Makindo Medical Notes

Related Subjects:Multiple System Atrophy (MSA) |Parkinson Plus syndromes |Parkinsonism |Idiopathic Parkinson disease |Progressive Supranuclear Palsy |Drug Induced Parkinson disease

Parkinson's Disease (PD) is a chronic, progressive neurological disorder affecting movement and various non-motor functions. It typically presents in older adults, though genetic variants may cause symptoms in younger patients.

About

• Idiopathic Parkinson's Disease is characterized by progressive motor symptoms, including tremor, rigidity, and bradykinesia.
• More common in elderly adults, but genetic forms may manifest in younger populations.

Aetiology

• Characterized by loss of dopaminergic neurons in the substantia nigra, a brain region crucial for motor control.
• Loss of dopamine results in disrupted communication between the basal ganglia and other parts of the brain.
• Lewy bodies, or protein inclusions containing alpha-synuclein, are found within affected neurons and are considered a hallmark of PD pathology.

Pathology: Braak Staging of Parkinson’s Disease

• Braak’s Staging: Suggests a progression of pathology from the lower brainstem (dorsal motor nucleus of the vagus nerve) to the cerebral cortex.
• This stepwise pattern of neuron degeneration correlates with symptom progression, moving from non-motor symptoms (e.g., constipation) to motor symptoms as the disease advances to the midbrain.

Genetics

• Several genetic mutations are linked to PD, especially in young-onset cases.
• PARK1 (alpha-synuclein gene): Mutation associated with early-onset PD; autosomal dominant.
• PARK2 (parkin gene): Mutation in this autosomal recessive gene is associated with sensitivity to L-Dopa and a good response to treatment.

Clinical Features

• Tremor: A classic resting tremor with a “pill-rolling” characteristic.
• Bradykinesia: Slowed movement and difficulty initiating movements, affecting daily activities.
• Rigidity: Stiffness in the limbs and neck, often with cogwheel quality.
• Postural Instability: Difficulty with balance and increased risk of falls.
• Non-motor symptoms: Depression, constipation, sleep disturbances, and anosmia (loss of smell).

Stages of Parkinson's Disease

• Stage 1: Mild symptoms, usually unilateral tremor.
• Stage 2: Bilateral symptoms, possible walking difficulties, slower movements.
• Stage 3: Increased motor difficulty, loss of balance, and fall risk.
• Stage 4: Severe symptoms, significant disability, assistance required.
• Stage 5: Advanced stage, bedridden or requiring wheelchair, hallucinations may appear.

Diagnostic Imaging

• MRI: Useful for excluding alternative diagnoses such as vascular Parkinsonism or normal-pressure hydrocephalus.
• DaT Scan: Dopamine transporter scan helpful for distinguishing PD from essential tremor.

Commas are normal. Full stop/period is abnormal

Management of Parkinson’s Disease

• Early Disease: Treatment is often withheld until symptoms impact daily function. Monitoring progression with regular reviews is key. Early pharmacologic intervention may include MAO-B inhibitors such as Rasagiline.

Pharmacological Treatment

• Levodopa: The most effective drug for motor symptoms. Often combined with carbidopa (e.g., Sinemet) to prevent peripheral conversion of levodopa to dopamine.
• COMT Inhibitors (e.g., Entacapone): Used to prolong Levodopa’s effect, especially for managing “off” periods in advanced PD.
• Dopamine Agonists (e.g., Ropinirole, Pramipexole): Often used in younger patients to delay the need for Levodopa and minimize dyskinesias.
• MAO-B Inhibitors (e.g., Rasagiline): Help reduce dopamine breakdown and provide symptomatic relief.
• Anticholinergics: Useful for tremor-dominant PD, but less effective for other symptoms.
• Amantadine: Helps reduce dyskinesias in later-stage PD.

Surgical Management

• Deep Brain Stimulation (DBS): An option for patients with advanced disease and motor complications. Electrodes are implanted in the subthalamic nucleus or globus pallidus to improve motor symptoms.

Multidisciplinary Support

• Parkinson's Nurse Specialist: Provides patient education, medication management, and symptom monitoring.
• Physiotherapy: Focuses on maintaining mobility, flexibility, and posture to enhance independence.
• Speech and Language Therapy: Assists with dysarthria (difficulty speaking) and dysphagia (difficulty swallowing).
• Occupational Therapy: Provides adaptive equipment and strategies to support daily activities.

Hospital Admission and Acute Management

• Ensure PD medications are administered on time, even if the patient is NBM (nil by mouth). Consider NG administration or Rotigotine patch if necessary.
• Avoid contraindicated medications that worsen PD symptoms or interact negatively with dopaminergic therapy.

Non-Motor Complications and Management

• Constipation: Treat with macrogol laxatives, increase fluid intake, and promote mobility.
• Orthostatic Hypotension: Consider fludrocortisone or midodrine for severe cases; ensure adequate hydration and salt intake.
• Urinary Infections: Prevent by promoting hydration and addressing constipation.
• Psychosis and Hallucinations: Low-dose antipsychotics (e.g., quetiapine) may be considered. Clozapine is effective but requires regular blood monitoring.
• Dementia: Rivastigmine may be useful for cognitive symptoms but may worsen tremors.

Advance Care Planning

• Advance Directives: Encourage discussion about future care, including advance decisions and lasting power of attorney.
• Support Services: Provide information on community resources for personal care, respite, and financial assistance.

References

• Visanji et al. Acta Neuropathologica Communications 2013, 1:2