Asterixis associated with anatomic cerebral lesions: a study of 45 cases

Introduction – Asterixis is an uncommon sign in structural central nervous system disorders. When asterixis is present, one cannot rule out the possibility of a focal lesion, but it is almost always due to a metabolic encephalopathy. Patients and methods – In the last five years all patients with uni-or bilateral neurologic asterixis attended in our hospital have been studied. Cerebral computed tomogram or magnetic resonance imaging was performed in all patients with uni or bilateral asterixis. Results – We describe 45 patients with different forms of structural cerebral pathology who presented unilateral (37 patients) or bilateral (8 patients) asterixis not associated to either toxic or metabolic disorder. Central nervous system ischemic or hemorrhagic disorders were found to be the most frequent causes of asterixis (95.5%) and the thalamus the most frequent localization for unilateral asterixis to result (54%). Conclusion – Bilateral asterixis is not always associated with toxic or metabolic disorders and it may be a sign of some structural neurologic alterations. A good correlation was found between the presence of unilateral asterixis and structural intracranial disease.     

The measurement of spatial contrast sensitivity in cases of blurred vision associated with cerebral lesions.

Thirty-five patients with known cerebral lesions complained of recently acquired blurred vision. None of them had evident oculomotor or pupillary abnormalities, and each had intact central fields and normal visual acuity by conventional standards. Examination of spatial contrast sensitivity was carried out with sinusoidal grating patterns, by determining the minimum contrast between alternate light and dark bars required to distinguish the pattern from a homogeneous field. This was done at each of several spatial frequencies which were established by varying the width of the bars and hence the coarseness of the pattern. The contrast sensitivities were plotted as "visuograms" which, by analogy to audiograms, record the sensitivities in comparison to normal standards. Of the 35 patients, most showed significant losses, amounting to greater than 50 per cent elevation of contrast thresholds. Eighteen showed high frequency losses; 11 had uniform reductions over the entire visible spatial frequency range and 6 had selective frequency losses in the intermediate frequency ranges. These defects in spatial contrast sensitivity, which were not predictable from standard acuity scores, indicate that the visual symptoms in our patients may have been caused by damage to frequency-selective neural elements in the central visual systems. The method may be used to advantage in clinical investigations as well as in physiological investigations of the functional pathways subserving central vision.     

Facial and neuroepithelial abnormalities in a neurological mutant with congenital hydrocephalus. A scanning electron microscope study

This investigation was carried out to determine the early structural abnormalities of the cephalic region in a genetic mutant of the rat characterized by prenatal aqueductal stenosis and hydrocephalus. The appearance of hydrocephalic and control embryos was examined on days 13-15 of gestation, and the structure and organization of the neuroepithelium and basal lamina were studied using scanning electron microscopy. In addition to some overall developmental delay, hydrocephalic embryos were characterized by abnormalities of forebrain and midbrain development, and eye and external ear anomalies. There were also associated defects of the midfacial region. The lateral cell surface of the neuroepithelium reflected the developmental delay of hydrocephalic embryos, and failed to undergo the morphogenetic cell-shaping changes seen in control embryos. There were also variations in the number of lateral cell-cell specializations as well as regions of neuroepithelial disorganization and occasional herniation into the mesenchymal compartment. The role of the neuroepithelial basal lamina and extracellular matrix in the development of these defects is considered.     

Primary cerebral neuroblastoma. A clinicopathological study of 35 cases.

A series of 35 primary cerebral neuroblastoma is reported. These rare tumours occur most often in children in the first half of the first decade. Grossly the tumors are often massive, discrete, lobular, firm and cystic. Histologically three variants, largely determined by the extent and distribution of the fibrous connective tissue stroma, are recognized: (1) a classical variant, which most resembles the peripheral neuroblastoma and is characterized by a high frequency of Homer Wright rosettes and a relatively high frequency of ganglionic differentiation; (2) a desmoplastic variant, which is characterized by an intense connective tissue stroma; and (3) a transitional variant, in which both the classical and the desmoplastic features may be present within the same case, either concurrently or consecutively. Both the desmoplastic and the transitional forms are less likely to exhibit differentiation to mature ganglion cells, but the importance of identifying the primitive cell elements as neuroblasts is emphasized. With rare exceptions, this can be established only by specific silver impregnations on frozen material. Occasionally the direction of growth may be largely leptomeningeal. Seven illustrative clinical histories with pathological correlations are described. The over-all clinical behaviour of these tumours is that of malignant neuroepithelial neoplasms, characterized by a high recurrence rate. Recurrence may, however, be a late development, in some cases occurring five or seven years after apparently successful surgical removal. The tumour shows shows a high incidence of metastatic spread, almost 40 per cent of the cases examined at autopsy having disseminated in the cerebrospinal pathways. Exceptionally, extraneural metastases may also develop. However, long post-operative survival occasionally occurs, and the subsequent clinical course is not always predictable in the individual case. The differential diagnosis is briefly discussed. The cellular nature of the tumour and its biological behaviour recall those of the cerebellar medulloblastoma. Post-operative radiation to the entire neuraxis should be considered for these neoplasms.     

电刺激小脑顶核治疗急性脑梗死75例临床疗效观察

目的:观察电刺激小脑顶核治疗急性脑梗死的临床疗效。方法:150例急性脑梗死患者(n=75)随机分为A,B两组。A组(n=75),常规治疗基础上接受电刺激小脑治疗,10d1个疗程,而B组对照组(n=75),仅按常规治疗。然后观察其疗效并与对照组作比较。结果:发现接受电刺激组患者疗效明显优于对照组。治疗组在10d以及三个月时神经功能缺损评分和日常生活活动能力评分均高于对照组。治疗组有效率高于对照组,两组比较有统计学差异(10dp<0.05,三个月p<0.01)。结论:电刺激小脑顶核治疗有利于急性脑梗死患者神经功能早期恢复。     

Intellectual impairment and cerebral lesions in multiple cerebral infarcts. A clinical-computed tomography study

The relation between cerebral lesions studied by computed tomography and the dementia syndrome has been evaluated in 40 patients with multi-infarct dementia, in 44 nondemented subjects with multiple infarcts, and in 30 controls matched for age and sex. Our study of the volume of ischemic lesions showed a slightly greater loss of cerebral substance in patients with multi-infarct dementia than in nondemented subjects with multiple infarcts, particularly in subjects with unilateral focal lesions and in patients with bilateral multiple cortical and subcortical lesions. The dementia syndrome was significantly associated with multiple locations of lesions in the thalamic and cortical areas supplied by the middle cerebral arteries. Moreover, patients with the dementia syndrome showed a significantly higher degree of cerebral atrophy than nondemented subjects and controls as evaluated by measurements of ventricular size, area of ventricular space, and area of subarachnoid space.     

Comparative study on pathogenesis of selective cerebral lesions in carbon monoxide poisoning and nitrogen hypoxia in cats

Summary Since in a previous study hypoxia and subsequent hypotension were considered to be essential for the pathogenesis of carbon monoxide encephalopathy (CO-encephalopathy), experiments were conducted to see whether a combination of nitrogen hypoxia and subsequent systemic hypotension of similar degree and duration as in the previous experimental CO poisoning could induce the same lesion in the CNS of cats. The partial pressure of blood oxygen was reduced to less than 26 mm Hg by increasing the concentration of nitrogen in N₂/O₂ gas to be inhaled in 1.5 h and then the aortic blood pressure (BP) was reduced to 60–80 mm Hg by blood depletion and ganglion-blockage for 1 h. In 11 of the 15 cats, lesions were produced in the CNS which were similar by light and electron microscopy to those in CO-encephalopathy. In control groups which were treated by hypoxemia only, hypotension only or a combination of CO₂-gas inhalation and hypotension without hypoxemia, such lesions were not found in the cerebral white matter.Considering the pathogenesis of lesions in the cerebral white matter in both nitrogen hypoxia and CO-poisoning, two factors, i.e., hypoxemia and subsequent systemic hypotension, are common and essential. Further, the enormous vasodilation in the cerebral white matter induced by hypoxemia and subsequent drop in BP seem to cause a more severe circulatory disturbance in the cerebral white matter than in the cortex.Supported by the Nissan Science Foundation     

The differential diagnosis of cerebello-pontine angle lesions. A multidisciplinary approach with special emphasis on the brainstem auditory evoked potential

92 patients thought to have a cerebello-pontine angle tumour on initial presentation were studied prospectively using standard neuro-otological techniques, brainstem evoked potential recording with a variety of montages, middle latency auditory evoked potentials and CT scanning. 64 patients had a tumour, 40 of which were acoustic neuromas. By analysing the data from all disciplines it has been possible to delineate clusters of variables that are of value in the differential diagnosis of cerebello-pontine angle lesions.     

脑白质损害的认知功能研究

目的 :观察脑白质损害 (WML )与事件相关电位 P30 0变化关系 ,探讨 WML在认知功能降低中的作用。方法 :35例经 MRI证实的 WML ,进行影像学、简易智能状态检测 (MMSE)和事件相关电位 P30 0测定 ,依据 WML体积将其分为轻度 (<5 cm3)、中度 (5～ 15 cm3)和重度 (>15 cm3) ,并对 WML与 P30 0潜伏期变化进行相关分析。结果 :轻度 WML 11例 ,中度 17例 ,重度 7例 ,主要表现为 T2和质子密度加权像上高信号 ,分布在脑室周围、半卵园中心及皮层下白质。轻度及中度 WML时 MMSE测定值无降低 ,重度 WML时 MMSE也只降低为 2 6 .9。随 WML的程度加重 ,P30 0潜伏期延长越明显 ,相关分析提示两者具有正相关。结论 :观察老年性 WML主要依靠 T2像或质子密度加权像。MMSE在反应 WML导致的认知功能障碍时不够敏感。 WML能引起事件相关电位 P30 0延长 ,其损害程度与 P30 0潜伏期变化呈正相关。     

神经影像辅助下双侧大脑前动脉分布区急性脑梗死发病机制研究-附4例病例报道

目的 借助现代神经影像方法探讨双侧大脑前动脉(anterior cerebral artery,ACA)分布区梗死可能的机制.方法 回顾性分析4例急性双侧ACA分布区脑梗死患者的临床及头MRI、MRA或血管造影等影像学资料.结果 4例患者均有脑血管病危险因素,包括高血压、糖尿病、高脂血症、吸烟等.动脉硬化及血管变异是双...     

脂肪因子visfatin与脑梗死发病机制的相关性研究

目的通过检测急性脑梗死中血清visfatin水平来探讨该因子与脑梗死的相关性及发病的关系。方法分为健康对照组（A组）和实验组（B组）,根据测定的颈总动脉内膜中层厚度（IMT）,B组又分为无动脉粥样硬化组（B1组）和动脉粥样硬化组（B2组）,常规化验空腹血清总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、血糖,用酶联免疫吸附试验（ELISA）法来测定各组血清visfatin水平,分析visfatin与脑梗死的相关性及发病的关系。结果 visfatin水平B组高于A组,B2组高于B1组,logistic回归分析示visfatin含量越高越容易患动脉粥样硬化。结论 visfatin可作为动脉粥样硬化的独立危险因素,高水平血清visfatin与脑梗死的发病相关。