Myoinositol abnormalities in temporal lobe epilepsy

This study used magnetic resonance spectroscopy (MRS) to examine metabolite abnormalities in the temporal and frontal lobe of patients with temporal lobe epilepsy (TLE) of differing severity.

We investigated myoinositol in TLE by using short-echo MRS in 34 TLE patients [26 late onset (LO-TLE), eight hippocampal sclerosis (HS-TLE)], and 16 controls. Single-voxel short-echo (35 ms) MR spectra of temporal and frontal lobes were acquired at 1.5 T and analyzed by using LCModel.

The temporal lobe ipsilateral to seizure origin in HS-TLE, but not LO-TLE, had reduced N-acetylaspartate (NA) and elevated myoinositol (MI; HS-TLE NA, 7.8 +/- 1.9 mM, control NA, 9.2 +/- 1.3 mM; p < 0.05; HS-TLE MI, 6.1 +/- 1.6 mM, control mI 4.9 +/- 0.8 mM, p< 0.05). Frontal lobe MI was low in both patient groups (LO-TLE, 4.3 +/- 0.8 mM; p < 0.05; HS-TLE, 3.6 +/-.05 mM; p < 0.001; controls, 4.8 +/- 0.5 mM). Ipsilateral frontal lobes had lower MI (3.8 +/- 0.7 mM; p < 0.01) than contralateral frontal lobes (4.3 +/- 0.8 mM; p < 0.05).

MI changes may distinguish between the seizure focus, where MI is increased, and areas of seizure spread where MI is decreased.