Spinal cord stimulation for freezing of gait in Parkinson's disease and progressive supranuclear palsy: a case series

Background: Freezing of gait (FOG) in Parkinson's disease (PD) and progressive supranuclear palsy (PSP) exert a significant adverse impact on the patients quality of life, the degree of their disability, and the risk of falls. A specific characteristic of FOG is a poor response to medical treatment. According to the data of open-label clinical trials and clinical case series published in the last decade, spinal cord stimulation (SCS) can be considered as one of the methods to improve this type of movement disorders. Materials and methods: We present a clinical series of patients with PD and PSP, who underwent implantation of a chronic epidural SCS system at the mid-thoracic level to correct FOG. The efficacy of surgical treatment was assessed at 2 and 5 months with the following scales and questionnaires: part III Unified Parkinson's Disease Rating Scale of Movement Disorder Society (MDS-UPDRS), Freezing of Gait Questionnaire (FOG-Q), Activity-Specific Balance Confidence Scale (ABC), Parkinson's Disease Quality of Life Questionnaire-8 (PDQ-8), Time up and Go Test (TUG), 10 Meter Walk Test. The patients were asked to report possible adverse reactions after the procedure. Results: The results of a 5-month follow-up were obtained from 4 patients (2 with PD and 2 with PSP). There were no adverse events associated with SCS. Оnly one patient with PD experienced a decrease in the severity of motor symptoms according to the MDS-UPDRS part III scale. An increase in the speed of 10 meters' walking distance and TUG test performance was observed in 3 patients. All patients reported an improvement in the quality of life (according to the PDQ-8 questionnaire) and confidence in maintaining balance (according to the ABC questionnaire) by month 2 after surgery. However, at month 5, a negative trend was noted again. Conclusion: The SCS method was safe in all 4 clinical cases described. There was a positive effect of SCS on the improvement of FOG and postural balance in PD and PSP. However, the duration of the therapeutic effect may vary.