Long-repetition-time spin-echo MR images showed symmetric hyperintensi
ty of the intracerebral corticospinal tracts in two patients with clin
ical and neurophysiologic diagnosis of primary lateral sclerosis and a
myotrophic lateral sclerosis. In both, axial low-flip-angle gradient-e
cho images of the cervical spine showed hyperintensity of the lateral
columns of the cord consistent with antegrade degeneration of the cros
sed cortico-spinal tracts.