Cortical Activation Changes in Patients Suffering from Post‐Stroke Arm Spasticity and Treated with Botulinum Toxin A

Abstract

Relief of post-stroke arm spasticity may be associated with changes at several hierarchical levels of the cortical sensorimotor system, including the prefrontal cortex.

Cortical activity modulation by botulinum toxin type A in patients with post-stroke arm spasticity: Real and imagined hand movement

“…BoNT application significantly relieved spasticity across paretic patients and this beneficial effect was associated with substantial reduction of activation in the most of previously active areas at W4. This BoNT-related reduction in the extent of the active sensorimotor networks is consistent with results of our pilot study reported by Tomášová et al [45] and a similar effect was reported by Manganotti et al [30]. We have previously hypothesized about the similarity of this phenomenon with motor recovery after stroke.…”

“…Our BoNT-off data (W11) yielded a pattern nearly similar to W4. This particular trend differs from Tomášová et al [45] where BoNT-off data (W11) again resembled the pre-BoNT examination (W0). Synergic effect of BoNT application and physiotherapy in less severely affected patients may play a crucial role in this phenomenon.…”

“…In the paretic group as well as in the previously cited study of paretic patients [45], post-hoc contrasts W0 N W4 yielded significant BoNTrelated changes in the ipsilesional DLPFC and Broca's area. Both areas have been reported to participate in motor learning, rather than volitional motor performance and control [3].…”

“…It is well known that under pathological conditions, such as stroke damaging the sensorimotor network, motor control involves structures outside the classical motor system [51]. We have previously shown that additional brain areas may be recruited in the presence of PSS [37,45,48]. This overactivation in such areas then diminished after effective BoNT treatment that reduces spastic muscle contraction and thus alters inappropriate sensory inputs to the CNS.…”

Spasticity after stroke: Physiology, assessment and treatment

“…Some studies have investigated the effects of Botulinum Toxin A (BoNT-A) on spasticity in patients post-stroke. They have shown a decrease in activation of the posterior cingulate cortex and precuneus [68] following treatment and a decrease in activation in contralateral frontoparietal areas including inferior frontal, post-central and middle frontal gyrus, with activation limited to midline and contralateral sensorimotor cortices [69].…”