Influence of task complexity during coordinated hand and foot movements in MS patients with and without fatigue. A kinematic and functional MRI study.

Kinematic and functional magnetic resonance imaging were combined to investigate how movement complexity (in-phase vs. anti-phase) and rate (maximum rate vs. 1 Hz) influence the brain sensorimotor network of relapsing- remitting fatigued (F) and not-fatigued (NF) MS patients during the performance of coordinated hand and foot movements.Kinematic measures did not differ between F and NF patients. Task and disease showed an interaction in the right precuneus and posterior lobe of the cerebellum during in-phase/anti-phase conditions and in the right precuneus and posterior and anterior lobes of the cerebellum during maximum vs. 1 Hz rate. Task, disease and fatigue showed an interaction in the right precentral gyrus, the left postcentral gyrus, the left SII, the right precuneus, the right basal ganglia, the left lingual gyrus, and the posterior lobe of the cerebellum, bilaterally, during in-phase/ anti-phase conditions and the left postcentral gyrus, the left SII, the right anterior lobe of the cerebellum, and the posterior lobe of the cerebellum, bilaterally during maximum vs. 1 Hz rate.Investigations of motor task performance in MS patients require careful control of several variables, including task complexity, movement rate, and the presence of "subtle" clinical disturbances, such as fatigue, which might be underestimated at a standard neurological assessment.

Influence of body segment position during in-phase and antiphase hand and foot movements: a kinematic and functional MRI study.

Behavioral studies have provided important insights into the mechanisms governing interlimb coordination. In this study, we combined kinematic and functional magnetic resonance imaging (fMRI) analysis to investigate the brain cortical and subcortical areas involved in interlimb coordination and the influence of direction of movement and of body segment position on the activity of those areas. Fifteen right-handed healthy subjects were studied while performing cyclic in-phase and antiphase hand and foot movements with the dominant, right limbs, with the upper limb positioned either prone or supine, and in front or behind with respect to the trunk. When contrasting antiphase to in-phase movements, fMRI analysis demonstrated an increased recruitment of a widespread sensorimotor network (including regions in the frontal and parietal lobes, bilaterally, the cingulated motor area, the thalami, the visual cortex, and the cerebellum) considered to function in motor, sensory, and multimodal integration processing. When contrasting the anterior to the posterior position of the upper limb with respect to the trunk, we found different recruitment patterns in the frontal and parietal regions as well as the preferential recruitment of the basal ganglia, the insula, and the cerebellum during the first condition and of regions located in the temporal lobes during the second one. Different brain areas are engaged at a different extent during interlimb coordination. In addition to the relative difficulty of the movement, the different cognitive and sensorial loads needed to control and perform the motor act might be responsible for these findings.