Diffusion-weighted imaging abnormalities in wernicke encephalopathy: reversible cytotoxic edema?

BACKGROUND: Wernicke encephalopathy (WE) is a metabolic disorder of the central nervous system resulting from vitamin B(1) deficiency. The exact mechanisms underlying the pathogenesis of the lesions in WE are not completely understood. Vitamin B1 deficiency is associated with intracellular and extracellular edema by glutamate(N-methyl-D-aspartate) receptor-mediated excitotoxicity. Conventional magnetic resonance imaging (MRI) cannot differentiate the types of edema. Diffusion-weighted imaging (DWI) has been reported to detect early ischemic damage (cytotoxic edema) as bright areas of high signal intensity (SI) and vasogenic edema as areas of heterogeneous SI. OBJECTIVES: To describe the DWI findings and to characterize the types of edema in WE using DWI. SETTING: Tertiary referral center. DESIGN AND METHODS: Two patients with WE underwent DWI and conventional MRI with gadolinium enhancement. Wernicke encephalopathy was diagnosed with salient conventional MRI findings (high SIs in the paramedian thalamus, periaqueductal gray matter, and mamillary bodies) and typical clinical history and symptoms. Apparent diffusion coefficient (ADC) values were measured in abnormal lesions by visual inspection of DWIs and T2-weighted echo planar images. RESULTS: T2-weighted and fluid-attenuated inversion recovery MRIs showed high SIs in the bilateral paramedian thalamus, mamillary bodies, and periaqueductal gray matter. The DWIs showed bright high SI in the corresponding lesions, and ADC values were decreased (patient 1: 512-545 x 10(-6)mm2/s; patient 2: 576-612 x 10(-6)mm2/s). The ADC decrease and the DWI high SI were normalized in 2 weeks with administration of thiamine hydrochloride. CONCLUSIONS: Abnormalities on DWI and ADC decrease became normalized with adequate therapy. The MRI abnormalities in WE might be owing to the "reversible cytotoxic edema" caused by vitamin B1 deficiency.     

Serial MRI and (1)H-MRS of Wernicke's encephalopathy: report of a case with remarkable cerebellar lesions on MRI.

Before and after the administration of thiamine (vitamin B(1)), MRI and proton magnetic resonance spectroscopy ((1)H-MRS) were serially performed in a patient with Wernicke's encephalopathy demonstrating remarkable cerebellar lesions on MRI. Before thiamine administration, high signal intensities were observed in the thalamus around the third ventricle and in the superior portion of the cerebellar vermis and hemisphere on fluid-attenuated inversion recovery (FLAIR) and T2-weighted MR images. After thiamine administration, the high signal intensity in the former region disappeared immediately, while that in the latter regions persisted. The low level of N-acetylaspartate (NAA)/creatine (Cr) in the thalamus before thiamine administration improved to some degree on the (1)[H]-MRS images taken after thiamine administration. In the cerebellum, a lactate peak was observed before thiamine administration, and the NAA/Cr level did not improve after thiamine administration, suggesting that irreversible necrosis occurred. It is suggested that serial MRI/(1)H-MRS observation may be helpful in determining the neuronal viability of Wernicke's encephalopathy and the prognostic implications of sequelae such as Korsakoff's syndrome and cerebellar ataxia.     

Neurological complications in hyperemesis gravidarum

Hyperemesis gravidarum can impair correct absorption of an adequate amount of thiamine and can cause electrolyte imbalance. This study investigated the neurological complications in a pregnant woman with hyperemesis gravidarum. A 29-year-old pregnant woman was admitted for hyperemesis gravidarum. Besides undernutrition, a neurological examination disclosed weakness with hyporeflexia, ophthalmoparesis, multidirectional nystagmus and optic disks swelling; the patient became rapidly comatose. Brain MRI showed symmetric signal hyperintensity and swelling of periaqueductal area, hypothalamus and mammillary bodies, medial and posterior portions of the thalamus and columns of fornix, consistent with Wernicke encephalopathy (WE). Neurophysiological studies revealed an axonal sensory-motor polyneuropathy, likely due to thiamine deficiency or critical illness polyneuropathy. Sodium and potassium supplementation and parenteral thiamine were administered with improvement of consciousness state in a few days. WE evolved in Korsakoff syndrome. A repeat MRI showed a marked improvement of WE-related alterations and a new hyperintense lesion in the pons, suggestive of central pontine myelinolysis. No sign or symptom due to involvement of the pons was present.     

非酒精性Wernicke脑病二例

目的探讨Wernicke脑病患者的临床和影像学特点。方法分析2例非酒精性Wernicke脑病患者的临床资料。结果 2例患者均为消化道晚期肿瘤行手术治疗、术后有营养不均衡、发病前有葡萄糖注射液补液史。2例患者均有意识障碍和典型的头颅MRI信号改变,即双侧丘脑内侧、中脑顶盖及导水管周围的高T_2信号;维生素B_1补充治疗后患者的症状有不同程度的好转。结论导致维生素B_1缺乏的高危因素、临床表现及典型的头颅MRI表现是临床上Wernicke脑病早期诊断的重要线索。早期足量维生素B_1治疗效果好。高危患者应注意预防Wernicke脑病的发生。     

Diffusion-weighted MR findings in a reversible case of acute Wernicke encephalopathy

We report a case of acute Wernicke encephalopathy (WE) in which apparent diffusion coefficient maps showed areas of increased diffusion in the bilateral medial thalami that corresponded to the hyperintense lesions on T2-weighted imaging. The hyperintense lesions on T2-weighted imaging disappeared with full recovery from symptoms. These findings suggest that the hyperintense lesions of the acute changes of WE include reversible vasogenic edema and are not caused by acute ischemia.     

Magnetic resonance imaging of skeletal muscles in idiopathic inflammatory myopathies of adults

The purpose of the study was to describe typical MRI findings in various types of idiopathic inflammatory myopathies in adulthood and to correlate the MRI with histopathological and electromyographic findings, and the serum creatine kinase (CK) activity. A third goal was to assess the diagnostic value of the use of gadolinium-DTPA (Gd-DTPA). Fifty-eight patients (35 women, 23 men), aged 21–83 years (median age 59 years), suffering from idiopathic myositides (13 with acute and 45 chronic diseases; 25 with polymyositis, 14 with dermatomyositis, 8 with granulomatous and 11 with inclusion body myositides) were examined with MRI. Seventeen of them received an intravenous infusion of Gd-DTPA. Histopathological and MRI findings of 21 muscles of 18 patients were compared. MRI of skeletal muscles showed abnormal signal intensities in 56 (96.6%) of the 58 patients. MRI abnormalities were found more often than elevated CK activity (P < 0.001). The hyperintensity of T2-weighted images was more conspicuous than on T1-weighted images in 26 (44.8%) patients, indicating oedema-like abnormalities. MRI of 50 (86.2%) patients showed fat replacement. In acute myositides, oedema-like abnormalities were more often visible and in muscle lipomatosis less often visible than in chronic diseases (P < 0.05 each). In dermatomyositis oedema-like abnormalities were more and lipomatosis less frequent than in the other types of myositis (P < 0.005) and correlated with the acuteness of the disease. In 3 of 17 patients in whom contrast-enhanced T1-weighted images were obtained in addition to plain T1- and T2-weighted images, T2-weighted images were more sensitive in the detection of oedema-like abnormalities than the contrast-enhanced T1-weighted images. In no patient was the opposite true. Thus, contrast-enhanced T1-weighted images did not provide more information than T2-weighted images. Nine patients with poly-, dermato- and inclusion body myositis showed clearly asymmetrical findings. Imaging of the thighs and legs was of similar sensitivity. The different types of myositides showed typical but not specific distributions of the mesenchymal abnormalities in MRI. The findings indicate that MRI of skeletal muscles in myositides can visualize the presence and distribution of oedema-like abnormalities and intramuscular lipomatosis and is suitable for the assessment of the chronicity and severity of the disease.     

Detection of acute thalamo-mesencephalic infarction: diffusion abnormality precedes T2 hyperintensity

OBJECTIVE: To examine the time course of signal changes in diffusion-weighted magnetic resonance imaging (DW-MRI) and T2-weighted MRI in a case of cerebral infarction in the posterior circulation territory. MATERIALS AND METHODS: Diffusion- and T2-weighted MRI and comparison of signal changes in these sequences at 4 h, 1 day and 4 days after the onset of clinical symptoms caused by acute thalamo-mesencephalic infarction. RESULTS: Four hours after the onset of symptoms, signal changes in DW-MRI revealed an infarction in the territory of the posterior perforating thalamic artery, whereas no signal changes were detected in T2-weighted MRI. In follow-up MRI 1 and 4 days after infarction, however, a marked hyperintensity matching the location of the diffusion deficit could be identified in T2 images. CONCLUSION: Signal changes in DW-MRI precede T2 hyperintensity after infarction in the posterior circulation territory after hemispheric infarction.     

Restricted Diffusion of the Splenium in Acute Wernicke''s Encephalopathy

Acute Wernicke's encephalopathy (WE) is caused by profound vitamin B1 (thiamine) deficiency and commonly presents with the classic clinical triad of mental confusion, ataxia, and ophthalmoplegia. This characteristic presentation results from the propensity of acute thiamine deficiency to preferentially injure specific brain regions: the dorsomedial thalamus, periaqueductal gray, and mamillary bodies. In these regions, abnormal magnetic resonance signaling on conventional sequences has been well described; however, diffusion restriction has only recently been reported. The authors demonstrate diffusion-weighted imaging (DWI) abnormalities of the splenium of the corpus callosum in a patient with acute WE, which has not been reported previously, and suggest a potential pathological mechanism. With the recent addition of DWI, MRI is becoming more sensitive to the changes in acute WE. Furthermore, the use of apparent diffusion coefficient mapping to evaluate the extent of likely underlying cytotoxic injury may help determine long-term response to vitamin therapy and, thus, disability.     

Wernicke脑病

Wernicke脑病（WE）是一种急性或亚急性起病的维生素B1缺乏症。表现为眼部体征、躯干性共济失调、意识障碍和情感淡漠及多发性周围神经病。M砌的表现有助于提示本病。WE是由于胃肠道手术、酗酒和胰腺炎等病因引起,补充维生素B1有助于恢复。     

Magnetic resonance imaging and brain-stem auditory evoked potentials in neuro-Behcet's disease

We studied central nervous system lesions in patients with neuro-Behcet's disease using magnetic resonance imaging (MRI) of the brain and recording of brain-stem auditory evoked potentials (BAEPs). MRI revealed abnormal findings in seven of eight patients. MRI studies demonstrated extensive regions with high intensity signal in the brain stem and/or basal ganglia on T2-weighted images obtained during the acute stage of the disease in three patients. One of these patients had a strongly gadolinum-enhanced round lesion in the lower pons. In four of the other five patients with chronic disease, brain-stem atrophy was observed on T1-weighted images. Atrophic changes were more severe in the brain stem than in the cerebellum. Abnormal BAEPs were observed in three patients and consisted of prolongation of interpeak latency of waves III-V and defects of wave III or V. Abnormal BAEPs were recorded in patients with severe inflammatory changes or progression of atrophic changes in the brain stem. Our findings show that MRI and BAEPs are useful in detecting the presence and assessing the degree of neurological involvement in patients with neuro-Behcet's disease.     

A case of acute cerebellar ataxia with an MRI abnormality

A 5-year-old boy with acute cerebellar ataxia was examined by means of magnetic resonance imaging (MRI) and was found to have a lesion showing low and high signal intensity in T1- and T2-weighted images, respectively, in the left cerebellar peduncle in the acute phase. The lesion disappeared in the convalescent phase.     

Clinical and pathological features of alcohol-related brain damage

One of the sequelae of chronic alcohol abuse is malnutrition. Importantly, a deficiency in thiamine (vitamin B(1)) can result in the acute, potentially reversible neurological disorder Wernicke encephalopathy (WE). When WE is recognized, thiamine treatment can elicit a rapid clinical recovery. If WE is left untreated, however, patients can develop Korsakoff syndrome (KS), a severe neurological disorder characterized by anterograde amnesia. Alcohol-related brain damage (ARBD) describes the effects of chronic alcohol consumption on human brain structure and function in the absence of more discrete and well-characterized neurological concomitants of alcoholism such as WE and KS. Through knowledge of both the well-described changes in brain structure and function that are evident in alcohol-related disorders such as WE and KS and the clinical outcomes associated with these changes, researchers have begun to gain a better understanding of ARBD. This Review examines ARBD from the perspective of WE and KS, exploring the clinical presentations, postmortem brain pathology, in vivo MRI findings and potential molecular mechanisms associated with these conditions. An awareness of the consequences of chronic alcohol consumption on human behavior and brain structure can enable clinicians to improve detection and treatment of ARBD.     

Wernicke’s encephalopathy in a patient with acute pancreatitis: unusual cortical involvement and marvelous prognosis

Wernicke's encephalopathy (WE) is a severe neurological disorder caused by thiamine deficiency. Clinically, it is most frequently observed in people with alcohol abuse. WE, however, can occur in any clinical condition associated with malnutrition or thiamine deficiency. We present the case of a 47-year-old woman with prolonged therapeutic fasting who presented with ophthalmoplegia, ataxia and deep coma. MRI showed unusual symmetric cortical abnormalities in the frontal and parietal lobes, as well as typical lesions surrounding the third ventricle and aqueduct. Although the patient entered a vegetative state, she finally regained consciousness after thiamine supplementation unexpectedly. To the best of our knowledge, it has never been reported to date that the patient with WE in a vegetative state with cortical damage shows a marvelous prognosis, which prompts us to report this case. In the present report, we highlight the role of MRI in the diagnosis of acute WE.     

MRI volumetric correlates of white matter lesions in dementia with Lewy bodies and Alzheimer's disease

The aim of the study was to examine the relationship between white matter changes on magnetic resonance imaging (MRI), brain atrophy and ventricular dilation in late-life dementias. T(1)-weighted, T(2)-weighted, and proton density MRI scans were acquired in subjects with Alzheimer's disease (AD, N=25) and dementia with Lewy bodies (DLB, N=27). Total brain and ventricular volumes were measured and white matter lesions rated using a semi-quantitative scale. Periventricular hyperintensities (PVH) were found to independently correlate with advancing age and increasing ventricular dilatation in all subjects. In contrast, deep white matter hyperintensities (DWMH) did not correlate with measures of brain atrophy, ventricular dilatation or age, but were associated with a history of hypertension. These findings support the hypothesis that PVH and DWMH are pathologically diverse and that white matter change in AD and DLB may be determined by similar processes. In particular, PVH appear to be linked to atrophic processes involving ventricular enlargement and DWMH to ischaemic risk factors.     

颅脑MRI检查对Wernicke脑病的诊断价值

目的 探讨颅脑MRI检查对Wemicke脑病(WE)的诊断价值.方法 回顾性分析8例WE患者的临床资料及MRI检查结果.结果 8例WE患者MRI示脑部T2 WI、Flair成像及弥散加权成像(DWI)有对称性异常高信号影,其中出现在丘脑内侧6例、中脑导水管周围灰质4例、第三脑室周围灰质3例、乳头体2例及壳核、视交叉、小脑上蚓部、皮质下白质各1例;2例有增强效应.2例发病早期T2 WI、Flair无异常信号影,DWI示丘脑内侧对称性异常高信号影.结论 MRI对WE具有诊断价值,DWI对WE的早期诊断价值更高.     

Topographic distribution and severity of brain lesions in Wernicke's encephalopathy

The distribution and severity of the brain lesions were studied in 45 cases (age range: 26-84 years) of Wernicke's encephalopathy. The process was acute or subacute (active) in 24 cases and chronic (inactive) in 21. Cases with acute and subacute disease had more extensive and severe lesions than the chronic ones. The majority of the acute cases had lesions involving the mammillary bodies and thalamus and the subependymal structures along the third and fourth ventricles and the aqueduct. Only three acute cases had lesions restricted to the mammillary bodies. Among the chronic cases, the majority of the lesions were restricted to the mammillary bodies and the thalamus. Only two lesions extended as far down as the inferior collicles. Eleven out of 21 chronic cases has isolated lesions of the mammillary bodies. The affection of the mammillary bodies in chronic cases varied from barely visible to subtotal destruction of the tissue. Similarly, the lesions in the thalamus varied from slight gliosis in the dorsomedial nucleus to extensive nerve cell loss in several nuclei. There were similar variations in the severity of the clinical picture. Memory loss was recorded in three cases with isolated lesions of the mammillary bodies.     

Value of MRI findings in Gayet-Wernicke encephalopathy

Wernicke encephalopathy (Wernicke-Korsakoff encephalopathy) is related to thiamine deficiency. We report the MRI findings in four patients with visualization of bilateral and symmetrical hyperintense foci on T2W and FLAIR images involving the periaqueductal gray matter, the mamillary bodies and around the third ventricle. Diffusion weighted images obtained in two patients demonstrated mild hypersignal in the same areas. Contrast enhancement within the mamillary bodies was noted in one patient. Follow-up MRI obtained in three patients showed rapid regression of signal abnormalities without correlation with good clinical outcome.     

Acute severe spinal cord dysfunction in bacterial meningitis in adults: MRI findings suggest extensive myelitis

BACKGROUND: Bacterial meningitis is rarely complicated by acute spinal cord involvement (eg, myelitis, ischemic infarction, spinal abscess, or epidural hemorrhage). In spinal cord dysfunction, magnetic resonance imaging (MRI) is the imaging modality of choice. Still, MRI findings of myelitis due to bacterial meningitis in adults have not been reported. METHODS: Spinal MRIs were obtained during the acute stage of meningitis and on follow-up in 3 adults with bacterial meningitis that was complicated by paraparesis or tetraparesis and bowel and bladder incontinence. The causative pathogens were Streptococcus pneumoniae and Neisseria meningitidis; in 1 patient, the pathogen was not identified. RESULTS: In all cases, spinal MRI ruled out a compression of the cord by an extramedullary mass but demonstrated hyperintensities on T2-weighted images that predominantly involved the gray matter and extended from the cervical to the lumbar cord. Leptomeningeal and discrete nodular intramedullary enhancement on T1-weighted images was detected only in 1 patient. Follow-up examinations revealed that hyperintensities resolved completely in 1 patient, while a central cavitation developed in the cervical spinal cord of another, and the MRI findings were progressive during the first 4 weeks in the third patient. In all cases, severe paresis and bowel and bladder incontinence persisted. CONCLUSION: We demonstrate for the first time the MRI findings of adults with acute spinal cord involvement during bacterial meningitis. Magnetic resonance imaging showed central intramedullary hyperintensities on T2-weighted images that extended from the cervical to the lumbar cord, indicating myelitis. Clinical follow-up examinations suggest that myelitis during bacterial meningitis has an unfavorable prognosis.     

MRI for the management of neonatal cerebral infarctions: importance of timing

PURPOSE: Focal ischemic stroke in neonates is a rare occurrence. Diagnosis with most imaging modalities is difficult, but necessary for initiating an anticoagulatory treatment. The purpose of this study was to evaluate the sensitivity of MRI sequences within the first 14 days of birth. PATIENTS AND METHODS: Four patients with neonatal stroke presenting as seizures were examined using a standard MRI protocol including diffusion-weighted images (DWI) and magnetic resonance angiography (MRA) within 72 h of birth. The time between the onset of symptoms and MRI ranged from 6 h to 48 h. Follow-up examinations were performed on days 5 ( n=1), 7 ( n=2), and 14 ( n=1) for the control of a treatment with low-molecular heparin. RESULTS: Eight infarctions were detected in the four patients, 5 in the middle cerebral artery (MCA), three in the posterior cerebral artery (PCA) territory. All lesions were visible using DWI, four on T2-weighted images. Whereas in two patients small lesions contralateral to a large stroke were missed on T2-weighted images, the diagnosis would have been missed altogether without DWI in one patient. On follow-up, the visibility of the infarctions had declined using DWI after 5 days and the lesions were invisible after 1 week. Fourteen days after the stroke, an increased diffusion was detected in the infarcted brain tissue. By this time, all lesions were visible on T2-weighted images. CONCLUSION: In neonates, infarcted brain tissue can be detected using DWI with high sensitivity during the first 2 days after stroke and before other sequences are diagnostic. However, the diffusion restriction does not persist beyond 1 week. After 5 days, diagnosis has to rest mainly on T2-weighted images.     

Brain magnetic resonance imaging and neuropathology of cortical laminar necrosis

INTRODUCTION: The most frequent acute and sub-acute complications of chronic alcoholism are delirium tremens, hepatic encephalopathy and Gayet-Wernicke encephalopathy. Morel laminar sclerosis is a rare and less known complication, often reported with Marchiafava-Bignami disease. CASE REPORT: A 57-year-old alcoholic man presented delirium after surgery. Anterograde and retrograde amnesia as well as wrong recognitions appeared progressively and one generalized seizure occurred. He then developed mutism and became bedridden. Magnetic resonance imaging (MRI) showed high-intensity bilateral temporoparietal signals from white matter on T2-weighted images and high-intensity signals from the parietal cortex on T1-weighted images. The patient died four months after the onset of the delirium. Post-mortem examination of the brain showed cortical laminar necrosis with Alzheimer Type II gliosis but without demyelinisation of the corpus callosum. CONCLUSION: Cortical laminar necrosis with chronic ethylism is usually called Morel's laminar sclerosis. Nevertheless, histology is not typical of this diagnosis, because of necrosis especially of the second (and not the third) layer of the cortex, and because of the absence of lesion of the corpus callosum. MRI data are of interest here because they were rarely reported in cases of Morel's laminar sclerosis.