief history of windsurfing, a relatively new recreational and competitive sport activity also known as sailboarding; a brief summary of physiologic studies of windsurfers; and a review of windsurfing injuries with a focus on the neurological complications of windsurfing.

Zoster paresis of the shoulder. Case report and review of the literature.

More than 95% of people in the United States are infected with the varicella zoster virus at some time in life, and this infection usually is manifested as chicken pox during childhood. The virus then establishes a latent infection of sensory ganglia, from which it may reactivate many years later to cause herpes zoster (shingles), a cutaneous painful rash along a dermatomal distribution. Less commonly, the varicella zoster virus may result in myotomal motor weakness or paralysis in addition to a painful dermatomal rash. A case of unilateral left C5-C6 segmental paresis attributable to herpes zoster in an otherwise healthy individual and a current review of the literature are presented. A case of zoster paresis of the shoulder muscles is presented to remind the orthopaedic community that this diagnosis may be confused with other diagnoses, including rotator cuff tear, and should be considered in the differential diagnosis of shoulder pain and shoulder girdle muscle weakness.

Postoperative lateral femoral cutaneous neuropathy.

Lateral femoral cutaneous (LFC) neuropathy was diagnosed in a woman who developed pain and paresthesias in the right thigh 6 days after abdominal hysterectomy by a suprapubic approach. After surgery, the patient slept in the fetal position to control the postoperative suprapubic pain. The LFC neuropathy improved with therapy including avoidance of hip flexion during sleep. Prolonged postoperative hip flexion to relieve the abdominal incisional pain provides an explanation for LFC neuropathy after abdominal surgery when the onset of symptoms is delayed.

Lateral antebrachial cutaneous neuropathy in a windsurfer.

Lateral antebrachial cutaneous neuropathy (LACN) was diagnosed in a young woman who developed pain and paresthesias in the right forearm after a long day of windsurfing (board sailing). The symptoms resolved with conservative treatment, including cessation of windsurfing and a brief course of oral corticosteroids. There was a permanent residual cutaneous sensory deficit in the distribution of the LACN. LACN is important to recognize because the symptomatology may mimic pathology of a cervical root, the brachial plexus, and the radial and median nerves at the level of the elbow.

American Association of Electrodiagnostic Medicine guidelines for outcome studies in electrodiagnostic medicine.

Based on a review of the literature and the clinical research experience of the authors and reviewers, the AAEM proposes 17 criteria which should be used to construct and evaluate diagnostic and/or therapeutic outcome studies for patients with symptoms and signs of neuromuscular diseases. Neuromuscular diseases are defined as diseases that cause pathology and/or dysfunction of the sensory, motor, and/or autonomic nerve offers and/or muscles.

Mutations in the gene-encoding SERCA1, the fast-twitch skeletal muscle sarcoplasmic reticulum Ca2+ ATPase, are associated with Brody disease.

Brody disease is a rare inherited disorder of skeletal muscle function. Symptoms include exercise-induced impairment of skeletal muscle relaxation, stiffness and cramps. Ca2+ uptake and Ca2+ ATPase activities are reduced in the sarcoplasmic reticulum, leading to the prediction that Brody disease results from defects in the ATP2A1 gene on chromosome 16p12.1-12.2, encoding SERCA1, the fast-twitch skeletal muscle sarcoplasmic reticulum Ca2+ ATPase. A recent search, however, did not reveal any mutations in the ATP2A1 gene in three Brody patients. We have now associated Brody disease with the autosomal recessive inheritance of three ATP2A1 mutations in two families, suggesting that the disease is genetically heterogeneous. One mutation occurs at the splice donor site of intron 3, while the other two mutations lead to premature stop codons, truncating SERCA1, deleting essential functional domains and raising the intriguing question: how have these Brody patients partially compensated for the functional knockout of a gene product believed to be essential for fast-twitch skeletal muscle relaxation?

Focal lipoatrophy.

Focal atrophy of a limb is usually caused by loss of muscle due to nerve or muscle disease. However, focal atrophy of subcutaneous tissues, an uncommon but well described entity, can mimic neuromuscular disease by producing a similar appearance of the limb. The clinical sign of thinness of the subcutaneous tissues (the "pinch-an-inch" test) suggests lipoatrophy as the cause of the limb asymmetry.

Literature review of the usefulness of nerve conduction studies and electromyography for the evaluation of patients with carpal tunnel syndrome. AAEM Quality Assurance Committee.

The sensitivity and specificity of nerve conduction studies (NCS's) and electromyography (EMG) for the diagnosis of carpal tunnel syndrome (CTS) were evaluated by a critical review of the literature. With a search of the medical literature in English through May 1991, 165 articles were identified and reviewed on the basis of six criteria of scientific methodology. The findings of 11 articles that met all six criteria and the results of 48 additional studies that met four or five criteria are presented. We concluded that median sensory and motor NCS's are valid and reproducible clinical laboratory studies that confirm a clinical diagnosis of CTS with a high degree of sensitivity and specificity. Clinical practice recommendations are made based on a comparison of the sensitivities of the several different median nerve conduction study (NCS) techniques.

AAEM case report #3: myasthenia gravis.

Reported here are the electrodiagnostic findings in a patient with myasthenia gravis who had dysarthria, dysphagia, and dyspnea. The use of repetitive nerve stimulation and single fiber electromyography studies for the evaluation of patients suspected of myasthenia gravis is reviewed.

Survival prediction in amyotrophic lateral sclerosis.

This longitudinal study of 194 patients with sporadic ALS demonstrated that it is possible for physicians to predict the approximate survival time for an individual ALS patient given: (1) the age of the patient, (2) the duration of his weakness and (3) an estimate of his clinical disability (ALS Score). This information is of value in the clinical management of ALS patients, and it should facilitate construction of experimental therapeutic trials in ALS.

Electromyography in infants and children.

Electromyography (EMG) is of proven value in the diagnosis of acute and chronic neuromuscular diseases in infants and children. When this technique is combined with nerve conduction studies, including repetitive nerve stimulation studies, it is often possible upon completion of the studies to identify the disorder as one of nerve, neuromuscular junction, or muscle. The purpose of this article is to review the principles and techniques of EMG in infants and children and to describe the EMG findings in several neuromuscular disorders.

Electrodiagnostic evaluation of patients with myasthenia gravis and related disorders.

The technique of repetitive nerve stimulation was developed as a means of confirming a diagnosis of MG. The application of this test in the clinical evaluation of patients with muscle weakness has identified other disorders of neuromuscular transmission such as LEMS, infantile botulism, and several forms of congenital myasthenia. Repetitive nerve stimulation to several different nerves, before and after exercising the muscles, usually permits identification of disorders of neuromuscular transmission more readily than very detailed study of one muscle. There are other useful electrodiagnostic tests, but in most cases, repetitive nerve stimulation of weak muscles will permit the identification of a disorder of neuromuscular transmission.

Autoradiographic localization of new RNA synthesis in hypertrophying skeletal muscle.

Work-induced growth of rat soleus muscle is accompanied by an early increase in new RNA synthesis. To determine the cell type(s) responsible for the increased RNA synthesis, we compared light autoradiographs of control and hypertrophying muscles from rats injected with tritiated uridine 12, 24, and 48 h after inducing hypertrophy. There was an increased number of silver grains over autoradiographs of hypertrophied muscle. This increase occurred over connective tissue cells; there was no increase in the number of silver grains over the muscle fibers. Quantitative studies demonstrated that between 70 and 80% of the radioactivity in the muscle that survived fixation and washing was in RNA. Pretreatment of the animals with actinomycin D reduced in parallel both the radioactivity in RNA and the number of silver grains over autoradiographs. Proliferation of the connective tissue in hypertrophying muscle was evident in light micrographs, and electron micrographs identified the proliferating cells as enlarged fibroblasts and macrophages; the connective tissue cells remained after hypertrophy was completed. Thus, proliferating connective tissue cells are the major site of the increase in new RNA synthesis during acute work-induced growth of skeletal muscle. It is suggested that in the analysis of physiological adaptations of muscle, the connective tissue cells deserve consideration as a site of significant molecular activity.