Changes in cerebral activity after decreased upper-limb hypertonus: an EMG-fMRI study

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.…”

BoNT-A related changes of cortical activity in patients suffering from severe hand paralysis with arm spasticity following ischemic stroke

“…This clinical improvement expressed in MAS scores was associated with partial reduction of active network volume in most of the observed areas. This trend agrees with findings in our previous pilot studies and other recent studies focused on fMRI cerebral changes after BoNT-A application in stroke patients [19][20][21][22]. A notable exception to this trend regards the cerebellar hemispheres, which either appear similarly active across the three imaging sessions (ipsilesional) or manifest transient activation at the time of maximal BoNT-A effect (contralesional).…”

“…Most of previous fMRI studies in stroke patients have described changes in task-related cortical activity following physiotherapy treatment, e.g., constraint-induced therapy [18]. Only several studies reported cortical changes after BoNT-A injections into the spastic muscles [19,20].…”

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

“…First, BoNT treatment induced a clear reduction in the extent and also more prominent lateralization of the active sensorimotor network (see Fig 2), similar to that shown previously in motor recovery after stroke 20,34 . A similar effect representing a trend toward normalization of movement‐induced brain activation was reported by Manganotti and colleagues 10 in a study similar to ours, involving stroke patients with hemiparesis and upper‐limb spasticity studied treated with BoNT‐A and studied with fMRI. However, there are several methodological differences between Manganotti and colleagues 10 and our study, which limit a more detailed comparison of their results: First, their study involved two examinations and no rehabilitation; our study included three examinations and concomitant rehabilitation.…”

“…BoNT probably alters sensory inputs to the central nervous system with reduction of Ia afferent signals, and thus may indirectly induce secondary central changes in activation at several hierarchical levels of the motor system, presumably including cerebral cortex. This phenomenon has been already described in dystonia 7–9 and observations at the CNS level have recently been reported also for cerebral spasticity 10–11 …”