Full length articleImpairments of balance, stepping reactions and gait in people with cervical dystonia
Introduction
Dystonia is a poorly understood but relatively common neurological movement disorder; the third most prevalent movement disorder after Parkinson’s disease and essential tremor [1]. Cervical dystonia (CD) is an isolated dystonia characterised by sustained and involuntary contractions of neck muscles, resulting in non-functional neck and head postures [2], [3]. The pathophysiology of CD involves multiple brain structures, including sensorimotor cortex, basal ganglia, cerebellum, trigeminal and vestibular nuclei and is considered a brain network disorder [4], [5], [6], [7]. People living with neurological movement disorders commonly display poor postural control, impaired mobility and balance when walking, turning and transferring and delayed stepping reactions [8], [9], [10], [11]. Impairments in balance are known to influence gait and slow walking speed [12], [13], [14] and may lead to falls in those with neurological disorders and in older adults [15], [16].
Clinically people with CD often report that fear of falling curtails their physical activity [17]. To date there is little understanding as to whether people with CD experience balance and gait deficits, even though they are known to have issues with proprioceptive and vestibular function [18], [19], [20], [21] and impaired vision secondary to the twisted head posture. Growing evidence for the involvement of the cerebellum in CD suggests there may be an impact on balance and function given the importance of the cerebellum in motor coordination and gait. People with CD are known to walk at slower speeds than healthy controls [22], have low falls self-efficacy and balance confidence [17], [22]. The primary aim of this study was to compare balance, gait and stepping reactions in people with CD with control adults. Secondary aims were to explore if abnormal head posture, dystonia severity or fear of falling impacted on function.
Section snippets
Methods
This study was a point in time observational study of people diagnosed with CD by a neurologist, and of age and sex matched healthy adults. Participants provided written informed consent and the study was approved by the local Human Research Ethics Committee. Participants were included whether or not they underwent regular treatment with botulinum toxin injections and, as we did not specify a specific time point in their treatment cycle, time (weeks) since the last injections was recorded. To
Results
Ten people with CD (9 female, mean age 53.9 ± 12.6 years) and 10 gender and age matched controls (mean age 52.8 ± 12.2 years) were included in the study. Seven of the people with CD had a cervical tilt bias to the left. The average duration of disease from diagnosis was 12.1 ± 9.7 years. Eight of the ten participants were undergoing treatment by botulinum toxin injections at the time of the study; the average time post-injection on the day of the study was 5.9 ± 2.8 weeks. No participants
Discussion
Functional measures of mobility, gait, reaction time and balance were compared in ten people with CD and ten healthy adults. There were several new findings with relevance for understanding functional limitations in people with CD. People with CD walked more slowly, took longer steps, spent more time in double leg support during gait when gait speed was taken into account, and demonstrated differences in gait variability to healthy control adults. People with CD also had slower stepping
Conflicts of interest
None.
Authors’ roles
Christopher Barr PhD
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(1)Conception and design of the study, acquisition of data and analysis and interpretation of data
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(2)drafting the article and revising it critically for important intellectual content
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(3)final approval of the version to be submitted
Rhiannon Barnard MSc
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(1)acquisition of data and analysis and interpretation of data
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(2)drafting the article
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(3)final approval of the version to be submitted
Lauren Edwards MSc
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(1)acquisition of data and analysis and interpretation of data
- •
(2)drafting the
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
References (52)
- et al.
Dystonia as a network disorder: what is the role of the cerebellum?
Neuroscience
(2014) Neuropsychological, balance, and mobility risk factors for falls in people with multiple sclerosis: a prospective cohort study
Arch. Phys. Med. Rehabil.
(2014)- et al.
Interactions between voluntary head control and neck proprioceptive reflexes in cervical dystonia
Parkinsonism Relat. Disord.
(2014) In idiopathic cervical dystonia movement direction is inaccurate when reaching in unusual workspaces
Parkinsonism Relat. Disord.
(2011)Postural control and sensory integration in cervical dystonia
Clin. Neurophysiol.
(2007)Validity and reliability of the Nintendo Wii Balance Board for assessment of standing balance
Gait Posture
(2010)Walking for six minutes increases both simple reaction time and stepping reaction time in moderately disabled people with Multiple Sclerosis
Mult. Scler. Relat. Disord.
(2014)Assessing gait variability in transtibial amputee fallers based on spatial-temporal gait parameters normalized for walking speed
Arch. Phys. Med. Rehabil.
(2015)Gait impairments in persons with multiple sclerosis across preferred and fixed walking speeds
Arch. Phys. Med. Rehabil.
(2012)Sensorimotor disturbances in neck disorders affecting postural stability, head and eye movement control-part 2: case studies
Man. Ther.
(2008)