95. Effect of spinal cord stimulation on balance and gait in failed back surgery syndrome patients

Abstract

<h3>BACKGROUND CONTEXT</h3> While spine surgery can produce good outcomes in many patients, there are patients who do not benefit from the intervention and have conditions not thought not to be addressable by surgical intervention. These failed back surgery syndrome (FBSS) patients may be candidates for spinal cord stimulation (SCS) for pain management. While multiple studies have reported benefits of SCS related to pain reduction, improved quality of life, and reduced pain medication intake, there has been little investigation into measurable physical functional improvement in this population. <h3>PURPOSE</h3> The purpose of this study was to evaluate the effect of SCS on traditional self-reported pain and functional measures, the psychological parameter of kinesiphobia, as well as functional measures of balance and gait, in FBSS patients. <h3>STUDY DESIGN/SETTING</h3> Prospective repeated-measures design. <h3>PATIENT SAMPLE</h3> A total of 15 symptomatic FBSS patients eligible for SCS. <h3>OUTCOME MEASURES</h3> Outcome assessment was based on visual analog scales (VAS) for back and leg pain, Oswestry Disability index (ODI), Tampa Scale for Kinesiophobia (TSK) and functional testing components including balance, sway and gait. <h3>METHODS</h3> Patients completed patients reported outcomes and functional evaluations prior to the SCS trial procedure (Pre) and at 6 (Post6) and 12 (Post12) weeks after SCS implantation. Gait and balance were evaluated using 3D human motion capture and dynamic surface EMG. Balance effort and Cone of Economy (CoE) dimensions were as measured by total sway and range of sway (RoS), respectively. Repeated measurements and one-way analysis of variance (ANOVA) were used to analyze data. <h3>RESULTS</h3> SCS implant significantly improved gait and balance in FBSS patients. The following gait parameters showerd significant improvement: Walking speed (Pre: 0.75, Post6: 0.86, Post12: 0.92 m/s, p<0.011), cadence (Pre: 85.42, Post6: 94.1, Post12: 95.94 steps/m, p<0.032), stride length (Pre: 0.98, Post6: 1.05, Post12: 1.07 m, p<0.049), and gait deviation index (GDI; Pre: 74.0, Post6: 83.2, Post12: 90.8, p<0.012). Additionally, significant improvements were seen in balance effort (head sway, Pre: 80.2, Post6: 52.2, Post12: 50.0 cm, p<0.049) sway dimensions as seen by reduced sagittal (p<0.047) and coronal (p<0.042) sway. For patient-reported outcomes, significant improvements were noted for VAS low back (Pre: 6.5, Post6: 3.6, Post12: 3.9, p<0.036), ODI (Pre: 57.6, Post6: 39.7, Post12: 38.3, p<0.006). Scores on the and TSK also improved significantly (p<0.044). <h3>CONCLUSIONS</h3> The results of this study support prior literature reporting significant improvement in pain and self-reported function reflected in VAS and ODI scores. Additionally, significant improvements were found post-SCS in gait and balance. The results suggest that SCS is associated not only with significant improvement in patient self-reported outcome measures, but also with physical functional testing. The patients included in this study showed more efficient gait patterns and improves balanced. This may be reflective of an overall improvement in activities of daily living following SCS implantation. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.