Sylvie Trefouret, Jean-Philippe Azulay, Paule Peretti, Jean Pouget
Tuesday April 15 3:00 pm / Exhibit Hall A

OBJECTIVE:
To evaluate the correlation between clinical impairment scales, MRI and motor evoked potentials (MEPs) elicited by magnetic stimulation of the motor cortex in the grading of pyramidal tract involvement in ALS and PLS.

BACKGROUND:
T2 weighted MRIs in ALS patients have shown hyperintense signal along the trajectory of pyramidal tract but studies are controversial on the significance of this signal. Abnormal MEPs in ALS are very frequent but no previous study gave a range of pyramidal dysfunction.

DESIGN/METHODS:
31 patients with definite ALS and 7 patients with PLS had clinical evaluation of pyramidal involvement. 24 ALS and 6 PLS had brain MRI to scored signals abnormalities along pyramidal tracts. MEP abnormalities were defined in 21 ALS and 6 PLS.

RESULTS:
A strong correlation was found between clinical involvement and MEP grading (p=0.0001) but not with the presence of high signals areas on T2 images along pyramidal tract.

CONCLUSIONS:
We suggest to grade MEPs abnormalities into 5 stages, which are strongly correlated with clinical involvement and could be useful in quantify central motor tract alteration.