Fig 3. Cortical thickness distribution in control subjects and patients with primary lateral sclerosis (PLS) for M1 cortical thickness (A), M1 cortical thickness normalized to S1 cortical thickness (B), and M1 normalized to the thickness of the anterior and posterior banks of the precentral sulcus (C). Although thresholds with identical sensitivity and specificity can be identified, normalization to the precentral sulcus reduces the overlap between the 2 populations.