Often non-motor symptoms of Parkinson’s Disease can be overlooked and thought to be unassociated with PD, especially in the early stages of the disease. However, there are a variety of non-motor symptoms that can affect up to 50% of the PD population. Two of the major non-motor symptoms include cognitive changes and mood disorders.
Cognitive Changes – This is a blanket term for any changes of cognition including thinking, memory, problem solving, executive function, and multitasking. Subtle cognitive changes may be noticed early in the course of PD, especially difficulty with multi-tasking. As age and duration of PD increase, the risk of cognitive decline and dementia increases. Dementia is present in about 40% of PD patients and is the most common cause of PD patients being placed into nursing homes. If a PD patient develops dementia within one year of being diagnosed, it is referred to as dementia with Lewy bodies. However, if a PD patient develops dementia several years after PD diagnosis, it is referred to as Parkinson’s disease dementia (PDD).
Mood Disorders – This is also a blanket term for any change in mood including but not limited to depression, apathy, impulse control disorder, and anxiety. Depression can occur in up to 50% of patients and adversely affects quality of life as much motor symptoms. Depression can cause changes in weight, sadness, fatigue, and a reduced concentration. Depression can be treated with medication and/or psychotherapy.
Apathy – is a reduced interest in activity or lack of motivation. It is important to distinguish if the apathy is a symptom of depression or an independent symptom. Apathy is most noticeable when PD patients quit participating in activities they normally enjoyed such as exercising, cooking, watching TV, or other hobbies.
Impulse control disorder – (ICD) is characterized by an excessive drive or interest in certain activities. Some examples of these activities include: compulsive shopping, hypersexuality, pathologic gambling, binge eating, or compulsive cleaning. ICD arises as a side effect from some Parkinson’s Medications, specifically dopamine agonists.
Anxiety – like depression, is very common amongst PD patients and will affect up to 40% of PD patients. Anxiety can be present with or without depression and is often worse when the motor symptoms of PD are worse. Anxiety, like some motor symptoms of PD will fluctuate but can be treated with medication and psychotherapy.
Hallucinations – are not as common as some of the other non-motor symptoms listed above but still occur. Hallucinations are most commonly visual in nature, but rarely can be other types such hearing voices (auditory). Hallucinations are more common in advanced stages of PD, when patients are on very high doses of PD medications, or in Parkinson’s Disease Dementia (PDD) and Dementia with Lewy Bodies (DLB).
Other non-motor symptoms of Parkinson’s Disease include but are not limited to:
- Orthostatic Hypotension
- Bladder Dysfunction
- Erectile Dysfunction
- Profuse sweating
- Sleep Disorders (insomnia, REM Sleep Behavior Disorder, excessive daytime sleepiness)
- Restless leg syndrome
- Increased sensitivity to pain
- Vision problems
- Loss of smell or taste
It is important to note that some of these non-motor symptoms may arise before any motor symptoms arise.