Subacute Changes in N-Acetylaspartate (NAA) Following Ischemic Stroke: A Serial MR Spectroscopy Pilot Study

Area of Science:

• Neuroscience
• Neurology
• Biochemistry

Background:

• Neuronal tissue preservation is vital for stroke recovery.
• Studies indicate prolonged neuronal loss post-ischemia.
• Subacute stroke progression and its impact on recovery need further investigation.

Purpose of the Study:

• To assess the temporal pattern of neuronal loss in subacute ischemic stroke patients.
• To correlate magnetic resonance spectroscopy (MRS) findings with functional motor recovery.
• To explore potential mechanisms behind progressive neuronal damage and its effect on recovery.

Main Methods:

• Utilized 1H magnetic resonance spectroscopy (MRS) to measure brain metabolites (NAA, choline, myoinositol, lactate) in stroke patients and controls.
• Assessed patients at 2, 6, and 12 weeks post-stroke.
• Correlated MRS metabolite concentrations with motor function using the Fugl-Meyer scale at 12 weeks.

Main Results:

• Significant decrease in N-acetylaspartate (NAA) in the ipsilesional thalamus from week 2 to 12 (p=0.003).
• Significant increases in choline, myoinositol, and lactate concentrations in the ipsilesional thalamus.
• Higher ipsilesional thalamus NAA at 2 and 12 weeks correlated with better 12-week motor recovery (p=0.004 and p=0.006).

Conclusions:

• Progressive fall in NAA and rise in other metabolites suggest ongoing non-ischemic neuronal loss or metabolic depression in subacute stroke.
• These metabolic changes negatively impact motor recovery.
• Interventions targeting subacute tissue damage may enhance stroke recovery outcomes.