Journal of Child Neurology http://jcn.sagepub.com/ Spasticity in Cerebral Palsy and the Selective Posterior Rhizotomy Procedure Warwick J. Peacock and Loretta A. Staudt J Child Neurol 1990 5: 179 DOI: 10.1177/088307389000500303 The online version of this article can be found at: http://jcn.sagepub.com/content/5/3/179 Published by: http://www.sagepublications.com Additional services and information for Journal of Child Neurology can be found at: Email Alerts: http://jcn.sagepub.com/cgi/alerts Subscriptions: http://jcn.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://jcn.sagepub.com/content/5/3/179.refs.html Downloaded from jcn.sagepub.com at UCLA on June 13, 2011 Spasticity in Cerebral Palsy and the Selective Posterior Rhizotomy Procedure Warwick J. Peacock, MD; Loretta A. Staudt, MS, PT Abstract A review of the selective posterior rhizotomy procedure for reduction of spasticity in cerebral palsy is presented. The history of the procedure, selection of patients, operative technique, and results are described. The neurophysiologic basis for spasticity is considered, as well as the role of spasticity in the complex motor disorder of cerebral palsy. Cerebral palsy is a multifaceted disorder of which spasticity is only one aspect. Reduction of spasticity can be effectively achieved using the current technique of selective posterior rhizotomy, but careful patient selection and establishment of realistic goals are vital to successful outcome. Postoperative physical and occupational therapy are felt to be essential for regaining strength and improving motor function following the rhizotomy procedure. Further study in the areas of spasticity, cerebral palsy, and the effects of rhizotomy is expected to advance our treatment of spastic children. (J Child Neurol 1990;5:179-185). ’ posterior rhizotomy is a neurosurgi- History . Selectivecal procedure designed to reduce spasticity. Rhizotomy or &dquo;cutting roots&dquo; was originally per- Although the procedure was first used for this pur- formed on dorsal spinal nerve roots for relief of pose almost 100 years ago/ it has recently become pain. Robert Abbe described his cases performed in repopularized for patients with spastic cerebral New York as early as 1888 and credited C. L. Dana palsy, due to refinements in technique. 2,3 The pro- with the original concept. 5 Abbe reported his own cedure today involves an L2 to L5 laminectomy, fol- four cases of upper extremity pain or pain plus lowed by the selective division of certain lumbo- spastic athetosis and also mentioned a slightly ear- sacral posterior spinal nerve rootlets, based on the lier case by Bennett in London who performed- electromyographic (EMG) responses to their electri- lumbosacral dorsal rhizotomy for lower extremity cal stimulation. It has been found to be beneficial in pain. carefully selected patients.3 In particular, spastic di- By 1908, Otfrid Foerster, a German neurosur- plegic patients with pure spasticity, no underlying geon, had used lumbosacral posterior rhizotomy to weakness or severe contractures, and the ability to relieve spasticity, although Munro is also credited walk have shown the most functional improvement with similar work as early as 1904.1,5 This followed from the procedure. Postoperative physical and oc- Sherrington’s neurophysiologic studies in the late’ cupational therapy were felt to be essential for suc- 1800s describing reduction of hypertonus following cessful surgical outcome. 3,4- division of afferent posterior nerve roots in decere- brate cats.6 Foerster described 159 cases in 1913, including 88 cases of &dquo;congenital spastic paraplegia.&dquo;’ He di- . vided the whole posterior nerve roots from L2 to S2, &dquo; either L4 or L5 to knee extensor From the Division of of California sparing preserve Neurosurgery, University tone. Foerster used electrical stimulation Los Angeles, Los Angeles, CA. during the Address correspondence to Dr Warwick J. Peacock, Pediatric procedure to identify the nerve root associated with Neurosurgery, UCLA School of Medicine, 74-137 CHS, 10833 Le knee extension and to between anterior Conte Los CA distinguish Avenue, Angeles, 90024. and roots. He features Received Dec 21, 1989. Accepted for publication Dec 22, posterior emphasized many 1989. of patient selection and treatment that continue to 179 Downloaded from jcn.sagepub.com at UCLA on June 13, 2011 be important today, such as identification of &dquo;real&dquo; bowel sphincters could be positively identified and spasticity and exclusion of cases with athetosis and spared. Thus, an L2-L5 laminectomy was used, and underlying paralysis. He reported better results in posterior nerve rootlets between L2 and S2 were those with lower extremity involvement and empha- each electrically stimulated and selectively divided, sized the benefit of motivation and intelligence to based on the EMG and visually observed muscular participate in a postoperative exercise program. responses. Foerster’s procedure fell from favor, presumably be- We now use 10 channels of EMG to simulta- cause of difficulties with sensory loss, particularly neously monitor activity in the hip adductors, quad- proprioception. 7 riceps femoris, anterior tibialis, hamstrings, and In the 1960s, Gros et al revised the procedure in gastrocnemius muscles bilaterally. The clinical pic- order to preserve sensation by cutting only a fraction ture of the child is taken into account in cases where of the posterior nerve rootlets that constitute the the EMG responses are equivocal. Follow-up for as posterior root.8 Gros had some difficulty with in- long as 7 years has shown maintenance of reduction complete relief of spasticity, as ivell as weakness, in muscle tone and functional improvements in pa- and later adapted the procedure by attempting to tients with spastic cerebral palsy. Careful patient se- spare rootlets innervating functionally useful muscle lection and postoperative therapy are felt to be vital groups. Following exposure of the posterior roots at to successful surgical outcome. 3. the level of the conus, he used electrical stimulation of posterior nerve roots and EMG, working closely with a physiotherapist and neurophysiologist to Cerebral Palsy map out the rootlets innervating &dquo;useful&dquo; muscles, Cerebral palsy’ is a motor disorder resulting from such as the abdominal muscles, gluteus maximus, damage to the immature nervous system. Spastic ce- quadriceps femoris, and gastrocnemius. These root- rebral palsy is the most frequent type. 11,12 This is of- lets were spared, while rootlets innervating muscles ten associated with the sequelae of premature birth. deemed to have &dquo;handicapping&dquo; spasticity, such as The dyskinetic types of cerebral palsy have become the adductors and hip flexors, were CUt.7,9 .. less common presumably due to the reduced inci- In the 1970s, Fasano et al discovered that the re- dence of kernicterus from successful treatment of sponse to electrical stimulation was variable among neonatal jaundice. 13 Despite the marked reduction the posterior nerve rootlets in patients with spasti- in the incidence of dyskinesia, the overall incidence City.2 Some rootlets responded to a train of electrical of cerebral palsy has remained at about 2 per 1000 stimuli with a localized brief muscular contraction, live births. 14 This is probably due to improved sur- _ while others showed a continuous or prolonged re- vival of low-birth-weight infants who sustain hy- sponse that diffused to other muscle groups, includ- poxic brain injury or the damaging effects of ing the upper limb and trunk musculature. The intraventricular hemorrhage. - rootlets associated with the brief localized responses Cerebral palsy is a multifaceted disorder with a were spared, and the others were cut. This proce- range of types and severity. Individuals may present dure was found to relieve spasticity without signifi- with one or more tonal abnormalities, including cant recurrences or sensory disturbances. It was spasticity, rigidity, dystonia, and hypotonia. Persis- found to be most useful in spastic cerebral palsy, and tent primitive reflexes and impairments of balance, improvement in function frequently accompanied re- strength, selective motor control, and coordination duction in spasticity. Children without dystonia who are usually present in varying degrees. Secondary had good underlying strength were identified as ap- joint contractures and deformities, including hip dis- propriate surgical candidates. Cooperation between location and scoliosis, often occur as a result of ab- the orthopedic surgeon and the neurosurgeon was normal tone and postures. Disorders of vision, Laitinen et al the of and emphasized. applied approach speech, hearing, sensory processing, cognition, ’. Fasano et al to a small group of adults with spinal learning may be associated with cerebral palsy. cord injury and multiple sclerosis, with positive re- These children may fail to thrive and may have sei- sults.10 zure disorders, hydrocephalus, or other medical Peacock et al adapted the procedure of Fasano problems. ’ et al to allow for positive identification of the exact The selective posterior rhizotomy procedure is neuroanatomical level.~ By working at the level of aimed at improving function or care in children who the cauda equina rather than the conus, the lower have spasticity as their primary handicapping factor, sacral nerve roots that supply the bladder and