Spasticity after spinal cord injury can usually be controlled by treatment with medications, PT, physical therapy, and botulinum toxin injections. When spasticity cannot be relieved by drugs or other methods, surgical treatment can be considered. This is about 1% to 2% of patients. Surgery can disrupt nerve conduction pathways to relieve spasticity. Surgery should accurately target the abnormally elevated muscle tone without damaging residual motor and sensory function. The methods are as follows.
I. Selective peripheral nerve dissection (SPN)
1.Selective tibial nerve branch dissection (SPN)
It is mainly used to relieve ankle joint spasm. The tibial nerve is a branch of the sciatic nerve and has 7-8 major branches. During surgery, a small transverse incision is made in the s-fossa area to reveal the medial and lateral heads of the gastrocnemius muscle and the flounder branch of the tibial nerve. The operation is very safe and the spasm disappears immediately after the operation.
2.Selective foramen ovale neurotomy (SPN)
It is mainly used to relieve the hip joint flexion and inversion spasm. It is divided into intrapelvic foramen ovale neurectomy and extra-pelvic foramen ovale neurectomy. In the former procedure, a transverse incision is made across the pubic symphysis, and a longitudinal incision is made from the anterior sheath of the rectus abdominis muscle to reveal the peritoneum after blunt separation. The procedure is relatively safe, and the spasm of the adductor muscle disappears immediately after surgery.
3.Selective upper limb peripheral nerve dissection (SPN)
For patients with severe spasticity of the upper limb, selective peripheral nerve dissection of the upper limb can be performed to relieve local spasm and improve the function of the upper limb and hand.
4.Selective sciatic neurectomy
Selective sciatic neurectomy (SPN) can be considered for patients with severe spasticity of flexion and knee contracture. A longitudinal incision is made between the sciatic node and the greater trochanter in the buttock to reveal the sciatic nerve. The sciatic nerve is divided into several bundles under the microscope, and the part of the innervated s cord muscle is confirmed by electrical stimulation, and then the branch is further divided into several small bundles, and the part with the highest excitability is confirmed by the electrical stimulation instrument and cut off.
Highly selective posterior spinal nerve rhizotomy (SPR)
It is suitable for severe spastic paralysis of the upper and lower extremities caused by neuronal injury in the upper and lower extremities, and is currently considered one of the best means to release the spasticity.
1.Cervical SPR
For patients with severe upper limb and hand spasticity and dysfunction, cervical SPR surgery can be considered when rehabilitation training is ineffective and medication is ineffective. A posterior median incision is made in the cervical spine to reveal the vertebral plates, and the plates are removed bilaterally or on one side. The dura mater and arachnoid are cut open to reveal the posterior cervical nerve roots, and the nerve segments are identified by stimulation with an electrical stimulator, and the posterior nerve roots are divided into several bundles under a microscope. It is usually necessary to treat the posterior roots of the cervical 5 to thoracic 1 nerve. Postoperatively, the patient will experience increased numbness and radicular sensation, but this will gradually disappear after 1-2 months. The spasm of the upper limb will be significantly relieved after the operation, and the improvement of function is greatly related to the functional exercise. The long-term loss of the upper limb requires a long-term hard exercise process to achieve a more satisfactory result.
2.SPR of lumbar spinal cone area
For patients with severe lower extremity spasticity, SPR surgery can be considered in the spinal cone area. The spasm of the lower limbs will be significantly relieved after surgery, which will facilitate the patient’s rehabilitation training and improve the function of the lower limbs.
C. Destruction of posterior spinal root entry (DREZ)
This method coagulates and destroys the posterior horn of the spinal cord in the pain plane, thus blocking the nerve conduction in the corresponding plane. In addition to relieving pain, it is also effective for spasticity of the extremities. Therefore, this procedure is suitable for spasticity of the extremities with severe pain. Tear-like pain is more appropriate.
Bischof’s spinal cord dissection
It is a method to cut off the anterior or posterior part of the spinal cord or all of it, also for the purpose of destroying the reflex arc. It is reported to have few side effects and is effective, and can be considered for severe spasticity due to complete spinal cord injury. However, in actual clinical practice, this procedure is rarely used at present.
V. Summary
Surgical treatment of spasticity is a neurosurgical procedure performed under the premise that conservative treatment is ineffective, and surgical treatment should be considered with great caution, only when severe spasticity affects recovery. If the indications for surgery are chosen appropriately, it can reduce limb spasticity, improve limb function, and improve the patient’s quality of life. The surgery should be performed in a hospital with the conditions and needs to be operated by an experienced physician to minimize complications.