After reading this chapter the reader will be able to:
Discuss the neural plastic changes that occur following cervical spinal cord injury (SCI) that impact upper limb function
Describe the impact of level of injury and chronicity on arm and hand function, cortical plasticity, and spinal plasticity in individuals with cervical SCI
Compare and contrast the prognosis for recovery of arm and hand function in individuals with motor-complete and motor-incomplete cervical SCI
Describe non-surgical interventions for improvement of hand function in individuals with cervical SCI
Describe the cortical and spinal mechanism for recovery of function following non-surgical rehabilitation interventions for arm and hand function
The most common form of spinal cord injury (SCI) is to the cervical spinal cord. Injury to the cervical spinal cord frequently results in impaired arm and hand function, which impacts an individual's ability to participate in self-care, work, and recreational activities. Many individuals with tetraplegia cite recovery of arm and hand function as the most important goal during rehabilitation.1,2 In a survey of 681 individuals with chronic SCI, 48.7% of the individuals with tetraplegia stated that regaining arm and hand function would be the single factor that would most improve their quality of life.1 In another report, 77% of individuals with tetraplegia stated they expected a significant change in their quality of life if they regained hand function.2 Therefore, improving arm and hand function should be a compelling goal for rehabilitation specialists working with individuals with cervical SCI.
The activity limitations that an individual experiences is dependent on the chronicity, severity, and level of the injury. Here, we will discuss the etiology of upper extremity dysfunction in individuals with cervical SCI and how the chronicity of the injury, severity of the injury, and level of the injury influences upper limb function. We will conclude with a comparison of interventions that are designed to optimize upper extremity function in individuals with cervical SCI.
Etiology of Upper Extremity Dysfunction in Individuals With Cervical SCI
On the surface, the mechanisms underlying upper extremity dysfunction following SCI seem unambiguous. Information from the cortex is essential for functional hand and arm movement, and damage to the spinal tracts limits the amount and rate of transmission of information from the cortex to the muscle.3 This leads to impaired activation of intrinsic and extrinsic hand muscles, impaired sensory perception of the hand and arm, and disrupted modulation of muscle tone.4 However, beyond damage to the spinal tracts, evidence suggests that additional mechanisms contribute to upper extremity dysfunction in individuals with cervical SCI by decreasing effectiveness of the remaining corticospinal tract connections. Detrimental plastic reorganization in the cortical motor areas and spinal cord may create further loss of function. Fortunately, preliminary evidence suggests that these plastic changes may be reversible through interventions provided by rehabilitation specialists, ...