parkinsons-2016_posters-accepted-abstracts

15 / 20

Page 66
Parkinsons 2016
December 05-07, 2016
Volume 6 Issue 6(Suppl) J Alzheimers Dis Parkinsonism
ISSN: 2161-0460 JADP, an open access journal
conferenceseries .com
December 05-07, 2016 Phoenix, USA
2nd International Conference on
Parkinson’s Disease & Movement Disorders
J Alzheimers Dis Parkinsonism 2016, 6:6(Suppl)
Multi-muscle synergies: A sensitive tool for Parkinson’s disease
Ali Falaki1, Xuemei Huang1,2, Mechelle M Lewis2 and Mark L Latash1
1Pennsylvania State University, USA
2Milton S. Hershey Medical Center-Pennsylvania State University, USA
Postural instability is one of the cardinal signs of Parkinson’s disease (PD). Quantifying postural stability is commonly
used to measure PD severity. We hypothesized that postural synergy indices in the space of activation of muscle groups
(M-modes) may be used to measure changes in motor coordination due to PD and dopamine-replacement therapy. Synergy
indices stabilizing the center of pressure (COP) were compared between 11 patients without clinical symptoms of postural
instability (Hoehn-Yahr stage-II) and 11 age-matched controls, and between 10 patients (stage II and III) tested off-drug and
on-drug. Electromyographic signals from 13 leg and trunk muscles, recorded during cyclic body sway and releasing a load from
extended arms, were used to quantify synergy indices by comparing the variance that had no effect on the COP coordinate and
the variance that changed COP coordinate. Since this analysis needs multiple trials to identify the variance structure, we also
quantified components of motion in the space of M-modes that had (non-motor equivalent) and did not have effect (motor
equivalent) on COP coordinate using individual sway cycles. PD patients showed significantly lower synergy indices, and
reduced ability to adjust these indices in preparation to an action. Motor equivalence analysis confirmed these differences.
Impaired ability to adjust synergy indices in preparation to an action may contribute to rigidity and episodes of freezing. We
conclude that analysis of motor equivalence in muscle activation space, using a few trials, can be used as a clinical measure for
early diagnosis of PD and tracking disease progression.
Identifying Park-weight phenotype in Parkinson’s disease: Implications on disease management
Jagdish Sharma1,2
1Lincoln County Hospital, UK
2University of Lincoln, UK
Anumber of phenotypes are being identified in the neurodegenerative Parkinson’s disease, mostly in reference to the non-
motor symptoms. One purpose of identifying phenotypes is to manage disease process more effectively. PD patients have
variable impairment of olfaction; high proportions develop body-weight change (gain or loss) as the disease advances. PD
patients have a lower body weight as compared to non-PD controls. Weight loss in PD is not a benign phenomenon. Lower
initial body weight and weight loss during the course of the disease predispose to the risk of dyskinesia; there being a relationship
between body weight and levodopa dose per kilogram for dyskinesia. Additionally weight loss increases the risk of under-
nutrition, frailty, poor quality of life and mortality. Patients at the risk of weight loss may be identified by their severe olfactory
loss (anosmia) at an early stage, since anosmia, as compared to hyposmia, seems to represent more severe neurodegenerative
process predisposing to weight loss and dyskinesia describing the “olfaction-weight-dyskinesia” phenotype in Parkinson’s
disease. Weight loss is not due to higher energy expenditure or lower energy intake. The basis of severe neurodegenerative
process and weight loss might be a longer pre-clinical phase in this phenotype. PD patients should be monitored for weight loss
and the dose of levodopa adjusted accordingly as the disease advances. Measures should be taken to prevent weight loss in such
patients to prevent the low body-weight related non-motor and motor adverse effects. This may result into better quality of life.