Improving mobility and balance in Parkinson*s disease through circuit class training:
Effects on clinical outcomes, posturography and brain connectivity

Parkinson*s disease (PD) is a progressive neurodegenerative disease, for which
curative treatments are lacking. Clinical motor symptoms of PD include tremor,
rigidity, bradykinesia and postural instability. These symptoms lead to
impaired mobility affecting activities of daily living and quality of life.
There is growing evidence that physical training interventions such as exercise
training and physical therapy can positively influence mobility and
mobility-related problems such as falls (De Goede, Keus, Kwakkel, & Wagenaar,
2001; Hirsch & Farley, 2009; Kwakkel, De Goede, & Van Wegen, 2007). Positive
effects of training on postural con-trol have been suggested in a number of
studies (Goodwin, Richards, R. S. Taylor, A. H. Tay-lor, & Campbell, 2008) but
results are yet moderate at best. Although recent animal studies have suggested
that physical exercise in PD may yield beneficial dopaminergic changes by
promoting adaptive neuroplasticity (Hirsch & Farley, 2009; 2009; Yoon et al.,
2007), it is unknown if improvements in motor tasks (such as standing balance)
are in fact due to a restitution of function using existing dopaminergic
pathways or due to substitution of function by means of compensation strategies
using non-dopaminergic pathways. It is hence of great relevance to develop
training protocols that target the more specific needs of PD patients.
Unfortunately, human studies on the relationship between functional
improvements and exercise-induced plasticity are still lacking.
Providing additional visual feedback during quiet stance offers a promising new
perspective for balance therapy as it prompts PD patients directly to achieve
proper postural control. However, to what extent motor training with visual
feedback yields lasting improvements is yet unknown. If the training does
affect balance control, we ask whether this is manifested in the accompanying
neural activity in the central nervous system, in particular in the cortex.
Quiet stance paradigms provide convenient ways to study feedback-based balance
control given the relative ease and safety with which such tasks can be
recorded in older healthy adults and in patients. In the current study we will
use a quiet stance paradigm to test to what degree postural control and thus
balance is modulated with specific balance-oriented exercise training, i.e. a
circuit class training using balance workstations. We will quantify effects
through selected posturographic outcome measures, like the variability of the
center-of-pressure (COP) and correlate these with clinical balance assessments
and changes in brain dynamics (EEG). With the current study we aim to typify
the relationships between outcome measures from clinical questionnaires,
posturography, and clinical neurophysiology.

Primary objective is to investigate whether a VF-based balance training program
leads to improved balance control in PD patients and how posturographic
outcomes are associated with changes in clinical outcome measures.

Secondary objective is to investigate the effects of a balance training program
on patterns of functional cortical connectivity as determined by EEG.

This study is a randomized clinical trial (RCT) comparing two treatment groups
under blinded assessment.

Patients will be recruited from the Neurology Department and from patient
databases of the Department of Physical Therapy of the VU University Medical
Center. Patients who are likely to meet the criteria for inclusion will be
asked to participate in the RCT. They will randomly be assigned to either the
experimental or conventional exercise circuit class training. Groups convene
during 60-minute group sessions, two times a week for six weeks.
Patients will fill in questionnaires and undergo clinimetric assessments, EEG
recordings, and posturography prior to, after, and 6 weeks after completion of
the training program. An MRI scan will also be obtained to substan-tiate
off-line source localization of the EEG signals. All training sessions will
take place at the VU University Medical Center outpatient center. Assessments
will take place at the VU University Medical Center outpatient center as well
as at the VU University, Faculty of Human Movement Sciences.

Patients will be assigned to one of two balance training groups and will
convene in groups (~6 patients per session) during twice-weekly training
sessions of one hour, for six weeks. Two types of balance training will be
administered, one focusing on restitution of function using a set of
conventional repetitive balance exercises, the other focusing on substitution
of function by using several visual feedback techniques.

Patients take part in a training program two times a week during six weeks.
Before, after, and 6 weeks after completion of the training program assessments
will be performed (75 min). In addition one MRI scan will be obtained for each
patient (30-60 minutes). Participation in this study will involve minimal risk.