Diffusion-weighted MRI in acute lacunar syndromes. A clinical-radiological correlation study.

BACKGROUND AND PURPOSE: Clinical-radiological correlation studies in lacunar syndromes have been handicapped by the low sensitivity of CT and standard MRI for acute small-vessel infarction and their difficulty in differentiating between acute and chronic lesions. METHODS: We prospectively studied 43 patients presenting with a classic lacunar syndrome using diffusion-weighted MRI, a technique with a high sensitivity and specificity for acute small-vessel infarction. RESULTS: All patients were scanned within 6 days of stroke onset. An acute infarction was identified in all patients. Pure motor stroke was associated with lesions in the posterior limb of the internal capsule (PLIC), pons, corona radiata, and medial medulla; ataxic hemipareses with lesions in the PLIC, corona radiata, pons, and insular cortex; sensorimotor stroke with lesions in the PLIC and lateral medulla; dysarthria-clumsy hand syndrome with lesions in the PLIC and caudate nucleus; and pure sensory stroke with a lesion in the thalamus. Supratentorial lesions extended into neighboring anatomic structures in 48% of the patients. CONCLUSIONS: Lacunar syndromes can be caused by lesions in a variety of locations, and specific locations can cause a variety of lacunar syndromes. Extension of lesions into neighboring structures in patients with lacunar syndromes appears to be more frequent than previously described in studies using CT and standard MRI.     

The classic lacunar syndromes: clinical and neuroimaging correlates

Background:  Although lacunar syndromes (LSs) are aimed to be linked to lacunar infarcts, the relation between both is still not very well defined.
Purpose:  The present retrospective study tries to define more specifically the clinical and the neuroimaging characteristics of the five most classic LSs.
Patients and methods:  Out of a series of 1617 consecutive stroke patients, admitted to the Ghent University Hospital, 293 presented a classic LS. Magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) was performed within 5 days after stroke onset in 227 patients. An acute territorial infarct was demonstrated in 54 patients. The study population finally consisted of 173 patients with a classic LS in whom the responsible lacune was demonstrated or in the absence of another type of infarct.
Results:  The responsible lacune was demonstrated with DWI in 104 patients. Pure motor stroke (MS) correlated significantly with the presence of the responsible lacune in the internal capsule ( P  = 0.000147) and with the stroke severity ( P  = 0.00724). No significant correlation was observed between the location of the lacunes and the other LS's.
Conclusion:  Pure MS has to be considered as the most specific lacunar syndrome.     

Predictive value of clinical lacunar syndromes for lacunar infarcts on magnetic resonance brain imaging

OBJECTIVE: We prospectively investigated the predictive value of clinical and CT-supported lacunar syndromes for lacunar infarcts on magnetic resonance (MR) brain imaging. PATIENTS AND METHODS: The 54 prospective, consecutive patients had clinical lacunar syndromes of acute onset and early computed tomography (CT; on admission day, i.e. < or =48 h after onset of symptoms) showing either a small deep infarct or no corresponding lesion. Taking MR (at day 2 to 4 after admission) as the gold standard, the positive predictive value of the CT-supported clinical syndrome for corresponding lacunar lesions was calculated. RESULTS: In 27 (50%) patients, early CT showed a lacunar infarct corresponding to the clinical syndrome, a further 27 (50%) patients had no fresh ischemic lesion. In 51 patients (94%), MR showed a recent lacunar infarct (hyperintense lacune in T2-weighted scans, no demarcation on T1-weighted scans and/or positive gadolinium-enhancement) corresponding to the clinical syndrome (positive predictive value 0.94, 95%, CI: 0.88 to 0.98). In 3 (6%) patients MR was normal. Aside from old unrelated ischemic (macro- and/or microangiopathic) lesions, MR revealed no acute non-lacunar infarct. CT and MR sites of lacunar lesions were matching. Compared to gold standard MR, the sensitivity of early CT for suspected lacunar lesions was 0.53 (95% CI: 0.38 to 0.67). CONCLUSION: Lacunar syndromes were highly predictive for small deep infarcts on MR. Magnetic resonance brain imaging may be redundant in the setting of a lacunar syndrome supported by a CT that excludes non-ischemic causes of stroke; it may therefore be abandoned in order to reduce costs in the health care system.     

Clinical study of 39 patients with atypical lacunar syndrome

The aim of this study was to describe the clinical characteristics of atypical lacunar syndrome (ALS) based on data collected from a prospective acute stroke registry. In total, 2500 acute stroke patients were included in a hospital based prospective stroke registry over a 12 year period, of whom 39 were identified as having ALS and radiologically proven (by computed tomography or magnetic resonance imaging) lacunes. ALS accounted for 1.8% of all acute stroke patients, 2.1% of acute ischaemic stroke, and 6.8% of lacunar syndromes. ALS included dysarthria facial paresis (n = 12) or isolate dysarthria (n = 9), isolated hemiataxia (n = 4), pure motor hemiparesis with transient internuclear ophthalmoplegia (n = 4), pure motor hemiparesis with transient subcortical aphasia (n = 3), unilateral (n = 2) or bilateral (n = 3) paramedian thalamic infarct syndrome, and hemichorea hemiballismus (n = 2). Atypical lacunar syndromes were due to small vessel disease in 96% of patients. Atherothrombotic infarction occurred in one patient and cardioembolic infarct in another, both presenting pure dysarthria. Outcome was good (in hospital mortality 0%, symptom free at discharge 28.2%). After multivariate analysis, the variables of speech disturbances, nausea/vomiting, ischaemic heart disease, and sensory symptoms were found to be significantly associated with ALS. In conclusion, atypical lacunar syndrome is an infrequent stroke subtype (one of each 14 lacunar strokes). ALS occurred in 6.8% of lacunar strokes. Isolated dysarthria or dysarthria facial paresis were the most frequent presenting forms. The prognosis of this infrequent non-classic lacunar syndrome is good.     

MRI findings of small subcortical “lacunar-like” infarction resulting from large vessel disease

Small subcortical infarctions resulting from large-vessel disease are often observed. It is important to distinguish these from pure lacunar infarction resulting from small-vessel disease because the investigations and examinations differ. We investigated the differences on brain magnetic resonance imaging (MRI) between small subcortical "lacunar-like" infarcts resulting from large-vessel disease and pure lacunar infarcts. Thirteen subjects with small lacunar-like infarcts (size < 2 cm), resulting from large-vessel disease, and 30 subjects with lacunar infarcts (< 2 cm), without large-vessel disease were studied. We measured infarction size using a 1.5-T MRI device and evaluated silent subcortical hyperintensity lesions using the modified Scheltens' score. Large-vessel lesion was confirmed by conventional angiography, duplex carotid scan, and magnetic resonance angiography. There was no difference in the mean age of the two groups. Cerebrovascular risk factors and atherosclerotic complications were also comparable for the two groups. Progressive stroke was more common in the lacunar-like infarction group than in the lacunar infarction group (P = 0.004). Scores for periventricular hyperintensity, white matter hyperintensity, basal ganglia hyperintensity, and total subcortical hyperintensity scores were significantly higher in the lacunar infarction group than in the lacunar-like infarction group. The difference in basal ganglia hyperintensity scores was remarkable (P = 0.001). The enlargement of the perivascular space was also significantly greater in the lacunar infarction group than in the lacunar-like infarction group. These findings seem to reflect differences in the pathogenesis of infarction between the two groups. Silent subcortical hyperintensity lesions and enlargement of perivascular space are useful for between distinguishing small lacunar-like infarct resulting from large-vessel disease and pure lacunar infarction. This may have significant implications for the management of patients with lacunar-sized infarctions. It suggests that the pathogenesis of lacunar-sized infarction is variable.     

Cerebral microbleeds and white matter changes in patients hospitalized with lacunar infarcts

Abstract. Microbleeds (MBs) detected by gradient-echo T2*-weighted MRI (GRE-T2*),white matter changes and lacunar infarcts may be regarded as manifestations of microangiopathy. The establishment of a quantitative relationship among them would further strengthen this hypothesis. We aimed to investigate the frequency and the number of MBs in patients hospitalized with lacunar infarcts and their quantitative relationship with the severity of white matter changes (WMC) and the number of old lacunar infarcts. We performed a hospital-based survey of patients with acute lacunar infarct. Eighty-two consecutive Chinese patients with acute lacunar infarcts on diffusion-weighted imaging were recruited in 2002. The number of MBs, number of old lacunar infarcts on T2-weighted imaging and the severity of WMC on MRI on admission were recorded. MBs were detected in 22 (27%) patients. The number of MBs ranged from 1 to 42 (mean 6.59, median 3). Advancing age and previous transient ischemic attacks or cerebrovascular accidents (TIA/CVA) were more common in patients with MBs than those without. There were significant correlations among the number of MBs, extent of WMC and number of lacunar infarcts: lacunar infarcts and MBs (r = 0.297, p = 0.007); lacunar infarct and WMC (r = 0.331, p = 0.002); WMC and MBs (r = 0.522, p < 0.0001). In conclusion, linear associations exist among MBs, WMC and lacunar infarcts. Our results suggest that all three may have a shared pathogenesis such as advanced microangiopathy.     

磁共振扩散加权成像在鉴别新陈腔隙性脑白质梗死中的价值

目的分析新陈腔隙性脑白质梗死的T2WI、扩散加权成像(DWI)信号特点，比较两种梗死的病灶与脑白质、病灶与脑脊液对比度及表观扩散系数(ADC)，评价DWI在鉴别新陈腔隙性脑白质梗死方面的作用。方法急性期腔隙性脑白质梗死患者27例，选择43例陈旧腔隙性脑白质梗死患者作对照。测量病灶、正常脑白质、脑脊液信号强度，计算病灶与脑白质、病灶与脑脊液的对比度。测量病灶、正常脑组织、脑脊液的ADC值并比较。结果(1)急性脑白质腔隙性梗死DWI呈高信号，ADC图呈等或低信号。DWI的病灶与脑白质、病灶与脑脊液对比度均优于T2WI。(2)陈旧脑白质腔隙性梗死DWI呈等信号，ADC图呈高信号。DWI的病灶与脑白质对比度不如T2WI。(3)DWI图像上，急性腔隙性脑白质梗死病灶与脑白质、病灶与脑脊液对比度明显高于陈旧病灶，ADC则明显低于陈旧病灶，有助于区分新陈腔隙性梗死。结论DWI的检查时间短，诊断和鉴别意义大，建议在可能的情况下，将DWI作为急性卒中样发作患者的常规检查序列。     

Virchow-Robin spaces relate to cerebral small vessel disease severity

BACKGROUND AND PURPOSE: Virchow-Robin spaces (VRs) are perivascular spaces surrounding the deep perforating brain arteries. VRs dilatation is pathologic, and it could be a manifestation of cerebral small vessel disease. In the present study we assessed the relation between VRs and silent ischemic lesions in a cohort of patients with cerebral small vessel disease. METHODS: We divided dilated VRs on MRI (1.5 Tesla) into three semi-quantitative categories in 165 first ever lacunar stroke patients. We counted asymptomatic lacunar infarcts and graded white matter lesions, and compared the prevalence of vascular risk factors in different categories of VRs. We also determined independent predictors of silent ischemic lesions. RESULTS: VRs at basal ganglia level related to age, hypertension, asymptomatic lacunar infarcts, and white matter lesions. VRs at basal ganglia level predicted silent ischemic lesions (odds ratio 10.58 per higher VRs category; 95 %- confidence interval 3.40 - 32.92). CONCLUSION: Dilated VRs in the basal ganglia relate to the severity of cerebral small vessel disease and might be a manifestation of the same small vessel abnormality that causes silent ischemic lesions. This adds a role for VRs as a potential marker for small vessel disease.     

Aberrant white matter networks mediate cognitive impairment in patients with silent lacunar infarcts in basal ganglia territory

Silent lacunar infarcts, which are present in over 20% of healthy elderly individuals, are associated with subtle deficits in cognitive functions. However, it remains largely unclear how these silent brain infarcts lead to cognitive deficits and even dementia. Here, we used diffusion tensor imaging tractography and graph theory to examine the topological organization of white matter networks in 27 patients with silent lacunar infarcts in the basal ganglia territory and 30 healthy controls. A whole-brain white matter network was constructed for each subject, where the graph nodes represented brain regions and the edges represented interregional white matter tracts. Compared with the controls, the patients exhibited a significant reduction in local efficiency and global efficiency. In addition, a total of eighteen brain regions showed significantly reduced nodal efficiency in patients. Intriguingly, nodal efficiency–behavior associations were significantly different between the two groups. The present findings provide new aspects into our understanding of silent infarcts that even small lesions in subcortical brain regions may affect large-scale cortical white matter network, as such may be the link between subcortical silent infarcts and the associated cognitive impairments. Our findings highlight the need for network-level neuroimaging assessment and more medical care for individuals with silent subcortical infarcts.     

Diffusion-weighted imaging identifies a subset of lacunar infarction associated with embolic source

BACKGROUND AND PURPOSE: Small infarcts in the territory of penetrator arteries were described as causing a number of distinct clinical syndromes. The vascular pathophysiology underlying such infarcts is difficult to ascertain without careful pathological study. However, the occurrence of multiple, small infarcts, linked closely in time but dispersed widely in the brain, raises the possibility of an embolic mechanism. The current study determines the frequency and clinical characteristics of patients with well-defined lacunar syndromes and the diffusion-weighted imaging (DWI) evidence of multiple acute lesions. METHODS: Sixty-two consecutive patients who presented to the emergency room with a clinically well-defined lacunar syndrome were studied by DWI within the first 3 days of admission. RESULTS: DWI showed multiple regions of increased signal intensity in 10 patients (16%). A hemispheric or brain stem lesion in a penetrator territory that accounted for the clinical syndrome ("index lesion") was found in all. DWI-hyperintense lesions other than the index lesion ("subsidiary infarctions") were punctate and lay within leptomeningeal artery territories in the majority. As opposed to patients with a single lacunar infarction, patients with a subsidiary infarction more frequently (P<0.05) harbored an identifiable cause of stroke. CONCLUSIONS: Almost 1 of every 6 patients presenting with a classic lacunar syndrome has multiple infarctions demonstrated on DWI. This DWI finding usually indicates an identifiable cause of stroke and therefore may influence clinical decisions regarding the extent of etiologic investigations and treatment for secondary prevention.     

Hemorrhagic lacunar stroke

A total of 17 patients with lacunar syndromes due to intracerebral hemorrhage or hemorrhagic lacunar stroke (pure motor hemiparesis 9, sensorimotor stroke 5, pure sensory stroke 3) are reported. Data from these patients were obtained from consecutive stroke patients included in the prospective Hospital Sagrat Cor-Alian?a Stroke Registry. Hemorrhagic lacunar stroke accounted for 3.8% of all cases of lacunar syndrome (n = 439) and 7.4% of all cases of intracerebral hemorrhage (n = 229) entered in the database. Demographic, anamnestic, clinical and neuroimaging variables in patients with hemorrhagic lacunar stroke, non-lacunar intracerebral hemorrhage and non-hemorrhagic lacunar stroke were compared. Predictors of hemorrhagic lacunar stroke were assessed by logistic regression analysis. Hypertension, cigarette smoking and involvement of the internal capsule were significantly more frequent in patients with hemorrhagic lacunar stroke than in those with non-lacunar intracerebral hemorrhage, whereas nausea and vomiting, altered consciousness, speech disturbances, hemianopia, and ventricular hemorrhage were significantly less frequent. As compared with non-hemorrhagic lacunar stroke, patients with hemorrhagic lacunar stroke were more likely to have hypertension, sudden stroke onset (minutes), head injury, headache, and basal ganglia involvement and less likely to have diabetes, gradual stroke onset (hours), and dysarthria. After multivariate analysis, only headache (OR 10.14), sudden onset (OR 9.89), and dysarthria (OR 0.10) were independent predictors of hemorrhagic lacunar stroke. Accordingly, the presence of headache and sudden onset of symptoms and absence of dysarthria may be useful signs for distinguishing hemorrhagic lacunar stroke from other causes of lacunar stroke.     

Neuropsychological abnormalities associated with lacunar infarction

The objective of this study was to assess neuropsychological abnormalities in 40 patients with lacunar infarction. Topography of infarction, presence of isolated or multiple silent infarcts and white matter hyperintensities were correlated with results of neuropsychological tests and subtypes of lacunar infarction. Patients were studied within 1 month after stroke. A total of 21 patients were males and the mean age was 70.7 years; 30% had a single infarction (mean number of infarctions was 3.4). Twelve patients had pure motor hemiparesis, 9 pure sensory stroke, 8 dysarthria-clumsy hand/ataxic hemiparesis, 8 atypical lacunar syndrome, and 3 sensorimotor stroke. The mean score of the Mini-Mental State Examination was 28.4. Mild cognitive impairment of subcortical vascular features occurred in 23 patients and isolated executive disturbances in 4. Neuropsychological results showed that patients with atypical lacunar syndrome followed by pure motor hemiparesis showed significantly more cognitive executive disturbances. Patients with dysarthria-clumsy hand/ataxic hemiparesis accounted for the best scores in some tests of visuoconstructive function and visual memory. In summary, mild neuropsychological disturbances (57.5%) are not infrequent in acute lacunar infarcts especially in patients with atypical lacunar syndrome and pure motor hemiparesis. Neuropsychological impairment should be considered as common clinical feature in acute lacunar infarction.     

Auditory ear extinction in lacunar syndromes

A dichotic listening test was administered to 28 patients with lacunar syndromes in order to contribute to the investigation of the subcortical route of interhemispheric auditory pathways. Topographic study showed that lesions in the external capsule or in the anterior limb of the internal capsule in both hemispheres produced left ear extinction. The possibility that some of the auditory fibres travel through the external capsule, as well as the anterior limb of the internal capsule, before crossing the contralateral cerebral lobe is suggested.     

Microbleeds and free active MMP‐9 are independent risk factors for neurological deterioration in acute lacunar stroke

Background and purpose: In this prospective study, we evaluated mutual relationships amongst microbleeds, matrix metalloproteinase‐9 (MMP‐9) and neurological deterioration in patients with their first acute lacunar stroke. Methods: Based on diffusion‐weighted image findings, we recruited 206 patients with their first acute lacunar stroke. Those without a MRI scan were excluded. Small (a maximum lesion diameter of 15 mm) areas of subcortical gray and white matter with increased signals were considered as lacunar infarctions. GRE images were obtained within 24 h of the onset of stroke symptoms. Venous blood was sampled at base line (within 24 h). Clinical, biochemical, rheological and inflammatory parameters, neurological scales and free, active MMP‐9 levels were compared between patients with and without microbleeds. Neurological deterioration was defined as an increase in more than two points on the National Institutes of Health Stroke Scale Score baseline 14 days after the onset of lacunar stroke. Results: Of the patients, 79 (38.3%) had microbleeds and 48 (23.3%) showed neurological deterioration. Free, active MMP‐9 and C‐reactive protein (CRP) levels were significantly increased amongst patients with microbleeds (P < 0.001 and P = 0.047, respectively). Existence of microbleeds (RR = 2.47, 95% CI = 1.25–3.83) and increased free, active MMP‐9 (RR = 1.10 per 10 ng/ml, 95% CI = 1.03–1.19) were identified as independent risk factors for neurological deterioration after adjusting for potential confounders. Discussion: Increased levels of active MMP‐9 and the existence of microbleeds might be useful in predicting the deterioration following an initial acute lacunar stroke.     

Higher ambulatory blood pressure relates to enlarged Virchow-Robin spaces in first-ever lacunar stroke patients

Enlarged Virchow-Robin spaces (EVRS) are considered to be a sign of cerebral small vessel disease. Hypertension is an important risk factor for cerebral small vessel disease, whereas ambulatory blood pressure (BP) is the strongest predictor of hypertension-related brain damage. However, the association between ambulatory BP levels and EVRS has never been investigated. The aim of this study was to determine the association between ambulatory BP levels and EVRS. In 143 first-ever lacunar stroke patients, we performed 24-h ambulatory BP monitoring after the acute stroke phase. On brain MRI we counted EVRS in the basal ganglia and the centrum semiovale. We graded the number of EVRS at each level into a three-category severity scale. We assessed the association between BP levels and EVRS by ordinal regression analysis. After adjusting for age, sex, extensive white matter lesions, and asymptomatic lacunar infarcts, higher day systolic (OR 1.21; 95 % CI 1.00–1.46 per 10 mmHg), day diastolic (1.18; 95 % CI 1.02–1.37 per 5 mmHg) and 24-h diastolic (OR 1.18; 95 % CI 1.01–1.37 per 5 mmHg) ambulatory BP levels were associated with EVRS at the basal ganglia level. No relation was found between ambulatory BP levels and EVRS in the centrum semiovale. Higher day ambulatory BP levels are associated with EVRS in the basal ganglia. This association was independent of the presence of extensive white matter lesions and asymptomatic lacunar infarcts. Our results imply that basal ganglia EVRS should be regarded as a separate manifestation of BP-related brain damage.     

Are sensorimotor strokes lacunar strokes? A case-control study of lacunar and non-lacunar infarcts.

To determine whether sensorimotor strokes should be considered as lacunar syndromes 34 consecutive patients with first-ever ischaemic sensorimotor stroke were evaluated and compared with 103 patients with non-lacunar infarcts and another 88 patients with lacunar infarcts. Potential thromboembolic sources were more frequent in patients with non-lacunar infarcts (p = 0.003, versus sensorimotor strokes). Although the overall prevalence of hypodense lesions at CT scan was not significantly different among the three groups, lacunar lesions were found in 47.1% of sensorimotor strokes, compared with 6.8% of non-lacunar infarcts (p less than 0.0001). In a mean follow up period of 28.7 months, the incidence of stroke and myocardial infarction among sensorimotor strokes was similar to that of patients with lacunar infarct, but significantly lower than in non-lacunar infarcts (p less than 0.05). These results demonstrate important differences between sensorimotor and non-lacunar infarcts, but quite similar findings in sensorimotor and lacunar strokes, and thus support the theory that sensorimotor strokes are commonly due to lacunar lesions.     

Correlation between symptomatic, radiological and etiological diagnosis in acute ischemic stroke

OBJECTIVES: The aim of this study was to correlate with the symptomatic, radiological and etiological diagnosis in acute ischemic stroke. SUBJECTS AND METHODS: Two hundred and fifty patients with first-ever ischemic stroke within 24 h of onset were prospectively studied with 3-step diagnoses: 1) symptomatic diagnosis based on the Oxfordshire Community Stroke Project criteria (OCSP), 2) radiological diagnosis (CT or MRI) and 3) etiological diagnosis based on the Lausanne Stroke Registry criteria. RESULTS: Most of the patients with symptoms of total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI) and posterior circulation infarcts (POCI) had corresponding lesions on CT or MRI, while only 68% of lacunar infarcts (LACI) patients had small subcortical infarction (SSI). More than 60% of patients with TACI were classified into cardioembolism in the third diagnosis, while the etiology of PACI was either CE or large-artery atherosclerosis (LAA) in equal numbers. Only 58% of LACI patients were classified into small-artery disease (SAD) and 29% of them (30 cases) into LAA, of which 23 patients had lesions other than SSI. The positive predictive value of SAD in the combination of LACI and SSI was 0.78. The etiology of POCI was variable. CONCLUSION: Except for LACI, the symptomatic classification by OCSP corresponds well to the radiological diagnosis. The etiological diagnosis can be predicted by OCSP in TACI and PACI, but it is hard in POCI, and a number of LACI are due to LAA.     

Clinical-computed tomographic correlations of lacunar infarction in the Stroke Data Bank

Lacunar stroke was diagnosed in 337 (26%) of the 1,273 patients with cerebral infarction among the 1,805 total in the Stroke Data Bank. We analyzed the 316 patients with classic lacunar syndromes. Among these, 181 (57%) had pure motor hemiparesis, 63 (20%) sensorimotor syndrome, 33 (10%) ataxic hemiparesis, 21 (7%) pure sensory syndrome, and 18 (6%) dysarthria-clumsy hand syndrome. No striking differences were found among the risk factors for the lacunar subtypes, but differences were found between lacunar stroke as a group and other types of infarcts. Compared to 113 patients with large-vessel atherosclerotic infarction, those with lacunar stroke had fewer previous transient ischemic attacks and strokes. Compared to 246 with cardioembolic infarction, patients with lacunar stroke more frequently had hypertension and diabetes and less frequently had cardiac disease. We found a lesion in 35% of the lacunar stroke patients' computed tomograms, with most lesions located in the internal capsule and corona radiata. The mean infarct volume was greater in patients with pure motor hemiparesis or sensorimotor syndrome than in those with the other lacunar stroke subtypes. In patients with pure motor hemiparesis and infarcts in the posterior limb of the internal capsule, there was a correlation between lesion volume and hemiparesis severity except for the few whose infarct involved the lowest portion of the internal capsule; in these patients severe deficits occurred regardless of lesion volume. Taken together, the computed tomographic correlations with the syndromes of hemiparesis showed only slight support for the classical view of a homunculus in the internal capsule.