Increase tone of muscles is called as spasticity however generally spasticity means stiffness and difficulty in free movements of joints through its full range. Our movements are planned by brain and executed by a fine checks and balances of feedbacks mechanisms through nerves and spinal cord to brain. But when brain is diseases as in cerebral palsy or the connection is breached as in spinal cord injury, these feedbacks are affected and results in spasticity or stiff limbs.
In spasticity, muscles are under continuous contracted state hence joints become stiff. There are many problems with spasticity. Mainly, range of movements of joints is decreased and joint become immobile and tendons and muscles go in state of permanent contractures or shortening. Secondly, this can lead to pressure sores at multiple locations. Thirdly, as muscles are contracting continuously, they are working without any goal, but this causes energy expenditure and patients lose weight.
There are many diseases associated with spasticity however important and common are a. Cerebral Palsy b. Severe Head Injury c. Spinal cord injury. d. Multiple sclerosis e. Spastic paparesis
Treating spasticity is of utmost importance for early ambulation and prevention of contractures and bedsores. Physiotherapy is mainstay of preventing spasticity. Oral medications are standard initial care for early and mild spasticity however dose of oral medicines needed to control severe spasticity is associated with severe side effects like dizziness, hypotension and many others. Hence simple surgical treatments are utilized for relieving spasticity.
Baclofen is oral medicine helpful in spasticity however dose related side effects are more in severe spasticity. Hence, a small pump is put in body which deliver very small amount of baclofen but directly at the site of action i.e. CSF space around the spinal cord. Baclofen pumps are safe, simple, easy to implant and standard of care in western countries in spasticity management. Patient need to come for refill of pumps every three months. Refilling can be done with simple injection at OPD basis. Life of these pumps can range from 5-8 years and more.
Baclofen pump installation is overall safe procedure. However, implant related problems are reported in approx 10-15 % of cases including kinking of catheter, blockage or failure to deliver drug or infection of pump needing revision. Cost of baclofen procedure is prohibitive for Indian population which is approximately 5 lakhs with need for follow up every three months to refill the drug. If baclofen drug delivery stops for any reason like pump failure or inability to come for follow up and refill, patient slips into baclofen withdrawal syndrome which can be fatal at times.
As discussed above, our movements are fine tuning of checks and balances of various feedback mechanisms at the level of spinal cord supervised by brain input. In spasticity, these feedback mechanisms become hyperactive due to absence of brain supervision. In selective posterior rhizotomy procedure, we do selective deafferentiation meaning reducing the hyperactive inputs from muscles hence affecting the reflex arc. This decreases the muscle nerve input to nerve thus reducing the spasticity. This is done at the level of nerve roots joining the spinal cords.
This procedure per say does not need any special tests however detailed evaluation by physiotherapist for grade of spasticity, muscle power, gait or walking pattern of patient are needed. Overall assessment for predicting the benefit to patient is carried out in OPD basis. In cerebral palsy cases, we need to go for IQ testing and other evaluations to predict the outcomes of surgery. Few blood tests as initial screening for surgical fitness are carried out. Primary fitness to undergo surgery is also evaluated.
This surgery is highly specialized surgery and needs multitude of technological gadgets at backend at operation theatre apart from especially trained neurosurgeon. A small incision is taken at midback level in midline. After identifying the nerve roots and spinal cord, we identify incoming nerves to spinal cord. After fine dissection under microscope, these nerves are split into fine fibers. These individual fibers are stimulated to grade the muscle response and classified as normal or abnormal response on the basis of graph they produce. Selectively, those fibers with abnormal response were divided to optimize the outcomes.
Surgery is very effective and reduction of spasticity is noted immediately after surgery in post operative period. This relief of spasticity is long lasting and many times permanent. Patient is typically discharged after 7-8 days of surgery and sent to rehabilitation unit. Post operative physiotherapy and rehabilitation training program is of utmost importance for optimum outcomes. No need of regular follow up is needed once patient attends rehabilitation program. Improvements are noted in gait, walking speed, walking distance, independent ambulation and confidence of patient.
Selective posterior rhizotomy is safe, simple and effective procedure if performed by trained neurosurgeon under optimum operative theatre infrastructure. Few patients complain of hyperesthesia for few weeks. Few have temporary urinary complaints like difficulty in micturition and may need urinary catheter for couple of weeks. Temporary constipation can be observed. Weight gain is observed in few patients.
When spasticity is focal meaning limited to any one limb or one side of body in that case we selectively cut a specific nerve to get rid of unwanted spasticity. This has similar principle of disturbing the reflex arch and feedback mechanism however this procedure is done under local anesthesia and day care procedure so that patient can go home the same day. Efficacy of this procedure is long lasting and improves ambulation and walking. These are cost effective procedure with expenses upto 30 thousands and much cheaper compared to botox injections which are offered to patients.
Selective peripheral neurectomies are mainly used in rehabilitation of post stroke patients with hemiplegia or monoplegia and severe spasticity affecting ambulation. Other indications include focal spasticity of any origin affecting one side observed in spinal cord injuries. Hemiplegic form of cerebral palsy patients are hugely benefitted with selective peripheral neurectomies.