J. Perret

Prospective study of lacunar infarction using magnetic resonance imaging.

Using computed tomography and magnetic resonance imaging, we prospectively studied 100 patients hospitalized with a lacunar infarct. Our aim was to evaluate the capabilities of magnetic resonance imaging in the detection and delineation of lacunes in a project of clinicotopographic correlations. Seventy-nine patients had a classic lacunar syndrome; 35 had pure motor stroke, 26 had ataxic hemiparesis, seven had sensorimotor stroke, and 11 had pure sensory stroke. A miscellaneous group of 21 patients had less typical lacunar syndromes, primarily with brainstem signs and symptoms. Among a total of 153 lacunes, magnetic resonance imaging detected at least one lacune appropriate to the symptoms in 89 patients. In 16 patients at least two lesions correlated with the clinical features, and precise clinicotopographic correlations were possible in 68 patients. Magnetic resonance imaging was more effective when it was performed a few days after the stroke. Lesions causing different types of lacunar syndromes had significantly different volumes, suggesting that the size of the lesion may influence clinical features. Magnetic resonance imaging may be the imaging technique of choice in the study of lacunar syndromes.

Long-term prognosis of symptomatic lacunar infarcts. A hospital-based study.

This study concerns the long-term prognosis of lacunar infarcts. Methods We report the analysis of our hospital-based series of 178 patients consecutively admitted for a lacunar syndrome due to a lacunar infarct diagnosed with computed tomography and magnetic resonance imaging. Demographic data, medical history, vascular risk factors, and imaging data were recorded for each patient. The follow-up was 35 ±22 months. Results The lacunar syndrome was pure motor hemiparesis in 69 patients (39%), ataxic hemiparesis in 45 patients (25.4%), pure sensory stroke in 15 patients (8.5%), sensorimotor stroke in 14 patients (7.9%), and miscellaneous syndrome in 34 patients (19.2%). The 4-year survival rate was 80±4% and the 4-year survival rate without recurrent stroke was 85 ±3.5%. Using Cox proportional-hazards analysis, the predictors of death were age (P<.02), diabetes mellitus P<.05), and cigarette smoking (P<.05). We did not find any predictors of recurrence. After 1 year, 74% of the patients had mild or no disability. Using logistic regression analysis, the predictive factors of disability were age more than 70 years P<.01), diabetes (P<.01), history of stroke or transient ischemic attack (P<.05), and type of lacunar syndrome P<.01). Imaging data, number of lacunes, and presence of leukoaraiosis were not predictors of outcome. Conclusions Our study suggests that with a high survival rate, a low recurrence rate, and a relatively good functional recovery, lacunar infarcts have a relatively favorable prognosis.

Is It Clinically Possible to Distinguish Nonhemorrhagic Infarct From Hemorrhagic Stroke

BACKGROUND AND PURPOSEnDiagnosis of the nonhemorrhagic ischemic type of stroke by analysis of patients clinical features is considered unreliable because no clinical feature is specific. The diagnosis is so difficult to establish that we cannot hope to use the same method to make a reliable diagnosis in all stroke cases. In this study, we propose a simple scoring system with a positive predictive value of close to 100% to distinguish nonhemorrhagic infarct from hemorrhagic stroke. This scoring is available for all physicians in bedside diagnosis even if this score can be applied to a subgroup of patients.nnnMETHODSnTwenty-six clinical variables that might potentially distinguish cerebral hemorrhage from infarction were recorded in patients consecutively admitted to our stroke unit for stroke lasting more than 24 hours with at least unilateral motor weakness affecting face and/or arm and/or leg (internal validity study). Patients previously receiving anticoagulant therapy were excluded. We used CT scan as the gold standard. We used multivariate logistic regression to establish a clinical score from which we derived the classification rule. This rule was validated with data from the next 200 consecutive patients hospitalized in the stroke unit (external validity study).nnnRESULTSnThree hundred sixty-eight patients were enrolled in the internal study. The obtained score was (2 x alcohol consumption) + (1.5 x plantar response) + (3 x headache) + (3 x history of hypertension)--(5 x history of transient neurological deficit)--(2 x peripheral arterial disease)--(1.5 x history of hyperlipidemia)--(2.5 x atrial fibrillation on admission). All patients with a score less than 1 (n = 123) had a nonhemorrhagic infarct (ie, 40% of the 305 patients with a nonhemorrhagic infarct). No threshold was found to diagnose cerebral hemorrhage with a sufficiently high positive predictive value. Among the 200 patients enrolled in the external validity study, 72 patients with a score below 1 had a nonhemorrhagic infarct (ie, 43% of patients with a nonhemorrhagic infarct).nnnCONCLUSIONSnDiagnosis of nonhemorrhagic infarct can be made in 36% (95% confidence interval [CI], 29 to 43) of patients with a high level of accuracy (100% in the external validity study, which gives a 95% CI of 93 to 100). Thus, 43% (95% CI, 36 to 50) of patients with a nonhemorrhagic infarct could receive a bedside diagnosis. The score is simple and can be calculated from information available to all physicians.

Hemiplegia in posterior cerebral artery occlusion.

We report 4 patients with hemiplegia due to a posterior cerebral artery occlusion. Associated clinical signs were aphasia, alexia or a neglect syndrome, hemianopia, and hemisensory loss. Hemiplegia was due to infarction in the lateral midbrain. The level of the occlusion in the posterior cerebral artery may be located distal to the junction with the posterior communicating artery.

Pure sensory stroke due to a pontine lacune.

A 53-year-old hypertensive man presented with the sudden onset of an isolated lemniscal sensory syndrome of the entire left side of his body. Magnetic resonance images showed a small lacune in the right paramedian pons corresponding to the location of the medial lemniscus.

Risk Factors for Lacunar Infarcts

Lacunar infarcts represent a stroke subgroup with controversial risk factors. Lacunar syndromes may be divided into two groups: the classic group (pure motor hemiplegia, pure sensory stroke, ataxic hemiparesis, dysarthria-clumsy hand syndrome, sensorimotor stroke) and the miscellaneous group including all other lacunar syndromes. We studied risk factors of 200 consecutive patients with symptomatic lacunar infarcts diagnosed by magnetic resonance imaging. This study tested whether lacunar infarcts represent a homogeneous subgroup of strokes or not. Using descriptive and bivariate statistics, we found that the prevalences of arterial hypertension and cigarette smoking are lower in the miscellaneous group. Analysis of variance shows a significant difference in age between subgroups without interaction of sex. Nevertheless, using multivariate analysis, we did not find a difference between subgroups. Thus, lacunar infarcts seem to be a homogeneous subgroup of strokes, and the miscellaneous group of lacunar infarcts may be included into the lacunar infarct group and not into the vertebrobasilar large-artery infarct group.

Brachiofacial Pure Motor Stroke

Pure motor stroke is the commonest lacunar syndrome, but it may be associated with nonlacunar mechanisms of infarction. Pure motor brachiofacial weakness has been considered as a partial syndrome depending on a lacunar mechanism. We studied the correlations between stroke type, topography of infarction and etiology in 22 patients with pure motor brachiofacial weakness who were consecutively admitted to our stroke unit during a 10-year period. Seventeen patients had a small deep infarct, 4 had a cortical infarct in the superficial MCA territory and 1 had no specific lesion. The part of the cardiovascular risk factors was about 36% for smoking, 13% for diabetes mellitus, 60% for dyslipidemia and 40% for heart disease. Hypertension was present in 75% of our cases. None of the patients had a large artery stenosis on Doppler ultrasonography. We concluded that brachiofacial pure motor stroke is not always correlated to lacunar infarcts and may be due to a cortical infarct. MRI should be performed when brain CT is normal because of the implications it may have in management and therapy.