Pain, cognition and motor behavior in Parkinson's disease

Parkinson's disease is a progressive neurodegenerative disorder characterized
by cardinal motor symptoms and is caused by degeneration of dopaminergic
neuronal systems. However, also a range of non-motor symptoms arise during the
progressive course of the disease. Amongst others there are sleeping-disorders,
cognitive impairment, depression, sensory disorders and pain.
Pain has a major negative impact on the quality of life and seems to be present
in the majority of the patients. In other studies in the field of dementia is
found that the perception of pain changes when cognition declines. This is
worrisome, because cognitive declined patients might be undertreated for their
pain. Different types of pain have been observed. A frequently occurring type
of pain in patients with Parkinson's disease is (central) neuropathic pain.
Although this is reported as being the most troublesome type of pain, there
seems to be little familiarity about this type of pain and its best treatment.
One of the motor disturbances that may cause orofacial pain and has hardly
received attention in Parkinson's disease, is bruxism. Bruxism is reported in
various movement disorders and consensus is emerging that central mechanisms,
particularly the basal ganglia network, seems to be involved.

Objective: The primary objective of this study is to investigate whether pain
experience decreases or increases when cognitive functions decline in patients
with Parkinson's disease. Furthermore will be investigated whether this is
influenced by different aspects of motor behavior, including bruxism.
The secondary objective of this study is the determination of the role of
general practitioners, neurologists and dentists in their assessment of and
their knowledge about pain in patients with PD. This will be determined through
questionnaires and followed by the construction of a "toolkit", in forms of an
flowchart for the management of the different types of pain in Parkinson's
disease to be used by neurologists, general practitioners and dentists.

The design is an observational cross-sectional study.

The burden associated with participation will be once the assessment of
cognitive functioning (60 minutes), assessment on pain perception through
scales and questionnaires (10 minutes), observation of motor behavior (15
minutes), assessment of sensory functioning (10 minutes), and assessment of
mood through questionnaires (15 minutes).
There will be no risks besides possible fatigue after the cogntive testing,
which ususally disappears after a short break.
There will be no direct benefit for the patients participating in this study.
However, more insight in the relationship between the main study parameters,
might have an important positive effect on the treatment of pain by GPs,
neurologists and dentists in patients with PD in the nearby future.