ABSTRACT
Neuromuscular junctional disorders (NMJ) in children are distinct entity. They may be acquired or hereditary. They pose problem in diagnosis because of the higher occurrence of sero negative Myasthenia Gravis (MG) cases in children. The identity of MusK antibody positivity in a good percentage of sero negative cases further adds to problems in diagnosis. The Congenital Myasthenic Syndrome (CMS) which are rare disorders of hereditary neuromuscular transmission (NMT) has to be differentiated because immunotherapy has no benefit in this group. Molecular genetic studies of these diseases helps to identify specific type of CMS which is important as other drugs like Fluoxetine, Quinidine are found to be effective in some. In infancy, all can manifest as floppy infant syndrome. The important key to diagnosis is by detailed electrophysiological studies including repetitive nerve stimulation at slow and high rates and its response to anticholinesterases and estimation of Acetyl choline receptor antibodies. Other causes of neuromuscular transmission defects viz. snake venom poisoning and that due to drugs are discussed.
Subject(s)
Antibodies/immunology , Child , Cholinesterase Inhibitors/diagnosis , Electromyography , Humans , Infant , Myasthenia Gravis/diagnosis , Neostigmine/diagnosis , Neuromuscular Junction/immunology , Receptors, Cholinergic/immunologyABSTRACT
BACKGROUND: While erectile dysfunction is frequent among people with disorders of the spinal cord, the role of various clinical neurophysiological tests in assessment is not clear. AIMS: To study the role of clinical neurophysiological investigations in assessing erectile dysfunction among men with spinal cord disorders. SETTING: National Institute of Mental Health and Neurosciences, India. DESIGN: Survey. MATERIALS AND METHODS: Subjects with a score of 21 or less on the International Index of Erectile Function-5 were classified as with erectile dysfunction and with a score of more than 21 as without erectile dysfunction. Clinical neurophysiological studies done were Sympathetic Skin Response from limbs, posterior tibial sensory evoked potential, pudendal sensory potential and bulbocavernous reflex. STATISTICAL ANALYSES: Chi-square test. RESULTS: Among 40 subjects 26 had erectile dysfunction. The frequency of abnormalities in clinical neurophysiological studies were: pudendal sensory evoked potentials--16, posterior tibial sensory evoked potentials--26, bulbocavernous reflex--5, sympathetic skin response from sole--24 and, sympathetic skin response from palm--18. Significant associations were noted between erectile dysfunction and abnormal pudendal sensory evoked potentials (P=0.0479), and absent sympathetic skin response from palm (P=0.0279) and sole (P< 0.001). There was no correlation between erectile dysfunction and posterior tibial sensory evoked potentials (P=0.133) or bulbocavernous reflex (P=0.418). Sympathetic skin response from sole was most sensitive (80.8%) and had best positive (87.5%) and negative predictive (68.8%) values. The specificity of these three tests was 78.6%. CONCLUSIONS: Sympathetic skin response from the sole of the foot was the most sensitive and specific clinical neurophysiological test for erectile dysfunction in spinal cord disorders.