DORSAL ROOT ENTRY ZONE RHIZOTOMY (DREZotomy)
- DREZotomy is indicated in patients with paraplegia and severe pain.
- In this surgery, lesion is made at the level of the dorsal horn where the sensory nerve roots enter. This interrupts the spinal reflex arc and hence relieves the spasticity.
- Following this surgery any scope of motor function returning is lost. Therefore this surgery is offered to those patients who have no chance of improving their motor function.
- The biggest advantage of this procedure is that it is only performed one time and the relief from spasticity is life-long.
- The surgery not only relieves the spasticity but also alleviates pain.
- For severe spastic paraplegia, it is usually recommended to resect at least five roots and leave the fourth lumbar root intact, as this root generally guarantees the extensor reflex of the knee which is necessary for standing and walking. However, in order to know by which lumbar roots the extension reflex of the knee is effected, we must have recourse to the intraoperative neurophysiological monitoring during the operation.
- Thus, the general rule is resection of the second, third and fifth lumbar, and first and second sacral roots.
- To reduce the sensory secondary effect, one rootlet is preserved out of five (on average) for each root, from L1 to S1.