What are the stages of Parkinson's disease?

Parkinson's disease can be seen as a neurodegenerative disease because it is associated with the loss of nerve cells in the substantia nigra pars compacta that produce dopamine. Parkinson's disease is a long-term chronic and progressive movement disorder that slowly develops over time. Parkinson's has been called "the great imitator" because so many of its symptoms mimic other diseases. Parkinson's disease is characterized by resting tremor, rigidity, slowness of movement and impaired balance and coordination. Parkinson's disease primarily affects movement and has no cure, but medications and therapies can help manage symptoms. Parkinson's disease is most commonly diagnosed between the ages of 50 and 60 years old, but it can occur at any age.

The neurotransmitter dopamine is responsible for coordinating movement. Dopamine transmits signals from between the substantia nigra and the corpus striatum. During Parkinson’s disease, the neurons which produce dopamine are lost resulting in problems with movement. Evidence shows that there is a loss of 60-80% of dopamine during Parkinson’s disease.

Another common hallmark of Parkinson’s disease are lewy bodies. Lewy bodies form when misfolded alpha-synuclein protein aggregates into oligomers. The misfolded alpha-synuclein can move in between neurons and it can act as a template for the misfolding of alpha-synuclein.

The cause of Parkinson's disease is unknown but it is believed to involve both genetic and environmental factors. Genetics is said to cause roughly 10-15% of all Parkinson’s disease. Having a first-degree relative (a parent or sibling) which has Parkinson’s will increase your chances of developing the condition. Some genes which are investigated in relation to developing Parkinson’s disease are LRRK2, DJI, ATP 13A2, PARK2, PARK7, PINK1 or the SNCA gene.

Stage one is the earliest detectable stage of Parkinson's disease. The patient experiences mild symptoms such as stiffness and tremors on one side of the body. Some changes in facial expressions, walking and the person’s posture may be noticeable during this stage.

During stage two the symptoms start to get worse. Stiffness and tremors become more pronounced, but the disease is still relatively stable at this point. Symptoms that appear in stage two include uncoordinated movement of free limbs (arms and legs). The majority of people in stage 2 of Parkinson’s disease can still live alone.

Stages three and four involve loss of balance, increased risk of falls and further disability. Stiffness is present at all times with some "on-off" periods where stiffness disappears for a short period of time. This is known as the wearing-off effect which comes and goes unpredictably. The patient may be able to stand up straight or maintain a sitting position in one place, but when they try to use their muscles they feel stiffer than before. Stages three and four are the times where the patient needs crutches or a wheelchair. When people are in stage four of Parkinson’s disease, it is unsafe for them to live alone.

Stage 5 is the most severe and advanced stage of Parkinson's disease. People who are in this stage of the disease rely on a wheelchair due to the fact that their ability to stand or walk has diminished. Often patients are bedridden due to the severity of their illness. Hallucinations and delusions are common during this stage. Normal day tasks like swallowing causes problems during this stage and it can lead to weight loss.

• Neuroscience Biomarkers
• NEFL Biomarker Discovery Tools
• Tau Antibodies, Proteins & ELISA Kits
• Autophagy alterations in Alzheimer’s disease
• The Science of Neuroimmune Dysfunction in Multiple Sclerosis