Providing Evidence Based Oral Health Care to Individuals Diagnosed with Degenerative Disorders, Part 2: Parkinson’s Disease
What is Parkinson's Disease?

Parkinson’s disease (PD) is a chronic, progressive, brain disorder resulting from degeneration of nerve cells in the substantia nigra. The damaged neurons in the substantia nigra usually display a primary diagnostic marker of PD called Lewy body.^1-3 This degeneration results in decreased availability of dopamine, a chemical that is partially responsible for transmitting messages to control movement and coordination in the midbrain and emotions in the forebrain.^1,3-6 Typically dopamine acts as an inhibitory neurotransmitter and acetylcholine act as an excitatory neurotransmitter.³ These two neurotransmitters complement each other in individuals without PD symptoms.

The absence of dopamine leaves the dopamine receptors in the striatum inadequately stimulated and permits acetylcholine to overpower dopamine.³ As PD progresses, the amount of dopamine produced in the brain continues to decrease and individuals lose the ability to control their body movements in an ordinary manner.^1,6 It is common for individuals to experience tremors, bradykinesia, gait disturbances, muscle rigidity, and postural instability.^1-6 This can ultimately result in unemployment, inability to complete activities of daily living independently-including the ability to perform oral self-care, and a decreased quality of life.⁷

Occasionally “Parkinsonism” (secondary parkinsonism) is mistaken for PD as many of the signs and symptoms are the same; however, the underlying pathologies are different. Parkinsonism is a clinical syndrome that can result from a variety of items such as medications, repeated head trauma, brain lesions, exposure to toxins, metabolic disorders, neurodegenerative disorders, and PD. Individuals with Parkinsonism will not respond to dopamine replacement therapy.⁸