Annals of neurology
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Annals of neurology · Jun 1981
A comparison of stapedial reflex fatigue with repetitive stimulation and single-fiber EMG in myasthenia gravis.
The pattern of stapedial reflex fatigue in response to pulsed acoustic stimulation was measured and compared to results of repetitive nerve stimulation and single-fiber electromyography (EMG) in 89 patients with myasthenia gravis. Studies were also made on 22 patients with other neuromuscular disorders and 40 control subjects with no evidence of neuromuscular impairment. Stapedial reflex fatigue exceeded normal control values in 84% of the patients with myasthenia gravis. ⋯ Of 22 nonmyasthenic patients with neuromuscular disease tested, 6 had abnormal stapedial reflex fatigue according to our normal values, indicating that this form of testing also detects other diseases of the motor unit. The measurement of stapedial reflex fatigue is painless, is easy to perform, and requires minimal patient cooperation. Due to the relatively high occurrence of abnormal stapedial reflex fatigue in patients with myasthenia gravis, this procedure appears to have considerable potential value in screening and monitoring patients for the presence of defects in neuromuscular transmission.
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The past decade has seen advances in the management of patients with epilepsy. The development of practical long-term electroencephalographic techniques, with or without simultaneous video recording, has increased the accuracy of diagnosis of seizure types. The technique also provides clinicians and investigators with a method for establishing the clinical efficacy of antiepileptic drugs and determining their therapeutic serum concentrations. ⋯ Half of those who are successfully employed did not disclose their disorder at the time of employment. Several prognostic indicators have been reported, but the validity of many of these indicators is questionable. For example, does shorter life expectancy apply to all subgroups, or does it vary according to seizure type and cause? The life expectancy, treatment response, and probability of remission in epileptic persons must be reevaluated after consistent applications of current methods of epilepsy management.
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Lorazepam, a dichloro-3-hydroxy-1,4-benzodiazepine, has been shown to be a potent anticonvulsant in animal models of epilsepsy and has minimal depressant effects on respiration and circulation in humans. The effects of this compound were studied in status epilepticus. Twenty-five patients were given intravenous lorazepam during status epilepticus of varying cause. ⋯ Studies of plasma drug levels suggest that most patients attain good seizure control at concentrations between 30 and 100 ng per milliliter. Clinical observations indicate that repetitive injections are not required for continuing control of seizures in patients whose seizures are initially controlled. Lorazepam appears to be an effective and safe drug for treatment of status epilepticus, with a duration of control longer than that achieved with diazepam.
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Annals of neurology · Aug 1978
Case ReportsNeurological manifestations of hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease): report of 2 cases and review of the literature.
Two cases of hereditary hemorrhagic telangiectasia (HHT) with neurological involvement are presented. One patient had multiple vascular malformations including telangiectasias of the brain, medulla, and spinal cord and a berry aneurysm of the internal carotid artery; she also had a large cerebellar abscess, presumably reflecting the presence of a pulmonary arteriovenous fistula. The second patient had an idiopathic subarachnoid hemorrhage. ⋯ In 36% of the patients with neurological involvement and HHT, vascular malformations of the brain and spinal cord were documented, and in 3%, portal-systemic encephalopathy was noted. Multiple lesions were frequent. HHT should be considered a generalized vascular dysplasia (universal or systemic angiomatosis), and not simply a benign mucocutaneous disease.
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Annals of neurology · Jul 1978
Acetylcholine release in diaphragm of rats with chronic experimental autoimmune myasthenia gravis.
Recent evidence indicates that in chronic experimental autoimmune myasthenia gravis (EAMG) and in human myasthenia gravis, the defect of neuromuscular transmission results from immune-mediated destruction of post-synaptic membrane at the neuromuscular junction, with a reduction in the density of acetylcholine (ACh) receptors and decreased sensitivity to ACh released by nerve impulses. In the present study, the amount of ACh released by nerve impulse in rats with chronic EAMG and control rats of the same age, weight, and sex was compared. ⋯ Despite a marked reduction in the amplitude of miniature end-plate potentials in chronic EAMG, ACh output at rest and during stimulation was not different from that of control rats. These data support the concept that the defect of neuromuscular transmission is due to a reduction of postsynaptic sensitivity to ACh.