Functional Electrical Stimulation in Stroke Rehabilitation
Age-related changes in the spinal column produce a degenerative process known as spondylosis. Cervical spondylotic myelopathy (CSM) is associated with changes in spinal column resulting in direct compressive and ischemic dysfunction of the spinal cord. Some symptoms, such as motor and sensory abnormalities, have been related to this dysfunction.1 Genetic, environmental, and occupational factors influence in the development of this condition, affecting not only old people, but also a spectrum of different ages, being a big source of disability and affecting negatively quality of life. 2
Clinical findings in cervical spondylotic myelopathy can be subtle, such as reduction in hand skill or difficulties in balance, or can be severe, conducing to a complete paralysis and incontinence.1 Painful stick neck, brachialgia and numb hands, and spatic leg weakness with instability of walk, are the symptoms in the most characteristic CSM syndrome. Upper extremity dysfunction is one of the classical signs of cervical spondylotic myelopathy.2 Particularly, a dysfunction of the hand, “myelopathy hand”, is found in different cervical spinal disorders where spinal cord is involved, including changes, such as loss of power of adduction and extension of the ulnar two or three fingers, and the inability to clasp and release quickly with these fingers. In severe cases, an atrophy of the hand muscles is presented. All these aspects demonstrated that CSM is a human problem reducing the quality of life.3
Non-surgical and surgical treatments have been proposed to treat cervical spondylotic myelopathy. One non-surgical treatment is the electric stimulation. Three different electrical stimulations are used in therapy to restore some activities in the body; neuromuscular electric stimulation (NMES), functional electric stimulation (FES), and transcutaneous electrical nerve stimulation (TENS). Functional electric stimulation is based on the application of low energy electrical stimulus to the body to restore or achieve function in paralyzed or injured individuals, related to problems in the central nervous system. These electric pulses in the nerves innervated in targeted muscles, allow the control of movement in the limbs and the body, generating synergistic activation of the muscle and producing some movement, such as reaching and grasping, that was impaired.4 Activated electrical stimulation showed a more efficiency than non-activated electrical stimulation, in the recovery of motor skills of upper extremities after a stroke.5
The use of functional electric stimulation therapy (FEST) by a group of researchers is based on the application of FES in a short-term therapeutic intervention with a limited number of FEST sessions by a patient, in order to recover the partial or complete voluntary motor function in the extremity having trouble. Sessions are usually 40-60-1 h long. In the therapy, there is a combination of unassisted execution of the specific motor task and the application of FES to the muscle in order for the individual to complete the task. As therapy evolves, functional electric stimulation assistance is reduced, and finally eliminated. Different aspects influence in the success of the therapy, including the participation of the patient; how the FES system makes the movement; and the fidelity, accuracy and repetitiveness of the movement produced by FES. Many previous studies supported results found in relation to FEST.2
Strong evidence supports the FEST as useful in treatment the recovery of some neurological function after a stroke or spinal cord injury. A particular case study using FEST was done by applying it to a 61-year-old male participant in the program, having cervical spondylotic myelopathy-related surgical treatment. He presented a progressive weakness of his right hand, having an incapacity to open and close his hand to manipulate objects. Treatment was initiated after 22 month of the surgical intervention.2
The participant had a posterior laminectomy and instrumented fusion of C3-C7 in 2012, through a cervical myelopathy. In 2013, a redo cervical decompression and extension of fusion down T2 level was done, because of a progressive weakness in right hand experienced by the patient. After this, a moderate foaminal stenosis at C5-T1 was detected and bilateral foraminotomies, at C5–C6, C6–C7, and C7–T1 was performed. Development of numbness and advance of hand weakness was detected after all surgical intervention with not acute findings or epidural hematoma revealed after a cervical spine magnetic resonance imaging (MRI). These symptoms were related to intraoperative nerve root manipulation. Due to no recovery after 22 months of surgical intervention and deterioration of the hand function, the FEST was applied and individual was studied.2
After completing the therapy, considerable and clinical improvements in his hand function, measured by THR-HFT and ARAT, were determined. Improvement in voluntary hand function was demonstrated. An important finding and significance in this research was the ability to obtain changes in only 15 1-h sessions in people with subacute stroke and traumatic SCI, making FEST a viable therapeutic intervention in these cases, improving the daily activities of those people and increasing their level of independence. Personal improvement was also reported for the participant, including improvement in his arm and hand function with more independence, and a higher level functioning.2 Previous studies confirm these results, demonstrating an improvement in voluntary upper limb function in people with chronic stroke by using FES therapy, particularly if FEST is used intensively because paralyzed muscle become active and are voluntary controlled by the patient after completion of the therapy.6
FEST is presented as an important treatment both for people having some extremities impaired associated to neurological function after a stroke or spinal cord injury, and for medical personnel, as an option of treatment. Particularly in this study, the use of an individual without a control group, limits its application and conclusions. More studies are needed with a larger number of patients and a control group, since the FEST looks like a promising technology in clinical practice in order to contribute to significant quality of life improvements.
References
Lebl DR, Hughes A, Cammisa FP, O’Leary PF. Cervical Spondylotic Myelopathy: Pathophysiology, Clinical Presentation, and Treatment. HSS Journal. 2011;7(2):170-178. doi:10.1007/s11420-011-9208-1.
Popovic MR, Zivanovic V, Valiante TA. Restoration of Upper Limb Function in an Individual with Cervical Spondylotic Myelopathy using Functional Electrical Stimulation Therapy: A Case Study. Case report article. Front. Neurol. 2016;| http://dx.doi.org/10.3389/fneur.2016.00081 Accessed July 24, 2016.
Ono K, Ebara S, Fuji T, Yonenobu K, Fujiwara K, Yamashita K. Myelopathy Hand: New Clinical Signs of Cervical Cord Damage. J Bone Joint Surgery Br. 1987;69:215–9.
Martin R, Sadowsky C, Obst K, Meyer B, McDonald J. Functional Electrical Stimulation in Spinal Cord Injury: From Theory to Practice. TSCIR. 2012;18(1):28-33. doi:10.1310/sci1801-28.
Hara Y. Rehabilitation with Functional Electrical Stimulation in Stroke Patients. Int J Phys Med Rehabil. 2013;1(147) doi:10.4172/2329-9096.1000147.
Kawashima N, Popovic MR, Zivanovic V. Effect of Intensive Functional Electrical Stimulation Therapy on Upper-Limb Motor Recovery after Stroke: Case Study of a Patient with Chronic Stroke. PTC. 2013;65(1):20-28. doi:10.3138/ptc.2011-36.
