Functional MR imaging and traumatic paraplegia: Preliminary report

Purpose: To evaluate residual activity in the sensorimotor cortex of the lo wer limbs in paraplegia. Methods: 5 patients suffering from a complete paralysis after traumatic med ullar lesion (ASIA = A). Clinical evaluation of motility and sensitivity. 1. Control functional MR study of the sensorimotor cortex during simultaneo us movements of hands, imaginary motor task and passive hands stimulation. 2. Concerning the lower limbs, 3 fMRI conditions : 1-patient attempts to mo ve his toes with flexion-extension, 2-mental imagery task of the same movem ent, 3-peripheral passive proprio-somesthesic stimulation (squeezing) of th e big toes. Results. Activations were observed in the primary sensorimotor cortex (M1), premotor regions and in the supplementary motor area (SMA) during movement and mental imaginary tasks in the control study and during attempt to move and mental imaginary tasks in the study concerning the lower limbs. Passive somesthesic stimulation generated activation posterior to the centr al sulcus for 2 patients. Conclusion: Activations in the sensorimotor cortex of the lower limbs can b e generated either by attempting to move or mental evocation. In spite of a clinical evaluation of complete paraplegia, fMRI can show a persistence of sensitive anatomic conduction, confirmed by Somesthesic Evoked Potentials.