Parkinson’s disease (PD) is a progressive neurological disorder that primarily affects movement. It is classified as a neurodegenerative condition, meaning it involves the gradual loss of nerve cells in the brain.

PD is the second most common neurodegenerative disorder after Alzheimer’s disease, affecting more than 10 million people worldwide. The condition typically develops in people over the age of 60, though early-onset cases can occur.

Historical Background

Parkinson’s disease is named after Dr James Parkinson, an English physician who, in 1817, first described the condition in his work “An Essay on the Shaking Palsy”. In his observations, he detailed the major motor symptoms such as tremors, rigidity, and postural instability.

Over time, research advanced our understanding, linking the disease to the progressive loss of dopamine-producing neurones in the substantia nigra, a region of the brain critical for controlling movement.

Causes and Risk Factors

The exact cause of Parkinson’s disease remains unknown, but it is believed to result from a combination of genetic, environmental, and biological factors.

1. Genetic Factors

   • Mutations in specific genes such as LRRK2, PARK7, PINK1, PRKN, and SNCA have been linked to familial forms of the disease.

   • While hereditary cases are rare, genetics can predispose individuals to PD.

2. Environmental Factors

   • Long-term exposure to pesticides, herbicides, and industrial toxins has been associated with increased risk.

   • Rural living and well-water consumption may also contribute due to environmental toxins.

3. Biological Factors

   • The primary biological hallmark of PD is the loss of dopamine-producing neurones in the substantia nigra.

   • Abnormal protein deposits, known as Lewy bodies, are also found in the brain cells of people with PD, disrupting normal brain function.

4. Age and Gender

   • Age is the strongest risk factor, with most cases occurring after age 60.

   • Men are more likely than women to develop PD.

Symptoms of Parkinson’s Disease

Symptoms generally develop gradually and worsen over time. They are broadly divided into motor symptoms and non-motor symptoms.

1. Motor Symptoms

• Tremors: Shaking, usually starting in the hands or fingers, often described as a "pill-rolling" movement.

• Bradykinesia: Slowness of movement, making simple tasks time-consuming.

• Rigidity: Muscle stiffness that can cause pain and restrict movement.

• Postural Instability: Impaired balance and coordination, increasing the risk of falls.

2. Non-Motor Symptoms

• Cognitive impairment, including memory problems and slowed thinking.

• Mood disorders such as depression and anxiety.

• Sleep disturbances, including insomnia and REM sleep behaviour disorder.

• Autonomic dysfunction, such as constipation, low blood pressure, and urinary problems.

• Loss of sense of smell (anosmia).

Stages of Parkinson’s Disease

Doctors often use the Hoehn and Yahr scale to describe the progression:

1. Stage 1 – Mild symptoms, usually on one side of the body.

2. Stage 2 – Symptoms on both sides but minimal disability.

3. Stage 3 – Balance problems emerge; independence is still maintained.

4. Stage 4 – Severe symptoms; daily living requires assistance.

5. Stage 5 – Advanced stage; patient may be bedridden or wheelchair-bound.

Diagnosis

There is no single test for PD. Diagnosis is made based on:

• Medical history and clinical examination.

• Neurological assessment focusing on motor symptoms.

• Brain imaging (MRI, PET, or DaTscan) may help rule out other conditions.

Treatment and Management

Although there is no cure for PD, treatment can significantly improve quality of life.

1. Medications

   • Levodopa (L-DOPA): The most effective drug, replenishing dopamine levels.

   • Dopamine agonists: mimic dopamine effects in the brain.

   • MAO-B inhibitors: Prevent breakdown of brain dopamine.

   • COMT inhibitors: Extend the effect of levodopa.

2. Surgical Options

   • Deep Brain Stimulation (DBS): Electrodes implanted in the brain deliver impulses to control abnormal activity.

3. Lifestyle and Rehabilitation

   • Regular exercise to maintain flexibility and balance.

   • Physical, occupational, and speech therapy.

   • Healthy diet rich in fibre and hydration to manage non-motor symptoms.

Outlook and Research

Parkinson’s disease is a lifelong condition, but advancements in medical treatment, neuroprotective therapies, and experimental research—such as stem cell therapy and gene therapy—offer hope for better management and potential future cures.

Conclusion

Parkinson’s disease, first described over two centuries ago, remains a significant global health challenge. With its complex mix of motor and non-motor symptoms, it affects not just movement but also the overall quality of life. Early diagnosis, appropriate treatment, and supportive care remain essential for managing the disease while ongoing research strives toward a cure.