A Pilot Study of Botulinum Toxin for Jerky, Position-Specific, Upper Limb Action Tremor.
BACKGROUND
We aimed to investigate the efficacy and safety of botulinum toxin (BT) injections for jerky action tremor of the upper limb.


METHODS
We performed an uncontrolled, prospective study of electromyography (EMG)-guided BT injections for jerky, position-specific, upper limb action tremor. The primary outcome was clinical global impression at 3-6 weeks after baseline.


RESULTS
Eight patients with jerky, position-specific action tremor involving the upper limb were consecutively recruited. After a median follow-up of 4.4 weeks (interquartile range [IQR] 3.6-6 weeks), four of them rated themselves as "improved" and two as "much improved." Five of these six subjects reported improvements in specific activities of daily living (bringing liquids to mouth, feeding, shaving, and dressing). Upper limb subscore of the Fahn-Tolosa-Marin Tremor Rating Scale (FTM) significantly decreased from 4.5 (4-6) to 3 (2-5) (p = 0.01).


CONCLUSIONS
This pilot, prospective cohort study suggests that EMG-guided BT injections may improve jerky, position-specific, upper limb action tremor. Placebo-controlled studies evaluating larger samples of patients are warranted to confirm these findings.
Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom.
Tabish A
TA
Saifee
Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom; Department of Cardiovascular and Cell Sciences, St George's University of London, London, United Kingdom; Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Serviço de Neurologia, Hospital de Santa Maria, Lisboa, Portugal.
Tiago
T
Teodoro
Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom; Dipartimento di Scienze Neurologiche e del Movimento, Università di Verona, Verona, Italy.
Roberto
R
Erro
Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom; Department of Cardiovascular and Cell Sciences, St George's University of London, London, United Kingdom.
Mark J
MJ
Edwards
Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom.
Carla
C
Cordivari
Upper limb tremor; action tremor; botulinum toxin