Understanding & Living with PD
What is Parkinson’s?
Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by four cardinal symptoms known as TRAP: tremor, rigidity, akinesia or bradykinesia, and postural instability. Non-motor symptoms are not as easily quantified but may be as impactful or more impactful than motor symptoms. These symptoms can be neuropsychiatric (e.g., depression, anxiety, confusion, cognitive impairment) or affect activities of daily living (ADLs) with gastrointestinal problems, fatigue, sleep disorders, and generalized pain. Pathologically, dopamine neurotransmitters are depleted by nearly 90% in the substantia nigra within the midbrain before symptoms first appear. Therefore, it is critical to preserve dopaminergic neurons, which play a role in various brain functions such as voluntary motor movement, motivation, sleep, attention, working memory, learning, and other modulators of cognition and behavior. Most people with Parkinson’s disease (PwPD) take pharmacological medication to increase dopamine bioavailability by administering dopamine replacement, called levodopa, or L-dopa, in combination with a dopamine decarboxylase inhibitor, such as carbidopa. Treatments for PwPD are limited, with most focused on dopaminergic tone in the striatum. However, treatment does not slow pathology, reduce neuron loss, or attenuate the disease course. Therefore, new research has been focused on neuroplasticity and various ways to preserve cognitive functioning.
Currently available PD medications do offer valuable symptomatic relief, but as PD progresses, their use is often associated with significant and sometimes intolerable side effects. For example, levodopa, one of the most effective treatments for PD can normalize motor function for years but later cause involuntary muscle movements known as dyskinesia and dystonia (sustained muscle contractions). In addition, people in the mid to late stages of PD often experience a wearing-off of the beneficial effects of PD drugs and a re-emergence of motor and non-motor symptoms before their next scheduled dose. In more advanced PD, drug-resistant motor symptoms (e.g, postural instability, freezing of gait, loss of balance, frequent falls), behavioral changes (impulse control disorders, hallucinations, and psychosis), and often dementia are leading causes of impairment.
Currently available PD medications do offer valuable symptomatic relief, but as PD progresses, their use is often associated with significant and sometimes intolerable side effects. For example, levodopa, one of the most effective treatments for PD can normalize motor function for years but later cause involuntary muscle movements known as dyskinesia and dystonia (sustained muscle contractions). In addition, people in the mid to late stages of PD often experience a wearing-off of the beneficial effects of PD drugs and a re-emergence of motor and non-motor symptoms before their next scheduled dose. In more advanced PD, drug-resistant motor symptoms (e.g, postural instability, freezing of gait, loss of balance, frequent falls), behavioral changes (impulse control disorders, hallucinations, and psychosis), and often dementia are leading causes of impairment.
Stages of Parkinson’s Disease
In 1967, Hoehn & Yahr defined five stages of PD based on the level of clinical disability. Clinicians use it to describe how motor symptoms progress in PD. On this scale, stages 1 and 2 represent early-stage, 2 and 3 mid-stage, and 4 and 5 advanced-stage PD.
Stage I
Stage II
Stage III
Disability is mild to moderate at this stage.
Stage IV
Stage V
- During this initial stage, the person has mild symptoms that generally do not interfere with daily activities.
- Tremor and other movement symptoms occur on one side of the body only.
- Changes in posture, walking and facial expressions occur.
Stage II
- Symptoms start getting worse.
- Tremor, rigidity and other movement symptoms affect both sides of the body or the midline (such as the neck and the trunk).
- Walking problems and poor posture may be apparent.
- The person is able to live alone, but daily tasks are more difficult and lengthier.
Stage III
- Considered mid-stage, loss of balance (such as unsteadiness as the person turns or when he/she is pushed from standing) is the hallmark.
- Falls are more common.
- Motor symptoms continue to worsen.
- Functionally the person is somewhat restricted in his/her daily activities now, but is still physically capable of leading an independent life.
Stage IV
- At this point, symptoms are fully developed and severely disabling.
- The person is still able to walk and stand without assistance, but may need to ambulate with a cane/walker for safety.
- The person needs significant help with activities of daily living and is unable to live alone.
Stage V
- This is the most advanced and debilitating stage.
- Stiffness in the legs may make it impossible to stand or walk.
- The person is bedridden or confined to a wheelchair unless aided.
- Around-the-clock care is required for all activities.
