Affiliations: The Michael Trimble Neuropsychiatry Research Group,
Department of Neuropsychiatry, BSMHFT and University of Birmingham, Birmingham,
UK | Neuroscience and Trauma Centre, Barts and The London
School of Medicine and Dentistry, Queen Mary University London, London,
UK | Neurology Department, Princess Royal University
Hospital, South London NHS Trust, Orpington, Kent, UK
Note: [] Corresponding author: Sejal Patel, Department of
Neuropsychiatry, The Barberry National Centre for Mental Health, Birmingham B15
2FG, UK. Tel.: +44 121 3012317; Fax: +44 121 3012291; E-mail:
[email protected]
Abstract: Background: Dystonia is a chronic disorder characterised by an
aberration in the control of movement. Sustained co-contraction of opposing
agonist and antagonist muscles can cause repetitive and twisting movements, or
abnormal postures. Cervical dystonia (CD), often referred to as spasmodic
torticollis, is a type of focal dystonia involving the muscles of the neck and
sometimes the shoulders. Methods: This systematic review collates the available evidence
regarding the safety and efficacy of a range of treatments for CD, focusing on
their effectiveness as shown by double-blinded, randomised controlled trials.
Results: Our review suggests that botulinum toxin type A (BTA),
botulinum toxin type B (BTB) and trihexyphenidyl are safe and efficacious
treatments for CD. Evidence shows that botulinum toxin therapies are more
reliable for symptomatic relief and have fewer adverse effects than
trihexyphenidyl. When comparing BTA to BTB, both are found to have similar
clinical benefits, with BTA possibly having a longer duration of action and a
marginally better side effect profile. BTB is also safe and probably just as
efficacious a treatment in those patients who are unresponsive or have become
resistant to BTA. Discussion: The current evidence shows that the pharmacological
management of CD relies on BTA and BTB, two agents with established efficacy
and tolerability profiles.
