Excitation-inhibition imbalance in the motor control network: a key factor in post-stroke spasticity

Spasticity is a recognized motor dysfunction that frequently arises following a stroke and significantly impacts the quality of life of affected patients. It is characterized by involuntary muscle activation resulting from overexcitation of the stretch reflex. Currently, therapeutic options for post-stroke spasticity are limited, and the underlying pathological mechanisms remain inadequately understood. Evidence suggests that stretch reflex hyperactivity is attributable to a combination of factors, including abnormal supraspinal projections, imbalances within the intraspinal network, and peripheral muscle alterations. This review aimed to examine supraspinal projections, specifically addressing the imbalance between excitatory and inhibitory output signals within the neural network of the brain's motor control region, and to discuss the significant role of the associated nerve bundles in the disease's pathogenesis.