Rhizotomy as a treatment for hypertonia, spasticity, and dystonia

Selective dorsal rhizotomy (SDR) improves ambulation in children with spastic bilateral cerebral palsy (CP) when paired with inpatient physiotherapy; SDR is widely published, debated, and iterated upon and is supported by Level I evidence. Dystonia, a separate form of limb hypertonia from spasticity, has a pathophysiology unaffected by disruptions of the myotatic circuit and is at least relatively contraindicated for SDR.1 Ambulant and non-ambulant patients with hypertonia are candidates for intrathecal baclofen (ITB), though this therapy is limited by complications, implant cost, and frequent follow-up. When patient or caregiver goals are focused on relieving lower extremity hypertonia, some centers offer microsurgical lumbosacral combined dorsal/ventral rhizotomy (CDVR) as an alternative to ITB therapy. Glaser et al. should be commended for submitting the largest-to-date North American cohort demonstrating acceptable safety and improved lower extremity hypertonia in 33 individuals with mixed movement disorders undergoing lumbosacral CDVR.2 This manuscript reports comparable safety and efficacy results to multiple small North American case series and the largest series from Egypt (n = 50).3 It also uniquely characterizes quality of life (QoL) improvements using CP-CHILD, which indicated significantly improved aggregate QoL without subsection significance at 12 months post-procedure. The study addresses two widely held concerns of ventral root sectioning limiting widespread adoption: weakness which limits assistive device use and permanent urinary dysfunction. In the present study, some included patients were newly able to tolerate gait-assistive devices, and only one patient required permanent urinary catheterization with an average cohort time until spontaneous urination of 13 days. Microsurgical CDVR is increasingly popular as a primary surgical technique and as an alternative to ITB therapy for appendicular hypertonia, though there are multidimensional limitations to broad acceptance. Wide surgical variation exists including the name of the surgery (e.g. CDVR, dorsal-ventral rhizotomy, ventral dorsal rhizotomy, anterior posterior rhizotomy, palliative rhizotomy, and nonselective rhizotomy), roots selected, the percent of both ventral and dorsal root sectioning, and the characterization of hypertonia treated. The reported results add significantly to the existing literature supporting CDVR as both safe and effective for the treatment of severe appendicular hypertonia, with improved QoL metrics for at least 1 year. A commensurate low complication rate supports multidisciplinary consideration when compared to ITB therapy. Lumbosacral CDVR is classically considered for non-ambulant individuals with severe mobility impairment (Gross Motor Function Classification System levels IV–V). Glaser et al. report some patients are newly able to participate with gait-assist devices, a finding deserving cautious context. We currently lack the ability to parameterize ventral root function, and therefore ventral root sectioning remains nonselective by nature; consequently, CDVR and its iterations do not reliably lead to gain in function and patients and caregivers should be appropriately counseled. Continued surgical evolution is warranted for brachial hypertonia as well as for currently infeasible surgical corridors.4, 5 Further prospective registry-based studies may help us standardize the procedure and understand the durability of the measured outcomes. Not required.