Skip to main content
. 2019 Feb 20;121(4):1465–1477. doi: 10.1152/jn.00694.2018

Fig. 6.

Fig. 6.

Conceptual model for abnormal movement planning and preparation following stroke [model is adapted from Cohen et al. (2010)]. During movement planning and preparation, normally two primary pathways affect spinal motoneuronal circuitry. The first pathway delivers task-related information from premotor areas (PMAs) to primary motor cortex (M1) and subsequently to spinal cord over the corticospinal pathway. The second cortico-reticulospinal pathway from PMAs to spinal cord via the pontomedullary reticular formation (PMRF) applies inhibitory modulation to prevent premature release and specify magnitude scaling of the motor action. A: after stroke, hyperexcitability in PMAs leads to excessive inhibitory input via the cortico-reticulospinal pathway (“inhibitory modulation;” dashed ellipse) and consequently impairs movement planning preparation and performance as shown by absent/reduced StartReact (SR) response during the nonparetic arm reaching. B: during the paretic arm reaching, there is possible inhibition (small dashed ellipse) from increased activation in contralesional M1 on the ipsilesional M1. Thus movement preparation and performance is impaired to a greater extent compared with that during the nonparetic arm reaching movement.