Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Malnutrition is a worldwide problem of enormous magnitude. The growth of the central nervous system in human beings is retarded in case of malnutrition in the very early part of life. Likewise, the peripheral nerves in infants and children and young growing animals appear susceptible to nutritional deprivation including protein as well as protein-calorie deficiency. Motor weakness, hypotonia, and hyporeflexia in infants and children are the essential clinical neurological signs in protein-calorie malnutrition (PCM). Motor and sensory nerve conduction are significantly impaired in children with PCM as well as in animals subjected to protein or protein-calorie deficiency. Histological studies have revealed reduced diameter of myelinated nerve fibers, retardation of myelination, segmental demyelination and remyelination, axonal degeneration, and shortened longitudinal growth of internodes. Diffusion barrier by perineurium may be broken. There is reduction in myelin lipids and impaired synthesis of myelin as shown by the biochemical and radioisotope incorporation studies. Presence of cholesterol esters in the biochemical synthesis of nerves suggests degeneration changes. Experimental studies have revealed that most effects of PCM on peripheral nerves can be reversed by nutritional rehabilitation, although complete recovery in the sensory nerve action potential, fiber size of dorsal nerve roots, and myelin-specific lipids does not occur. Skeletal muscle also shows many changes including muscle fiber atrophy, reduction in duration and amplitude of motor unit potentials, and/or fibrillation on electromyography (EMG) and biochemical estimation of muscle enzymes. These changes may be the reflection of a direct effect of PCM on muscles or secondary to the abnormal structural or biochemical changes in the peripheral nerves. PCM affects the central nervous system, especially the neuropsychological functions, in a lasting manner. Learning deficits and impairment of manual dexterity are the most obtrusive features. Neurotransmitter abnormalities and maturation lag in electroencephalogram have been demonstrated in experimental animals. Spinal cord dysfunction sometimes manifests overtly as clinical myelopathy. Degenerative changes in the cerebellum have been noted.
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PMID:Neurological consequences of protein and protein-calorie undernutrition. 193 90

The authors report the clinical and electromyographic (EMG) findings in a series of 13 children with a pseudomyopathic motor deficit in the context of malnutrition (Body Mass Index < or = 3rd percentile) caused by primary protein-calorie deficiency or secondary to chronic disease. The infants (nine cases) manifested a regression or stagnation of motor abilities, with hypotonia and amyotrophy; older children and adolescents (four cases) presented clear amyotrophy with a deficit in muscle strength consisting primarily of proximal muscular weakness. Detection and stimulation-detection EMG demonstrated myogenic signs in at least two muscles in all patients. Myogenic signs were dominant in all proximal muscles. Latencies were normal in all patients. Motor nerve conduction velocities were slowed in three infants and in one adolescent. A temporal dispersion of motor responses was observed in 11 proximal muscles. The muscle biopsy, performed in five cases, revealed an inequality in the calibre of fibres, with atrophy dominating in type II fibres. The authors emphasize the value of EMG in disclosing the myopathic process, thereby contributing to the etiological diagnosis of motor difficulties in children suffering from malnutrition or a chronic disease.
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PMID:Muscle complications of malnutrition in children: a clinical and electromyographic study. 833 12