Abstract 99: A Magnetic Resonance Spectroscopy [1H-MRS] Study of Peri-infarct Neuro-glial Interactions in Recovering Stroke Patients
Background: The adult brain has the capacity to reorganize after acute stroke and the ability to follow neuroplastic processes can be useful in predicting and monitoring recovery after stroke. This study investigates the ability of 1H-MRS to measure metabolic events in the structurally intact peri-infarct region between 2-12 weeks after stroke and their relationship to motor recovery.
Method: The study included 15 first-ever stroke patients aged 18-75 years and age/sex matched controls. Structural, perfusion and 1H-MRS imaging was undertaken to measure regional cerebral blood flow (rCBF), N-acetylaspartate (NAA), choline (Cho), myoinositol (mI), creatine (cr) and lactate in the ipsilesional and contralesional hemisphere of stroke patients at 2 weeks, 6±1 and 12±3 weeks after stroke onset. Simultaneous clinical assessments were undertaken to measure motor impairments using the Fugl-Meyer [F-M]) scale. Patients were compared with controls at all time-points and the relationships between metabolites and with motor outcome were assessed.
Results: Stroke patients were aged 51.4 (SD 13.3) years and all improved significantly between 2 and 12 weeks. Ipsilesional rCBF was decreased (22.7 v 36.8 mL/100 g/min, p=0.0036) at 2 weeks but increased to normal values by 12 weeks. Cr concentration (energy balance) were decreased in parallel and increased to normal concentration by 12 weeks. Ipsilesional NAA (neuronal integrity) was similar to healthy controls at 2 weeks it decreased significantly by 6 weeks. Cho (membrane turnover) significantly higher compared with controls at all time points; mI (glial cells) did not differ at 2 weeks but increased significantly between 2 and 12 weeks and there was a significant rise in lactate (inflammation) concentration at 12 weeks. There were strong positive correlations of rCBF with NAA at 12 weeks (r=0.42, p <0.002), NAA at 2 and 12 weeks with FM scores at 12 weeks (r = 0.79, p= 0.004, r = 0.799, p = 0.006) and rCBF with change in F-M score between 2-12 weeks (r = 0.44, p=0.01).
Conclusions: Ipsilesional CBF and metabolite estimation may be a sensitive tool to quantify vascular and neuro-glial interactions in the spared cortex after stroke that can be used to predict and monitor recovery.
Author Disclosures: N. Mazibuko: None. R. O'Gorman: None. O. O’Daly: None. F. Zelaya: None. S. Williams: None. M. O'Sullivan: None. L. Kalra: None.
- © 2015 by American Heart Association, Inc.