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1.
Although hyperthyroidism arising from primary thyroid disease is rare in pregnancy, transient gestational hyperthyroidism is not uncommon. This condition can be associated with hyperemesis gravidarum (HG), and Wernicke's encephalopathy. We present the case of a woman with toxic nodular goiter complicating HG-associated Wernicke's encephalopathy. A 38-year-old Caucasian woman, who had received a diagnosis of hyperthyroidism and HG early in her pregnancy, had intrauterine fetal death at Week 16 of gestation. One day after undergoing therapeutic abortion, she was admitted to our clinic with persistent thyrotoxicosis, nausea, and vomiting. A toxic thyroid nodule was detected. She was given antithyroid medication, total parenteral nutrition. On Day 10 of hospitalization, she developed ataxia, aphasia, and somnolence. Cranial magnetic resonance imaging showed increased bilateral thalamic signalization. She was given a diagnosis of Wernicke's metabolic encephalopathy, for which she received thiamine and multivitamin preparations. She responded dramatically on the second day of thiamine therapy. Her consciousness improved rapidly and she began to speak. Her muscle tone was slightly weak and she had paresthesias in both legs. Absorption of thiamine may be particularly impaired in pregnant women with hyperemesis and hyperthyroid disease. Wernicke's encephalopathy should be considered in hyperthyroid women with HG who develop neurological abnormalities.  相似文献   

2.
Pyrithiamine-induced thiamine-deficiency encephalopathy in the rat shows many neuropathological and biochemical similarities to Wernicke's encephalopathy in humans. Treatment of rats with pyrithiamine resulted in moderate reductions of glutamate in thalamus and pons and in generalized severe reductions of aspartate in pons (by 89%, p less than 0.01), thalamus (by 83%, p less than 0.01), cerebellum (by 53%, p less than 0.01), and cerebral cortex (by 33%, p less than 0.05). Alanine concentrations were concomitantly increased. Activities of the thiamine-dependent enzyme alpha-ketoglutarate dehydrogenase (alpha KGDH) were decreased in parallel with the aspartate decreases; pyruvate dehydrogenase complex activities were unchanged in all brain regions. Following thiamine administration to symptomatic pyrithiamine-treated rats, neurological symptoms were reversed and concentrations of glutamate, aspartate, and alanine, as well as alpha KGDH activities, were restored to normal in cerebral cortex and pons. Aspartate levels and alpha KGDH activities remained below normal values, however, in thalamus. Thus, pyrithiamine treatment leads to reductions of cerebral alpha KGDH and (1) decreased glucose (pyruvate) oxidation resulting in accumulation of alanine and (2) decreased brain content of glutamate and aspartate. Such changes may be of key significance in the pathophysiology of the reversible and irreversible signs of Wernicke's encephalopathy in humans.  相似文献   

3.
Abstract: Culture of neuroblastoma cells in a medium of low-thiamine concentration (6 n M ) and in the presence of the transport inhibitor amprolium leads to the appearance of overt signs of necrosis; i.e., the chromatin condenses in dark patches, the oxygen consumption decreases, mitochondria are uncoupled, and their cristae are disorganized. Glutamate formed from glutamine is no longer oxidized and accumulates, suggesting that the thiamine diphosphate-dependent α-ketoglutarate dehydrogenase activity is impaired. When thiamine (10 µ M ) is added to the cells, the O2 consumption increases, respiratory control is restored, and normal cell and mitochondrial morphology is recovered within 1 h. Succinate, which is oxidized via the thiamine diphosphate-independent succinate dehydrogenase, is also able to restore a normal O2 consumption (with respiratory control) in digitonin-permeabilized thiamine-deficient cells. Our results therefore suggest that the slowing of the citric acid cycle is the main cause of the biochemical lesion induced by thiamine deficiency as observed in Wernicke's encephalopathy.  相似文献   

4.
The encephalopathy caused by severe thiamine depletion of the mammalian CNS is accompanied by regionally selective changes in neurotransmitter function. Thiamine deficiency induced by administration of the central thiamine antagonist, pyrithiamine, causes more widespread lesions and accompanying changes in neurotransmitter function than does the deficiency state induced by chronic deprivation of the vitamin. There is convincing evidence for a central muscarinic cholinergic lesion in pyrithiamine-treated rats and neuropharmacological studies show that this lesion is partially responsible for the neurological deficit resulting from this treatment. There is also good evidence to suggest that thiamine deprivation selectively affects cerebellar afferent and efferent systems. Included in these are a loss of serotoninergic mossy fibres and of the functional integrity of glutamatergic granule cells. In addition, abnormalities of both nerve terminals and glial cells are found in lateral vestibular nucleus and it has been proposed that a loss of Purkinje cell terminals and concomitant decreases of pontine GABA may reflect these changes. The selective vulnerability of brain structures to thiamine deprivation is reflected in (i) the turnover rate of total thiamine in these areas and (ii) the selective decreases in activity of the thiamine pyrophosphate dependent enzyme pyruvate dehydrogenase.  相似文献   

5.
Treatment of rats with the central thiamine antagonist, pyrithiamine, results in severe neurological symptoms such as loss of righting reflex. Measurement of gamma-aminobutyric acid (GABA) content of brain tissue from symptomatic pyrithiamine-treated (PT) rats revealed significant reductions in thalamus, cerebellum, and pons. GABA content of cerebral cortex, however, was unaltered. Activities of the thiamine-dependent enzyme alpha-ketoglutarate dehydrogenase (alpha KGDH) were reduced in parallel with the GABA changes. On the other hand, activities of the GABA-synthetic enzyme glutamic acid decarboxylase (GAD) remained within normal limits, with the exception of a small but significant decrease in thalamus of symptomatic PT rats. Affinities and densities of high-affinity [3H]muscimol binding sites on crude cerebral membrane preparations from symptomatic PT rats were unchanged. Thiamine administration to symptomatic animals resulted in correction of abnormal righting reflexes and in normalization of decreased GABA levels and reduced alpha KGDH activities in cerebellum and pons. Thalamic GABA levels and alpha KGDH activities, on the other hand, remained significantly lower than normal. These results suggest that the reversible symptoms of pyrithiamine treatment may result from imparied GABA synthesis in cerebellum and pons of these animals. Similar mechanisms may play a role in the pathogenesis of the reversible symptoms of Wernicke's encephalopathy in man.  相似文献   

6.
Wernicke's encephalopathy is a cerebral disorder caused by thiamine (vitamin B1) deficiency (TD). Neuropathologic consequences of TD include region-selective neuronal cell loss and blood-brain barrier (BBB) breakdown. Early increased expression of the endothelial isoform of nitric oxide synthase (eNOS) occurs selectively in vulnerable brain regions in TD. We hypothesize that region-selective eNOS induction in TD leads to altered expression of tight junction proteins and BBB breakdown. In order to address this issue, TD was induced in C57BL/6 wild-type (WT) and eNOS−/− mice by feeding a thiamine-deficient diet and treatment with the thiamine antagonist pyrithiamine. Pair-fed control mice were fed the same diet with additional thiamine. In medial thalamus of TD-WT mice (vulnerable area), increased heme oxygenase-1 and S -nitrosocysteine immunostaining was observed in vessel walls, compared to pair-fed control-WT mice. Concomitant increases in IgG extravasation, decreases in expression of the tight junction proteins occludin, zona occludens-1 and zona occludens-2, and up-regulation of matrix metalloproteinase-9 in endothelial cells were observed in the medial thalamus of TD-WT mice. eNOS gene deletion restored these BBB alterations, suggesting that eNOS-derived nitric oxide is a major factor leading to cerebrovascular alterations in TD. However, eNOS gene deletion only partially attenuated TD-related neuronal cell loss, suggesting the presence of mechanisms additional to BBB disruption in the pathogenesis of these changes.  相似文献   

7.
Downregulation of astrocytic glutamate transporters is a feature of thiamine deficiency (TD), the underlying cause of Wernicke's encephalopathy, and plays a major role in its pathophysiology. Recent investigations suggest that ceftriaxone, a β-lactam antibiotic, stimulates GLT-1 expression and confers neuroprotection against ischemic and motor neuron degeneration. Thus, ceftriaxone treatment may be a protective strategy against excitotoxic conditions. In the present study, we examined the effects of ceftriaxone on the glutamate transporter splice-variant GLT-1b in rats with TD and in cultured astrocytes under TD conditions. Our results indicate that ceftriaxone protects against loss of GLT-1b levels in the inferior colliculus during TD, but with no significant effect in the thalamus and frontal cortex by immunoblotting and immunohistochemistry. Ceftriaxone also normalized the loss of GLT-1b in astrocyte cultures under conditions of TD. These results suggest that ceftriaxone has the ability to increase GLT-1b levels in astrocytes during TD, and may be an important pharmacological strategy for the treatment of excitotoxicity in this disorder.  相似文献   

8.
Chronic thiamine deprivation in the rat leads to selective neuropathological damage to pontine structures. Onset of neurological symptoms of thiamine deprivation (ataxia, loss of righting reflex) was accompanied by selective decreases (of the order of 30%) in the activity of -ketoglutarate dehydrogenase (KGDH) in lateral vestibular nucleus and hypothalamus. Enzyme activities were decreased to a lesser extent in medulla oblongata, striatum and hippocampus and were unchanged in other brain structures. No changes in KGDH occurred prior to the onset of neurological signs of thiamine deprivation. Administration of the central thiamine antagonist, pyrithiamine, results within 3 weeks in loss of righting reflex and convulsions and in more widespread neuropathological changes than those observed following thiamine deprivation. KGDH activities were found to be substantially diminished in all brain regions studied following pyrithiamine treatment with most severe changes occurring in brain regions found to be vulnerable to pyrithiamine (lateral vestibular nucleus, hypothalamus, midbrain, medullapons). In some cases, KGDH changes preceded the appearance of neurological symptoms of pyrithiamine treatment. Such decreases in KGDH may explain previous findings of region-selective changes in energy metabolism and of decreased synthesis of glucose-derived neurotransmitters (acetylcholine, GABA, glutamate) in pyrithiamine-treated rat brain. Thiamine administration to symptomatic pyrithiamine treated rats resulted in reversal of neurological signs of encephalopathy and in normalisation of defective KGDH activity in all brain regions. These findings suggest that the reversible neurological symptoms associated with Wernicke's Encephalopathy in man likely result from region-selective impairment of KGDH.  相似文献   

9.
Thiamine phosphate esters (thiamine monophosphate-TMP; thiamine diphosphate-TDP and thiamine triphosphate-TTP) were measured as their thiochrome derivatives by High Performance Liquid Chromatography in the brains of pyrithiamine-treated rats at various stages during the development of thiamine deficiency encephalopathy. Severe encephalopathy was accompanied by significant reductions of all three thiamine phosphate esters in brain. Neurological symptoms of thiamine deficiency appeared when brain levels of TMP and TDP fell below 15% of normal values. Activities of the TDP-dependent enzyme -ketoglutarate dehydrogenase were more severely reduced in thalamus compared to cerebral cortex, a less vulnerable brain structure. On the other hand, reductions of TTP, the non-cofactor form of thiamine, occurred to a greater extent in cerebral cortex than thalamus. Early reductions of TDP-dependent enzymes and the ensuing metabolic pertubations such as lactic acidosis impaired brain energy metabolism, and NMDA-receptor mediated excitotoxicity offer rational explanations for the selective vulnerability of brain structures such as thalamus to the deleterious effects of thiamine deficiency.  相似文献   

10.
《Endocrine practice》2014,20(12):e237-e240
ObjectiveTo present a case of gestational thyrotoxicosis and hyperemesis gravidarum associated with Wernicke’s encephalopathy.MethodsWe present a detailed case report with the clinical, imaging, and laboratory findings of the patient and review the pertinent literature.ResultsA 36-year-old woman at 14 weeks of gestation was admitted to the hospital for management of severe hyperemesis gravidarum (HG). While hospitalized, she developed low-grade fever, tachycardia, hypotension, and altered mentation. Laboratory tests were diagnostic of hyperthyroidism. Physical examination revealed a confused, lethargic woman with a normal-size thyroid and pendular nystagmus in primary and lateral gaze. She was treated empirically for thyroid storm with methimazole and other measures. A brain magnetic resonance imaging (MRI) study done later showed hyperintense abnormal signals in bilateral thalamic regions, consistent with Wernicke’s encephalopathy (WE). She was immediately started on intravenous thiamine and her mental status improved considerably within 3 to 4 days. Within 2 weeks, the patient’s thyroid-function tests normalized and methimazole was discontinued. A repeat brain MRI 6 months later showed marked reduction of signal intensity in both thalamic regions.ConclusionThis case demonstrates that gestational thyrotoxicosis in a patient with HG can precipitate acute WE, which may mimic thyroid storm and thus delay appropriate management of this neurologic disorder. We conclude that prophylactic thiamine administration may be considered before caloric replacement in patients who present with HG and acute neurologic dysfunction. (Endocr Pract. 2014;20:e237-e240)  相似文献   

11.
Chronic thiamine deprivation in the rat leads to ataxia, loss of righting reflex and neuropathological damage to lateral vestibular nucleus. Before onset of neurological symptoms, transketolase (TK) activities were found to be selectively reduced by 25% in lateral vestibular nucleus and surrounding pons. Further progression of thiamine deprivation resulted in a generalized reduction in TK activity. Measurement of enzyme activity in the presence of added TPP cofactor in vitro did not lead to normalisation of enzyme activities suggesting loss of apoenzyme. Administration of thiamine to symptomatic thiamine-deprived rats resulted in reversal of neurological symptoms and to normalisation of defective TK activities in less vulnerable structures such as cerebral cortex striatum and hippocampus; reduction of TK activity, however, persisted in brainstem and cerebellar regions. Pyrithiamine treatment results, within 3 weeks, in loss of righting reflex, convulsions and more widespread neuropathological damage compared to that observed following thiamine deprivation. TK activity was found to be significantly decreased before the onset of neurological symptoms in all brain regions and appearance of symptoms was accompanied by more severe reductions of TK. In contrast to chronic thiamine deprivation, TK activities following pyrithiamine treatment were: (i) equally reduced in magnitude in vulnerable and non-vulnerable brain structures, (ii) unchanged following reversal of neurological abnormalities by thiamine administration.  相似文献   

12.
Supersensitivity of GABA-A receptors in hepatic encephalopathy   总被引:2,自引:0,他引:2  
During the past decade a new approach to pathogenetic, studies of hepatic encephalopathy has been undertaken to identify the neurochemical alterations which characterize the syndrome. Using animal models of hepatic encephalopathy electrophysiological, behavioral, pharmacological and biochem evidence were provided of an increased functional activity of the GABA-A receptors, including the Benzodiazepine site. These demonstrations seem to explain the increased sensitivity of patients with acute or chronic liver disease to sedative administration. The described increased tone of the GABAergic receptor complex seems to play a key role in the generalized depression of the central nervous system which characterizes hepatic encephalopathy, but other factors seem to contribute to the neuronal derangement present in this syndrome leading to an imbalance between inhibitory and excitatory receptor systems in the brain. Based on these findings a new symptomatic treatment with antibenzodazepine compounds which seem temporarely to counteract the symptoms of hepatic encephalopathy, was introduced.  相似文献   

13.
Pellagra.     
Pellagra due to malnutrition occurred in an Ottawa women in 1973. She was given a normal diet with supplements of riboflavin, thiamine, niacin and ascorbic acid. The clinical response was striking. Although pellagra is still common in some parts of the world, it is now rare in North America. The disease may occur secondary to malnutrition or malabsorption; inborn errors of metabolism or transport, as in Hartnup disease; deviation of precursors of niacin, as in carcinoid syndrome; or competitive inhibition of niacin incorporation into nicotinamide-adenine dinucleotide, as with administration of isoniazid.  相似文献   

14.
目的:探讨引起慢性阻塞性肺疾病合并精神神经异常的原因,以制订有针对性的治疗对策。方法:回顾性分析我院自2010 年1 月到2013 年1 月期间收治的250 例慢性阻塞性肺疾病急性发作期患者的临床资料。结果:32 例患者出现精神神经异常症 状,占12.80%。其中17 例为肺性脑病,占53.13%(17/32),8 例为低渗性脑病,占25.00%(8/32),5 例为药物的不良反应,占15.63% (5/32),2 例为脑梗死,占6.25%(2/32)。所有患者均给予慢性阻塞性肺疾病急性发作的常规治疗方案进行治疗,同时肺性脑病患 者给予积极纠正二氧化碳潴留;低渗性脑病患者给予积极纠正电解质紊乱;脑梗死的患者根据情况给予溶栓、脱水、营养脑神经、 抗凝、抗血小板聚集等治疗;药物不良反应的患者则给予停止应用相应的药物。经过治疗后,29 例症状恢复,占90.63%,3 例最终 死亡,死亡率为9.38%,其中2 例为肺性脑病患者,1 例为低渗性脑病患者。结论:对于慢性阻塞性肺疾病急性发作合并精神神经 异常的治疗,应根据患者的症状、体征以及辅助检查结果,尽早明确诊断,及时干预,尽快控制病情,防止病情恶化。  相似文献   

15.
Beriberi is a disease caused by thiamine deficiency (TD), which may lead to heart problems, including heart failure. Despite the fact that thiamine prevalence is reduced in the industrialized world, it remains a health hazard especially due to chronic alcohol consumption. Diagnosing the presence of TD based on both electrocardiogram and echocardiogram exams is particularly challenging because of its non-specific symptoms. TD diagnosis is unique, which then leads to determination of its severity. If thiamine infusion abrogates its symptomology, only then can the case be definitely diagnosed as TD. Another condition eliciting increased likelihood of developing TD in humans is furosemide administration to heart failure patients. Furosemide administration worsens heart failure due to heightened TD. However, literature data provided are contradictory and require clarification. Up until now, the rat has been the preferred TD animal model. However, the results are even more contradictory than those in humans. It seems that if the rat TD models are separated into two distinct groups, according to animal age, the results appear to be more consistent: younger rats are more prone to develop TD signs similar to those found in humans. Their symptoms stem from changes in cardiac myocyte function that are reversed after thiamine supplementation. However, it remains an open question as to why only younger rats are able to develop human-like symptoms and deserve further investigation.  相似文献   

16.
Emerging evidence suggests that thiamine deficiency (TD), the cause of Wernicke's encephalopathy, produces alterations in brain function and structural damage that closely model a number of maladies in which neurodegeneration is a characteristic feature, including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, multiple sclerosis, along with alcoholic brain disease, stroke, and traumatic brain injury. Impaired oxidative metabolism in TD due to decreased activity of thiamine-dependent enzymes leads to a multifactorial cascade of events in the brain that include focal decreases in energy status, oxidative stress, lactic acidosis, blood-brain barrier disruption, astrocyte dysfunction, glutamate-mediated excitotoxicity, amyloid deposition, decreased glucose utilization, immediate-early gene induction, and inflammation. This review describes our current understanding of the basis of these abnormal processes in TD, their interrelationships, and why this disorder can be useful for our understanding of how decreased cerebral energy metabolism can give rise to cell death in different neurodegenerative disease states.  相似文献   

17.
章敬玉  吴刚  宋花花  邓桂胜  罗勇 《生物磁学》2014,(13):2473-2475
目的:探讨引起慢性阻塞性肺疾病合并精神神经异常的原因,以制订有针对性的治疗对策。方法:回顾性分析我院自2010年1月到2013年1月期间收治的250例慢性阻塞性肺疾病急性发作期患者的临床资料。结果:32例患者出现精神神经异常症状,占12.80%。其中17例为肺性脑病,占53.13%(17/32),8例为低渗性脑病,占25.00%(8/32),5例为药物的不良反应,占15.63%(5/32),2例为脑梗死,占6.25%(2/32)。所有患者均给予慢性阻塞性肺疾病急性发作的常规治疗方案进行治疗,同时肺性脑病患者给予积极纠正二氧化碳潴留;低渗性脑病患者给予积极纠正电解质紊乱;脑梗死的患者根据情况给予溶栓、脱水、营养脑神经、抗凝、抗血小板聚集等治疗;药物不良反应的患者则给予停止应用相应的药物。经过治疗后,29例症状恢复,占90.63%,3例最终死亡,死亡率为9.38%,其中2例为肺性脑病患者,1例为低渗性脑病患者。结论:对于慢性阻塞性肺疾病急性发作合并精神神经异常的治疗,应根据患者的症状、体征以及辅助检查结果,尽早明确诊断,及时干预,尽快控制病情,防止病情恶化。  相似文献   

18.
The effects of various treatments, which affect membrane structure, on microsomal thiamine diphosphatase and thiamine triphosphatase activities of rat brain, were examined. The treatment of micorosomes at alkaline pH caused a 2-fold activation of the thiamine diphosphatase, this being related to a change in membrane structure which was evidenced by a decrease of the turbidity of the microsomal suspension. Repeated freezing and thawing after hypo-osmotic treatment also increased the activity of microsomal thiamine diphosphatase. In addition, the thiamine diphosphatase activity was enhanced by treatment of the microsomes with phospholipase C or acetone. This lipid depletion resulted in a marked reduction in the apparent Km value of the thiamine diphosphatase with a corresponding loss in heat stability of the enzyme. We found further that brain thiamine diphosphatase was solubilized by Triton X-100. This decreased the phospholipid content in the preparation, but did not affect the apparent Km value and heat stability of the enzyme. In contrast with thiamine diphosphatase, thiamine triphosphatase was inactivated by treatment at alkaline pH or with acetone. However, treatment with phospholipase C did not affect the activity of thiamine triphosphatase.  相似文献   

19.
Young male ferrets developed hyperammonemia and encephalopathy shortly after eating a diet lacking in arginine. The dietary supplementation of arginine or intraperitoneal injection of ornithine prevented hyperammonemia and shortened the duration of encephalopathy. Therefore, young ferrets were assumed to be unable to meet their ornithine needs from sources other than arginine. Adult ferrets did not develop hyperammonemia and encephalopathy after eating arginine-free diet. Because young ferrets are also susceptible to human influenza infections, they were further tested as animal model of Reye's syndrome. Reye's syndrome is a serious childhood disorder that develops following influenza infections and is characterized in part by an encephalopathy, hyperammonemia and elevated serum transaminases. In young ferrets, concurrent administration of aspirin with human influenza inoculation and an arginine-free diet produced symptoms similar to those seen in humans with Reye's syndrome. The ferret model appears to be useful for studying the roles of various etiologic agents and their interactions in producing Reye's syndrome-like disorders. The ammonia metabolism in ferrets is reviewed and the ferret model for Reye's syndrome and its applications for the better understanding of this disorder in humans are discussed.  相似文献   

20.
Lyme borreliosis is a multisystem disorder caused by Borrelia burgdorferi (Bb). Neurological symptoms such as lymphocytic meningoradiculoneuritis (Bannwart's syndrome), cranial neuritis (II,III,IV,V,VI), encephalitis, transverse myelitis are found in about 10% of cases during the second phase of the disease. In the chronic stage, many months or years after the initial infection, other neurologic complications may occur, such as encephalomyelitis, epileptic crises, cognitive impairment, peripheral neuropathy and psychiatric disturbances such as depression, anxiety, panicc attacks, catatonia, psychosis etc. Some patient continue to experience symptoms of fatigue, insomnia or psychiatric disorder in the post borrelia syndrome. We describe here a patient with a triad of unusual symptoms in chronic LNB including tremor, seizures and psychosis. Standardized medical interview, neurologic examination, neuroimaging, serum and CSF serology as well as EEG and EMNG evaluation were performed. The patient was treated with intravenous ceftriaxone and doxycycline and responded with rapid clinical and functional improvement.Newertheless, he suffered from multiple systemic and neurologic sequelas that influenced his daily activities in post treatment period. Emphasis is placed on the atypical onset and evolution, the difficulties encountered in formulating diagnosis, early treatment and the uncertainties concerning the sequelae after treatment. In patients with non-specific long lasting symptoms in the absence of overt clinical signs suggesting CNS involvement, routine treatment with i.v. ceftriaxone is not to be encouraged.  相似文献   

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