The differential roles of contralesional frontoparietal areas in cortical reorganization after stroke

Abstract

Background: Studies examining the contribution of contralesional brain regions to motor recovery after stroke have revealed conflicting results comprising both supporting and disturbing influences. Especially the relevance of contralesional brain regions beyond primary motor cortex (M1) has rarely been studied, particularly concerning the temporal dynamics post-stroke. Methods: We, therefore, used online transcranial magnetic stimulation (TMS) interference to longitudinally assess the role of contralesional (right) frontoparietal areas for recovery of hand motor function after left hemispheric stroke: contralesional M1, contralesional dorsal premotor cortex (dPMC), and contralesional anterior intraparietal sulcus (IPS). Fourteen stroke patients and sixteen age-matched healthy subjects performed motor tasks of varying complexity with their (paretic) right hand. Motor performance was quantified using three-dimensional kinematic data. All patients were assessed twice, (i) in the first week, and (ii) after more than three months post-stroke. Results: While we did not observe a significant effect of TMS interference on movement kinematics following the stimulation of contralesional M1 and dPMC in the first week post-stroke, we found improvements of motor performance upon interference with contralesional IPS across motor tasks early after stroke, an effect that persisted into the later phase. By contrast, for dPMC, TMS-induced deterioration of motor performance was only evident three months post-stroke, suggesting that a supportive role of contralesional premotor cortex might evolve with reorganization. Conclusion: We here highlight time-sensitive and region-specific effects of contralesional frontoparietal areas after left hemisphere stroke, which may influence on neuromodulation regimes aiming at supporting recovery of motor function post-stroke.

Increased prevalence of a frontoparietal brain state is associated with better motor recovery after stroke affecting dominant-hand corticospinal tract

“…Though reduced frontoparietal network involvement has been observed in stroke subjects relative to controls, as replicated here, there is evidence that within stroke subjects, increased activity of the frontoparietal network is related to better motor recovery (Tscherpel et al, 2020). Recent work has shown that individuals with CST damage (measured using motor-evoked potentials) have greater resting-state functional connectivity in the frontoparietal network compared to individuals without CST damage (Hordacre et al, 2021a).…”

“…In this paper, we aim to identify patterns of activation that are associated with better motor recovery. Recent work has highlighted the importance of frontoparietal areas in supporting motor abilities in the chronic phase of stroke (Tscherpel et al, 2020) specifically in patients with poor corticospinal tract (CST) integrity (Hordacre et al, 2021a). When these descending motor pathways are significantly damaged, descending white matter tracts from higher-order motor areas, such as the premotor cortex, may support motor output.…”

Recovery from stroke: current concepts and future perspectives

“…Similar supportive effects of the contralesional dorsal premotor cortex were also observed in other fMRI and TMS studies [ 4 , 37 ]. Furthermore, a more influential role of the dorsal premotor cortex for hand movements has also been observed in physiological aging [ 69 ], implying a general neural mechanism to support hand motor function. In summary, the roles of contralesional areas in the recovery of motor function post-stroke are region-specific and time-sensitive, which needs to be considered when using non-invasive brain stimulation to improve the functional outcome after stroke.…”

Predictive models for response to non-invasive brain stimulation in stroke: A critical review of opportunities and pitfalls

“…Furthermore, the VL approach has shown promise in tracking the longitudinal change of the recovery-facilitating role of particular brain regions. A study by Tscherpel and colleagues [54] of patients with first-ever ischemic stroke in the left hemisphere and mild to moderate motor deficit (N=14) found that the time-sensitivity of interference to contralesional frontoparietal areas is region-specific. Another study by the same group [55] found that slow and simple electroencephalogram responses to TMS were associated with both severe motor impairment and poor motor recovery of stroke patients (N=25).…”