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Biomedical subjects

L Gutmann

Publications and source records attributed to L Gutmann.

At least 271 records · Page 15Linked to original sources

Nitrous oxide-induced myeloneuropathy: report of cases.

The development of neurologic symptoms, especially a myeloneuropathy, remains a serious hazard of nitrous oxide exposure. The need to use it in a well-ventilated environment with a scavenger system and the avoidance of its self-use are clear from the cases reported. The findings of the questionnaire disclose that the majority of dentists have experienced none of these problems while using nitrous oxide in a professional manner; however, self-use of nitrous oxide, with its potential neurologic sequelae, may be a serious problem among dental personnel.

Adult↗

Hereditary aspects of median-ulnar nerve communications.

Median-ulnar nerve communications, resulting in anomalous innervation of intrinsic hand muscles, was found to occur in 28% of the general population and 62% of family members of five propositi with this variant. This variant appears to be dominantly inherited.

Adult↗

Facial myokymia. Pathological features.

Pathologic examination in a case of facial myokymia showed edema and mild astroglial proliferation of the ipsilateral seventh nerve nucleus; gliomatous tumor involvement occurred rostral to this nucleus. These findings give circumstantial support to functional deafferentation as the cause of facial myokymia.

Adult↗

Nitrous oxide-induced myelopathy-neuropathy: potential for chronic misuse by dentists.

The myelopathy and neuropathy associated with chronic misuse of nitrous oxide are potentially reversible if the habit is discontinued. This occurred in each of the reported cases, including our case, when it was transiently discontinued. Although a causal relationship between nitrous oxide and this myelopathy-neuropathy has not been proved, the circumstantial evidence is convincing. Both physicians and dentists should be aware of this potentially serious complication of chronic self-administration of nitrous oxide, especially in persons inclined to misuse drugs. Dentists, with their access to nitrous oxide, may be particularly at risk.

Adult↗

Type B botulism outbreak caused by a commercial food product. West Virginia and Pennsylvania, 1973.

In the week of May 7, 1973, seven persons contracted botulism after eating together. The most common symptoms were vomiting, constipation, dry mouth, dysphagia, and dysphonia. All were treated with trivalent botulinal antitoxin, and none died. Serum specimens obtained from all seven patients were negative for botulinal toxin, but stool specimens from three patients were positive for type B toxin. Electromyographic studies performed on five patients documented the neurophysiologic abnormalities of botulism. Commercially canned peppers in oil were implicated epidemiologically, and type B toxin was identified in leftover peppers. The processor voluntarily recalled the pepper product, and no further cases were reported.

Botulinum Antitoxin↗

Stapedius reflex decay in myasthenia gravis.

Stapedius reflex decay, in response to a one-minute sound stimulus of 500 Hz occurred in six patients with myasthenia gravis. This decay is analagous to the decremental response of muscle action potentials to rapid nerve stimulation. Edrophonium chloride decreases the degree of decay. This represents a useful test in the diagnosis of myasthenia gravis.

Acoustic Stimulation↗

Median--ulnar nerve communications and carpal tunnel syndrome.

Carpal tunnel syndrome in the presence of anomalous median to ulnar nerve communications in the forearm produces a characteristic change in motor conduction studies. Median nerve stimulation at the elbow evokes a thenar muscle action potential (MAP) with an initial positive deflection not seen on stimulation at the wrist. In 63 patients this change occurred in 16 (25%) and is a useful additional criterion in the diagnosis of carpal tunnel syndrome. The initial positive deflection is due to the volume-conducted MAP from the first dorsal interosseous and some thenar muscles whose motor point lies some distance from the recording electrode over abductor pollicis brevis. The first dorsal interosseous and thenar MAPs resulting from elbow stimulation of those median nerve axons crossing to ulnar nerve in forearm, are generated before that from thenar muscles supplied by the axons going through the carpal tunnel.

Carpal Tunnel Syndrome↗

Pathophysiologic aspects of human botulism.

Physiologic studies were carried out in six patients with botulism. Abnormalities were those of a defect of acetylcholine release. Although the most consistent findings were small, evoked muscle action potentials (MAP) and posttetanic facilitation similar to the Eaton-Lambert syndrome, there were differences. In botulism as opposed to the Eaton-Lambert syndrome, the following were true: (1) posttetanic facilitation of the amplitude of the evoked MAP was considerably less and did not approach the normal value when the block was severe; (2) posttetanic facilitation persisted at least several minutes during the postactivation cycle; (3) posttetanic depression did not occur; (4) significant tetanic facilitation of the amplitude of the MAP occurred in less than half the patients and, even then, did not approach normal (on the other hand, a decremental response, as in myasthenia gravis, is not seen); and (5) no decremental response of the MAP occurred during slow rates (two per second) of nerve stimulation. Evidence of transient physiologic denervation occurred as in experimental animals affected by botulinum toxin. All physiologic abnormalities revert to normal in association with clinical recovery.

Adult↗

Dapsone motor neuropathy--an axonal disease.

Dapsone produces a potentially reversible toxic neuropathy, with its primary effect on the soma and axons of motor neurons as opposed to myelin. There is very little evidence to suggest involvement of sensory axons in most cases; if present, it would appear minimal. A "dying back" of motor axons is postulated to produce the clinical features of primarily distal weakness and wasting. Recovery appears to occur via axon regeneration and peripheral sprouting. The sporadic occurrence of this neuropathy may be due to slow acetylation of dapsone in some patients.

Action Potentials↗

Myasthenia gravis. Current concepts.

The prevalent theory of the past two decades, that the defect in myasthenia gravis (MG) is the packaging of achetylcholine (Ach) into smaller quantal units, has recently been revised. The current theory is based on (1) electron microscopical studies of motor end plates in patients with MG; (2) radioisotope study with alpha-bungarotoxin of postsynaptic membrane Ach receptor (Ach R) sites; (3) sensitization of rabbits with the use of purified Ach R from the electric eel, inducing experimental autoimmune myasthenia gravis (EAMG); (4) detection of antibodies to the Ach R in patients with MG by radioimmunoassay; and (5) apparent induction of MG in mice by passive transfer of immunoglobulin from patients with MG. Thus, the emphasis on pathogenesis of MG is now placed on an autoimmune process involving Ach R in the subsynaptic membrane of neuromuscular junctions.

Acetylcholine↗

Fusariosis, myasthenic syndrome, and aplastic anemia.

Fusarium, a fungus, produces a potent mycotoxin that, when ingested with contaminated cereal grains, produces a serious illness in man called alimentary toxic aleukia (USSR) and Akakabi-byo (Japan). The illness includes gastrointestinal symptoms and weakness and if ingestion of Fusarium contaminated grain persists, culminates in aplastic anemia. A 66-year-old woman had Eaton-Lambert syndrome and a clinical course similar to alimentary toxic aleukia. Several months before her death, pancytopenia, initially thought guanidine-induced, developed and progressed to aplastic anemia despite discontinuation of guanidine 2 1/2 months before death. Autopsy showed numerous granuloma in the liver, spleen, esophagus, and cecum from which Fusarium oxysporum was isolated. Although the unique finding of systemic fusariosis may relate to altered host resistance terminally, a causal relationship with her defect of neuromuscular transmission and/or aplastic anemia is a distinct possibility.

Aged↗

Hereditary aspects of accessory deep peroneal nerve.

Hereditary aspects in the anomalous innervation of the extensor digitorum brevis muscle by the accessory deep peroneal nerve, were investigated. Utilizing electrophysiological techniques, 22% of 100 healthy unrelated individuals demonstrated this variation in innervation of one or both extensor digitorum brevis muscles. The study of family members of five of these subjects with the variation showed that 78% of relatives also had this anomalous innervation. These data suggest that hereditary factors may be significant in the occurrence of this variation and a dominant mode of inheritance may be the case.

Action Potentials↗