副腎皮質ステロイドが奏功した脳アミロイドアンギオパチー関連白質脳症の1例

Not Just Blood: Brain Fluid Systems and Their Relevance to Cerebrovascular Diseases.

Objective To evaluate whether MRI fluid attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH) is an effective indicator for severe vascular stenosis or occlusion and disease severities in patients with acute anterior circulation infarction. Methods Three hundred and forty consecutive patients with acute anterior circulation infarction, admitted to our hospital from May 2013 to May 2014, were enrolled as subjects. All subjects were completed brain MR diffusion-weighted imaging (DWI), FLAIR and neck vascular or brain magnetic resonance angiography (MRA). According to the extent of FVH, all subjects were classified into negative FVH and positive FVH groups. Clinical data were obtained and compared among patients with different grades of FVH, and receiver operating characteristic (ROC) curve was used to calculate the sensitivity and specificity of FVH diagnosis of vascular severe stenosis or occlusion. The value of FVH in evaluating the disease severities of patients with large artery atherosclerosis combined with acute cerebral infarction according to new TOAST classification was evaluated. Results FVH was observed in 109 (32.06%) of the 340 patients. Significant differences were noted in the new TOAST classification ratio and vascular stenosis grading between the two groups; in the positive FVH group, the largest ratio was patients with large-artery atherosclerosis (82.6%), while that was patients with small vessel diseases (56.3%); the ratio of patients with severe vascular stenosis and occlusion in positive FVH patients was significantly higher than that in negative FVH patients (34.9% vs. 5.6%, 39.5% vs. 0.9%). Spearman rank correlation analysis indicated that the degrees of vascular stenosis of carotid artery-middle cerebral artery were positively correlated to FVH (r=0.599, P=0.000). As compared with the negative FVH group, FVH patients had larger infarct volume and higher initial NIHSS scores (P<0.05). ROC curve indicated that FVH had a sensitivity of 84.38% and a specificity of 88.52% in detecting artery stenosis (area under the curve [AUC]=0.892, 95% CI=0.85-0.94, P<0.05), and a sensitivity of 88.89% and a specificity of 85.76% in detecting the vessel occlusion (AUC=0.929, 95%CI: 0.89-0.97, P<0.05). In patients with acute cerebral infarction combined with artery atherosclerosis, patients with high FVH scores showed smaller infarct volumes and slighter neurological symptoms as compared with those with low FVH (P<0.05). Conclusions FVH predicts vascular severe stenosis or occlusion with high sensitivity and specificity. In severe vascular stenosis or occlusion group, higher FVH scores are associated with lighter strokes. Key words: Magnetic resonance imaging; Fluid attenuated inversion recovery; Vascular hyperintensity; Acute cerebral infarction; Atherosclerosis

A middle-aged male presented with complaints of mild headache and unsteadiness of gait for past 2 years. His physical examination and lab results, including the cerebrospinal fluid (CSF) examination were unremarkable. Magnetic resonance imaging (MRI) of brain was done which revealed a cluster of cysts in the midbrain isointense to CSF on all sequences [Figures 1 and 2]. No enhancement of the cyst walls was seen on post-gadolinium images [Figure 3]. MR spectroscopy did not show any choline, lipid, or amino acid peak in the lesions. These were seen to cause mass effect on aqueduct of Sylvius and mild obstructive hydrocephalus. Review of MRI done before 2 years revealed the same lesions in the mesencephalothalamic region; no change in size or signal intensity was observed in the present scan. The final diagnosis was tumefactive Virchow-Robin spaces causing mild hydrocephalus. The patient was referred to neurosurgery department for further management. A VP shunt was placed with dramatic resolution of symptoms.Figure 1: Axial T1-weighted images show cluster of cysts in the mesencephalic region isointense to cerebrospinal fluid (CSF)Figure 2: Coronal fluid attenuated inversion recovery (FLAIR) image shows CSF isointense cysts in mesencephalothalamic region causing mild hydrocephalus. Periventricular hyperintense signal is due to transependymal seepage and/or microvascular ischemiaFigure 3: Coronal post-gadolinium T1-weighted images do not reveal any enhancement of cysts, consistent with the diagnosis of tumefactive perivascular spacesThe Virchow-Robin or perivascular spaces are pial-lined, fluid-filled spaces accompanying perforating arteries and venules. Typical perivascular spaces occur along lenticulostriate arteries above the anterior perforating substance and anterior commissure. They may occur less commonly in subcortical location, subinsular region, and cerebellum.[1] Rarely they may become enlarged (called tumefactive Virchow-Robin spaces) and cause mass effect and hydrocephalus (especially those found in mesencephalothalamic region); these need to be distinguished from cystic neoplasms.[2] Some authors have proposed the term Virchoma for enlarged mesencephalic perivascular spaces.[3] Tumefactive or cavernous dilation of Virchow-Robin spaces occurring in mesencephalothalamic region may be associated with hydrocephalus. The diagnostic features for tumefactive or cavernous dilation of Virchow-Robin spaces in this case are, an absence of signal from the lesion on the fluid attenuated inversion recovery (FLAIR) imaging, no abnormal signal in the adjacent neuroparenchyma, no contrast enhancement on post-gadolinium scans, and no change in size or appearance over 2 years. The differential diagnosis of tumefactive perivascular spaces includes cystic neoplasms, parasitic cysts, ventricular diverticulae, nonneoplastic neuroepithelial cysts, and mucopolysaccharidosis.[345] Extreme unilateral dilation of Virchow-Robin spaces may also be encountered.[6] Large Virchow-Robin spaces (VRS) have been associated with age, dementia, multiple sclerosis, trauma, hypertension, and incidental white matter lesions.[178] Surgical shunting of the hydrocephalus associated with VR spaces has produced variable clinical results (with improvement in gait disturbances, bradykinesia, and urinary symptoms). We conclude that mesencephalic tumefactive Virchow Robin spaces can cause obstructive hydrocephalus, and rare manifestations of a common entity should always be considered.

Background: Several studies have shown that well-known cerebrovascular risk factors are associated with a higher incidence of white matter lesions (WML). The knowledge of the role of alcohol in the development of WML still is poor. The aim of this study is to investigate the prevalence of WML in younger alcohol addicts. Well-known and potential risk factors for WML were taken into account. Methods: N=100 patients aged 25-60 years (mean age 44 years) fulfilling the diagnostic criteria of alcohol dependency (ICD F10.2) were examined with 1,5 Tesla magnetic resonance imaging according to a standard protocol concerning localization and dissemination of WML. All patients were voluntary in-patients. Data concerning medical history, education, occupation, exposure to toxic substances, nutrition, smoking, laboratory values, vitamin levels, ApoE-genotype, parameters of alcohol dependency and consumption of other drugs than alcohol were collected. Results: WML could be found in 39 patients. 34 had subcortical focal WML (≤ 5 mm), 13 periventricular WML (twelve patients ≤ 5 mm, one patient 6-10 mm). 26 had exclusively subcortical WML, five had exclusively periventricular WML and eight had WML of both localizations. Significant positive associations were found to higher age, higher amount of daily alcohol consumption, lower haematocrit and lower creatine kinase. There was a trend towards more frequent malnutrition, less frequent consumption of dairy products and a lower haemoglobin level in patients with WML. Patients in the fifth decade of life had significantly more often WML and reported significantly higher levels of daily alcohol consumption. Well-known cerebrovascular risk factors were not associated with WML. Conclusion: Our data suggest that the amount and the duration of higher alcohol consumption, in combination with higher age, are possible risk factors for WML as early as from the fifth decade of life. Most of the patients had subcortical WML. These are known to be associated to cerebrovascular risk f actors rather than to higher age. Nutrition might play a role in the development of WML. Consumption of dairy products might have a protective effect. The significantly lower levels for haematocrit and creatine kinase and the trend towards lower haemoglobin levels might be the consequence of an alcohol induced diabetes insipidus. We can support the assumption that there is an association between changes in blood count and brain morphology, reported by other authors. Moreover we can support the thesis that higher alcohol consumption is a risk factor for a higher vulnerability of the cerebral white matter. We assume that higher alcohol consumption accelerates aging processes of the brain and increases the risk for preterm WML.

Asymmetrical manifestation of dystonia was investigated in 26 patients with Wilson's disease with modified dystonia rating scale and correlated with the asymmetricity of CT and/or MRI findings. Ten patients (eight men and two women) had dystonia. The age of disease onset ranged from 11 to 30 years with a mean of 18.6 ± 5.2 years. The duration of the illness was from 2 to 15 years (mean 7.0; S.D. 3.6). Six patients had subcortical white matter lesions in the frontal and/or parietal lobes, as well as lesions in the basal ganglia. Five patients, who had asymmetrical white matter lesions in the frontal lobes and symmetrical lesions in the basal ganglia and the thalamus, developed more severe contralateral dystonia. The other four patients with symmetric lesions in the basal ganglia and the thalamus had nearly‐symmetrical dystonia. One patient with symmetrical lesions in the frontal lobes and the basal ganglia also had symmetrical manifestation of dystonia. We suggest that the interruption of the loop between the thalamus and premotor cortex by subcortical white matter lesions may enhance contralateral dystonia.

A 61-year-old man who had suffered two episodes of generalized convulsion in a two-year period was admitted to our hospital because of progressive gait disturbance during the previous five months. Neurological examination revealed cognitive impairment, spasticity of the lower limbs, truncal ataxia, and dysautonomia including orthostatic hypotension, dysuria and hypohydrosis. Brain fluid-attenuated inversion recovery (FLAIR) MRI detected high-signal-intensity lesions in the periventricular white matter and centrum semiovale, with punctate gadolinium (Gd) enhancement. Spinal MRI detected swollen cervical long cord lesions extending from C2 to C6. Although methylprednisolone pulse treatment initially ameliorated the symptoms and MRI abnormal findings, clinical symptoms and MRI abnormalities including new cervical lateral column lesions reminiscent of those in autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy (GFAP-A) relapsed two months later. At this point, anti-GFAPα antibody was detected in the cerebrospinal fluid. Although the clinical course of GFAP-A has been well reported, the present case showed a chronic refractory course.

Cerebral white matter lesions are frequently observed on magnetic resonance imaging (MRI) scans in elderly people and are associated with stroke and dementia. Elevated blood pressure is presumed one of the main risk factors, although data are almost exclusively derived from cross-sectional studies. We assessed in 10 European cohorts the relation between concurrently and previously measured blood pressure levels, hypertension, its treatment, and severe cerebral white matter lesions. In total, 1805 nondemented subjects aged 65 to 75 years were sampled from ongoing community-based studies that were initiated 5 to 20 years before the MRI. White matter lesions in the periventricular and subcortical region were rated separately using semiquantitative measures. We performed logistic regression analyses adjusted for potential confounders in 1625 people with complete data. Concurrently and formerly assessed diastolic and systolic blood pressure levels were positively associated with severe white matter lesions. Both increases and decreases in diastolic blood pressure were associated with more severe periventricular white matter lesions. Increase in systolic blood pressure levels was associated with more severe periventricular and subcortical white matter lesions. People with poorly controlled hypertension had a higher risk of severe white matter lesions than those without hypertension, or those with controlled or untreated hypertension. Higher blood pressure was associated with an increased risk of severe white matter lesions. Successful treatment of hypertension may reduce this risk; however, a potential negative effect of decreasing diastolic blood pressure level on the occurrence of severe periventricular white matter lesions should be taken into account.

To determine the clinical utility of gadolinium-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging of the brain by comparing results with those at gadolinium-enhanced T1-weighted MR imaging with magnetization transfer (MT) saturation. In 105 consecutive patients referred for gadolinium-enhanced brain imaging, FLAIR and T1-weighted MR imaging with MT saturation were performed before and after administration of gadopentetate dimeglumine (0.1 mmol per kilogram of body weight). Pre- and postcontrast images were evaluated to determine the presence of abnormal contrast enhancement and whether enhancement was more conspicuous with the FLAIR or T1-weighted sequences. Thirty-nine studies showed intracranial contrast enhancement. Postcontrast T1-weighted images with MT saturation showed superior enhancement in 14 studies, whereas postcontrast fast FLAIR images showed superior enhancement in 15 studies. Four cases demonstrated approximately equal contrast enhancement with both sequences. Six cases showed some areas of enhancement better with T1-weighted imaging with MT saturation and other areas better with postcontrast fast FLAIR imaging. Superficial enhancement was typically better seen with postcontrast fast FLAIR imaging. Fast FLAIR images have noticeable T1 contrast making gadolinium-induced enhancement visible. Gadolinium enhancement in lesions that are hyperintense on precontrast FLAIR images, such as intraparenchymal tumors, may be better seen on T1-weighted images than on postcontrast fast FLAIR images. However, postcontrast fast FLAIR images may be useful for detecting superficial abnormalities, such as meningeal disease, because they do not demonstrate contrast enhancement of vessels with slow flow as do T1-weighted images.

Cerebral microbleeds (CMBs), cortical superficial siderosis, white matter lesions (WML), and cerebral atrophy may signify greater bleeding risk particularly in patients in whom anticoagulation is to be considered. We investigated their prevalence and associations with stroke type in patients with stroke and atrial fibrillation (AF). Cross-sectional sample, Monash Medical Centre (Melbourne, Australia) between 2010 and 2013, with brain MRI. MRI abnormalities were rated using standardized methods. Logistic regression was used to study associations adjusting for age and sex. There were 170 patients, mean age 78 years (SD 9.8), 154 (90.6%) with ischemic stroke. Prevalence of MRI markers were any microbleed 49%, multiple (≥2) microbleeds 30%, confluent WMLs 18.8%, siderosis 8.9%, severe cerebral atrophy 37.7%. Combinations of the severe manifestations of these markers were much less prevalent (2.9-12.4%). Compared with ischemic stroke, those with hemorrhagic stroke were more likely to have ≥10 microbleeds (OR 5.50 95% CI 1.46-20.77, p = 0.012) and siderosis (OR 6.24, 95% CI 1.74-22.40, p = 0.005). Siderosis was associated with multiple microbleeds (OR 8.14, 95% CI 2.38-27.86, p = 0.001). Patients admitted with hemorrhagic stroke and multiple microbleeds were more frequently anticoagulated prior to stroke (6/7, 85.7%) than in those with single (1/2, 50%) or no microbleeds (4/7, 57%). Multiple CMBs, severe WML, and severe cerebral atrophy were common individually in hospitalized patients with stroke and AF, but less so in combination. A higher burden of CMBs may be associated with intracerebral hemorrhage in stroke patients with AF.

Silent Brain Infarction and Subcortical White Matter Lesions Increase the Risk of Stroke and Mortality: A Prospective Cohort Study

Objective To elucidate significance of hyperintense vessel signs(HVS)on FLAIR MRI in patients with cerebral infarction. Methods Two hundred and sixty-two patients with cerebral infarction admitted in our hospital were included in this study. We retrospectively defined HVS on FLAIR MRI in these patients in comparison with time of flight(TOF)on MR angiograms(MRA), hyperintense lesions on diffusion-weighted images(DWI). Results HVS on FLAIR MR[were identified in 117 patients with cerebral infarction(45.4%), of which 47 patients(83.9%)were obtained within 24 hours of symptom onset. HVS on FLAIR MRI were detected in 74 patients at sylvian fissure(62.2%), 11 at cortical sulci (9.2% ,11/119),34 at the posterior circulation regions(28.6% ,34/119). HVS on FLAIR MRI coincided well with ischemia of TOF on MRA and lesion patterns on DWI (χ2 test,P<0.01, respectively). Conclusion HVS on FLAIR MRI is helpful to evaluate abnormal major cerebral arteries of patients with cerebral infarction. Key words: Brain infarction; Magnetic resonance imaging

MR imaging findings in mild traumatic brain injury with persistent neurological impairment

To evaluate the ability of brain MRI SE sequences to differentiate between SLE and MS we reviewed the brain scans of 30 SLE patients (30 female, mean age 38.5 +/-12 years) and of 30 definite MS patients (23 female, 7 male, mean age 35.5 +/- 8 years). We analyzed the number and location of white matter lesions (WML) and classified them in different regions. We also pointed out associated brain abnormalities, such as large hemispheric lesions. We found periventricular, paraventricular and subcortical WML in MS and paraventricular and subcortical WML in SLE; a confluent pattern of WML was seen only in MS; infratentorial WML were more frequent in MS; corpus callosum involvement was found only in MS; large hemispheric areas of increased signal representing strokes were present only in SLE. MRI shows different lesion patterns in MS and SLE and may play an important role in the differential diagnosis between these diseases.

Histologic examination of multiple sclerosis (MS) brain lesions reveals heterogeneity including the presence or absence of a central blood vessel. Recent work has shown that T2* weighted magnetic resonance imaging at 7T allows the identification of small parenchymal veins within MS lesions. The aims of this study were (1) to compare whether a comparable sequence at 3T was also capable of demonstrating parenchymal veins within MS brain lesions, and (2) to investigate the potential of 7T T2* weighted imaging to differentiate between MS white matter lesions and age-related vascular lesions seen in controls. Seven patients with demyelinating brain disease and 7 healthy volunteers were scanned at 3T and 7T. Fluid attenuated inversion recovery (FLAIR) images acquired at 3T were used to identify each brain lesion in each patient. A comparison of images from both field strengths was then made to determine whether white matter lesions seen in 3T FLAIR images could be identified in T2*-weighted images, and whether a central vein could be detected. A total of 358 brain lesions were identified in the brains of the 7 patients using 3T FLAIR images. The 3T T2* sequence detected 89% of FLAIR lesions compared with 94% using the 7T T2* sequence (P = 0.0002). A central vessel could be identified in 45% of visible lesions using 3T T2* and 87% of visible lesions using 7T T2* (P < 0.0001). Using 7T T2* imaging, a central vein was evident in only 8% of the discrete white matter lesions found in the brains of healthy volunteers. This study suggests that ultra high field imaging is advantageous in demonstrating detailed structural anatomy of MS lesions. 7T T2* imaging can be used in the future to investigate the pathogenesis of MS lesions. The potential for ultra high field imaging to discriminate between MS white matter lesions and microangiopathic lesions warrants further investigation as this would represent a clinically useful application.

White matter lesions (WML) have been proven to be associated with cognitive impairment. As (1) the decline of cognitive function is the most frequent comorbid disorder in epilepsy, and (2) patients with epilepsy have a relatively high prevalence of WML, the question is raised whether WML in patients with epilepsy are also associated with cognitive decline. A high-resolution magnetic resonance imaging examination was performed at 3.0 T, comprising T1-weighted, T2 relaxometry, and fluid-attenuated inversion recovery (FLAIR) sequences. Patients with localization-related epilepsy with impaired and unimpaired cognitive functioning and a healthy control group were included. Furthermore, the performance of an automated WML detection algorithm, based on regional intensity evaluation, was assessed. The prevalence of WML, detected on 3.0 T FLAIR images, is 63% in healthy volunteers and 46% in patients with localization-related, cryptogenic epilepsy. No relationship between WML volume and cognitive performance was observed. The WML volumes from the automated segmentation method were found to be significantly correlated to the volumes obtained by neuroradiologic assessment. No relations could be found between WML and cognition in the well-defined population of patients with epilepsy. Other clinical characteristics of chronic epilepsy, such as seizures, age of onset, and medication are more likely to play an important role in cognitive decline. Furthermore, the automated WML detection algorithm using a regional Z-score analysis can successfully segment and quantify the WML on FLAIR images.