Clinical characteristics associated with corticospinal tract hyperintensity on magnetic resonance imaging in patients with amyotrophic lateral sclerosis

Objective The usefulness of conventional magnetic resonance imaging (C-MRI) for diagnosing amyotrophic lateral sclerosis (ALS) remains controversial. The aim of this study was to investigate the utility of C-MRI in identifying ALS, specifically the association between corticospinal tract (CST) hyperintensity on C-MRI and clinical characteristics in patients with ALS. Methods Between June 2008 and April 2012, we retrospectively enrolled consecutive patients diagnosed with sporadic ALS who underwent C-MRI. Patients with ALS were classified as definite-phase ALS (D-ALS) and indefinite-phase ALS (ID-ALS). We focused on the hyperintensity of T2-weighted images in the CST in patients with ALS. Based on the MRI results, we divided patients into two groups: a positive CST group showing CST hyperintensity; and a negative CST group with no such findings. Clinical characteristics of the two groups were compared. Results Seventeen patients (median age, 62 years; 8 women, 9 men) were enrolled in this study, with D-ALS in eight (47%) and ID-ALS in nine (53%). Eight patients (47%) showed CST positivity. The rate of CST positivity was higher in patients with D-ALS (75%) than in patients with ID-ALS (22%, p = 0.03). Conclusions CST positivity appears significantly increased in D-ALS patients. C-MRI can play an important role in diagnosing ALS.