title: Medio-lateral balance impairment differentiates between Parkinson's disease and atypical parkinsonism.
abstract: In early disease stages, it can be difficult to differentiate clinically between Parkinson's disease and the various forms of atypical parkinsonism, like multiple system atrophy or progressive supranuclear palsy. Balance impairment in the medio-lateral plane (i.e. sideways) is often seen in patients with a form of atypical parkinsonism, but not in patients with Parkinson's disease. This is reflected by the distance between the feet during gait, which is typically normal (or even narrow) in Parkinson's disease, but widened in atypical parkinsonism. Estimating this stance width depends on subjective judgement, and is difficult to quantify in clinical practice. Here, we emphasize that this medio-lateral balance impairment can also be revealed using two simple tests: (1) inability to perform tandem gait (taking one or more side steps being abnormal); and (2) self-report by patients who have lost the ability to ride a bicycle. Both tests have a good diagnostic yield in differentiating between Parkinson's disease and atypical parkinsonism, even early in the course of the disease.
authors.affiliation: Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Rehabilitation, Nijmegen, The Netherlands.
authors.forename: Jorik
authors.initials: J
authors.lastname: Nonnekes
authors.affiliation: Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, The Netherlands.
authors.forename: Marjolein B
authors.initials: MB
authors.lastname: Aerts
authors.affiliation: Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, The Netherlands.
authors.forename: W F
authors.initials: WF
authors.lastname: Abdo
authors.affiliation: Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, The Netherlands.
authors.forename: Bastiaan R
authors.initials: BR
authors.lastname: Bloem
mesh_terms: D020233:Gait Disorders, Neurologic / Q000209:etiology; D006801:Humans; D010300:Parkinson Disease / Q000150:complications* / Q000175:diagnosis*; D020734:Parkinsonian Disorders / Q000150:complications* / Q000175:diagnosis*; D004856:Postural Balance / Q000502:physiology*; D011597:Psychomotor Performance; D057566:Self Report; D012678:Sensation Disorders / Q000209:etiology*
keywords: Balance; Parkinson's disease; cycling; parkinsonism; postural control; tandem gait