Magnetic resonance spectroscopy in epilepsy

Abstract

Key points
• The clinical aims of MR spectroscopy (MRS) in
seizure disorders are to help identify, localize
and characterize epileptogeic foci.
• Lateralizing MRS abnormalities in temporal lobe
epilepsy (TLE) may be used clinically in combi-
nation with structural and T2measurements.
• Characteristic metabolite abnormalities are
decreased N-acetylaspartate (NAA) with
increased choline (Cho) and myoinositol (mI)
(short-echo time).
• Contralateral metabolite abnormalities are
frequently seen in TLE, but are of uncertain
significance.
• In extra-temporal epilepsy, metabolite abnor-
malities may be seen where MR imaging (MRI)
is normal; but may not be sufficiently local-
ized to be useful clinically.
• MRS may help to characterize epileptogenic
lesions visible on MRI (aggressive vs. indolent
neoplastic, dysplasia).
• Spectral editing techniques are required to
evaluate specific epilepsy-relevant metabolites
(e.g. -aminobutyric acid (GABA)) which may
be useful in drug development and evaluation.
• MRS with phosphorus (31P) and other nucleii
probe metabolism of epilepsy, but are less
useful clinically.