In patients suffering from spasticity with preserved owner, his surgery is indicated. It is most useful in cerebral palsy patients as it can selectively resect dorsal roots contributing to spasticity without affecting the motor power, thus improving their mobility. The most common indication for this surgery is cerebral palsy. Patients suffering from cerebral palsy, especially, diplegic CP patients have dystonia and spasticity impairing their locomotive function. They require a detailed evaluation to find out the muscles contributing to their spasticity as some spasticity can compensate for some loss of power in the limbs. At the Jaslok hospital a multidisciplinary team of Pediatric neurologist, orthopedic surgeon, pediatric physiotherapist and neurosurgeon assess the patient to determine the exact disability of the child. Following this a detailed plan is made as to how many rootlets should be sectioned in order to obtain reduction in the spasticity. Typically it ranges from 40-60% section of the dorsal roots. These roots do not directly contribute to the power of the legs and hence can be sectioned without compromising the power.
The Technique of Dorsal Rhizotomy
- Osteoplastic laminotomy is done in one single piece, from T11 to L1 that allows replacement of the laminae at the end of the procedure.
- Bipolar stimulation of the sensory roots (or rootlets), usually of L2 through S1 bilaterally, is carried out using a multichannel EMG recorder to allow electrical monitoring of the root being stimulated. In addition, it is important to palpate the leg muscles for evidence of contraction. Abnormally responsive rootlets are the candidates to be cut.
- Motor responses evoked by stimulation (with a bipolar electrical stimulator) are tested for ventral and then dorsal root (rootlets). The threshold for obtaining motor responses by stimulating the dorsal root (rootlets) is at three times more than the on corresponding ventral root (rootlets).
- For surgery to be effective, a total amount of 60% of dorsal rootlets must be cut.
Basic nursing care and physical treatments:
Reduction of noxious stimuli which may exacerbate hypertonia, by good nursing care, is most important.
- Avoidance of pressure sores, muscular retractions and articular ankyloses.
- Prevention of urinary tract complications, fecal impaction and venous thrombosis.
- Proper bed positioning and daily stretching program are also of prime importance for spasticity prevention.
- Extension is advocated to counterbalance the flexion in the upper limbs, and flexion-abduction to oppose usual extension adduction pattern in the lower limbs.
- Cold baths or topical applications of ice, the rationale of which is that cold probably decreases nerve conduction, may be effective for several hours.