Symptoms of Parkinson’s Disease

These motor symptoms and signs have come to define the disease over time. There are also signs that precede it (prodromal disease) and others characteristic of advanced disease or complications in its progression. 

The idea that the prodromal phase is non-motor and the established phase is motor has been mistakenly popularised. In reality, motor symptoms can appear during the prodromal phase, and non-motor symptoms - such as dementia - can be just as, or even more, disabling than motor symptoms in the advanced stages of the disease. Prodromal symptoms have also been referred to as risk factors, when they are not, but rather symptoms intrinsic to, and a consequence of, the disease.

Taking all this into account, it could be said there are three phases in which motor and non-motor symptoms often coexist in different combinations:

Prodromal Parkinson's disease. This can begin years or even decades before the onset of the disease. The symptoms are:

• Mild action tremor
• Loss of smell (hyposmia) 
• Constipation
• REM sleep behaviour disorder (nightmares with vigorous movements and vocalisations during sleep), insomnia, excessive sleepiness.
• Apathy
• Pain
• Visual illusions or minor hallucinations
• Others

Established Parkinson's disease.

• Initial. Defined by the cardinal motor symptoms detailed above, with a variable period of time of up to several years during which drug therapy results in very satisfactory control of the symptoms (honeymoon period).
• Intermediate. Motor fluctuations begin to appear with on-off periods, with or without dyskinesia; but these can be controlled with pharmacological adjustments of both conventional oral medications and rescue medication (subcutaneous apomorphine, inhaled levodopa).
• Complications. Motor fluctuations are refractory to the best medical treatment and complex therapies, such as drug infusions are required (e.g., subcutaneous apomorphine or levodopa infusion, intestinal levodopa infusion, deep brain stimulation).

Advanced Parkinson's disease. After 10-15 years or more (depending on the type of Parkinson's, age of onset and other factors), extranigral motor and non-motor complications, refractory to dopaminergic treatment, such as hallucinations, dementia, urinary incontinence, dysphagia, imbalance with falls. Many of these conditions have no specific treatment, and their management is based on supportive care. This stage has the highest level of dependency, with mortality usually due to complications arising from frailty and immobility: e.g., aspiration respiratory infections, urinary tract infections, intestinal subocclusion and pulmonary embolism.