Parkinson's disease

Parkinson’s disease is a complex neurodegenerative disorder that is characterised by the gradual depletion of dopamine in the brain. Some prevalence statistics of Parkinson's disease are presented below:

• Parkinson’s is the fastest growing neurological condition in the world
• It is estimated that there are 153 000 people with Parkinson’s disease in the UK. This number is expected to rise to 172 000 by 2030
• One in every 37 people will be diagnosed with Parkinson’s disease in their lifetime
• Parkinson’s disease is generally associated with older age, but the age of onset for nearly 25% of individuals is younger than 65 years, and 5–10% of people are younger than 50 years at diagnosis (Parkinson's UK, 2018; 2023)

Parkinsonism is the umbrella term for any conditions that causes slowness, stiffness or tremor and can include:

• vascular parkinsonism
• drug induced parkinsonism
• multiple system atrophy
• progressive supranuclear palsy
• corticobasal degeneration
• normal pressure hydrochephalus

The symptoms of Parkinson’s disease vary from person to person, but each individual will display two of more cardinal (motor) features of:

• bradykinesia - slowness of movement
• tremor - rest tremor which usually starts in the hand
• rigidity - causes muscle discomfort and/or pain
• postural instability - impaired righting reflexes, which increases risk of falls

The symptoms of Parkinson’s disease:

• usually start on one side of the body
• progress gradually over time (usually years) and can affect the whole body
• are life changing and can cause marked disability

Along with the motor features of Parkinson’s disease, individuals can also develop a vast array of non-motor symptoms:

• autonomic symptoms - eg urinary urgency and frequency, increased sweating and erectile dysfunction
• sleep disorders - eg restless legs, sleep behaviour disorders, insomnia and somnolence
• neuropsychiatric symptoms - eg depression, anxiety, cognitive impairment and dementia
• gastrointestinal symptoms - eg constipation, drooling and delayed gastric

Motor symptoms of Parkinson’s disease usually appear when at least 50-60% of dopamine levels have been lost (Hustad and Aasly, 2020). For the majority of cases the underlying cause for developing Parkinson’s disease remains unknown, hence the term 'idiopathic Parkinson’s disease'.

There are genetic causes of Parkinson’s disease for 3–5% of all cases. Men are at greater risk of developing Parkinson’s disease than women (Pringsheim et al, 2014).

Several risk factors for increasing your risk of developing Parkinson’s disease have been identified, such as:

• increasing age
• head injury
• lifestyle and environment factors (Dorsey et al, 2020)

Some protective factors that may reduce the risk of developing Parkinson’s include:

• increasing physical activity
• drinking less coffee
• smoking cessation
• reducing the use of anti-inflammatory drugs (Noyce et al, 2012)

Identification and early diagnosis of Parkinson’s disease is important to ensure individuals receive the correct care and support. Individuals will usually first present to their general practitioner, and if they complain of symptoms of tremor, stiffness or slowness, Parkinson’s disease should be suspected. The National Institute of Health and Care Excellence guidance (NICE, 2017) stated that people should be referred quickly to a specialist with expertise in Parkinson’s disease. This is because there are a number of different conditions that appear similar to Parkinson’s disease, but have a different aetiology, treatment options and prognosis.

Parkinson’s disease remains a clinical diagnosis. Currently there are no tests or scans that can be performed to confirm the diagnosis. The diagnosis is made through a combination of:

• assessment of the motor and non-motor signs and symptoms of Parkinson’s disease, in accordance with the Movement Disorders Society diagnostic criteria (Postuma et al, 2015)
• understanding when

There are many ways that people with Parkinson’s disease can contribute to their own quality of health. People are often encouraged to make lifestyle changes, including:

• regular exercise - various physiotherapy strategies have proven to be significantly beneficial to people with Parkinson’s disease (Domingos et al, 2018)
• appropriate diet - to help ease symptoms such as constipation, low mood, reduced bone density and weight changes

Currently, there is no medication that can slow, reverse or cure Parkinson’s disease. Parkinson’s disease medication can improve motor symptoms and work by increasing the dopaminergic activity in one of three main ways:

1. by directly replacing dopamine via a dopamine precursor (levodopa preparations)
2. by mimicking the effects of dopamine at the dopamine receptor sites (dopamine agonist)
3. preventing the breakdown of dopamine by enzymes (monoamine oxidase B inhibitors (MAO-B) or catechol-O-methyltransferase inhibitors (COMT))

The NICE Guidance for Parkinson’s disease (2017) provides recommendations for treatment, depending on

Nursing and Midwifery Council: standards of proficiency for registered nurses

Part 1: Procedures for assessing people’s needs for person-centred care

1. Use evidence-based, best practice approaches to take a history, observe, recognise and accurately assess people of all ages

Part 2: Procedures for the planning, provision and management of person-centred nursing care

7. Use evidence-based, best practice approaches for meeting needs for care and support with mobility and safety, accurately assessing the person’s capacity for independence and self-care and initiating appropriate interventions

11. Procedural competencies required for best practice, evidence-based medicines administration and optimisation

Armstrong MJ, Okun MS. Diagnosis and treatment of Parkinson disease: a review. Jama. 2020;323(6):548-60. https://doi.org/10.1001/jama.2019.22360  

Domingos J, Keus SHJ, Dean J et al. The European Physiotherapy Guideline for Parkinson’s disease: implications for neurologists. J Parkinsons Dis. 2018;8(4):499–502

Dorsey R, Sherer T, Okun MS, Bloem BR. Ending Parkinson's disease: a prescription for action. Hachette UK; 2020

Durcan R, Wiblin L, Lawson RA et al. Prevalence and duration of non‐motor symptoms in prodromal Parkinson's disease. Eur J Neurol. 2019;26(7):979-85. https://doi.org/10.1111/ene.13919

Hustad E, Aasly JO. Clinical and imaging markers of prodromal Parkinson's disease. Front Neurol. 2020;11:395. https://doi.org/10.3389/fneur.2020.00395

Mu J, Chaudhuri KR, Bielza C et al. Parkinson's disease subtypes identified from cluster analysis of motor and non-motor symptoms. Front Aging Neurosci. 2017;9:301. https://doi.org/10.3389/fnagi.2017.00301

National Institute for Health and Care Excellence. Parkinson’s disease in adults: diagnosis and management. 2017. https://www.nice.org.uk/guidance/ng71 (accessed 31 October 2023)

Noyce AJ, Bestwick JP, Silveira‐Moriyama L et al A. Meta‐analysis of early nonmotor features and risk factors for Parkinson disease. Ann Neurol. 2012;72(6):893-901.