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.