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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Profound hypothermia (core temperature of less than 28 degrees C) is a life threatening state and a medical emergency associated with a high mortality rate. The prognosis depends on underlying diseases, advanced or very early age, the duration prior to treatment, the degree of hemodynamic deterioration, and especially, the methods of treatment, including active external or internal rewarming. This is a case study of an 80-year-old female patient with severe accidental hypothermia (core temperature 27 degrees C). She was found in her home lying immobile on the cold floor after a fall. The patient was in a profound coma with cardiocirculatory collapse, and the medical staff treating her was inclined to pronounce her deceased. On her arrival at the hospital, she was resuscitated, put on a respirator and actively warmed. Very severe metabolic disorders were found, including a marked metabolic acidosis composed of diabetic ketoacidosis (she had suffered from insulin treated type 2 diabetes mellitus) and lactic acidosis with a very high anion gap (42) and a hyperosmotic state (blood glucose 1202 mg/dl). There were pathognomonic electrocardiographic abnormalities, J-wave of Osborn and prolonged repolarization. Slow atrial fibrillation with a ventricular response of 30 bpm followed by a nodal rhythm of 12 bpm and reversible cardiac arrest were recorded. The pulse and blood pressure were unobtainable. Despite the successful resuscitation and hemodynamic and cognitive improvement, rhabdomyolysis (CKP 6580 u/L), renal failure and hepatic damage developed. She was extubated and treated with intravenous fluids containing dopamine, bicarbonate, insulin and antibiotics. Her medical condition gradually improved, and she was discharged clear minded, functioning very well and independent. Renal and liver tests returned eventually to normal limits. Progressive bradycardia, hypotension and death due to ventricular fibrillation or asystole commonly occur during severe hypothermia. Respiratory and metabolic, sometimes lactic, acidosis, lethargy and coma, hypercoagulopathy, hyperosmolar state, acute pancreatitis and renal and hepatic failure are frequent complications of hypothermia. Underlying predisposing causes of hypothermia are diabetic ketoacidosis, cerebrovascular disease, mental retardation, hypothyroidism, pituitary and adrenal insufficiency, malnutrition, acute alcoholism, liver damage, hypoglycemia, sepsis, hypothalamic dysfunction, sepsis and polypharmacy, and especially, the use of sedative and narcotic drugs. Our case demonstrates once again that CPR once begun should continue until the successful rewarming because "no one is dead until warm and dead".
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PMID:[Severe accidental hypothermia in an elderly woman]. 1175 73

Mitochondrial ornithine transporter deficiency, or HHH syndrome, is a metabolic disorder resulting in various neurologic symptoms, including mental retardation, spastic paraparesis with pyramidal signs, cerebellar ataxia, and episodic disturbance of consciousness or coma caused by hyperammonemia. Several mutations have been reported in the ORNT1 gene encoding mitochondrial ornithine transporter of patients with this disorder. In this article, we report a new patient, a male 15 years of age, who had typical clinical features of HHH syndrome. Because the patient did not have any of the three mutations previously described in other Japanese patients with HHH syndrome, and the only material available from the patient was peripheral leukocytes, we established a genomic polymerase chain reaction method using intronic primers to amplify every exon of the ORNT1 gene, and we directly sequenced the polymerase chain reaction products. Using this method, we documented a novel mutation in this patient, P126R, and demonstrated that HHH syndrome is genetically heterogeneous, even in the Japanese population.
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PMID:A novel mutation, P126R, in a Japanese patient with HHH syndrome. 1181 39

Propionic acidemia is an inherited neurometabolic disorder characterized by progressive neurological deterioration with psychomotor delay/mental retardation, convulsions and coma, and whose pathophysiology is poorly unknown. In the present study, we investigated the effect of chronic administration (from the 5th to the 28th days of life) of propionic acid (PA), the major metabolite accumulating in tissues of patients affected by propionic acidemia, on the cognitive performance of adult rats in the Morris water maze task. PA doses ranged from 1.44 to 1.92 micromol/g body weight as a function of animal age. Control rats were treated with saline in the same volumes. Chronic postnatal days (5-28) PA treatment had no effect on body weight. However, it impaired spatial performance in the water maze. We also determined the effect of ascorbic acid (AA) administered, alone or combined with PA, on the same behavioral parameters in order to test whether free radicals could be responsible for the behavioral alterations observed in PA-treated animals. AA was able to prevent the behavioral alterations provoked by PA, implying that oxidative stress may be involved in these effects. Furthermore, we also investigated the total radical-trapping antioxidant potential (TRAP) in the hippocampus of the animals. We observed that TRAP was significantly reduced in the brain of propionic acidemic rats and that co-administration of AA prevented this effect. The results provide evidence that early PA treatment induces long-lasting behavioral deficits, which are possibly caused by oxygen reactive species generation, and suggest that oxidative stress may be involved in the neuropathology of propionic acidemia.
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PMID:Ascorbic acid prevents cognitive deficits caused by chronic administration of propionic acid to rats in the water maze. 1215 Oct 37

Maple syrup urine disease (MSUD) is an inherited disorder caused by deficiency of branched-chain L-2-keto acid dehydrogenase complex activity. Affected patients present severe brain dysfunction manifested as convulsions, coma, psychomotor delay and mental retardation. However, the underlying mechanisms of these neurological findings are virtually unknown. In this study, we tested the in vitro effect of L-leucine, L-isoleucine and L-valine, the amino acids accumulating in MSUD, on the lipid peroxidation parameters chemiluminescence and thiobarbituric acid-reactive substances (TBA-RS), as well as on total radical-trapping antioxidant potential (TRAP) and total antioxidant reactivity (TAR) in cerebral cortex from 30-day-old rats. L-Leucine significantly increased chemiluminescence and TBA-RS measurements and markedly decreased TRAP and TAR values. L-Isoleucine increased chemiluminescence and decreased TRAP measurements, but TAR and TBA-RS levels were not altered by the amino acid. Finally, TRAP measurement was diminished by L-valine. The results indicate a stimulation of lipid peroxidation and a reduction of brain capacity to efficiently modulate the damage associated with an increased production of free radicals by the branched-chain amino acids (BCAAs) accumulated in MSUD. It is therefore tempting to speculate that oxidative stress may be implicated in the brain damage found in MSUD patients.
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PMID:Induction of oxidative stress in rat brain by the metabolites accumulating in maple syrup urine disease. 1292 81

Lead poisoning affects an estimated 890,000 young children in the United States annually (American Academy of Pediatrics [AAP], 1998). Extremely high levels in the child can cause mental retardation, coma, seizures, and death. Chronic low level exposure is more commonly seen with multiple effects, including learning disabilities, impaired growth, and hearing loss. Lead poisoning prevention efforts have significantly reduced the number of children affected by this serious health hazard. Health care providers need to continue their vigilant efforts to educate families living in older homes about the risks, screening, and treatment.
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PMID:Lead poisoning: a summary of treatment and prevention. 1296 48

In presenting the neuropathology of asphyxia neonatorum and some related conditions, as illustrated in experiments with monkeys (12), I have tried to make six principal points. (i) Newborn monkeys need not be asphyxiated to the point of terminal apnea to suffer structural brain damage. Mental retardation has not been proved, but neither has it been excluded, in these monkeys. (ii) Asphyxia neonatorum requiring resuscitation of the offspring, which otherwise would die, is associated with a remarkably constant syndrome of bilaterally symmetrical, nonhemorrhagic lesions in thalamic and brain-stem nuclei, mainly those of afferent systems. The individuals in this category clearly are retarded. (iii) Asphyxia neonatorum of this second degree may be associated with postpartum complications leading to neocortical atrophy, often of considerable magnitude. The individuals are markedly retarded, often palsied, epileptic, and in a few instances even comatose. (iv) Increased intrauterine pressure in the monkey during prolonged labor leads to fetal and postpartum depression, in connection with which cerebral cortical injury occurs in the absence of typical asphyxial lesions. (v) The relationship of cerebral hemorrhages to mental retardation is not clear, but their presence at autopsy probably signifies trauma during birth, or is an agonal artifact associated with death after postpartum depression. (vi) Finally, kernicterus, a condition in which bile pigment escapes into the brain tissues from the blood when the bilirubin level is high and when there is, in combination with it, some depressing factor such as asphyxia, has been produced in the newborn monkey. It, too, is associated with mental retardation.
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PMID:Neuropathology of certain forms of mental retardation. 1400 Nov 40

An abnormally expanded CAG repeats (25, normal; 4-20) was identified in the alpha 1A voltage-dependent calcium channel (CACNA1A) gene of a 50-year-old Japanese man with 25 years history of schizophrenia. At age 45, he first noted unsteadiness of standing and gait, which gradually worsened subsequently. In addition to the psychiatric symptoms of schizophrenia, neurological examination revealed marked truncal ataxia and mild limb ataxia. Brain magnetic resonance imaging showed atrophy of the cerebellar vermis. Gene analysis confirmed the diagnosis of spinocerebellar ataxia type 6 (SCA 6). No family members showed similar neuropsychiatric symptoms except that the patient's father had been suffering from an unknown dementing disease. Occurrence of both schizophrenia and SCA 6 in the identical patient may be coincidental. However, growing evidence has shown that various mutations in the CACNA1A gene are associated with phenotypic variability, such as progressive ataxia, episodic ataxia, migraine, coma, epilepsy and mental retardation. Therefore, the schizophrenic symptoms, association of which with SCA 6 has previously reported in a few cases, may represent rare clinical features of the channelopathy associated with the mutation in the CACNA1A gene.
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PMID:[A case of spinocerebellar ataxia 6 accompanied with schizophrenia]. 1502 29

A1A2 Na+/K+-ATPase mutations cause familial hemiplegic migraine type 2 (FHM2). The authors identified three putative A1A2 mutations (D718N, R763H, P979L) and three that await validation (P796R, E902K, X1021R). Ten to 20% of FHM cases may be FHM2. A1A2 mutations have a penetrance of about 87%. D718N causes frequent, long-lasting HM, and P979L may cause recurrent coma. D718N and P979L may predispose to seizures and mental retardation. A1A2 does not play a major role in sporadic HM; only one variant, R383H, occurred in 1 of 24 cases.
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PMID:Variability of familial hemiplegic migraine with novel A1A2 Na+/K+-ATPase variants. 1515 95

Maple syrup urine disease (MSUD) or branched-chain alpha-keto aciduria (BCKA) is an inherited disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKAD) activity. The blockage of this pathway leads to tissue accumulation of the branched-chain amino acids (BCAA) leucine, isoleucine and valine and their respective keto-acids. The clinical features presented by MSUD patients include ketoacidosis, convulsions, coma, psychomotor delay and mental retardation. The mechanism of brain damage in this disease is still poorly understood. However, an increase in lipid peroxidation in vitro in cerebral cortex of young rats as well as a decrease in the antioxidant defenses has been previously observed. In the present work we evaluated different oxidative stress parameters, named reactive species of thiobarbituric acid (TBARS), total antioxidant reactivity (TAR) and total antioxidant status (TAS) in plasma of MSUD patients in order to evaluate whether oxidative stress is involved in this disorder. We verified a marked increase of plasma TBARS measurements, which is indicative of increased lipid peroxidation, as well as a decrease on plasma TAR reflecting a deficient capacity to efficiently modulate the damage associated with an increased production of reactive species. In contrast, TAS was not changed indicating that the total content of antioxidants in plasma of patients affected by MSUD was not altered. These results suggest that free radical generation is elicited in MSUD and is possibly involved in the pathophysiology of the tissue damage found in this disorder.
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PMID:Evidence that oxidative stress is increased in plasma from patients with maple syrup urine disease. 1709

Thyroid hormones are of primary importance for the perinatal development of the central nervous system, and for normal function of the adult brain. These hormones primarily regulate the transcription of specific target genes. They increase the cortical serotonergic neurotransmission, and play an important role in regulating central noradrenergic and GABA function. Thyroid deficiency during the perinatal period results in mental retardation. Hypothyroidism of the adults causes most frequently dementia and depression. Other less common clinical pictures include myxoedema coma, dysfunction of cerebellum and cranial nerves. Hypothyroidism also increases predisposition of stroke. Peripheral diseases frequently include polyneuropathy, carpal tunnel syndrome, myalgic state, and rarely myokymia. Nearly all the hyperthyroid patients show minor psychiatric signs, and infrequently psychosis, dementia, confusion state, depression, apathetic thyrotoxicosis, thyrotoxic crisis, seizures, pyramidal signs, or chorea occur. The peripheral complications may be indicated by chronic thyrotoxic myopathy, infiltrative ophthalmopathy, myasthenia gravis, periodic hypokalemic paralysis and polyneuropathy. Generalized resistance to thyroid hormone was confirmed in a number of patients with attention deficit-hyperactivity disorder. Significantly elevated antithyroid antibody titers characterize Hashimoto's encephalopathy. This condition is a rare, acute - subacute, serious, life threatening, but steroid-responsive, relapsing-remitting, autoimmune disease.
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PMID:[Some neurologic and psychiatric complications in endocrine disorders: the thyroid gland]. 1734 50


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