Two mesencephalic lacunar infarcts presenting as Claude's syndrome and pure motor hemiparesis

Two exceptional cases of mesencephalic lacunar infarcts located both in the anterior vascular territory are reported. In patient 1, the infarct selectively involved the red nucleus, thus resulting in a Claude's syndrome. In patient 2, the lesion was limited to the external 2/3 of the cerebral peduncle, and was responsible for a pure motor hemiplegia (PMH). CT scan easily demonstrated the lesion in both cases. Claude's syndrome is very unusual, and PMH has only been reported once before in a mesencephalic infarct. The reasons why these lesions are so uncommon are discussed.     

Primary pontine haemorrhage: clinical and computed tomographic correlations.

The clinical and computerised tomographic findings in 40 patients with primary pontine haemorrhage were reviewed. Twenty-nine patients were hypertensive. Four patients had angiographic or necropsy evidence of vascular malformations. In 33 cases, there was rapid deterioration to maximal neurological deficit; whereas in seven cases, there was sudden onset but subsequent progression to maximal deficit 24 hours to 5 days following the initial ictus. Seven patients had clinical features considered atypical for pontine haemorrhage. Five patients survived and four of these were capable of performing activities of daily living within 3 months of the haemorrhage. In all cases CT showed a hyperdense non-enhancing brain stem haematoma. There was evidence of ventricular extension in 27 cases. There was CT evidence of subarachnoid blood in only two patients who also had vascular malformations. In 26 cases, there was CT evidence that the haematoma extended to the midbrain and in four cases to the thalamic region. In six cases CT was repeated 6 to 21 days after the initial scan and it showed resolution of the haematoma in size and density; none of the haematomas showed post-contrast enhancement on initial or follow-up CT.     

Early somesthetic evoked potentials and sensory deficits in thalamic and juxta-thalamic lesions. Clinical, electrophysiological and x-ray computed tomographic study in 70 patients

Somatosensory Evoked Potentials (SEPs) have been recorded in 70 patients presenting a thalamic or capsular CT scan lesion. The loss of SEP parietal components confirmed the deafferentation of somatosensory cortex in infarctions of geniculothalamic or anterior choroidian arteries territory. SEPs were found to be normal in infarctions of other arterial territories, in agreement with the clinical evidence of normal somatosensory performances. In patients with haematomas, especially when located in the thalamus, there was no clear correlation between lesion sites and SEP data. Abnormal parietal responses were always associated to impaired tactile and joint sensations. The correlation was less significant for vibration sense. In four cases of selective loss of pain sensation SEPs were normal. In seven patients with abnormal parietal responses sterognosis was normal, a situation which is never encountered in cortical lesions. SEPs reliably documented the degree of somatosensory loss in patients with tactile extinction phenomenon. Contralateral parietal responses were reduced in four patients with tactile extinction but no attentional deficit for other sensory modalities. Thus normal SEPs are a prerequisite to consider thalamic neglect syndrome as a pure attentional disorder. Moreover SEPs demonstrated that there was no long-lasting deafferentation of somatosensory cortex in ataxic hemiparesis. It was found that selective loss of post-or prerolandic SEP components could occur in capsular lesions. This finding favors the hypothesis of parallel and independant thalamo-parietal and thalamo-frontal somatosensory projections that may be selectively damaged in lesions of thalamocortical radiations.     

Identification of lacunar infarcts before thrombolysis in the ECASS I study

BACKGROUND: The identification of lacunar infarcts before thrombolysis would make it possible either to exclude them from treatment or to show that they also may benefit from it. OBJECTIVE: To determine whether clinical presentation or early CT findings of patients enrolled in the first European Cooperative Acute Stroke Study (ECASS I) trial would identify lacunar infarcts before treatment. METHODS: Predictive values, sensitivity, specificity, and accuracy of clinical presentation as pure motor hemiparesis (PMH) or sensorimotor stroke (SMS) syndromes and of baseline CT findings in predicting lacunar infarcts were calculated in the ECASS I patients. RESULTS: Of 514 patients, 44 placebo (17%) and 44 recombinant tissue plasminogen activator (rt-PA) (18%) patients had PMH/SMS involving at least two of three areas. Thirty-one placebo (12%) and 32 rt-PA (13%) patients had PMH/SMS involving three areas. The 7-day CT was compatible with a lacunar infarct in 32 placebo (12%) and 44 rt-PA (18%) patients. PMH/SMS involving at least two areas had a positive predictive value of 30% both in placebo and rt-PA patients, whereas positive predictive values of the involvement of three areas were 23% and 31%. Those of absence of early CT signs were 21% and 30%, and those of leukoaraiosis or previous lacunar infarcts were 21% and 23%. Positive predictive values of PMH/SMS involving at least two areas combined with absence of early CT signs were 36% in placebo and 33% in t-PA patients, and those of PMH/SMS plus leukoaraiosis or previous lacunes were 28% and 7%, respectively. CONCLUSIONS: In the ECASS I trial, lacunar infarcts were not recognizable on clinical grounds, and early CT findings, alone or in combination with the clinical picture, added poorly to the differential diagnosis.     

Incidental focal intracranial computed tomographic findings.

Of 3000 consecutive computed tomography (CT) head scans there were 28 adult patients who had a focal intracranial lesion, who presented with nonspecific symptoms, and who had normal initial neurological examination. These lesions included cerebral infarction (8), focal atrophy (5), intracerebral haematoma (3), chronic subdural haematoma (3), focal calcification (3) and intracranial neoplasm (6). Neurological consultation was obtained after the CT in all cases. Angiography was subsequently performed in 16, and eight patients underwent surgery. In no case was there evidence that clinical outcome was improved because of the early CT diagnosis.     

Disappearing CT Lesions in Epilepsy

A striking but reversible computed tomographic (CT) lesion corresponding to seizure activity is reported in a series of 46 epileptic patients. None of these patients had evidence of tuberculosis or cysticercosis, and all were treated with antiepileptic drugs only. Maximal radiological changes occurred in the area of maximal epileptic discharge; however, multiple lesions were seen in three cases. The CT lesion reappeared with recurrence of the ictus in four cases during follow-up, and this, too, disappeared after complete arrest of the seizures. The clinical, CT scan, and other investigatory findings suggest that the seizures may occasionally cause a CT-demonstrable focal abnormality, probably cerebral edema, a consequence of abnormal vascular permeability. Awareness of this radiological entity should avoid misdiagnosis of cerebral tumor, infarction or tuberculoma in patients with seizure disorder.     

Striatocapsular infarction: large infarcts in the lenticulostriate arterial territory

A specific form of deep cerebral hemisphere infarction was identified in 11 of 1,600 stroke register patients. Despite the CT finding of a deep striatocapsular lesion, these patients showed evidence of both cortical and capsular abnormalities. Angiography showed significant proximal carotid artery lesions as well as evidence of occlusive or obstructive lesions in the region of the T junction of the internal carotid artery. The combination of these pathologic entities would explain this particular clinical picture.     

Value of Magnetic Resonance Imaging in West Syndrome of Unknown Etiology

Summary: Magnetic resonance imaging (MRI) studies of 46 patients with West syndrome (WS) of unknown etiology were reviewed retrospectively. The criteria for cryptogenic WS were met by 25 and 21 were considered symptomatic because other types of seizure or psychomotor retardation were apparent before spasm onset. Computed tomographic (CT) scans were normal in 38 patients and showed diffuse atrophy in eight symptomatic patients. In five patients, MRI was more informative than CT, demonstrating one case of delayed myelination and four cases of focal lesion. The focal lesion in 2 of these patients was similar on MRI consisting of poor gray-white matter demarcation in the parieto-occipitotemporal region. Surgical resection was performed in one because of intractable seizures, and neuropathological examination revealed cortical dysplasia. The remaining two cases with focal lesion had increased signal intensity on T₂-weighted images in the posterior frontal cortex and in the temporal lobe, respectively. Our data indicate that MRI is useful in some cases of WS, especially in demonstrating focal corticosubcortical lesions not visible on CT scan.     

CT in the diagnosis of cerebral vascular malformations

Summary In 72 patients with spontaneous intracranial haemorrhage and vascular malformation, 27 of 49 arterial aneurysms were diagnosed by CT (the smallest one of 4 mm diameter being stalked), as were all (18) of the arteriovenous aneurysms (angiomas), but of the venous malformations (5) only 2 (aneurysms of the vein of Galen) were so diagnosed. In the 25 patients with spontaneous subarachnoid haemorrhage, in whom vascular malformation had not been diagnosed through angiography or CT, CT showed the position and extent of the parenchymatous lesion or the existence of blood in the subarachnoid space or ventricules. Finally, in 15 patients with subjective or neuropsychiatric disturbances, 9 arterial and 6 arteriovenous aneurysms were diagnosed by CT and were verified by angiography, which would probably not have been performed if CT had not been performed. Thus it is clear that vascular malformations are often diagnosed by CT. In many cases information is revealed which would not be suspected with angiography, while in other cases angiography is more selective and accurate.     

Intracerebral cavernous angiomas

We studied 31 patients with histologically verified intracerebral cavernous angiomas. Twenty-two patients were symptomatic; nine were asymptomatic. All 22 symptomatic patients had seizures, three had intracranial hemorrhage, and one had signs of a space-occupying lesion. Twenty-seven lesions were located in the neocortex, three in the brainstem, and one in the cerebellum; all exhibited characteristic gross and microscopic features of cavernous angiomas. CT identified the location and extent of the lesion in 16 of 27 cases. Six of seven lesions demonstrated contrast enhancement, and ten of 27 scans harbored densities consistent with intracerebral calcium. Angiography was performed in 17 cases and was completely normal in eight. MRI revealed mixed signal intensity centrally with a ring of decreased signal intensity peripherally on T2-weighted images and was diagnostic in five cases. Surgical treatment offers an excellent prognosis for seizure control in patients with such lesions.     

Weakness of head turning in hemiplegia: a quantitative study.

The strength of head turning was measured in normal subjects and in patients with hemiplegia of vascular origin. In normals the strength of head turning to the two sides was not significantly different. In most patients with a cortical, capsular or high brainstem lesion the strength of head turning away from the side of the lesion was reduced. In patients with a medullary lesion the strength of head turning towards the side of the lesion was reduced. The significance of these findings is discussed in relation to the cortical control of the sternocleidomastoid muscle and other muscles involved in the movement of head turning.     

Spastic pure motor monoparesis

Pure motor hemiplegia (PMH) is, in most cases, caused by a lacunar infarction. However, pure motor monoparesis (PMM), i.e., isolated motor involvement with spasticity in one limb, has drawn little attention. We studied prospectively 5 patients with PMM and found that it was always due to a mass lesion in the contralateral superficial cerebral hemisphere. Our observation suggests that PMM should not be regarded as simply a variant of PMH.     

Relevance of computerized electroencephalographic topography (brain mapping) in ischemic stroke

BACKGROUND AND AIMS: Computerized electroencephalographic topography (CET) (brain mapping) is a non-invasive, spatially oriented procedure for depicting amplitude and frequency patterns by two-dimensional color-coded frequency and amplitude display of the electroencephalograph (EEG). MATERIAL AND METHODS: We prospectively studied the relationship between CT scan lesions, conventional EEG and brain mapping in 40 patients with ischemic stroke within 1 week of onset. EEG and brain mapping was done within 24 hours of doing CT scan. RESULTS: There were 32 males and 8 females and the mean age was 56 years (range 27-75 years). CET/EEG was normal in 2 patients with capsular infarct. Brain mapping showed abnormalities (most commonly low-frequency high-amplitude changes) in 95% of patients, whereas EEG abnormalities were seen in only 40%. Brain mapping abnormalities were appropriate to the side of the CT scan lesion in 20 (52.63%) patients and were present bilaterally n 18 (47.37%) patients. Brain mapping abnormalities were ipsilateral to the side of the CT lesion when the lesion was < 2 cm in diameter and they were bi-hemispherical when the CT lesion was > 2 cm in diameter. CONCLUSIONS: There was no correlation between motor deficits and brain map abnormalities.     

Moyamoya病的临床表现与影像学特点

目的 回顾分析12例Moyamoya病的临床和影像学特征，探讨Moyamoya病的影像学诊断价值。方法 分析12例Moyamoya病患的临床资料及数字减影血管造影(DSA)、磁共振血管造影(MRA)、磁共振成像(MRI)和CT结果。结果 所有病例均表现有颈内动脉或其分支不同程度的狭窄或闭塞和颅底异常血管网(MMD血管)；其中病变呈双侧8例．单侧4例。12例中头颅CT表现有梗塞灶4例，脑出血5例，其余3例表现正常。结论 除DsA外．MRI和MRA是两种可以很好评价Moyamoya病的影像学方法。若儿童或青壮年发生脑血管病，反复出现脑梗死或出现脑室出血、脑叶出血或蛛网膜下腔出血(SAH)则要考虑Moyamoya病的可能。     

Evidence of vascular disease from CT scanning in late onset epilepsy.

The CT scans of 74 patients presenting with late-onset epilepsy not due to cerebral tumour were compared with those of an age and sex-matched control group for evidence of cerebral vascular disease. Changes in the scan indicative of cerebral atrophy (enlarged ventricles and cortical sulci) were seen in similar numbers in both patients and controls. However, the scans revealed a highly significant excess of ischaemic lesions in the epileptic patients, in the form of discrete areas of infarction and low attenuation of the periventricular white matter. These changes, which were only seen in two of the controls, were present in 13 of the epileptic patients. The median age at the onset of epilepsy in the 13 patients with ischaemic lesions was 62 years, and they showed an increased incidence of systemic vascular disease and of abnormal neurological signs. In six of the 13 cases, however, clinical examination was normal and CT scanning provided the only evidence of underlying vascular disease.     

Hemiballismus and metastasis to the Luys' body. An anatomo-clinical case

A 55 year-old man complained of headaches, dizziness and vomiting. Neurological examination only showed a cerebellar syndrome. CT scan revealed two hyperdense round areas in the right frontal lobe and cerebellar vermis consistent with metastases and a lung carcinoma was diagnosed. Two months later he presented with typical right hemichorea. A second CT scan showed another hypodense lesion with slight contrast enhancement in the left subthalamic region. He died 6 months after clinical onset. Post mortem examination showed an adenocarcinoma of the right lung with liver metastases. Neuropathological examination revealed four intraparenchymatous metastases one of which involved the left subthalamic nucleus. Hemichorea secondary to metastatic neoplasm of the corpus Luysii is uncommon; only 6 cases have been reported previously; five of them had a post mortem examination of the brain. In three cases a CT scan was available and had demonstrated the site and nature of the lesion.     

Magnetoencephalographic localization of epileptic foci using a 37-channel biomagnetometer]

The magnetoencephalography (MEG) and electroencephalography (EEG) were recorded simultaneously from 10 normal subjects using a 37-channel biomagnetometer. No paroxysmal spikelike waveform was observed in MEG at rest with eyes closed. The MEG and EEG were recorded also from 16 patients with primary epilepsy and 24 patients with secondary epilepsy. The examination proved to be safe for both normal subjects and patients with epilepsy. Interictal spikes were observed in 27 cases during the examination. The percentage of spikes identified in MEG but not in EEG was found to be 2. 3% of all spikes. The foci of the spikes identified in MEG were localized and determined in 20 cases. In 10 patients with secondary epilepsy, the localization of the foci were compared with the lesion demonstrated by magnetic resonance imaging (MRI) or computerized tomography (CT) and with the findings of EEG. In 6 cases, the foci by MEG were consistent. In the 4 cases where the MEG foci did not correspond to the MRI or CT findings, MEG foci were supported by the findings of EEG. MEG allows three-dimensional localization and enables us to elucidate the propagation of paroxysms. MEG was very useful in diagnosing epilepsy.     

Diagnostic approaches to pituitary adenomas

The utility of diagnostic tests for pituitary adenoma was compared in 12 patients. Endocrine and radiologic studies were always abnormal, even when neuro-ophthalmologic tests were normal. In most cases, both tomography of the sella turcica and CT scan revealed a mass in the region of the sella turcica. For more precise definition of suprasellar extension of the mass, metrizamide CT cisternography or tomographic pneumoencephalography with metrizamide provided similar details, although CT cisternography was much more easily done. Angiography provides a means to exclude an aneurysm or vascular malformation, a vascular tumor, or an aberrant course of the internal carotid artery.     

Xenon-enhanced computed tomography cerebral blood flow measurements in acute cerebral ischemia: Review of 56 cases

Objective: Ischemic stroke must be diagnosed promptly if patients are to be treated with thrombolytic therapy. The diagnosis of acute cerebral ischemia, however, is usually based on clinical and computed tomography (CT) scan findings. CT scans are often normal in the first few hours after stroke. The purpose of this study was to determine whether Xenon-enhanced CT (XeCT) cerebral blood flow (CBF) studies could increase the sensitivity of stroke detection in the acute stage. Methods: CBF studies performed within 8 hours of symptom onset were evaluated in 56 patients who presented with hemispheric stroke symptoms. Mean CBF in the symptomatic vascular territory was calculated and compared with the corresponding contralateral area. CBF values below 18 mL/100g/min on 2 adjacent regions of interest were considered ischemic lesions. CT scans and angiograms were compared with the XeCt findings. Neurological condition on admission and discharge was evaluated by using National Institutes of Health Stroke Scale (NIHSS) scores. Results: The mean NIHSS score on admission was 12+/-5. Early CT scans were abnormal in 28 (50%) patients. There were 9 (16%) patients who had normal XeCT scans because of spontaneous reperfusion of the ischemic area. XeCT studies showed an ischemic lesion in 47 (84%) patients. In these patients, the mean CBF in the affected vascular territory was 16+/-8 mL/100g/min compared with 35+/-13 mL/100g/min in the contralateral specular territory (P<0.001). There were no false positive or negative XeCT studies, and the location of the perfusion defect corresponded with the CT and/or angiographic findings in all cases. Eight patients died (14%), and the 48 survivors (86%) had a mean NIHSS score of 9+/-6 on discharge. Conclusions: CBF measurements were correlated with the CT and angiographic results and greatly assisted in the diagnosis of acute ischemic stroke. XeCT studies used for estimating the location and extent of cerebral ischemia may be important in the triage of patients for acute stroke therapy.     

难治性精神分裂症的立体定向手术治疗——术后一年随访结果

目的探讨立体定向手术治疗难治性精神分裂症的临床疗效。方法对251例难治性精神分裂症患者,采用CT定位立体定向双侧杏仁核、内囊前肢、扣带回等多靶点组合毁损治疗,术中用电阻值和微电极电生理验证靶点,其中17例患者因首次手术后3~6个月疗效不佳而接受二次手术。术后1年由精神科医生对治疗效果进行评定。结果251例患者中,恢复13例、显著进步200例、进步29例、无变化9例,无严重并发症发生。结论CT导向立体定向多靶点组合毁损术安全,是难治性精神分裂症的有效治疗方法之一。