P176. Quantitative analysis of anticipatory postural adjustment in patients with Parkinson's disease. Issue 8 (August 2015)

• Record Type: Journal Article
• Authors: Maier, K.S.; Nußbaum, S.; Elshehabi, M.; Hobert, M.A.; Hasmann, S.E.; Berg, D.; Maetzler, W.
• Is Part Of: Clinical neurophysiology. Volume 126:Issue 8(2015:Aug.)
• Page Start: e162
• Page End: e163
• Publication Date: 2015-08
• Subjects: Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2015.04.272
• Languages: English
• ISSNs: 1388-2457

Abstract

<abstract xml:lang="en" abstract-type="author" id="ab005"> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title id="st005">Background</title> <p id="sp005">Step initiation is considered to be one of the central human balance networks, and is a complex movement. Deficits can lead to balance disturbances with consecutive falls and injuries, and often occur in Parkinson's disease (PD), where they are associated with akinetic-rigid subtype, freezing and falls. PD can therefore be seen as a model disorder for studying step initiation deficits. The movement consists basically of an initial lateral movement of the hip over the stance foot (anticipatory postural adjustment, APA; this is the most relevant part), and a consecutive release of the swing leg for performance of the first step. Despite the relevance of this movement deficit, little is known about (i) characteristic parameters of APA associated with PD subtypes, and (ii) the influence of dopaminergic treatment on APA.</p> </sec> <sec> <title id="st010">Methods</title> <p id="sp010">APA was repeatedly assessed with a standardized protocol after a 30 s standing phase in 120 PD patients during their medication off state. Sixty of them underwent the identical assessment also during on medication. Before the assessment, participants were equipped with wearable 6 sensors (Mobility Lab®, APDM, Oregon). The following parameters were extracted from the APA movement: amplitude in anterioposterior (AP) direction (AP), amplitude in mediolateral (ML) direction, time-to-peak AP, time-to-peak ML, total duration and mean velocity. Demographic and clinical data were collected based on questionnaires and surveys (e.g., with the Unified Parkinson's disease Rating scale, Mini Mental Status Examination, Montreal Cognitive Assessment and the Becks Depressions Inventory).</p> </sec> <sec> <title id="st015">Results</title> <p id="sp015">Preliminary analyses revealed that total duration and mean velocity of APA did not significantly differ between PD subtypes (tremor-dominant versus akinetic-rigid). However, amplitude in ML direction was significantly lower in the akinetic-rigid subtype, compared to tremor-dominant PD patients. Medication status did not influence any of the above-mentioned APA parameters significantly.</p> </sec> <sec> <title id="st020">Conclusion</title> <p id="sp020">This study on a large cohort shows that trunk acceleration in mediolateral direction is probably the most relevant parameter for proper APA performance in PD patients, and that dopaminergic medication does obviously not have a relevant influence on the movement. As APA is associated with severe symptoms and events of PD such as freezing, falls and injuries, non-medical treatment of PD patients should address potential APA deficits, and train them specifically.</p> </sec> </abstract>