Nonselective lumbosacral ventral-dorsal rhizotomy for the management of lower-limb hypertonia in nonambulatory children with cerebral palsy.

OBJECTIVE: Children with cerebral palsy (CP) often experience medically refractory hypertonia, for which there are surgical therapies including neuromodulation and rhizotomy. Traditional surgical treatment for medically refractory mixed hypertonia or dystonia includes intrathecal baclofen pumps and selective dorsal rhizotomy. A nonselective lumbosacral ventral-dorsal rhizotomy (VDR; ventral and dorsal roots lesioned by 80%-90%) has the potential to address the limitations of traditional surgical options. The authors highlighted the institutional safety and efficacy of nonselective lumbosacral VDR for palliative tone management in nonambulatory patients with more severe CP. METHODS: The authors performed a retrospective analysis of patients who had undergone lumbosacral VDR between 2022 and 2023. Demographic factors, clinical variables, and operative characteristics were collected. The primary outcomes of interest included tone control and quality of life improvement. Secondary outcome measures included, as a measure of safety, perioperative events such as paresthesias. Postoperative complications were also noted. RESULTS: Fourteen patients (7 female) were included in the study. All patients had undergone a T12-L2 osteoplastic laminoplasty and bilateral L1-S1 VDR. Nine patients had quadriplegic mixed hypertonia, 4 had quadriplegic spasticity, and 1 had generalized secondary dystonia. Following VDR, there was a significant decrease in both lower-extremity modified Ashworth Scale (mAS) scores (mean difference [MD] -2.77 ± 1.0, p < 0.001) and upper-extremity mAS scores (MD -0.71 ± 0.76, p = 0.02), with an average follow-up of 3 months. In the patient with generalized dystonia, the lower-extremity Barry-Albright Dystonia Scale score decreased from 8 to 0, and the overall score decreased from 32 to 13. All parents noted increased ease in caregiving, particularly in terms of positioning, transfers, and changing. The mean daily enteral baclofen dose decreased from 47 mg preoperatively to 24.5 mg postoperatively (p < 0.001). Three patients developed wound dehiscence, 2 of whom had concurrent infections. CONCLUSIONS: Lumbosacral VDR is safe, is effective for tone control, and can provide quality of life improvements in patients with medically refractory lower-limb mixed hypertonia. Lumbosacral VDR can be considered for palliative tone control in nonambulatory patients with more severe CP. Larger studies with longer follow-ups are necessary to further determine safety and long-term benefits in these patients.

Safety and efficacy of continuous intrathecal baclofen via cervical catheter tip: a retrospective case series.

OBJECTIVE: Intrathecal baclofen (ITB) is an effective treatment for hypertonia in children involving the implantation of a pump and catheter system. The highest concentration of ITB is at the catheter tip. The catheter tip location is most commonly within the lumbar or thoracic spine. The cervical tip location has traditionally been avoided because of concerns of hypoventilation and pneumonia; however, these complications in cervical compared with thoracic or lumbar placement have not been reliably proven. Some studies have suggested that cervical ITB location better treats upper-extremity hypertonia. There are limited data describing the safety and efficacy of cervical ITB on hypertonia. The authors present a single-institution retrospective case series highlighting the safety and efficacy of using cervical ITB location for the treatment of hypertonia. METHODS: Retrospective data analysis was performed for children who underwent continuous dosing cervical ITB between April 2022 and October 2023. Nonmodifiable risk factors, clinical variables, operative characteristics, and adverse outcomes were collected. RESULTS: This study included 25 patients (8 female). The mean age at implantation was 12.4 years, and the mean operative duration was 90 minutes. The mean Barry-Albright Dystonia Scale score decreased by 9.5 points (p = 0.01). The mean aggregated modified Ashworth scale score in the upper extremities decreased by 2.14 points (p = 0.04), and that in the lower extremities decreased by 4.98 points (p < 0.01). One patient each (4%) had infection and baclofen toxicity. Two patients (8%) had respiratory depression requiring continuous positive airway pressure. There was no incidence of pneumonia or wound dehiscence. CONCLUSIONS: The cervical catheter tip location for ITB is safe, is effective to control tone, and should be considered for the treatment of hypertonia. Larger studies with longer follow-up are necessary to further determine upper-limit dosing safety along with long-term functional benefits in these patients.

Safety and efficacy of intrathecal baclofen trials for the treatment of hypertonia: a retrospective cohort study.

OBJECTIVE: Intrathecal baclofen (ITB) is an effective treatment for refractory hypertonia in children. ITB has long been effective for the treatment of spasticity, and indications have naturally evolved to include dystonia and mixed pediatric movement disorders (PMDs). The established uses for ITB trials are insurance prerequisite, mixed tone, and family request. Despite agreement for ITB therapy by a multidisciplinary group of subspecialists in a complex PMD program, insurance companies often require an ITB trial be performed. A longitudinal cohort was identified to determine the safety and efficacy of ITB trials and to determine the utility of test dosing in this population. METHODS: Retrospective data analysis was performed for patients with hypertonia who underwent ITB bolus trials at the authors' institution between 2021 and 2023. Nonmodifiable risk factors and clinical variables were collected. RESULTS: Thirty-one patients (11 female) underwent 32 ITB trials. Of these patients, 67.7% had a diagnosis of mixed hypertonia, 32.3% pure spasticity, and 9.1% secondary dystonia. The mean age at test dose was 12.8 years, and 58.1% of patients were born premature. The mode Gross Motor Function Classification System score was 5. The mean difference in Barry-Albright Dystonia Scale (BADS) scores was -7.33 points (p = 0.01) at 2.5 hours postoperatively. The mean difference in upper-extremity modified Ashworth Scale (mAS) scores was -5.36 points (p = 0.003), and that for lower-extremity mAS scores was -6.61 (p < 0.001). In total, 21.9% of patients developed a post-dural puncture headache. Conversion to a permanent baclofen pump was performed in 22/32 (68.8%) patients. Of those who did not pursue pump placement, 1 patient had high surgical risk, 1 had an ineffective response, 1 had a bad reaction to the test dose and cited both regression and increased discomfort, and 2 declined despite an effective trial owing to family preferences. CONCLUSIONS: ITB trials require hospitalization in some form and carry risks of procedural complications. The decision to pursue a trial should be made on a case-by-case basis by clinicians and should not be determined by insurance companies. The complication rate of ITB trials is high, and a test dose is unnecessary in this fragile population.

Navigated Radiofrequency Ablation Peripheral Rhizotomy for Lumbosacral Hypertonia in a Nonambulatory Patient With Spinal Fusion: Indications, Surgical Techniques, and Lessons Learned.

BACKGROUND AND OBJECTIVES: Radiofrequency ablation (RFA) is a destructive therapy which causes target tissue destruction by application of a thermal dose. Neurosurgical applications of RFA are well-described for myriad chronic pain and movement disorder diagnoses. In fact, RFA pallidotomy and thalamotomy are the initial procedures from which the field of neurosurgical management for movement disorders emerged. RFA rhizotomy for post-traumatic spasms was popular in the 1970s and 1980s, although it was largely abandoned after the invention and Food and Drug Administration approval of intrathecal baclofen therapy. RFA has not been described as a primary treatment of hypertonia in nonambulatory children. METHODS: We report a case of computer-navigated, nonselective RFA peripheral rhizotomy for a nonambulatory child with a history of severe scoliosis and spinal fusion, where an open rhizotomy was technically impractical. RESULTS: Navigation to and ablation of the bilateral L1-L5 peripheral nerves with this approach was successful, and the patient experienced bilateral lower extremity tone improvement. CONCLUSION: We use this case to highlight considerations in indications, our applied operative technique, and lessons learned from this novel application of RFA peripheral rhizotomy in children.

Resident muscle stem cell myogenic characteristics in postnatal muscle growth impairments in children with cerebral palsy.

Children with cerebral palsy (CP), a perinatal brain alteration, have impaired postnatal muscle growth, with some muscles developing contractures. Functionally, children are either able to walk or primarily use wheelchairs. Satellite cells are muscle stem cells (MuSCs) required for postnatal development and source of myonuclei. Only MuSC abundance has been previously reported in contractured muscles, with myogenic characteristics assessed only in vitro. We investigated whether MuSC myogenic, myonuclear, and myofiber characteristics in situ differ between contractured and noncontractured muscles, across functional levels, and compared with typically developing (TD) children with musculoskeletal injury. Open muscle biopsies were obtained from 36 children (30 CP, 6 TD) during surgery; contracture correction for adductors or gastrocnemius, or from vastus lateralis [bony surgery in CP, anterior cruciate ligament (ACL) repair in TD]. Muscle cross sections were immunohistochemically labeled for MuSC abundance, activation, proliferation, nuclei, myofiber borders, type-1 fibers, and collagen content in serial sections. Although MuSC abundance was greater in contractured muscles, primarily in type-1 fibers, their myogenic characteristics (activation, proliferation) were lower compared with noncontractured muscles. Overall, MuSC abundance, activation, and proliferation appear to be associated with collagen content. Myonuclear number was similar between all muscles, but only in contractured muscles were there associations between myonuclear number, MuSC abundance, and fiber cross-sectional area. Puzzlingly, MuSC characteristics were similar between ambulatory and nonambulatory children. Noncontractured muscles in children with CP had a lower MuSC abundance compared with TD-ACL injured children, but similar myogenic characteristics. Contractured muscles may have an intrinsic deficiency in developmental progression for postnatal MuSC pool establishment, needed for lifelong efficient growth and repair.