What is Parkinson’s Disease?
Parkinson’s Disease (PD) is often described as a “movement disorder”. The most well-known symptom of PD is tremor, or shaking. Not everyone with PD experiences tremor. Other early symptoms include slowness of movement and loss of smell. Some PD symptoms are not movement related at all. Examples of non-motor symptoms are as depression, anxiety and constipation.
PD symptoms occur as a result of reductions in the amount of a chemical messenger produced by your brain called dopamine. Dopamine is a neurotransmitter. Dopamine carries signals from one brain cell to the next. For some reason, as yet unknown, the number of dopamine-producing cells is reduced in PD. As a consequence of this less dopamine is made. When dopamine is reduced, it makes it difficult to control movements that were once easy – the automatic nature of well learned movements is lost. Activities such as walking, nimble use of the hands, facial expression, and swallowing are affected by the loss of automaticity. These are some of the motor symptoms. Reduced dopamine can also affect other parts of the body’s function, such as mood, sensory and bladder functions – these are examples of non-motor symptoms.
Symptoms that other people notice
It’s very easy for someone affected by PD to assume that whatever is happening is part of ageing. Because of this, it may be easier for others to notice changes such as slowing, stooping and shuffling – all symptoms of PD. A person might walk along the street and look over into a window. They see a reflection of a slow, stooped, shuffling person, and realise to their surprise it is themself!
An increase in slowness, or other features, could mean there are other underlying causes which can be treated. For this reason, it’s important to go to a doctor, to be properly assessed and diagnosed. (Read here about assessment and diagnosis).
Pre-motor symptoms can begin developing 4-5 years before the early signs of PD
A loss or obvious reduction in the sense of smell
This may or may not be picked up by the affected person. People such as cooks or wine buffs, or flower lovers, may pick it up very quickly. Others may not be aware they’ve lost significant sense of smell. A telling question might be, “If someone was cooking a pizza at the back of the house, could you smell it at the front door?” A spouse may be aware of their partner’s loss of smell sense.
Two more questions to ask partners are, “How well does the affected person sleep?” and, “When asleep and apparently dreaming, is the affected person active?”
Dream enactment occurs in many people with Parkinson’s disease. When someone who does not have PD is asleep and dreaming, they are still. This paralysis is an evolutionary protective mechanism. It is often, but not always, lost in Parkinson’s disease. Arms, legs and vocal cords are paralysed. Dream enactment may involve pushing, kicking, punching, pinching or falling out of bed. The bed partner is most aware of this phenomenon. If dream enactment occurs with loss of smell sense it predicts a high risk of developing Parkinson’s disease motor symptoms in the coming 5 years. The concurrence of reduced smell sense (anosmia/hyposmia) and dream enactment should prompt a doctor to look very carefully for the motor signs of Parkinson’s disease that might be present early.
These early motor signs include:
- Loss of arm swing when walking, usually on one side
- Difficulty turning over in bed
- Loss of the social facial movements with reduced facial expression
- A softening of the voice
- General slowing down