Parkinson’s disease affects people differently. Though everyone with PD will experience slowness of movement and stiffness, not everyone will experience the full range of possible symptoms.
The presence and severity of symptoms, both motor and non-motor, and their progression varies greatly between people with PD. This variation makes it difficult to grade the severity of PD. The following classification of stages is one that is easy to apply in the clinical setting.
Parkinson’s disease is seen to progress through 4 broad clinical stages. The speed of this progression varies between people and may see some people not progressing to stage 4.
Early stage of the disorder is when symptoms are mild and initially affect one side of the body. The common motor symptoms include tremor, slowness of movement in the leg or arm on one side, stiffness and decreased facial expression. The person is still able to perform their usual activities and they are fully independent, unless they have another health condition. Symptoms are well controlled by medications. This period usually lasts for a maximum of 5 years from the time of diagnosis.
Fluctuation stage is when the benefits from the PD medications start to wear off before the next tablet is due to be taken and the person experiences the re-emergence of their symptoms. This stage requires the medications to be adjusted so that the slowing down or ‘end-of-dose’ periods are controlled. By this stage symptoms affect both sides of the body. The person remains independent with their daily activities.
Mid stage is when falls become common and it is more difficult to adjust the PD medications in order to control the symptoms. The control of motor symptoms may not be possible with medications alone. It is common for deep brain stimulation to be considered at this stage. The person can still walk without assistance but they may need a walking aid at times to be safe. The person is still fully independent in their daily living activities, such as dressing and domestic tasks but they are slower performing them. Non-motor symptoms become problematic in this stage.
Late stage sees the person severely disabled by their symptoms. Falls risk is very high and a walking aid is usually needed all of the time. They need assistance to remain at home. Non-motor symptoms, such as hallucinations, generally worsen in the late stage.
Eventually the person is confined to a chair or bed and can only stand up and walk with the assistance of another person. Balance control is severely affected causing the person to fall spontaneously unless assisted. Eating and swallowing are often compromised resulting in risk of choking and aspirating.