Therapeutic effectiveness of local Botulinum toxin injection on hand tremor severity and upper limb function in patients with idiopathic Parkinson disease - A Systematic Review

Abstract

Parkinson's disease (PD) is the second most common neurodegenerative disorder in the world and the clinical symptom of hand tremor is one of the primary and common motor symptoms of this disease. Tremor may be resistant to oral drug treatments that make its treatment challenging. Therefore, botulinum toxin (BoNT) is a suitable alternative treatment for tremor. The aim of this systematic review study was to investigate and analysis of studies with the efficacy and safety of botulinum toxin (BoNT) local injection on the hand tremor severity and upper extremity function in patients with idiopathic Parkinson's disease. Methods: A systematic comprehensive search was performed from 1990 to December 2020 in electronic databases including Cochrane Central Control Files, MEDLINE (PubMed), Scopus, Web of Science, EMBASE, Google Scholar, Clinicaltrial.gov, ProQuest for English, and SID, Magiran, Irandoc and Iranianmedex texts for Persian literature including all studies that investigated the effect of BoNT local injection on hand tremor control and upper extremity function in Parkinson's patients was performed. Results: In this systematic review study, finally was 10 studies in accordance with all inclusion criteria, which is including 1 randomized double-blinded crossover clinical trial and 9 studies of pilot single-center studies without randomized or open label that were classified as cohort studies. There were 131 patients in all. The mean duration of patient's hand tremor was5.93 ± 2.08 years. The tremor severity in patients ranged from 1 to 3. The injectable dose was between 68 -100 IU of Anabotolinium toxin in each upper extremity. In the studied studies were identified 3 outcome groups (1) The first outcome group includes non-kinematic assessment of hand tremor severity criteria which was evaluated by questionnaires such as Fahn-Tolosa-Marín scale (FTM), UPDRS (Unified Parkinson's Disease Rating Scale) and NIHCGC tremor severity scale. (2) The second outcome group was kinematic evaluation of hand tumor intensity which was measured by installing sensor devices on the affected hand. (3) The third outcome group was evaluated for pain intensity, daily functioning and patient's quality of life, which was evaluated by using with VAS, ADL, manual dynamometer, Ergometer, PDQoL questionnaire, QUEST questionnaire and PGIC (patient global impression) questionnaire. The results of this study showed a decrease in UPDRS_20 and UPDRS_21item, after botulinum toxin injection in the hands of individuals by 1.22 ±1.1 unites and 1.20 ± 0.9 units, respectively. In addition, BoNT local injection is tolerable for many patients without serious complications.