BA 4p BOLD response profile distinguishes low and high MS morbidity

This study investigates how multiple sclerosis (MS) selectively affects regional BOLD response to variable grip forces (GF). It is known that the anterior and posterior BA4 areas are anatomically and functionally distinguishable – and that in healthy subjects there are linear and non-linear BOLD response components. After modelling BOLD responses with a polynomial expansion of the applied GF during task, we showed that in BA4a MS subjects respond like healthy subjects. BOLD response in BA4p, instead, was altered in MS, with those with greatest disability showing the greatest deviations from the non-linear profile of the healthy response.