RT Journal Article SR Electronic T1 Grey matter correlates of clinical variables in amyotrophic lateral sclerosis (ALS): a neuroimaging study of ALS motor phenotype heterogeneity and cortical focality JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 766 OP 773 DO 10.1136/jnnp-2012-302674 VO 84 IS 7 A1 Peter Bede A1 Arun Bokde A1 Marwa Elamin A1 Susan Byrne A1 Russell L McLaughlin A1 Norah Jordan A1 Harald Hampel A1 Laura Gallagher A1 Catherine Lynch A1 Andrew J Fagan A1 Niall Pender A1 Orla Hardiman YR 2013 UL http://jnnp.bmj.com/content/84/7/766.abstract AB Background Body region of onset and functional disability are key components of disease heterogeneity in amyotrophic lateral sclerosis (ALS). Objectives To evaluate patterns of grey matter pathology in the motor cortex and correlate focal structural changes with functional disability. Methods We conducted a single-centre neuroimaging study of a cohort of 33 cognitively normal patients with amyotrophic lateral sclerosis (ALS) and 44 healthy controls. A voxel-wise generalised linear model was used to investigate the distribution of disease burden within the motor cortex in relation to clinical disability. Results Patients with bulbar onset have bilateral focal atrophy in the bulbar segment of the motor homunculus compared with patients with limb onset who have focal cortical changes in the limb segment of their motor strip. Furthermore, the extent to which different body regions are affected in ALS corresponds to the extent of focal grey matter loss in the primary motor cortex. Cortical ALS pathology also extends beyond the motor cortex affecting frontal, occipital and temporal regions. Conclusions Focal grey matter atrophy within the motor homunculus corresponds with functional disability in ALS. The findings support the existing concepts of cortical focality and motor phenotype heterogeneity in ALS.