title: Digitomotography in Parkinson's disease: a cross-sectional and longitudinal study.
abstract: Motor symptoms in Parkinson's disease (PD) are usually assessed with semi-quantitative tests such as the Unified PD Rating Scale (UPDRS) which are limited by subjectivity, categorical design, and low sensitivity. Particularly bradykinesia as assessed e.g. with speeded index finger tapping exhibits low validity measures. This exploratory study set out to (i) assess whether force transducer-based objective and quantitative analysis of motor coordination in index finger tapping is able to distinguish between PD patients and controls, and (ii) assess longitudinal changes. Sixteen early-stage and 17 mid-stage PD patients as well as 18 controls were included in the cross-sectional part of the study; thirteen, 16 and 16 individuals of the respective groups agreed in a reassessment 12 months later. Frequency, force, rhythmicity, regularity and laterality of speeded and metronome paced tapping were recorded by digitomotography using a quantitative motor system ("Q-Motor"). Analysis of cross-sectional data revealed most consistent differences between PD patients and controls in variability of tap performance across modalities assessed. Among PD patients, variability of taps and the ability to keep a given rhythm were associated with UPDRS motor and finger tapping scores. After 12 months, laterality parameters were reduced but no other parameters changed significantly. This data suggests that digitomotography provides quantitative and objective measures capable to differentiate PD from non-PD in a small cohort, however, the value of the assessment to track PD progression has to be further evaluated in larger cohorts of patients.
authors.affiliation: Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, Center of Neurology, University of Tuebingen, Tuebingen, Germany; DZNE, German Center for Neurodegenerative Diseases, Tuebingen, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Maetzler
authors.affiliation: Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, Center of Neurology, University of Tuebingen, Tuebingen, Germany; Clinical Center Lunenburg, Clinic of Neurology, Lunenburg, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Ellerbrock
authors.affiliation: Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, Center of Neurology, University of Tuebingen, Tuebingen, Germany; DZNE, German Center for Neurodegenerative Diseases, Tuebingen, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Heger
authors.affiliation: George-Huntington-Institute, Technology-Park Muenster, Muenster, Germany; Department of Radiology, University of Muenster, Muenster, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Sass
authors.affiliation: Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, Center of Neurology, University of Tuebingen, Tuebingen, Germany; DZNE, German Center for Neurodegenerative Diseases, Tuebingen, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.affiliation: Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, Center of Neurology, University of Tuebingen, Tuebingen, Germany; George-Huntington-Institute, Technology-Park Muenster, Muenster, Germany; Department of Radiology, University of Muenster, Muenster, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Reilmann
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D019719:Diagnostic Equipment; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D005385:Fingers; D006801:Humans; D018476:Hypokinesia / Q000175:diagnosis* / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology; D011597:Psychomotor Performance; D012720:Severity of Illness Index