Transmission within several spinal pathways in adults with cerebral palsy

Abstract

Many studies have investigated the changes of spinal neuronal networks in patients with cortico-subcortical or spinal lesions occurring during adulthood. In contrast, little is known about modifications of transmission within spinal networks implied in motor control for patients suffering from perinatal lesions. In the present series of experiments, we have investigated, in adult patients with cerebral palsy who suffered cerebral damage in the perinatal period, the efficacy of transmission within four spinal networks known for exhibiting pathophysiological changes following a central nervous system lesion occurring in adulthood. These are presynaptic Ia inhibition, post-activation depression, disynaptic reciprocal Ia inhibition and propriospinally-mediated Group I and Group II facilitations. In 28 patients with cerebral palsy and 35 age-matched healthy subjects we were able to show that: (i) disynaptic reciprocal Ia inhibition is intact in patients with cerebral palsy; (ii) both presynaptic Ia inhibition and post-activation depression are impaired in patients with cerebral palsy; and (iii) propriospinally-mediated Group I facilitation is undamaged in patients with cerebral palsy, whereas Group II facilitation is strongly enhanced. Only diminished post-activation depression was highly correlated to the severity of spasticity. Differences in the spinal transmission between patients with cerebral palsy and patients who suffered neuronal damage in adulthood are discussed.

Pathophysiology of Spasticity: Implications for Neurorehabilitation

“…In comparison to healthy controls, postactivation depression has been found to be lower in patients with spasticity [53]. A positive correlation has been reported between the diminished postactivation depression and the severity of spasticity following stroke [54] and cerebral palsy [55]. Moreover, in subjects with spinal cord injury, postactivation depression is normal in the acute phase and becomes depressed only just before the development of spasticity [56].…”

New evidence of corticospinal network modulation induced by motor imagery

“…To avoid monosynaptic facilitation in SOL motoneurons by Ia afferences of peroneal muscle (Meunier et al 1993), we carefully checked visually and by tendon palpation that the stimulation did not induce any contraction of this muscle. The conditioning stimulus was a triple pulse over the common peroneal nerve at 300 Hz (1 ms duration), with the intensity set at 120% of TA motor threshold (Achache et al 2010). A conditioning test interval was determined for each participant by testing several intervals between 15 and 25 ms, with 1 ms steps.…”

Post-activation depression of the lower extremities in stroke patients with spasticity and spastic equinovarus deformity

“…Previous studies have revealed a significant positive correlation between reduced post-activation depression and spasticity severity 6,7 . Our results provide additional evidence for this relationship.…”