Cranial computed tomographic observations in multi-infarct dementia. A controlled study.

BACKGROUND AND PURPOSE: We compared cranial computed tomography findings among 58 multi-infarct dementia index cases and 74 multi-infarct control subjects without cognitive impairment to identify potential determinants of multi-infarct dementia. METHODS: The cranial computed tomography records of acute ischemic stroke patients with a history of multiple cerebral infarcts were compared to determine the number, location, and size of cerebral infarcts; the pattern of infarction; brain volume loss; and the degree of white matter lucency, sulcal enlargement, and ventricular enlargement. Multi-infarct patients were divided into two groups: 1) index cases were defined as those with multi-infarct dementia as defined by the Diagnostic and Statistical Manual of Mental Disorders, edition 3 (DSM-III) criteria; and 2) control subjects were defined as those multi-infarct patients without dementia or multi-infarct dementia according to DSM-III criteria. RESULTS: Overall, multi-infarct index cases had more cerebral infarcts, more cortical and subcortical left hemisphere infarcts, higher mean ventricular volume to brain volume ratio, more extensive enlargement of the body of the lateral ventricles and cortical sulci, and a higher prevalence of white matter lucencies. Among multi-infarct cases and control subjects the most frequent site of infarction was the subcortical region, and the most frequent pattern of infarction was lacunar. Stepwise logistic regression analysis examined cranial computed tomography as well as other factors and showed that level of education, stroke severity, left cortical infarction, and diffuse enlargement of the left lateral ventricle were the best overall predictors of multi-infarct dementia. CONCLUSIONS: Level of education, stroke severity, and left hemisphere infarction may be predictors of multi-infarct dementia.     

Myelin lipids in ischemic stroke.

Slices of ischemic focus (infarct area) and of the contralateral frontal lobe were submitted to histological and biochemical studies. The obtained results indicate that in stroke cases the necrotic focus as well as contralateral brain hemisphere are characterized by a marked decrease of cholesterol and cerebrosides content and an increase of lysophosphatidylcholine and cholesterol esters in the myelin fraction. We conclude that ischemia as well as the degenerative aging process are both responsible for the abnormal lipid pattern in the myelin of the white matter in stroke cases. The long lasting hypoxia resulting from cerebral vessel atheromatosis contributes to biochemical changes in the myelin of the apparently healthy white matter of the contralateral hemisphere in brain infarction.     

Klinisch stumme Hirninfarkte

Silent brain infarctions are frequently found by modern cerebral imaging. Up to 30% of persons without a clinical history of stroke were found to have silent brain infarction in epidemiological studies. "Silent" refers to ischemic brain lesions for which no matching clinical syndrome can be found based on history or clinical investigation. Age, education, and ethnic background have a strong impact on noticing and reporting stroke symptoms. The current clinical definition of stroke is insensitive for cognitive deficits which can also be caused by brain infarctions. The majority of silent brain infarctions are localized in the subcortical white matter of the brain; however, about 10% of silent brain infarctions are cortical. Silent brain infarctions are strongly associated with stroke risk factors and comorbidities that are known to cause clinically overt stroke. Silent brain infarctions are 5 to 10 times more frequent than clinically overt strokes. Silent brain infarctions as defined by DWI lesions on MRI imaging are a frequent finding during operative or interventional procedures and their monitoring may help improve the respective techniques in order to decrease the risk of periprocedural stroke.     

A quantitative MRI study of vascular dementia.

We studied the MRI and clinical factors associated with dementia following stroke by quantifying ventricle-to-brain ratio (VBR), anatomic region of infarction, and cortical, subcortical, and white matter areas of infarction in 24 stroke patients with dementia and 29 nondemented stroke patients. The factors that most strongly correlated with dementia were total white matter lesion (WML) area, left WML, VBR, right WML, age, left cortical infarction area, left parietal infarction area, and total infarction area. Using discriminant analysis, these factors correctly classified 28 of 29 nondemented patients and 18 of 24 demented patients. Both cortical and white matter total infarction area measurements were strongly associated with dementia in stroke patients, suggesting that these factors strongly influenced the development of dementia following stroke. There was a strong association between dementia and left- but not right-hemisphere infarction area. The only demographic factor that strongly associated with dementia was age.     

Study of cerebral blood flow in patients with cerebral infarction by 133Xe inhalation method--comparison between affected and unaffected hemispheres, and sequential changes

Cerebral blood flow in both hemispheres was studied by the 133Xe inhalation method in 49 patients with cerebral infarction in the unilateral hemisphere. They were classified into three groups by computed tomographic findings as follows; relatively large low density lesion including the cerebral cortex and subcortex (cortical: C group), relatively large low density lesion including the subcortical white matter and basal ganglia (large subcortical: L group), and small low density lesion including the subcortical white matter (small subcortical: S group), respectively. Mean cerebral blood flow (mCBF) in the affected hemispheres was markedly low in C group, moderately low in L group, and slightly low in S group, in all of the examinations. Several cases in C and L groups revealed remarkable changes of mCBF less than one month after the onset. MCBF in both hemispheres was lower in C group than in L and S groups less than one week after the onset. Seven to twelve weeks after the onset, mCBF in the affected hemisphere was lower in C and L groups than in S group, and than in the unaffected hemisphere of C and L groups. There was no difference between mCBF in the affected hemisphere and that in the unaffected hemisphere in most of S group. Sequential changes of mCBF in both hemispheres were divided into seven types in 27 cases, who were examined first less than one week and repeatedly then. However, the sequential changes were classified roughly into two patterns.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence of silent stroke in patients presenting with initial stroke: the Framingham Study

It is common to find computed tomography scan evidence of prior stroke without a history of such an event. The frequency, risk factors for, and relevance of silent strokes are unknown. The Framingham cohort of 5,184 men and women aged 30-62 years and free of stroke at entry to the study have been followed with periodic examinations since 1950. We studied the silent strokes found on computed tomography scan of all initial strokes that occurred between January 1, 1979, and July 31, 1987. During these 8 1/2 years, 164 initial strokes occurred; 124 had computed tomography scans performed. There were 13 (10%) with silent stroke, 71 had abnormalities related to their presenting acute stroke, and 40 had normal computed tomography scans. There were 15 silent lesions; eight were lacunar infarcts in the basal ganglia-internal capsule area, seven were small cortical infarcts. Glucose intolerance was the sole risk factor that occurred significantly more frequently (11 of 13) in the group with silent lesions (p less than 0.04) than in the group with computed tomography evidence of acute stroke. Silent stroke is not rare; it was present in at least 10% of acute initial stroke patients arising in a general population. The relation of these silent lesions to the development of "vascular" dementia and poststroke disability deserves further study.     

Clinical aspects of silent cerebral infarction--MRI findings and its distribution

High-field MR scans have often showed patchy incidental findings especially in the elderly. We examined 91 patients, without episodes of cerebrovascular disorders previously, who had silent cerebral lesions noted by the 1.5 tesla superconductive system T2 weighted magnetic resonance imaging. They were divided into three subtypes by the localization of foci. The 23 subjects (25%) showed confined lesions to thalamus and/or internal capsule and/or basal ganglia (the basal ganglia type). The 39 subjects (43%) had lesions predominantly in cerebral cortex and/or subcortical white matter and/or cerebellum (the diffuse subcortical type). Finally, the 29 subjects (32%) had both features of above-mentioned two groups (the mixed type). These subtypes were correlated with age, sex and some of the other risk factors, such as systolic blood pressure, diastolic blood pressure, serum total cholesterol and uric acid, for stroke. The mean age of the basal ganglia type was significantly younger than that of the diffuse subcortical type (p less than 0.001) and than that of the mixed type (p less than 0.001). The diffuse subcortical type consisted of 11 men and 28 women. In the mixed type, it was composed of 21 men and 8 women. These two subtypes had the significant sex differences (the diffuse subcortical type, p less than 0.05 and the mixed type, p less than 0.025). Systolic and diastolic pressures of the basal ganglia type were lower than those of the diffuse subcortical type (systolic, p less than 0.001 and diastolic, p less than 0.025) and than those of the mixed type (systolic, p less than 0.001 and diastolic, p less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)     

The anatomy of unilateral neglect after right-hemisphere stroke lesions. A clinical/CT-scan correlation study in man

The anatomical correlates of extrapersonal visual neglect were investigated in 110 right-handed stroke patients with lesions confined to the right hemisphere. Neglect is much more frequently associated with retrorolandic damage, as compared with frontal lesions. The inferior parietal lobule appears to be the area most frequently involved in patients with cortical lesions showing signs of neglect. When the cerebral lesion is confined to deep structures, neglect occurs much more frequently when grey nuclei such as the thalamus and the basal ganglia are damaged; a remarkable number of negative cases were, however, found. Conversely, lesions limited to the subcortical white matter are rarely associated with neglect. The relevance of these results to anatomophysiological models of directed attention and neglect is discussed.     

Report of a patient with CADASIL having a novel missense mutation of the Notch 3 gene--association with alopecia and lumbar herniated disk]

We report a 52-year-old man with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) presenting dementia, alopecia and lumbar herniated disk. He had an episode of stroke and migraine-like headache lasting for 5 minutes. A lot of members had cerebral infarction in this family. Brain magnetic resonance imaging demonstrated, on T2-weighted images, numerous hyperintense lesions suggestive of small infarcts in the basal ganglia and diffuse hyperintense lesions in the cerebral white matter. The clinical symptoms, the family history and the MRI findings suggested the diagnosis of CADASIL. However, the patient also showed alopecia and lumbar herniated disk, both are characteristic features of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). The DNA analysis of the Notch 3 gene identified a novel missense mutation Cys174Phe in this patient. Our case report indicated the importance of the DNA analysis for the diagnosis of CADASIL.     

单侧孤立基底节区腔隙性脑梗死早期神经功能恶化的多因素分析及缺血耐受的相关性研究

目的 探讨单侧孤立的基底节区腔隙性脑梗死早期神经功能恶化（early neurological deterioration, END）的相关因素及其与脑缺血耐受（brain ischemic tolerance,BIT）机制的研究。 方法 回顾性分析经磁共振证实的167例单侧新发孤立的基底节区腔隙性脑梗死患者的临床资 料,并排除大动脉狭窄患者。根据卒中发生后1周内动态的美国国立卫生研究院卒中量表（National Institutes of Health Stroke Scale,NIHSS）评分情况将167例患者分为END阳性及END阴性两组,使用 Logistic回归分析研究与脑梗死早期神经功能恶化有关的因素。 结果 167例患者中42例发生END,125例未发生END。多因素分析结果显示病灶累及内囊后肢侧脑室 旁放射冠后部是预测END的独立危险因素,两组比较差异有显著性（P <0.01）;而发病年龄、脑梗死 病史、糖尿病史、入院收缩压及脑白质病变与END有相关性,且比较差异有显著性（P <0.05）。分别 以有无合并糖尿病、不同病灶位置进行分层并层间的单因素及多因素分析,结果显示,有无合并糖尿 病、病灶部位的不同不影响年龄、卒中史、脑白质与END阳性的关系,END与既往脑梗死病史、脑白质 病变、发病年龄存在相关性,比较差异有显著性（P <0.05）。 结论 单侧孤立基底节区腔隙性脑梗死早期END与病灶是否累及内囊后肢侧脑室体旁后部密切相关, 同时也与是否合并脑白质病变、既往脑梗死病史、糖尿病史、年龄等因素相关。年龄≥65岁、收缩压 高、卒中史、脑白质病变是END阳性的保护因素。缺血不耐受为腔隙性脑梗死发生END的主要机制。     

Arteriovenous malformation presenting as hemidystonia

Two men, aged 25 and 33 years, had progressive hemidystonia and an arteriovenous malformation (AVM) in the contralateral cerebral hemisphere. One patient with an AVM in the posterior basal ganglia of the right hemisphere had an older brother with severe generalized dystonia. The second patient had an AVM in the left cortical and subcortical parietal area with no obvious lesion in the basal ganglia. Unlike generalized dystonia, a focal lesion is commonly found in patients with unilateral dystonia. The association of AVM-induced hemidystonia and family history of dystonia suggests that genetic predisposition may be important in some patients with hemidystonia.     

脑梗死急性期梗死部位及白质病变与认知功能关系的临床分析

【摘要】
目的 研究急性脑梗死患者梗死部位及是否合并脑白质病变对患者早期认知功能的影响。
方法 采用临床痴呆评定量表、简易精神状态检查量表和中文版蒙特利尔认知评估量表对连续入组的急性脑梗死患者进行认知心理学评估,分析患者不同梗死部位包括皮层梗死、皮层下关键部位梗死和皮层下非关键部位梗死及是否合并白质病变对患者认知功能的影响。
结果 急性脑梗死患者血管性认知功能障碍组的平均年龄显著高于无认知功能障碍组（67.31 10.88 vs 57.09 9.91,P=0.015）,神经功能缺损评分显著高于无认知功能障碍组［3.0（2.0～4.0） vs 1.0（1.0～2.0）,P=0.012］。认知功能障碍组的日常生活能力评分显著低于无认知功能障碍组（81.67 23.55 vs 95.91 12.00,P=0.029）。两组患者梗死部位有显著差异（P=0.042）,皮层梗死更多见于血管性认知功能障碍组,皮层梗死患者的视空间与执行功能显著低于皮层下非关键位置梗死患者［1.5（0.0～3.0） vs 3.0（2.0～4.0）,P=0.016］。白质病变与认知障碍的发生无明显相关性。
结论 急性脑梗死患者早期认知障碍与年龄、严重的神经功能缺损、皮层梗死、日常生活能力下降密切相关。     

Clinical lacunar syndromes as predictors of lacunar infarcts. A comparison of acute clinical lacunar syndromes and findings on diffusion-weighted MRI

OBJECTIVES: To evaluate if patients with acute lacunar syndromes have acute lacunar infarcts or other types of cerebral lesions on diffusion-weighted MRI. METHODS: Patients with acute lacunar syndromes underwent echo-planar diffusion MRI of the brain within 3 days after stroke onset. Localization and size of lesions with hyperintense signal were determined, compared with clinical characteristics and with findings on follow-up T2-weighted MRI. RESULTS: Twenty-three patients participated in the study. Thirteen patients had pure motor stroke, 1 pure sensory stroke, 8 sensorimotor stroke, and 1 ataxic hemiparesis. Twenty-two patients had at least one lesion with increased signal on diffusion-weighted MR images. These acute lesions were in the internal capsule/ basal ganglia/thalamus in 13 patients, subcortical white matter in 5 patients, brainstem in 2 patients, cortex (multiple small lesions) in 1 patient, and cortex + basal ganglia in 1 patient. The median volume of the lesions was 0.6 ml on the initial examination and on follow-up, of 17 patients after 1 to 5 months, 0.5 ml. CONCLUSIONS: Almost all patients with acute ischemic lacunar syndromes have acute lesions on echo-planar diffusion-weighted MRI within 3 days after stroke onset. These lesions are mostly small and subcortical, compatible with lacunar infarcts caused by single penetrating artery occlusion, but in a minor proportion of patients (2 of 23 in our study) a cortical involvement is found.     

A case of neuro-Beh?et's disease with HLA B54 and predominant cerebral white matter lesions]

We report a 55-year-old woman with neuro-Beh?et's disease with HLA B54 and predominant cerebral white matter lesions. She showed a cryptogenic high fever and cerebral cortical symptoms such as perseveration, limbkinetic apraxia and dementia. CSF study showed an increase of cell count and protein and a decrease of sugar. MRI showed diffuse T2-high signal intensity mainly in the subcortical white matter of left parieto-occipital lobes and basal ganglia. Her clinical signs greatly improved after administration of prednisolone. Her HLA type was not B51 but B54. Though our patient did not completely satisfy clinical criteria for neither neuro-Beh?et's disease nor Sweet's syndrome, she showed partial features of both Beh?et's disease and Sweet's syndrome.     

Hemimegalencephaly: Localized Proton Magnetic Resonance Spectroscopy In Vivo

Summary: Two children with hemimegalencephaly were examined by magnetic resonance imaging (MRI) and localized proton MR spectroscopy (MRS). In both cases, structural changes in the enlarged hemisphere included pachy-or polymicrogyria and gliosis of white matter. Associated metabolic disturbances included a dramatic reduction of glutamate and N-acetylaspartate (NAA) in white matter. Less severe or no alterations were noted in cortical gray matter, basal ganglia, and cerebellum. The older child (13 years) showed increased myoinositol in both gray and white matter as well as markedly increased choline-containing compounds in gray matter. Both children also had mildly decreased NAA levels in the white matter of the contralateral hemisphere. The spectroscopic findings indicate loss of vital neuroaxonal tissue and glial cell proliferation. Metabolic disturbances were more pronounced in the older child. The normal-appearing hemisphere was mildly affected in both cases.     

Failure of the somatosensory evoked potential following middle cerebral artery occlusion and high-grade ischemia in the cat--effects of hemodilution

Acute focal ischemia was created in 10 cats by unilateral retro-orbital middle cerebral artery (MCA) occlusion. Regional cerebral blood flow (CBF) was determined utilizing the hydrogen clearance technique from electrode recordings within the gray matter and white matter of the ectosylvian gyrus of both hemispheres. The somatosensory evoked potential (SSEP) was obtained during contralateral median nerve stimulation. When the MCA was clipped the white and gray matter blood flows in the ipsilateral ectosylvian gyrus were reduced to 14.8 +/- 19.6% and 19.3 +/- 23.7% of control, and the cortical component of the SSEP was abolished. In the contralateral hemisphere an average increase of 3.5% above the control latency and a 10% mean depression in the amplitude of the cortical component of the SSEP were observed following occlusion. CBF in the contralateral hemisphere was unaffected by the MCA clip. Infusion of saline or dextran to lower the hematocrit by approximately 45% did not significantly improve blood flow or restore the SSEP in the hemisphere ipsilateral to the MCA clip. However, significant increases in the contralateral hemisphere gray matter CBF occurred following hemodilution while the latency of the cortical component of the SSEP in this same hemisphere was significantly extended. Elevations in gray and white matter blood flows were achieved in the experimental hemisphere of 3 of 10 cats suggesting a wide range of variation in the collateral circulation.     

Cortical Reorganization Due to Impaired Cerebral Autoregulation in Individuals With Occlusive Processes of the Internal Carotid Artery

Background and purposeTo study the impact of impaired cerebral autoregulation on cortical neurophysiology, long term potentiation (LTP)-like plasticity, motor learning and brain structure.Methods12 patients with unilateral occlusion or severe stenosis of the internal carotid artery were included. Impairment of cerebral autoregulation was determined by vasomotor reactivity in transcranial Doppler sonography. Corticomotor excitability, cortical silent period and LTP-like plasticity were assessed with transcranial magnetic stimulation, motor learning with a force production task, and brain structure with high-resolution MRI of the brain.ResultsIn the affected hemisphere, corticomotor excitability was significantly higher, cortical silent period and LTP-like plasticity significantly lower, compared to the contralateral side. No significant difference emerged for motor learning, cortical thickness and white matter integrity between the hemispheres.ConclusionDespite decreased LTP-like plasticity in the affected hemisphere, motor learning was comparable between hemispheres, possibly due to gamma-aminobutyric-acid (GABA)_B-mediated corticomotor excitability changes within the affected hemisphere. Our results may help to develop interventions to beneficially modulate cortical physiology in the presence of cerebral hypoperfusion.     

Hemineglect and seizures in Binswanger''s disease: clinical-pathological report.

The range of clinical effects from ischaemic damage to white matter in Binswanger's disease has not been fully characterised. Although focal deficits and seizures occur frequently, superficial infarcts often coexist, making the cause of these symptoms unclear. The case of a 69 year old woman is described who presented with acute left sided weakness and hemispatial neglect, followed a year later by electrographically documented seizures originating from the right hemisphere. Interim examinations showed bilateral pyramidal signs and mild intellectual decline. Serial CT and MRI studies showed bilateral diffuse ischaemic lesions of the cerebral white matter and old left sided lacunar infarcts but no evidence of acute infarction. Post-mortem examination showed gliosis and demyelination of the deep white matter which spared the subcortical arcuate fibres; this is consistent with Binswanger's disease. The neocortex was normal. This case and previous reports indicate that focal symptoms typically referable to the grey matter, including hemineglect and seizures, may occur as a manifestation of subcortical ischaemic injury to white matter in Binswanger's disease.     

Effect of thrombin inhibition in vascular dementia and silent cerebrovascular disease. An MR spectroscopy study

BACKGROUND AND PURPOSE: Silent cerebrovascular disease (CVD) has been proposed as a predisposing condition for clinically overt stroke and vascular dementia. Recently, we found increased thrombin generation in silent CVD patients. Here, we report the effect of thrombin inhibition using a potent selective thrombin inhibitor on the cerebral metabolism and function in peripheral arterial occlusive disease (PAOD) patients with or without silent CVD. METHODS: We examined 17 mild chronic PAOD patients, including 2 cases of vascular dementia. We divided the patients into 2 groups: 1 was the advanced CVD group with multiple lacunar infarction and/or advanced periventricular hyperintensity detected by brain MRI (n=12), and the other was the no CVD group that had none of these abnormalities (n=5). We assessed the cerebral biochemical compounds in the deep white matter area and cerebellar hemisphere (8 cm3) by proton MR spectroscopy before and after infusion of argatroban (10 mg/d IV) over 2 hours for 7 days. RESULTS: The ratio of N-acetylasparate (NAA) to total creatine (Cre) in the deep white matter area was significantly lower in the advanced CVD group than in the no CVD group, whereas there were no significant differences in this ratio in the cerebellar hemisphere between the 2 groups. In the former group, this decreased NAA/Cre ratio significantly increased after argatroban therapy, whereas there was no change in the latter group. The 2 patients with vascular dementia showed clinical improvement with marked increases in the NAA/Cre ratio and mini-mental score. CONCLUSIONS: These results suggest that increased thrombin generation may have some pathophysiological roles in developing vascular dementia and its chronic predisposing conditions. Thrombin inhibition may break this vicious cycle and lead to clinical improvement.     

脑白质区域非腔隙性梗死灶与颅内外血管狭窄关系的探讨

目的 探讨脑白质区域非腔隙性梗死灶与颅内外血管狭窄的关系.方法 对30例脑白质区域非腔隙性梗死患者的头颅MRI以及主动脉弓、全脑数字减影血管造影(DSA)检查资料进行分析.结果 本组MRI示12例单侧基底节区片状异常信号中,DSA表现为一侧颈内动脉(ICA)起始部闭塞或高度狭窄9例,一侧大脑中动脉(MCA)M1段高度狭窄2例,无明确血管病变1例.6例基底节以及侧脑室旁白质区域病灶中,一侧ICA起始部闭塞或高度狭窄3例,一侧ICA C5段闭塞1例,一侧MCA M1段闭塞2例.4例侧脑室旁或半卵圆中心白质区域病灶中,一侧ICA C6段闭塞1例,一侧MCA M1段高度狭窄2例,无明确血管病变1例.8例皮质下上型或皮质下侧型分水岭脑梗死患者中,一侧ICA起始部闭塞或高度狭窄6例,双侧ICA起始部闭塞1例,一侧MCA M1段高度狭窄1例.结论 脑白质区非腔隙性梗死灶的发生与ICA系统大血管的狭窄或闭塞有密切的关系.