Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1762617 (weakness)
 37,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A neurological disorder developed after prolonged exposure to nitrous oxide in 15 patients, all but 1 of whom were dentists. 13 patients had abused nitrous oxide to some extent for periods ranging from 3 months to several years, but 2 patients were exposed to nitrous oxide only professionally, by working in poorly ventilated surgeries. Symptoms included early sensory complaints, Lhermitte sign, loss of balance, leg weakness, gait ataxia, impotence, and sphincter disturbances. Neurological examination showed sensorimotor polyneuropathy, often combined with signs of involvement of the posterior and lateral columns of the spinal cord. Electrodiagnostic tests pointed to an axonal polyneuropathy, but other laboratory results were normal, including examination of the spinal fluid. The neurological picture is similar to that of subacute combined degeneration of the spinal cord, and it is possible that nitrous oxide interferes with the action of vitamin B12 in the nervous system.
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PMID:Myeloneuropathy after prolonged exposure to nitrous oxide. 8 36

A 68-year-old woman with clinical, electromyographic, and pharmacologic evidence of myasthenia gravis experienced increasing proximal and bulbar muscular weakness. The diagnosis of pernicious anemia was established by typical abnormalities in the peripheral blood and bone marrow aspirate, the serum B12 level, by results of the Schilling test, and by the presence of serum parietal cell antibody. The diagnosis of Hashimoto's thyroiditis was established by the presence of diffuse thyroid enlargement, microsomal thyroid antibodies, an increased thyroid stimulating hormone level, and depressed T2 and T4 levels.
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PMID:Myasthenia gravis, pernicious anemia, and Hashimoto's thyroiditis. 58 4

Five patients presenting clinically with a form B12-deficiency neuromyelopathy, with cord involvement in all and proximal muscle weakness in two of them, were investigated for their neurologic, hematologic and vitamin status. Megaloblastosis and achlorhydria were present in all, and impaired absorption of 57Co vitamin B12 and of D-xylose was detected in four. Total cyanide extracted vitamin B12 (A) was lowered in all cases and noncyanide extractable (B) in four of the five, being zero in three. All five responded to injections of hydroxocobalamin. In two patients sequential estimations showed that both A and B, especially the latter, rose steeply initially, normalizing at 50% of A after some weeks. Moiety B is suggested to be physiologically the more active and dissociable form of vitamin B12. Markedly elevated initial serum folate levels, and their subsequent fall under treatment with B12, indicated the operation of the "methyltetrahydrofolate trap". Blood levels of thiamin, nicotinic acid and pantothenic acid were within normal limits. However, serum riboflavin (B2) total vitamin B6 and pyridoxal were reduced in all where tested. Vitamin B6 deficiency could have resulted from its own malabsorption and have contributed to be B12 deficiency. Vitamin B2 and B6 levels also corrected themselves on B12 therapy. The B-vitamin deficiencies in our patients probably resulted from intestinal malabsorption, with a possible factor of malnutrition consequent to their strictly vegetarian diet.
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PMID:Interrelationships between the B-vitamins in B12-deficiency neuromyelopathy. A possible malabsorption-malnutrition syndrome. 124 17

We reviewed 153 episodes of cobalamin deficiency involving the nervous system that occurred in 143 patients seen over a recent 17-year period at 2 New York City hospitals. Pernicious anemia was the most common underlying cause of the deficiency. Neurologic complaints, most commonly paresthesias or ataxia, were the first symptoms of Cbl deficiency in most episodes. The median duration of symptoms before diagnosis and treatment with vitamin B12 was 4 months, although long delays in diagnosis occurred in some patients. Diminished vibratory sensation and proprioception in the lower extremities were the most common objective findings. A wide variety of neurologic symptoms and signs were encountered, however, including ataxia, loss of cutaneous sensation, muscle weakness, diminished or hyperactive reflexes, spasticity, urinary or fecal incontinence, orthostatic hypotension, loss of vision, dementia, psychoses, and disturbances of mood. Multiple neurologic syndromes were often seen in a single patient. In 42 (27.4%) of the 153 episodes, the hematocrit was normal, and in 31 (23.0%), the mean corpuscular volume was normal. Neutropenia and thrombocytopenia were unusual even in anemic patients. In nonanemic patients in whom diagnosis was delayed, neurologic progression frequently occurred although the hematocrit remained normal. In 27 episodes, the serum cobalamin concentration was only moderately decreased (in the range of 100-200 pg/ml) and in 2 the serum level was normal. Neurologic impairment, as assessed by a quantitative severity score, was judged to be mild in 99 episodes, moderate in 39 and severe in 15. Severity of neurologic dysfunction before treatment was clearly related to the duration of symptoms prior to diagnosis. In addition, the hematocrit correlated significantly with severity, independent of the longer duration of symptoms in nonanemic patients. Four patients experienced transient neurologic exacerbations soon after beginning treatment with cyanocobalamin, with subsequent recovery. Followup evaluation was adequate to assess the neurologic response to vitamin B12 therapy in 121 episodes. All patients responded, and in 57 (47.1%), recovery was complete, with no remaining symptoms or findings on examination. The severity score was reduced by 50% or greater after treatment in 91% of the episodes. Residual long-term moderate or severe neurologic disability was noted following only 7 (6.3%) episodes. The extent of neurologic involvement after treatment was strongly related to that before therapy as well as to the duration of symptoms. The percent improvement over baseline neurologic status after treatment was inversely related to duration of symptoms and hematocrit. Some evidence of response was always seen during the first 3 months of treatment.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Neurologic aspects of cobalamin deficiency. 164 56

Detailed electrophysiological studies were performed in 4 patients with myeloneuropathy induced by abuse of nitrous oxide for 1 to 4 years. All presented with paresthesias, weakness, and Lhermitte's phenomena, and exhibited signs of sensorimotor polyneuropathy, ataxia, and arreflexia. Two had subnormal serum vitamin B12 levels. Baseline electrophysiologic testing revealed reduced motor unit potentials, prolonged F wave latencies, absent H reflexes, denervation potentials, and delays in motor and sensory conduction. Three had peripheral and nuchal delay after median nerve stimulation. All were reevaluated after 3 to 12 months' abstinence and treatment with vitamin B12, and all showed substantial clinical improvement. Parallel improvement in electrophysiologic findings occurred, but residual minor conduction delays, loss of H reflexes, electromyographic evidence of denervation, or abnormalities of posterior tibial SEP were noted. These findings confirm the reversibility of myeloneuropathy of nitrous oxide abuse and describe the profile of electrophysiologic recovery in subjects who abstain from further neurotoxic exposure.
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PMID:Reversible myeloneuropathy of nitrous oxide abuse: serial electrophysiological studies. 199 94

We present a 9-month-old exclusively breast-fed baby of a strict vegetarian mother who had excluded all animal proteins from her diet. The patient's symptoms included dystrophy, weakness, muscular atrophy, loss of tendon reflexes, psychomotor regression and haematological abnormalities. Biochemical investigations revealed severe methylmalonic aciduria and homocystinuria in the patient, slight methylmalonic aciduria in the mother and low concentrations of serum vitamin B12 in both patient and mother.
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PMID:Maternal vegan diet causing a serious infantile neurological disorder due to vitamin B12 deficiency. 204 94

Coenzyme B12 serves as a cofactor in various enzymatic reactions in which a hydrogen atom is interchanged with a substituent on an adjacent carbon atom. Measurement of the dissociation energy of the coenzyme's cobalt-carbon bond and studies of the rearrangement of model free radicals related to those derived from methylmalonyl-coenzyme A suggest that these enzymatic reactions occur through homolytic dissociation of the coenzyme's cobalt-carbon bond, abstraction of a hydrogen atom from the substrate by the coenzyme-derived 5'-deoxyadenosyl radical, and rearrangement of the resulting substrate radical. The only role thus far identified for coenzyme B12 in these reactions--namely, that of a free radical precursor--reflects the weakness, and facile dissociation, of the cobalt-carbon bond.
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PMID:Mechanisms of coenzyme B12-dependent rearrangements. 285 3

Selenium levels were low in four children receiving long-term total parenteral nutrition (TPN) who developed erythrocyte macrocytosis (3/4), loss of pigmentation of hair and skin (2/4), elevated transaminase and creatine kinase activities (2/4), and profound muscle weakness (1/4). Initial mean selenium levels in serum and hair were 38 +/- 11 (SEM) ng/mL and 0.34 +/- 0.13 micrograms/g, respectively. Mean serum vitamin B12, folate, and vitamin E levels were normal. Intravenous supplementation with selenium was begun daily at 2 micrograms/kg/day. After 3 to 6 months, serum selenium levels rose almost threefold to 81 +/- 22 ng/mL. During this same time, erythrocyte mean corpuscular volume fell from 115 +/- 8 fL to 88 +/- 7 fL in the three children with macrocytosis. After 6 to 12 months of supplementation, hair selenium content had increased threefold to 1.02 +/- 0.19 micrograms/g. The two children with decreased pigmentation became darker skinned and their hair color changed from blonde to dark brown; a third child's hair, which had been blonde, also became darker. Transaminase and creatine kinase activities returned to near normal in those affected and, in the one child with severe myopathy, muscle weakness improved. Erythrocyte macrocytosis and loss of skin and hair pigmentation are previously undescribed manifestations of selenium deficiency. We recommend routine supplementation of TPN solution with selenium to avoid the clinical and biochemical syndrome of selenium deficiency in patients receiving long-term TPN.
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PMID:Macrocytosis and pseudoalbinism: manifestations of selenium deficiency. 311 96

Among 37 patients who underwent total gastrectomy for nonmalignant disease, operative mortality was 4 per cent after 27 elective operations and 10 per cent after 10 emergency operations. Three other patients died 1 to 6 months after operation. Major postoperative complications occurred in 24 per cent. Long-term follow-up of 26 patients (81 per cent of survivors) after a mean +/- SEM of 8.4 +/- 1.1 years showed that 73 per cent of patients had no or only occasional, easily controlled, mild abdominal symptoms and good enough health to enable them to work or carry out normal activities for their age. The patients lost a mean of 15 per cent of their body weight, however, and about one third of them had weakness and diarrhea. A quarter of them had anemia despite iron and vitamin B12 therapy. Our conclusion was that total gastrectomy is a reasonable operation for benign diseases. Nonetheless, in view of the substantial postoperative mortality and morbidity, the operation should be used only when less extensive operations will not suffice.
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PMID:Total gastrectomy for benign disease. 358 2

The preleukemic syndrome occurs mainly after middle age. We report 11 patients, aged 62 to 92 years, who presented with weakness, fatigue, malaise and pallor. Eight patients died; survival from the time of diagnosis was between 2 and 21 months. Two of them developed acute myelomonocytic leukemia. A third patient developed Philadelphia chromosome-negative chronic myeloid leukemia within 9 months. Serum unsaturated B12 binding capacity and transcobalamin I were elevated in this patient, preceding the transformation to chronic myeloid leukemia. Five other patients died from sepsis or pneumonia. All patients were anemic, and 10 were leukopenic. Bone marrow was hypocellular in 1 and hypercellular in 10 cases. Chromosomal studies were performed in five patients, with three showing abnormal findings: 47xx, trisomy 8 and a tetraploid karyotype 92xxyy5q-. No cytotoxic treatment should be given during the preleukemic phase until transformation to acute leukemia occurs. Since preleukemic patients are very susceptible to infections, early diagnosis of the condition is important, as is supportive care in the case of surgery.
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PMID:Preleukemic syndrome in elderly patients--report of 11 cases. 385 73


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