Measurement of initial N-acetyl aspartate concentration by magnetic resonance spectroscopy and initial infarct volume by MRI predicts outcome in patients with middle cerebral artery territory infarction
Ac. Pereira et al., Measurement of initial N-acetyl aspartate concentration by magnetic resonance spectroscopy and initial infarct volume by MRI predicts outcome in patients with middle cerebral artery territory infarction, STROKE, 30(8), 1999, pp. 1577-1582
Background and Purpose-H-1 MR spectroscopy can be used to study biochemical
changes occurring in the brain in stroke. We used it to examine the relati
onship between metabolite concentration (N-acetyl aspartate [NAA], lactate,
cholines and creatines), size of infarct, clinical deficit, and 3-month cl
inical outcome in patients with middle cerebral artery (MCA) territory infa
rction.
Methods-Thirty-one patients with acute MCA territory infarction were recrui
ted within 72 hours of the onset of symptoms. Single-voxel short echo time
stimulated echo acquistion mode spectroscopy was used to obtain metabolite
data from the infarct core. Metabolite concentrations were determined with
use of variable projection time domain-fitting analysis. Infarct size was d
etermined with T2-weighted images. Patient outcome groups at 3 months were
"independent," "dependent," or "dead."
Results-All patients (100%; 95% CI 75% to 100%) who had an infarct >70 mt d
id poorly. Eighteen of 20 patients (90%; 95% CI 68% to 99%) with a core NAA
concentration <7 mmol/L did poorly at 3 months, whereas 7 of 11 patients (
64%; 95% CI 31% to 89%) with an initial NAA concentration >7 mmol/L did wel
l. Combining these results showed that all patients who had an initial infa
rct volume >70 mt did poorly, irrespective of the NAA concentration. Of tho
se patients with infarcts <70 mL, those who had a core NAA concentration >7
mmo/L did well (88%; 95% CI 47% to 100%), whereas those with a lower NAA c
oncentration did poorly (80%; 95% CI 44% to 97%). There was no association
between other metabolite concentrations and outcome.
Conclusions-Infarct volume and NAA concentration can together predict clini
cal outcome in MCA infarction in humans.