Selective Dorsal Rhizotomy for Treatment of Hereditary Spastic Paraplegia-Associated Spasticity in 37 Patients

Background A limited number of publications have described a reduction of spasticity associated with hereditary spastic paraplegia (HSP) after selective dorsal rhizotomy (SDR). Typically, the SDR procedure is performed on patients with spastic cerebral palsy to remove spasticity and to help these patients with ambulatory function. Whether SDR has similar effects on HSP patients, requires further investigation. Thus, we are providing a personal experience of the effects of SDR on this specific cohort of patients. Objectives To examine the safety of SDR, changes in spasticity, and ambulatory function after SDR on patients with HSP. Methods The Institutional Review Board of Washington University School of Medicine approved this study (#201704003). A total of 37 children and adults received SDR for the treatment of HSP-associated spasticity between 1988 and 2021. SDR was performed through an L1 laminectomy, as we previously described in an earlier publication. The patients took part in the follow-up examination either in-person or by email. The follow-up focused on the patients' motor functions (primarily ambulation), adverse effects of SDR, and orthopedic treatments after SDR. Results Of the total 37 patients who participated in this study, 46% were female and 54% were male. The age range of when HSP was diagnosed was one month to 34 years. Six of the patients' diagnoses were made, based on the family history of HSP in six patients and the remaining 31 patients' diagnoses were confirmed by genetic tests. The most common genetic mutations were SPG4 and SPG3A. Of the patients with positive genetic tests, 40% had no family history of HSP. SDR was performed at the age of 2 to 45 years (mean: 14.7 years). The follow-up period ranged from 0 to 33 years (mean: 3.8 years). One patient developed a spinal fluid leak requiring surgical repair. Two patients reported mild numbness in parts of the lower limbs. Spasticity was removed in 33 patients (89%). Four patients (11%) experienced a return in spasticity. Regarding ambulatory function, 11% of patients reported a decline in function. Two patients walked independently before surgery but declined, requiring a wheelchair eight years and seven years, respectively, after surgery for each patient. In contrast, 16% saw an improvement in ambulatory function, improving from walking with a walker to walking independently. The remaining 73% of patients maintained their level of ambulation. These two groups of patients showed improvement in other motor functions and independence.  Conclusions The present analysis suggests the potential role of SDR in the management of spasticity in HSP patients. We found no sign of SDR being a direct cause of deleterious effects on patients with HSP.