Wernicke脑病

<正>Wernicke脑病是维生素B1缺乏导致的代谢性脑病,1881年由Wernicke首先描述,1940年Campbell和Russell提出其诱因是维生素B1缺乏。该病系维生素B1缺乏致特定区域神经细胞能量代谢障碍所致,呈急性或亚急性起病,临床主要表现为眼外肌瘫痪、共济失调和意识障碍,最常见于慢性酒精中毒和妊娠性呕吐;非维生素B1缺乏性Wernicke脑病系转酮醇酶(TK)基因     

Wernicke's encephalopathy

Experimental Wernicke's encephalopathy, induced in rhesus monkeys with a diet lacking thiamine (vitamin B1), is characterized by cavitary necrosis of the striatum as well as a microvacuolar periventricular lesion of the brain stem such as occurs in man. With high resolution light microscopy and electron microscopy, the primary structural alteration in the brain stem lesion, and probably also in the striatum, appears to be that of widespread "blister" formation due to splitting of myelin at the intraperiod line. Microvascular alterations were minimal, even in the most severely affected regions. It is the myelin blisters which give rise to the spongy texture of the neuropil. A similar splitting of myelin has been described in several other experimental encephalopathies, and it is probable that it also occurs in Wernicke's encephalopathy in man.     

Hypothermia in Wernicke's encephalopathy

Two cases of Wernicke's encephalopathy with severe hypothermia as a major presenting sign are reported. The outcome was favorable with thiamine treatment. The clinical features, frequency, prognostic value and clinico-pathological correlations of hypothermia in this condition are reviewed.     

Wernicke's encephalopathy in infancy

Summary Wernicke's encephalopathy documented by characteristic involvement of the mammillary bodies developed in a premature infant during parenteral nutrition. This case illustrates the need for thiamine supplementation in seriously ill patients with inadequate intake of the vitamin.     

MRI in non-alcoholic Wernicke's encephalopathy

Wernicke's encephalopathy (WE) is a potentially reversible disorder. It is often not considered in non-alcoholic patients unless MRI demonstrates lesions in the appropriate sites. However, specific MRI sequences only highlight some areas of abnormality and hence WE may not be considered unless a more complete study is performed and this is highlighted in the case described herein. The neuropathological basis for the imaging findings is also discussed.     

Vestibular responses in Wernicke's encephalopathy

Two patients with Wernicke's encephalopathy were evaluated with quantitative vestibulo-ocular reflex and ocular motor testing. Vestibulo-ocular reflex testing included caloric irrigation, earth vertical axis rotational sinusoids, and rotational impulses. Both patients demonstrated hypoactive vestibular responses to both caloric and rotational stimuli at the time of presentation. One patient had unbeating nystagmus that diminished with upgaze, downgaze, or convergence. Following treatment with thiamine, both patients' vestibular responses improved but remained abnormal, with a short vestibulo-ocular reflex time constant and increased low-frequency rotational phase lead. Impairment of the velocity storage element attributable to damage to the vestibular nucleus and nucleus prepositus hypoglossi may account for this permanent effect on the vestibulo-ocular reflex.     

Vascular changes in acute Wernicke's encephalopathy

The nature and distribution of vascular changes in acute Wernicke's encephalopathy (WE) were analyzed in three autopsy cases. Lesions of the lateral vestibular nucleus of the medulla oblongata (three cases) and lateral ventricular wall (one case) were examined by reconstruction of 200 serial sections, and the capillary diameter in the tegmentum of the medulla oblongata was measured morphometrically in all cases. The vascular changes commonly found in and around the parenchymal lesions in all cases were: (1) dilatation and endothelial swelling of almost all vessels ranging from small arteries to veins, being especially severe with undulation in small arteries and arterioles, and (2) fibrinoid degeneration and hemorrhage involving selectively the arterioles and capillaries on the arterial side. These vascular changes in the medulla oblongata were essentially the same as those in the third ventricular wall, but differed in their severity. Capillary diameter in these cases was significantly larger than that in seven control cases. Such vascular changes, especially a dysoric change on the arterial side, could not be ascribed to secondary change following changes in the parenchyma, and were, therefore, considered to be a lesion essential to WE, as in the case of the parenchymal lesion.     

Transketolase abnormality in tolazamide-induced Wernicke's encephalopathy

We studied a thiamine-dependent enzyme, transketolase, from fibroblasts of a diabetic patient who developed Wernicke's encephalopathy when treated with tolazamide, in order to delineate if this patient also had transketolase abnormality [high Km for thiamine pyrophosphate (TPP)], as previously reported in postalcoholic Wernicke-Korsakoff syndrome. In addition to this patient, we also studied this enzyme from three diabetic kindreds without any history of Wernicke's encephalopathy and from four normal controls. We found that the above-mentioned patient and one of the diabetic kindreds with no history of Wernicke's encephalopathy had abnormal transketolase as determined by its Km for TPP. These data suggest a similarity between postalcoholic Wernicke-Korsakoff syndrome and the patient with tolazamide-induced Wernicke's encephalopathy from the standpoint of transketolase abnormality.