While the exact cause of Parkinson’s remains unknown, research suggests a combination of genetic and environmental factors may contribute to diagnosis.
Parkinson’s is most common among people age 65 and older, but about 10%-20% of those diagnosed with Parkinson’s disease are under age 50. Since PD is a progressive disease, symptoms worsen over time and the disease advances. Onset can happen slowly over the period of several years and it can take over two decades for the disease to advance.
Motor symptoms, including resting tremor, slowness of movement (bradykinesia) and rigidity are the cardinal symptoms of Parkinsonism and can be accompanied by secondary symptoms ranging from depression to urinary incontinence.
While the progression of PD is different for everyone, 5 main stages have been identified. The Hoehn and Yahr Scale helps define the various stages of Parkinson’s disease.
Stage I: Early stage Parkinson’s Disease
During the first stage of PD, symptoms are mild and confined to one side of the body. Most commonly, a tremor is seen in only one limb. Symptoms are inconvenient, interfering with a person’s ability to complete day-to-day tasks but are not disabling. Family members and friends may begin to notice subtle changes in posture, balance, and facial expressions.
Stage II
Symptoms become bilateral, affecting both sides of the body in Stage II of Parkinson’s Disease. The condition begins to impact posture and gait to the extent of detracting from the person’s ability to complete activities of daily living.
Stage III: Moderate Parkinson’s Disease
Stage III is marked by the development of significant disability as a result of Parkinson’s. Patients have encounter impairment walking straight or standing. There is noticeable slowing of movement and generalized dysfunction.
Stage IV: Advanced Parkinson’s Disease
During this stage, patients’ symptoms worsen in severity, rendering them unable to alone. While tremors may lessen, rigidity and bradykinesia are visible.
Stage V
The final stage of Parkinson’s is referred to as the “cachectic stage”, because as the disease takes over patients lose control of their movements and is completely invalid. The person cannot stand, walk or take care of him or herself. Round-the-clock nursing care is required.
In recent times, new research methods have opted to utilize a different scale, The United Parkinson’s Disease Rating Scale (UPDRS) which is more complicated yet evaluates non-motor symptoms as well. The UPDRS is subdivided into three scales including cognitive and mood aspects, motor aspects, and activities of daily living (ADL). The UPDRS is available at: http://www.mdvu.org/library/ratingscales/pd/