PurposeLacunar stroke, in the context of small vessel disease, is a type of cerebral infarction caused by occlusion of a penetrating artery. Pulsatility index (PI) is an easily measurable parameter in Transcranial Doppler ultrasound (TCD) study. PI reflects distal cerebral vascular resistance and has been interpreted as a surrogate marker of small vessel disease. We hypothesized that an increased PI, a marker of small vessel disease, might be associated with a larger infarct volume in acute lacunar stroke.Materials and MethodsThis study included 64 patients with acute lacunar stroke who underwent TCD and brain MRI. We evaluated the association between the mean PI value of bilateral middle cerebral arteries and infarct volume on diffusion-weighted MRI using univariate and multivariate linear regression.ResultsThe mean infarct volume and PI were 482.18±406.40 mm3 and 0.86±0.18, respectively. On univariate linear regression, there was a significant positive association between PI and infarct volume (p=0.001). In the multivariate model, a single standard deviation increase of PI (per 0.18) was associated with an increase of 139.05 mm3 in infarct volume (95% confidence interval, 21.25 to 256.85; p=0.022).ConclusionWe demonstrated that PI was an independent determinant of infarct volume in acute lacunar stroke. The PI value measured in acute stroke may be a surrogate marker of the extent of ischemic injury.

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OBJECTIVESThe objective of these practice guidelines is to provide clinicians with recommendations for the diagnosis and treatment of bacterial meningitis. Patients with bacterial meningitis are usually treated by primary care and emergency medicine physicians at the time of initial presentation, often in consultation with infectious diseases specialists, neurologists, and neurosurgeons. In contrast to many other infectious diseases, the antimicrobial therapy for bacterial meningitis is not always based on randomized, prospective, double-blind clinical trials, but rather on data initially obtained from experimental animal models of infections. A model commonly utilized is the experimental rabbit model, in which animals are anesthetized and placed in a stereotactic frame. In this procedure, the cisterna magna can be punctured for frequent sampling of CSF and injection of microorganisms. Frequent sampling of CSF permits measurement of leukocytes and chemical parameters and quantitation of the relative penetration of antimicrobial agents into CSF and the effects of meningitis on this entry parameter, the relative bactericidal efficacy (defined as the rate of bacterial eradication) within purulent CSF, and CSF pharmacodynamics. Results obtained from these and other animal models have led to clinical trials of specific agents in patients with bacterial meningitis.