Parkinson’s disease (PD) is a progressive neurological disease that causes both motor symptoms and non-motor symptoms. There are two main rating scales that describe the stages of Parkinson’s and the symptoms to expect during each.
Symptoms of Parkinson’s Disease
No one can predict which symptoms will affect a particular patient or how severe they will be. The progression may take 20 years or more. In some people, however, the disease progresses much more quickly. Parkinson’s symptoms are generally broken down into the following categories.
Primary Motor Symptoms of Parkinson’s
According to the National Institute on Aging, the four main symptoms of Parkinson’s are tremors or trembling (especially when the body is at rest), slow movement (bradykinesia), rigidity, and postural instability (stooping and balance problems). Typically, these symptoms first appear gradually on only one side of the body.
Secondary Motor Symptoms of Parkinson’s
PD produces a wide range of other motor problems for patients, including walking difficulties like freezing, shuffling and festination that result in the characteristic “parkinsonian gait” and increase the risk of falling. Muscle cramps (dystonia), difficulty swallowing (dysphagia), masked facial expression (hypomimia), and soft speech (hypophonia) also fall under this category.
Non-Motor Symptoms of Parkinson’s
The American Parkinson Disease Association lists a number of PD symptoms that do not involve movement. These can include changes in smell, sleep problems, constipation, mood disorders like depression and anxiety, personality changes, excessive sweating, urinary problems, cognitive changes, psychosis, lightheadedness due to orthostatic hypotension, and vision issues.
Stages of Parkinson’s Disease: Hoehn and Yahr Scale
One of the most common tools used for staging PD is the Hoehn and Yahr (H-Y) Scale. The H-Y staging system was first published in a 1967 paper by Margaret Hoehn, M.D., and Melvin Yahr, M.D., which set out to better clarify and standardize the progression and severity of Parkinson’s symptoms in patients. This scale has been updated over the years, but focuses solely on the progression of motor symptoms. It is composed of five main stages.
Stage One (Mild Parkinson’s)
- Symptoms often appear on one side only—usually as a tremor in one limb.
- Symptoms tend to be mild.
- Symptoms may be inconvenient but are not disabling.
- Changes in posture, movement and facial expression may be noticeable.
- Symptoms are bilateral, affecting both sides of the body.
- Symptoms start to complicate activities of daily living (ADLs), making them more difficult and time consuming.
- Posture and gait are affected.
Stage Three (Moderate Parkinson’s)
- Body movements slow significantly.
- Difficulties with balance and coordination are evident when walking or standing.
- The patient is still independent, but their functional abilities, such as bathing, dressing and eating, are moderately affected.
- The patient can still walk to a limited extent, but is at high risk of falling. A walker or other mobility aid may be necessary for support.
- The severity of symptoms like rigidity and bradykinesia renders the patient unable to live alone.
- Tremors may be less severe than in the earlier stages.
Stage Five (Severe Parkinson’s)
- The patient may appear cachectic. (Symptoms of cachexia, or wasting syndrome, include weight loss, muscle loss or weakness, appetite loss, and fatigue.)
- Standing and walking are extremely difficult if not impossible. The patient may be bedridden or wheelchair bound.
- Constant nursing care is required.
- The patient may exhibit hallucinations and/or delusions.
The Unified Parkinson’s Disease Rating Scale
Another commonly used scale is the Unified Parkinson’s Disease Rating Scale (UPDRS). According to the American Physical Therapy Association (APTA), “The UPDRS was developed in 1987 as a gold standard by neurologists for monitoring the response to medications used to decrease the signs and symptoms of PD.” The International Parkinson and Movement Disorder Society (MDS) has made some revisions in recent years to improve the accuracy and inclusivity of this scale, resulting in the MDS-sponsored Unified Parkinson’s Disease Rating Scale (MDS-UPDRS).
Both the original UPDRS and the MDS-UPDRS are far broader in scope than the H-Y scale. In addition to motor symptoms, these tools also address patients’ non-motor symptoms and daily experiences through questions about behavior, mood, cognition, daily routines, functional abilities and experiences with PD medications. You can find the most recent full version of the MDS-UPDRS on the MDS website.
“Staging” Parkinson’s Disease Is Difficult
Parkinson’s disease and related conditions are very complex. Like Alzheimer’s disease and other forms of dementia, PD does not progress in neat stages at a set pace. The symptoms that present and their severity vary from patient to patient and so does their impact on functional abilities and quality of life. Most patients and their families ask physicians about staging because they want more detailed information about the progression of the disease and life expectancy, but pinpointing these things is near impossible.
While it is important for PD patients and their loved ones to understand the general progression of Parkinson’s, working closely with a trusted neurologist who specializes in movement disorders is the best way to weigh treatment options and plan for the future.
Sources: Parkinson's Disease (https://www.nia.nih.gov/health/parkinsons-disease); Common Symptoms of Parkinson’s Disease (https://www.apdaparkinson.org/what-is-parkinsons/symptoms/); Parkinsonism: Onset, Progression, and Mortality (https://n.neurology.org/content/neurology/17/5/427.full.pdf); Stages of Parkinson’s (https://www.parkinson.org/Understanding-Parkinsons/What-is-Parkinsons/Stages-of-Parkinsons); Unified Parkinson’s Disease Rating Scale (UPDRS), Movement Disorders Society (MDS) Modified Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) (https://www.apta.org/patient-care/evidence-based-practice-resources/test-measures/unified-parkinsons-disease-rating-scale-updrs-movement-disorders-society-mds-modified-unified-parkinsons-disease-rating-scale-mds-updrs); MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) (https://www.movementdisorders.org/MDS/MDS-Rating-Scales/MDS-Unified-Parkinsons-Disease-Rating-Scale-MDS-UPDRS.htm)