High plasma glutamate concentrations are associated with infarct growth in acute ischemic stroke

Background: Excitotoxic and inflammatory mechanisms have been demonstrated as mediating early neurologic deterioration (END) in patients with cerebral infarction. Here we investigate whether molecular markers associated with END are related to the volume and outcome of the diffusion weighted image (DWI) lesion in acute ischemic stroke. Methods: MRI was performed on admission and at 72 hours in 197 patients with acute hemispheric infarction of Results: DWI lesion growth was found in 144 (73%) patients (median increase 38 6.5, 83.4 cm3) and END occurred in 58 (29.4%) patients. Baseline glutamate (r = 0.71), l-arginine (r = −0.35), and IL-6 levels (r = 0.50) showed a high and significant correlation with the DWI lesion enlargement (all p p = 0.004). Conclusions: Molecular markers of early neurologic deterioration may play a role as mediators of lesion growth in cerebral ischemia. Plasma glutamate concentration is the most powerful and independent predictor biomarker of lesion enlargement in the acute phase of ischemic stroke, and so may well be useful as a signature of tissue at risk of infarction. GLOSSARY: CBF = cerebral blood flow; CBV = cerebral blood volume; DWI = diffusion-weighted imaging; END = early neurologic deterioration; FLAIR = fluid-attenuated inversion recovery; IL-6 = interleukin-6; MTT = mean transient time; NIHSS = NIH Stroke Scale; NO = nitric oxide; PWI = perfusion-weighted imaging; rt-PA = recombinant tissue plasminogen activator; T2-WI = T2-weighted imaging; TNFα = tumor necrosis factor-α.