Study of the features of proton MR spectroscopy ((1)H-MRS) on amyotrophic lateral sclerosis

To study the features of proton magnetic resonance spectroscopy ((1)H-MRS) on amyotrophic lateral sclerosis (ALS) and its relation with clinical scale.

Fifteen patients with definite or probable ALS and 15 age- and gender-matched normal controls were enrolled. (1)H-MRS was performed on a 3.0 Tesla GE imaging system (GE Healthcare, Milwaukee, WI). TE-averaged Point Resolved Selective Spectroscopy was used. N-acetylaspartate (NAA), creatine (Cr), Glu, and Glx (glutamate + glutamine) values of the motor cortex and posterior limb of internal capsule were acquired. The t-test was used to compare differences between groups, and the correlations between the above values and clinical scale were analyzed.

The motor area and posterior limb of the internal capsule of ALS patients had lower NAA/Cr (1.91 +/- 0.34, 1.53 +/- 0.17) compared with normal subjects (2.23 +/- 0.33, 1.66 +/- 0.07), and the differences between groups were statistically significant (P < 0.01, 0.01). ALS patients had higher Glu/Cr (0.34 +/- 0.05, 0.29 +/- 0.06) and Glx/Cr (0.40 +/- 0.04, 0.33 +/- 0.06) compared with normal subjects (0.30 +/- 0.03, 0.25 +/- 0.04) and (0.32 +/- 0.05, 0.26 +/- 0.03), and the differences between groups were statistically significant (P < 0.01, 0.01). The Norris scale was negatively correlated with Glx/Cr of primary motor cortex by lineal correlation analysis (r = -0.75), and this correlation had statistical significance (F = 16.60; P = 0.001).

Neuronal loss and Glu+Gln increase can be detected by using proton MRS in ALS patients. (1)H-MRS is an useful tool in reflecting the characteristic changes of metabolite in ALS.