Objective: To analyse the impact of the COVID-19 pandemic in the long-term efficacy of treatment with botulinum toxin (BoT).

Background: The COVID-19 pandemic brought new difficulties in the management of patients treated with BoT, leading to significant delays between treatment sessions and concerns relating to the long-term efficacy of this treatment.

Method: Ambispective observational study including a cohort of patients treated in an outpatient BoT clinic who had their treatment interrupted during the COVID-19 pandemic. Demographics, clinical data regarding treatment (time between treatment sessions and total BoT dose used), and patient outcome measures (time between the session and noticeable effects, time to loss of noticeable effects, and maximum perceived benefit at two weeks post-treatment on a Likert scale) was collected at three time points: T1 – last session before the beginning of the COVID-19 pandemic (03/11/2020); T2 – first session after the beginning of the pandemic, and T3 – most recent session, in the first trimester of 2023. Univariate analysis was performed, and significance was set for p<0.05.

Results: 23 patients were included, 69.6% females, mean age 65.9 (±11.2) years. Twelve patients were being treated for indications other than dystonia (hemifacial spasm, spasticity, and cervical tremor).

Time between treatment sessions increased significantly between T1 and T2 (from 3.78±0.65 to 6.15 ± 1.84 months,p<0.001), but not between T1 and T3 (4.13±0.97months,p=0.084). Time between treatment and noticeable effects showed a tendency to increase between T1 and T2 (from 5.52±4.45 to 7.04±5.35 days,p=0.051) but was not different between T1 and T3 (5.04±4.08 days,p=0.625). Time between treatment and loss of effect increased between T1 and T2 (from3.11±0.62 to 3.37±0.83 months,p=0.043) but remained similar between T1 and T3 (3.15±1.19 months,p=0.833). Maximal benefit at two weeks remained similar between T1 and T2 (4.00±0.63 and 3.82±0.60,p=0.441) and T1 and T3 (4.36±0.67,p=0.221). BoT total dose did not differ significantly between any of the time points, both in the overall analysis and in the subgroup analysis separating dystonia from other indications.

Conclusion: Dose of BoT needed, time between injections and clinical efficacy were not affected at long term after BoT temporary interruption during the COVID-19 pandemic in patients with dystonia or other indications.

« Back to 2023 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/impact-of-the-covid-19-pandemic-in-the-long-term-efficacy-of-botulinum-toxin-treatment/