Neuromuscular choristoma]

Neuromuscular choristomas are malformative pseudotumoral masses composed of striated muscle and peripheral nerves. This rare condition almost exclusively affects large nerve trunks of infants and young children, and may cause neurologic deficits of variable severity. We report a case of neuromuscular choristoma identified in the lumbosacral lipoma of a 4-month-old boy. The lesion was characterized by an organoid association of myogenic and neurogenic elements reminiscent of neuromuscular units. Myosin immunophenotyping revealed disordered groups of type-I and type-II extrafusal myofibers. There was no immunoreactivity for smooth muscle specific alpha actin. Most participating axons were of the large myelinated type. Pathogenetic theories of neuromuscular choristoma involve aberrant migration of developing peripheral nerves, dysgenesis of muscle spindles, as well as mesenchymal differentiation of the primitive neuroectoderm. Neuromuscular choristomas arising in connection with congenital lipomas may derive from a dysembryogenic process of stem cells of the caudal neural tube.     

Neuromuscular function in pesticide workers

Jager, K. W., Roberts, D. V., and Wilson, Andrew (1970).Brit. J. industr. Med.,27, 273-278. Neuromuscular function in pesticide workers. Electromyography (EMG) provides a sensitive, objective, and speedy method of detecting impairment of nerve and muscle function in pesticide workers who are apparently in good health. Exposure to two organophosphorus compounds (both were dimethyl phosphate esters) was associated with a high incidence (about 50%) of EMG signs of impaired nerve and muscle function. In workers exposed only to organochlorine compounds there was a much lower incidence (about 4%) of abnormal EMG. Exposure to these organophosphorus compounds was not associated with depression of blood cholinesterase activity even in those workers with typical EMG signs. It is concluded that measurement of blood cholinesterase activity does not provide a sensitive index of functional impairment of nerve and muscle.     

Neuromuscular disorders of the gastrointestinal tract

The neuromuscular disorders of the bowel, lacking defined structural abnormalities, have been poorly understood and too often misclassified as psychosomatic. With advancing technology, however, we are gaining increasing evidence of specific abnormalities in the gastrointestinal neuromuscular apparatus. Some specific therapies have already been developed for restoring function.     

Neuromuscular Disorders of the Gastrointestinal Tract

The neuromuscular disorders of the bowel, lacking defined structural abnormalities, have been poorly understood and too often misclassified as psychosomatic. With advancing technology, however, we are gaining increasing evidence of specific abnormalities in the gastrointestinal neuromuscular apparatus. Some specific therapies have already been developed for restoring function.     

Neuromuscular electrical stimulation in stroke rehabilitation

We briefly review the literature related to the use of neuromuscular electrical stimulation (ES) in promoting recovery from stroke. ES can be used to facilitate motor learning in ankle dorsiflexion and wrist extension. It also has been shown to be beneficial in reducing shoulder subluxation but inconsistent in reducing shoulder pain. The mechanism of benefit of ES is unknown, but increased synaptic effectiveness has been suggested.     

Neuromuscular syndromes of the critically ill

With the continuous improvement in the survival of critical patients, new neuromuscular syndromes are being described. The clinical finding is an acute-subacute onset of generalised weakness with difficulty in weaning the patient from the ventilator, due to polyneuropathy, myopathy, prolonged neuromuscular blockade or a combination of these disorders. Although having a multifactorial ethiopathology, the major risk factors in the development of these disorders are multiple organ failure and sepsis for polyneuropathy; corticosteroids and neuromuscular junction blocking agents (NMB) for myopathy; and NMB and renal and liver failure for prolonged neuromuscular blockade. No specific treatment exists, which is why--due to the high incidence of these syndromes and their poor prognosis, with a mortality rate higher than 50%--we should recognise, diagnose and avoid, where possible, the conditions that help the development of these disorders.     

Neuromuscular differences between male and female athletes

Female athletes who participate in jumping and cutting-type sports have a four- to six-fold higher incidence of serious knee injuries compared with male athletes in the same sports. Many of these injuries involve the anterior cruciate ligament, and occur by non-contact mechanisms. The susceptibility of the female athlete's knee to injury is likely multifactorial, although neuromuscular factors seem to have an important role. Recent studies have identified neuromuscular differences between male and female athletes. Specifically, female athletes have decreased stiffness and decreased potential for dynamic stabilization of the knee joint. Proprioception deficits involving the knee and side-to-side strength and coordination imbalances are more frequent in female athletes. Also, female athletes more commonly demonstrate imbalances in strength, timing of activation, and recruitment patterns of the lower extremity muscles. Based on these findings, neuromuscular training programs have been studied in an effort to correct lower extremity neuromuscular imbalances. Preliminary results from these programs have been encouraging in reducing peak landing imact forces in the knee, correcting strength and proprioception deficits, and ultimately in decreasing the incidence of serious knee injuries in female athletes.