MRI of the intracranial corticospinal tracts in amyotrophic and primary lateral sclerosis

Abstract

Our aim was to investigate the corticospinal tracts (CST) in motor neurone disease, using MRI, and to correlate findings with clinical data. We studied 31 patients with amyotrophic (ALS) and eight with primary lateral sclerosis (PLS). The signal from the CST was classified into four grades on T2-weighted images, and compared to T2-weighted images of 37 age-matched control subjects. No abnormalities were seen in the CST on T1-weighted images and were rarely evident on proton-density weighting. Variable high signal in the CST was found on T2-weighted images in 35 patients, and in 29 control subjects. Our grades 0 and 1 were more frequent in control subjects, grades 2 and 3 more frequent in patients. We found no correlation between the high signal and clinical data, including the duration of the illness. We therefore conclude that this technique is neither sensitive nor specific except in grade 3 which is quite specific for ALS. In half the patients we found atrophy of the superior parietal gyrus, which merits further study.

Combined MR spectroscopic imaging and diffusion tensor MRI visualizes corticospinal tract degeneration in amyotrophic lateral sclerosis

“…Similar signal changes were also present in a smaller percentage of normal controls. Our results are in agreement with previous reports, which have shown that hyperintensity in the CST was not specific for ALS; ischemic disease, vitamin B12 deficiency and Friedrich's ataxia may also cause similar findings on MRI [29,30]. Other studies have also found bilaterally symmetrical, sharply defined foci of high signal in the PIC in neurologically normal controls [31][32][33].…”

Whole brain-based computerized neuroimaging in ALS and other motor neuron disorders

“…There are few neuroimaging signs that might support the diagnosis directly by their presence, such as hyperintensities of the corticospinal tract (CST) in the brain or in the spinal cord, hypointensities in the precentral gyrus (decreased T2 signal: motor dark line), or atrophy of the precentral gyrus/enlargement of the central sulcus. However, MRI T2 hyperintensity along the CST was detected in only 40Á70% of cases (1,2), and the diagnostic value of T2 and proton density (PD) image abnormalities was debated (3,4). A combined MRI (80 ALS patients) and post mortem analysis (nine patients) confirmed a 65% occurrence of T2w and PD hyperintensity in the posterior limb of the internal capsule versus 51% in controls (5).…”

Aberrant interhemispheric homotopic functional and structural connectivity in amyotrophic lateral sclerosis

“…The superior parietal lobe is critical for sensorimotor integration by maintaining an internal representation of the body's state. A previous study23 observed atrophy of the superior parietal gyrus in half of their ALS sample. The paracentral lobule is mainly concerned with motor and sensory innervations of the contralateral lower extremity and the regulation of physiological functions, such as defaecation and micturition.…”