How Does Stroke Affect Skeletal Muscle? State of the Art and Rehabilitation Perspective

Abstract

Long-term disability caused by stroke is largely due to an impairment of motor function. The functional consequences after stroke are caused by central nervous system adaptations and modifications, but also by the peripheral skeletal muscle changes. The nervous and muscular systems work together and are strictly dependent in their structure and function, through afferent and efferent communication pathways with a reciprocal “modulation.” Knowing how altered interaction between these two important systems can modify the intrinsic properties of muscle tissue is essential in finding the best rehabilitative therapeutic approach. Traditionally, the rehabilitation effort has been oriented toward the treatment of the central nervous system damage with a central approach, overlooking the muscle tissue. However, to ensure greater effectiveness of treatments, it should not be forgotten that muscle can also be a target in the rehabilitation process. The purpose of this review is to summarize the current knowledge about the skeletal muscle changes, directly or indirectly induced by stroke, focusing on the changes induced by the treatments most applied in stroke rehabilitation. The results of this review highlight changes in several muscular features, suggesting specific treatments based on biological knowledge; on the other hand, in standard rehabilitative practice, a realist muscle function evaluation is rarely carried out. We provide some recommendations to improve a comprehensive muscle investigation, a specific rehabilitation approach, and to draw research protocol to solve the remaining conflicting data. Even if a complete multilevel muscular evaluation requires a great effort by a multidisciplinary team to optimize motor recovery after stroke.

Upper Limbs Muscle Co-contraction Changes Correlated With the Impairment of the Corticospinal Tract in Stroke Survivors: Preliminary Evidence From Electromyography and Motor-Evoked Potential

“…But these studies focused only on the changes in the properties of muscles. For better stroke rehabilitation, it is necessary to assess the peripheral muscle changes and alternation in descending motor pathway at the same time ( Azzollini et al, 2021 ).…”

“…Much remains to be understood about the correlation between the impairment of the CST and increased muscle co-contraction of the upper limbs of stroke survivors. The impaired motor function is not only the result of the dysfunction of central motor control system but the result of the alternation in muscle activation ( Azzollini et al, 2021 ). MEP evoked by TMS could reflect the function of the CST.…”

Effects of Home-Based Boxing Training on Trunk Performance, Balance, and Enjoyment of Patients With Chronic Stroke

“…This may be because most patients with multiple sclerosis and Parkinson's disease can control the movement of their upper limbs more accurately than patients with stroke and hemiparetic upper limbs. Although, patients with pontine and cerebellar stroke, which produce symptoms such as truncal and limb ataxia [24,25], were not recruited into this study, the majority of participants in this study were stroke patients with mid-dle cerebral artery infarction who presented with muscle weakness and poor muscle control [26].…”

Do Muscle Changes Contribute to the Neurological Disorder in Spastic Paresis?

“…The understanding of the role of the muscle disorder on the neural command and on motor function should encourage therapists to consider the muscle disorder as a nosologic entity in hemiparesis and to implement meaningful therapeutic interventions specifically on this target ( 21 , 91 ). Descriptive results found in this study will help to direct these interventions, addressing particularly the plantar flexors, GM and RF in the lower limb, and the shoulder muscles and FF in the upper limb.…”

“…Descriptive results found in this study will help to direct these interventions, addressing particularly the plantar flexors, GM and RF in the lower limb, and the shoulder muscles and FF in the upper limb. Besides the central nervous system, skeletal muscle is another plastic tissue with response to changes in stimulation and in the environment ( 18 , 91 – 93 ). Spastic myopathy should be treated with an appropriate physical treatment, using techniques such as prolonged daily self-stretch postures at high load ( 53 ), active stretching ( 94 ), short wave and ultrasound therapies ( 95 ), as it is known that botulinum toxin injections alone will not allow any long-term meaningful muscle lengthening ( 52 , 96 , 97 ).…”