Mobile digital gait analysis captures effects of botulinum toxin in hereditary spastic paraplegia.

BACKGROUND AND PURPOSE: Hereditary spastic paraplegias (HSPs) comprise a group of inherited neurodegenerative disorders characterized by progressive spasticity and weakness. Botulinum toxin has been approved for lower limb spasticity following stroke and cerebral palsy, but its effects in HSPs remain underexplored. We aimed to characterize the effects of botulinum toxin on clinical, gait, and patient-reported outcomes in HSP patients and explore the potential of mobile digital gait analysis to monitor treatment effects and predict treatment response. METHODS: We conducted a prospective, observational, multicenter study involving ambulatory HSP patients treated with botulinum toxin tailored to individual goals. Comparing data at baseline, after 1 month, and after 3 months, treatment response was assessed using clinical parameters, goal attainment scaling, and mobile digital gait analysis. Machine learning algorithms were used for predicting individual goal attainment based on baseline parameters. RESULTS: A total of 56 patients were enrolled. Despite the heterogeneity of treatment goals and targeted muscles, botulinum toxin led to a significant improvement in specific clinical parameters and an improvement in specific gait characteristics, peaking at the 1-month and declining by the 3-month follow-up. Significant correlations were identified between gait parameters and clinical scores. With a mean balanced accuracy of 66%, machine learning algorithms identified important denominators to predict treatment response. CONCLUSIONS: Our study provides evidence supporting the beneficial effects of botulinum toxin in HSP when applied according to individual treatment goals. The use of mobile digital gait analysis and machine learning represents a novel approach for monitoring treatment effects and predicting treatment response.

Development and validation of TreatHSP-QoL: a patient-reported outcome measure for health-related quality of life in hereditary spastic paraplegia.

BACKGROUND: Hereditary spastic paraplegia (HSP) is a rare neurodegenerative disease that lacks specific and validated patient-centered outcome measures (PCOMs). We aimed to develop and validate a health-related quality of life (HRQoL) questionnaire specific to HSP ("TreatHSP-QoL") that could be used as a PCOM. RESULTS: The pilot-items of the TreatHSP-QoL (45 five-level Likert scale items, with values per item between 0 and 4) were developed based on a qualitative data analysis of 54 semi-structured interviews, conducted in person with 36 HSP patients and 18 caregivers. It was then reduced and modified through the validation process to 25 items. The main validation was performed using the online questionnaire in 242 HSP patients and 56 caregivers. The exploratory factor analysis defined five subdomains. Cronbach's alpha ranged from 0.57 to 0.85 for the subdomains and reached 0.85 for the total score. The test-retest Pearson correlation reached 0.86 (95% Confidence Interval (CI) [0.79, 0.91]). Pearson correlations with the EuroQol-5 Dimension (5 levels) (EQ-5D-5L) and Friedreich Ataxia Rating Scale-Activities of Daily Living (FARS-ADL) questionnaires varied strongly among the subdomains, with the total scores reaching 0.53 (95% CI [0.42, 0.61]) and -0.45 (95% CI [- 0.55, - 0.35]), respectively. The caregiver-patient response Pearson correlation ranged between 0.64 and 0.82 for subdomains and reached 0.65 (95% CI [0.38, 0.81]) for the total score. CONCLUSIONS: TreatHSP-QoL can be used in high-quality clinical trials and clinical practice as a disease-specific PCOM (i.e., HRQoL measure) and is also applicable as a proxy questionnaire. Score values between 0 and 100 can be reached, where higher value represents better HRQoL. The Pearson correlations to the EQ-5D-5L and FARS-ADL support the additional value and need of HSP-specific PCOM, while non-specific QoL-assessment and specific clinical self-assessment tools already exist. All in all, the results demonstrate good validity and reliability for this new patient-centered questionnaire for HSP.