One of the areas of the brain that was highlighted in the first part of this module was the substantia nigra, which is rich in cells that produce the neurotransmitter dopamine. In some individuals, these cells start to break down and this means that there is less dopamine available to smooth out the movements of the body. This is Parkinson’s disease (PD), and while symptoms vary, there are usually thee main ones:

• Bradykinesia, or slow movements, relates to both getting started with a movement and taking longer to complete it. Many PD patients at first attribute this to the ageing process. Everyday tasks can become difficult and mobility is likely to be impacted due to the individual struggling to do more than walk with very small steps and lift their feet clear of the ground. Bradykinesia doesn’t just affect the muscles of the body: the face is also impacted, meaning facial expressions may be slow to change, blinking rate can be reduced and so on. This can have quite profound consequences on communication
• Shaking, often referred to as tremor, usually first affects the hand or arm and tends to be more obvious when the limb is relaxed
• Muscle stiffness, sometimes called rigidity, which further deepens the severity of the mobility issues being experienced.

There can be a whole host of other symptoms, including other physical problems such as impaired balance, putting the individual at increased risk of falls; loss of sense of smell; swallowing difficulties; excessive sweating and saliva production; insomnia; constipation; urinary frequency or incontinence; nerve pain; postural hypotension; and sexual dysfunction. There may also be cognitive and psychiatric symptoms, such as depression, anxiety, tiredness, difficulty planning and remembering things, personality changes, hallucinations and delusions. Some of these are also symptoms of dementia, and it is these – more so than changes in movement and mobility – that may be what trigger someone to seek medical advice.

In the UK, around 145,000 people have been diagnosed with PD, and it is viewed as a common condition among older people. Although age is definitely a factor, the fundamental cause is unclear.