Neurological Disorders: Stroke, TIA, Parkinson's Disease & Headache Syndromes

Neurological Disorders in Primary Care and Gerontology

Neurological conditions evaluated in primary care range from hyperacute cardiovascular crises such as stroke and transient ischemic attack (TIA) to chronic neurodegenerative conditions like Parkinson's disease and complex primary headache syndromes. The advanced practice registered nurse (APRN) must demonstrate competency in rapid risk stratification, initial emergency management, long-term secondary prevention, and evidence-based pharmacotherapy.

Ischemic Stroke and Transient Ischemic Attack (TIA)

Pathophysiology and Distinction

An Ischemic Stroke occurs when focal cerebral blood flow is abruptly interrupted by thrombus or embolus, causing brain tissue infarction and persistent neurological deficits. A Transient Ischemic Attack (TIA) is defined clinically as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia without acute cellular infarction on neuroimaging (such as diffusion-weighted MRI). TIAs carry up to a 10% to 15% risk of stroke within 90 days, with the highest risk occurring in the first 48 hours.

Clinical Presentation and Urgent Neuroimaging

Acute focal neurological deficits depend on the involved vascular territory:

• Middle Cerebral Artery (MCA): Contralateral hemiparesis and sensory loss affecting face and arm more than leg; dominant hemisphere involvement produces aphasia (expressive Broca's or receptive Wernicke's), while non-dominant involvement causes spatial neglect.
• Anterior Cerebral Artery (ACA): Contralateral weakness and sensory loss affecting leg and foot more than arm/face, often with abulia or urinary incontinence.
• Posterior Cerebral Artery (PCA): Contralateral homonymous hemianopia and visual agnosia.
• Vertebrobasilar Territory: Ataxia, vertigo, diplopia, dysarthria, and cranial nerve palsies.

Immediate Diagnostic Action: For any patient presenting with suspected acute stroke or TIA (utilizing the public FAST protocol: Facial drooping, Arm weakness, Speech difficulty, Time to call emergency services), the mandatory first step is an urgent non-contrast head CT. This excludes intracranial hemorrhage prior to considering thrombolytic therapy (intravenous alteplase or tenecteplase administered within 3 to 4.5 hours of last known normal) or endovascular thrombectomy (for large vessel occlusion within up to 24 hours).

Risk Stratification: The ABCD2 Score

To determine the urgency of inpatient admission and short-term stroke risk following a TIA, clinicians calculate the ABCD2 score:

• Age >= 60 years (1 point)
• Blood pressure >= 140/90 mmHg on initial assessment (1 point)
• Clinical features: Unilateral weakness (2 points) OR Speech disturbance without weakness (1 point)
• Duration of symptoms: >= 60 minutes (2 points) OR 10–59 minutes (1 point)
• Diabetes mellitus history (1 point)

Clinical Decision Making: Scores of 4 to 7 indicate moderate-to-high stroke risk, requiring urgent emergency department evaluation, hospital admission, urgent vascular imaging (carotid duplex or CTA/MRA), and rapid secondary prevention.

Secondary Ischemic Stroke Prevention

1. Antiplatelet Therapy: Non-cardioembolic stroke/TIA requires long-term single antiplatelet therapy (Aspirin 81 mg daily, Clopidogrel 75 mg daily, or Aspirin plus extended-release Dipyridamole). Short-term Dual Antiplatelet Therapy (DAPT) with Aspirin plus Clopidogrel initiated within 24 hours for 21 to 90 days is recommended for high-risk TIA (ABCD2 >= 4) or minor ischemic stroke (NIHSS <= 3) to reduce recurrent ischemic events.
2. Anticoagulation: Cardioembolic stroke/TIA secondary to atrial fibrillation requires oral anticoagulation with Direct Oral Anticoagulants (DOACs: Apixaban, Rivaroxaban, Dabigatran) rather than antiplatelet therapy. DAPT combined with anticoagulation is contraindicated long-term.
3. Lipid and Blood Pressure Optimization: Initiate high-intensity statin therapy (Atorvastatin 80 mg or Rosuvastatin 40 mg daily) targeting LDL < 70 mg/dL. Blood pressure target is < 130/80 mmHg using ACE inhibitors, ARBs, or thiazide diuretics after the acute phase.

Movement Disorders: Parkinson's Disease and Essential Tremor

Parkinson's Disease (PD)

PD is a progressive neurodegenerative disorder marked by loss of dopaminergic neurons in the substantia nigra. Diagnosis is clinical based on four cardinal motor manifestations:

1. Resting Tremor: Asymmetric 4–6 Hz "pill-rolling" tremor present at rest, decreasing with voluntary movement.
2. Bradykinesia: Slowness of movement execution and progressive reduction in speed/amplitude during repetitive movements (finger tapping). Manifests as masked facies, hypophonia, and micrographia.
3. Rigidity: Increased resistance to passive joint movement ("cogwheel" rigidity).
4. Postural Instability: Impaired postural reflexes leading to shuffling gait and falls (late stage).

Pharmacotherapy:

• Carbidopa/Levodopa (Sinemet): Most effective treatment. Levodopa converts to dopamine; carbidopa inhibits peripheral dopa-decarboxylase, preventing nausea and orthostasis. Long-term use (>5 years) leads to motor fluctuations ("wearing-off") and dyskinesias.
• Dopamine Agonists (Pramipexole, Ropinirole): Direct dopamine receptor agonists used as initial monotherapy in younger patients. Warning: High incidence of impulse control disorders (pathological gambling, compulsive shopping, hypersexuality), sleep attacks, and edema.
• MAO-B Inhibitors (Selegiline, Rasagiline): Inhibit dopamine breakdown in the CNS; used for mild early symptoms.

Essential Tremor (ET)

ET is a common, often familial (autosomal dominant) movement disorder. Unlike Parkinson's disease, ET is an action (postural and kinetic) tremor (5–10 Hz) affecting both hands during active movement (holding a cup, writing). It may involve the head ("yes-yes" or "no-no" titubation) or voice, spares the legs, and lacks rigidity or bradykinesia. Symptoms briefly improve with small amounts of alcohol.

• First-Line Pharmacotherapy: Propranolol (non-selective beta-blocker) or Primidone (anticonvulsant).

Primary Headache Syndromes

Clinical Management Guidelines

• Migraine Abortive: Triptans (Sumatriptan 50–100 mg PO or 6 mg SC) are 5-HT1B/1D agonists used first-line for moderate-to-severe attacks. Contraindications: Ischemic heart disease, prior stroke/TIA, uncontrolled hypertension, or peripheral vascular disease. Gepants (Rimegepant, Ubrogepant) are non-vasoconstrictive alternatives.
• Migraine Preventive: Recommended for >= 4 headache days/month. Options include beta-blockers (propranolol), Topiramate (watch for paresthesias, weight loss, nephrolithiasis), Amitriptyline, or CGRP monoclonal antibodies.
• Cluster Acute Therapy: 100% High-flow Oxygen (12–15 L/min via non-rebreather mask for 15–20 minutes) plus subcutaneous Sumatriptan 6 mg. Prophylaxis: High-dose Verapamil (ECG required to monitor PR interval).