Understanding Parkinson's Disease

Parkinson's Disease is a progressive neurodegenerative disorder caused by the loss of dopamine-producing neurons in the brain. This results in motor symptoms like tremors, muscle rigidity, bradykinesia (slowness of movement), and postural instability. Non-motor symptoms, including cognitive impairment, mood disorders, sleep disturbances, and autonomic dysfunction, also significantly affect quality of life. The exact cause is unknown, but it involves genetic and environmental factors. Diagnosis is clinical, based on medical history and neurological examination. While incurable, treatments such as medications, therapy, and deep brain stimulation can manage symptoms and improve quality of life.

Types of Parkinson's Disease

Parkinson's disease primarily falls into two broad categories:

1. Idiopathic Parkinson's Disease (IPD): This is the most common form, accounting for about 85-90% of all cases. The exact cause of IPD is unknown, though it is believed to result from a combination of genetic and environmental factors.

2. Atypical Parkinsonism: This includes various forms of parkinsonism  that differ from classic Parkinson's disease in symptoms and progression. These include:

   • Multiple System Atrophy (MSA): A rapidly progressing neurodegenerative disorder characterised by autonomic dysfunction, parkinsonism, and cerebellar ataxia. It affects multiple systems of the body, leading to symptoms like blood pressure fluctuations, bladder issues, movement difficulties, and poor coordination.

   • Progressive Supranuclear Palsy (PSP): is a rare, progressive neurodegenerative disorder characterised by severe balance problems, difficulty with vertical eye movements, muscle stiffness, and cognitive decline. It is often mistaken for Parkinson's disease but has distinct clinical features and a different progression.

   • Corticobasal Degeneration (CBD):is a rare, progressive neurodegenerative disorder characterised by asymmetrical motor symptoms, such as rigidity and dystonia, along with cognitive impairments, including apraxia and language difficulties. It involves atrophy in the cerebral cortex and basal ganglia, leading to significant functional decline.

Common Early Symptoms of Parkinson's

Early symptoms of Parkinson's can be subtle and may be mistaken for normal ageing. However, recognising these signs early can lead to a timely diagnosis and better management. Here are some common early symptoms:

1. Tremors: Often the most recognisable symptom, tremors typically start in a hand or fingers and may appear as a "pill-rolling" movement between the thumb and forefinger. These tremors usually occur at rest and may decrease with intentional movement.

2. Stiffness (Rigidity): Muscle stiffness can occur in any part of the body, leading to reduced range of motion and pain. This rigidity can be particularly noticeable in the arms, legs, and neck.

3. Bradykinesia: This refers to slowness of movement, which can make simple tasks difficult and time-consuming.

4. Postural Instability: Balance issues and a stooped posture can lead to an increased risk of falls.

5. Reduced Facial Expression and bodily gestures: Often called "masked face," this symptom involves a loss of facial expression due to decreased muscle movement.

6. Changes in Speech: Speech may become soft, rapid, or slurred, making it harder for others to understand.

Symptoms can be broadly split between motor (movement-related symptoms) and non-motor (cognition, mood, digestive system etc) symptoms. In future content we will look to cover these.

Diagnostic Tests and Criteria Used by Neurologists

Diagnosing Parkinson's disease is primarily clinical, based on medical history and a neurological examination. There are no definitive tests for Parkinson's, but several tools and criteria help neurologists make a diagnosis:

1. Medical History: The doctor will review the patient's symptoms, medical history, and family history of neurological conditions.

2. Neurological Examination: This includes assessments of motor symptoms looking for key cardinal signs , such as tremor, rigidity, and bradykinesia.

3. Unified Parkinson's Disease Rating Scale (UPDRS): A comprehensive tool used to evaluate the severity of Parkinson's symptoms.

4. DaTscan: A specialised imaging test that can help differentiate Parkinson's disease from other conditions with similar symptoms. It measures the density of dopamine transporters in the brain.

5. MRI and CT Scans: While these imaging tests are not used to diagnose Parkinson's, they can help rule out other conditions that may cause similar symptoms, such as strokes or brain tumours.

6. Levodopa Challenge Test: Patients may be given a dose of levodopa, a common Parkinson's medication. Significant improvement in symptoms can support a diagnosis of Parkinson's disease.

Different Stages of Parkinson's Disease

Parkinson's disease progresses through several stages, each with distinct features and challenges. The Hoehn and Yahr scale is commonly used to classify these stages:

1. Stage 1 (Diagnosis): Symptoms are mild and typically affect one side of the body. Patients may experience slight tremors, rigidity, or bradykinesia. The impact on daily activities is minimal, and diagnosis can be challenging due to the subtlety of symptoms.

2. Stage 2 (Maintenance): Symptoms become bilateral, affecting both sides of the body. Daily activities start to require more time and effort, but patients can still live independently. Balance is usually not yet significantly affected.

3. Stage 3 (Complex): Balance issues and postural instability become more pronounced, increasing the risk of falls. Patients may still be fully independent but might need assistance with some tasks. This stage marks the beginning of more significant disability.

4. Stage 4 (Advanced): Symptoms are severe and disabling. Patients may require substantial assistance with daily activities and may no longer be able to live independently. Movement becomes very limited, and rigidity and bradykinesia significantly impair quality of life.

5. Stage 5 (Palliative): This is the most advanced stage of Parkinson's disease. Patients are often bedridden or confined to a wheelchair and require full-time care. Non-motor symptoms, such as cognitive decline, depression, and hallucinations, may become more prominent.

The stages of Parkinson's progression

Managing Parkinson's Disease

While there is currently no cure for Parkinson's disease, various treatments can help manage symptoms and improve quality of life. These can be split between medications, therapy and surgical:

Medications:

1.  Levodopa

• How it helps: Levodopa is converted to dopamine in the brain, replenishing the diminished levels and improving motor symptoms like bradykinesia, rigidity, and tremor.

2.  Dopamine Agonists (e.g., Pramipexole, Ropinirole, Rotigotine)

• How they help: These medications mimic dopamine by stimulating dopamine receptors in the brain. They are often used in the early stages of Parkinson's or in combination with levodopa to smooth out fluctuations in motor symptoms.

3.  MAO-B Inhibitors (e.g., Selegiline, Rasagiline)

• How they help: These drugs inhibit monoamine oxidase-B, an enzyme that breaks down dopamine in the brain, thereby increasing and prolonging dopamine activity. This helps reduce symptoms and can have a mild antidepressant effect.

4.  COMT Inhibitors (e.g., Entacapone, Tolcapone)

• How they help: These medications inhibit an enzyme that breaks down levodopa. By prolonging the effect of levodopa, they help manage "off" periods when symptoms return as the medication wears off.

  
  

Therapies

• Physiotherapy: Promote and encourage increase in physical activity, help with postural control, address movement changes with walking aids/cueing and work on balance

• Occupational Therapy: Assists with fatigue management, assesses and monitors cognitive changes, and provides functional rehabilitation to maintain independence and participation in day-to-day tasks. Additionally, they address equipment needs.

• Speech Therapy: Assess and monitor for any swallowing difficulties, help with enhancing speech volume and formulating communication strategies as the condition progresses.

• Support Groups and Counselling: Emotional and psychological support is crucial for patients and their families. Support groups and counselling can provide valuable resources and coping strategies.

Surgical

Deep brain stimulation (DBS) is a surgical procedure that can help reduce motor symptoms in advanced cases of Parkinson's disease.

Conclusion

Parkinson's disease is a complex and progressive condition that requires comprehensive management and support. By understanding the symptoms, diagnostic processes, and stages of Parkinson's, patients and their families can better navigate the challenges of this disease. Early diagnosis and appropriate treatment (increasing physical activity) can significantly improve the quality of life for those affected by Parkinson's. As research continues, there is hope for more effective treatments and, ultimately, a cure for this debilitating condition.

References

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2. Pringsheim, T., Jette, N., Frolkis, A., & Steeves, T. D. (2014). The prevalence of Parkinson's disease: a systematic review and meta-analysis. Movement Disorders, 29(13), 1583-1590.

3. Jellinger, K. A. (2012). Neuropathology of sporadic Parkinson's disease: evaluation and changes of concepts. Movement Disorders, 27(1), 8-30.

4. Litvan, I., Agid, Y., Calne, D., Campbell, G., Dubois, B., Duvoisin, R. C., ... & Zee, D. S. (1996). Clinical research criteria for the diagnosis of progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome): report of the NINDS-SPSP international workshop. Neurology, 47(1), 1-9.

5. Benamer, H. T. S., Patterson, J., Grosset, D. G., Booij, J., de Bruin, K., van Royen, E., & Tatsch, K. (2000). Accurate differentiation of Parkinsonism and essential tremor using visual assessment of [123I]-FP-CIT SPECT imaging: the [123I]-FP-CIT study group. Movement Disorders, 15(3), 503-510.

6. https://www.parkinsons.org.uk