Symmetric Temporal Abnormalities on MR Imaging in Amyotrophic Lateral Sclerosis with Dementia

Abstract

Our aim was to clarify imaging findings of amyotrophic lateral sclerosis with dementia (ALSD). T2-weighted MR images (T2WI) of 3 patients with ALSD (2 men, 1 woman; 58-71 years of age) and 21 patients with ALS without dementia (12 men, 9 women; 46-74 years of age) were examined for frontotemporal lobar atrophy and signal-intensity alterations in the white matter of the anterior temporal lobes, corticospinal tracts (CST), and precentral gyri and in precentral cortices. The brain of one of the patients with ALSD was examined at autopsy. All patients with ALSD showed bilateral frontotemporal atrophy mostly with temporal lobe dominance. In the ALSD group, T2WI demonstrated hyperintensity in the subcortical white matter on the medial side of the anterior temporal lobes, whereas in the group without dementia, none showed this imaging finding. MR images demonstrated no abnormal signal-intensity changes in CST in the internal capsule or the brain stem in the ALSD group. In the group without dementia, 6 patients (28.6%) showed this imaging finding. In neuropathologic examinations of the brain of 1 patient with ALSD, myelin-stained sections of the brain demonstrated loss of myelin in the subcortical white matter on the medial side of the anterior temporal white matter. A symmetric pattern of frontotemporal atrophy and anteromedial subcortical hyperintensities in the temporal lobes on T2WI could be characteristic of ALSD.