3.3 Acute Neurological Problems

Acute Neurological Problems

Neurological emergencies require rapid recognition, diagnostic precision, and immediate management to prevent irreversible neurological damage or death. This section focuses on transient ischemic attacks (TIA), acute stroke, the classification of acute headaches, migraine prophylaxis, and red flags necessitating urgent neuroimaging.

TIA and Stroke Recognition

Stroke is a major cause of death and long-term disability worldwide. Prompt recognition and differentiation between ischemic and hemorrhagic events are paramount.

Definitions and Pathophysiology

• Ischemic Stroke (approx. 85%): Caused by focal cerebral ischemia secondary to vascular occlusion (thromboembolic or large vessel atherosclerosis).
• Hemorrhagic Stroke (approx. 15%): Caused by vessel rupture, leading to bleeding within the brain parenchyma (intracerebral hemorrhage) or subarachnoid space (subarachnoid hemorrhage).
• Transient Ischemic Attack (TIA): A transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without evidence of acute tissue infarction on neuroimaging. Although symptoms typically resolve within 1 hour, a TIA is a critical warning sign associated with a high risk of subsequent stroke, particularly within the first 48 hours.

The BE-FAST Assessment Tool

Immediate recognition of stroke symptoms in the community or clinic is facilitated by the BE-FAST mnemonic:

• Balance: Sudden loss of balance or coordination (ataxia).
• Eyes: Sudden loss of vision, double vision (diplopia), or hemianopia.
• Face: Asymmetric facial drooping.
• Arm: Sudden weakness or numbness in an arm or leg, often unilateral (drift).
• Speech: Slurred speech (dysarthria) or difficulty finding words (aphasia).
• Time: Critical window for intervention; activate emergency services.

Acute Diagnostics and Management

The most critical immediate diagnostic step for any patient with acute neurological deficits is a non-contrast head computed tomography (CT) scan or magnetic resonance imaging (MRI). The primary objective is to differentiate between ischemic and hemorrhagic stroke, as thrombolytic therapy is contraindicated in hemorrhage.

Reperfusion Therapy in Ischemic Stroke:

1. Intravenous Thrombolysis: Recombinant tissue plasminogen activator (rt-PA, e.g., Alteplase) should be administered to eligible patients within 4.5 hours of symptom onset (or "last known well" time).
   • Absolute Contraindications: Active internal bleeding, history of recent intracranial hemorrhage, intracranial neoplasm or aneurysm, recent major surgery or head trauma (within 14 days), platelets < 100,000, or severe uncontrolled hypertension (Systolic BP > 185 mmHg or Diastolic BP > 110 mmHg).
2. Mechanical Thrombectomy: For patients with large vessel occlusions in the anterior circulation, endovascular thrombectomy is indicated within 6 to 24 hours of symptom onset.

Secondary Stroke Prevention

Post-TIA or post-stroke management focuses on risk factor modification:

• Antiplatelet Therapy: Single antiplatelet (Aspirin 81 mg daily) or short-term Dual Antiplatelet Therapy (DAPT: Aspirin + Clopidogrel for 21–90 days for high-risk TIA or minor stroke) followed by monotherapy.
• Statin Therapy: High-intensity statin (Atorvastatin 80 mg daily) to achieve LDL targets.
• Hypertension: Gradual reduction in blood pressure after the acute phase.
• Anticoagulation: Indicated if the stroke/TIA was cardioembolic (e.g., due to atrial fibrillation).
• ABCD2 Score: Used in outpatient settings to stratify the risk of stroke within 2 days after a TIA, assessing Age (≥60 years), Blood pressure (≥140/90), Clinical features (unilateral weakness, speech impairment), Duration (≥60 mins), and Diabetes.

---

Acute Headache Classification

Headaches are broadly classified into primary (benign, recurrent) and secondary (symptom of an underlying disease).

Primary Headaches

1. Tension-Type Headache: The most common type. Pain is typically bilateral, non-pulsating ("band-like" tightness), mild-to-moderate, and is not aggravated by physical activity. There is no associated nausea or photophobia.
2. Migraine: Characterized by recurrent, throbbing, unilateral pain of moderate-to-severe intensity. It is often accompanied by nausea, vomiting, photophobia, and phonophobia, and can be aggravated by routine physical activity. Approximately 20-30% of patients experience an aura (reversible focal neurological symptoms, usually visual, like scotomas or flashing lights) preceding the pain.
3. Cluster Headache: Part of the trigeminal autonomic cephalalgias. It presents as severe, unilateral, sharp, orbital or temporal pain lasting 15–180 minutes, occurring in clusters for weeks or months. It is accompanied by ipsilateral autonomic symptoms (lacrimation, rhinorrhea, nasal congestion, miosis, ptosis, forehead sweating) and extreme restlessness.

Secondary Headaches and "Red Flags"

Secondary headaches can indicate life-threatening conditions. Clinicians must screen for warning signs using the SNOOP mnemonic:

• S - Systemic symptoms (fever, weight loss, night sweats) or secondary risk factors (history of cancer, HIV, immunosuppression).
• N - Neurological symptoms or signs (confusion, altered mental status, focal deficits, papilledema, meningismus).
• O - Onset that is sudden, abrupt, or split-second ("thunderclap" headache, reaching peak intensity within 1 minute, suggesting subarachnoid hemorrhage).
• O - Older age at onset (new-onset headache in a patient > 50 years of age, raising suspicion for temporal arteritis or intracranial mass).
• P - Pattern change or progressive headache (change in frequency or severity, headache worsening with Valsalva maneuvers or coughing, or positional headaches).

The presence of any SNOOP red flag mandates urgent neuroimaging (non-contrast head CT or brain MRI) to rule out intracranial hemorrhage, mass lesions, meningitis, or venous sinus thrombosis.

---

Migraine Prophylaxis

While acute migraine attacks are managed with NSAIDs, triptans (5-HT1B/1D agonists), or CGRP antagonists, preventive therapy is indicated for patients with frequent or disabling headaches (e.g., ≥ 4 migraine days per month, or attacks that severely impair daily functioning despite acute therapy).

First-line preventive pharmacotherapy options include:

1. Beta-Blockers (Propranolol, Metoprolol): Highly effective. Contraindicated in patients with moderate-to-severe asthma, bradycardia, or peripheral vascular disease.
2. Anticonvulsants (Topiramate, Valproic Acid): Topiramate is widely used and aids weight loss but can cause cognitive slowing and nephrolithiasis. Valproic acid is effective but has significant teratogenic risks and should be avoided in females of childbearing potential.
3. Tricyclic Antidepressants (Amitriptyline): Particularly useful for patients with comorbid insomnia, tension-type headaches, or chronic pain. Use with caution in elderly patients due to anticholinergic side effects (urinary retention, dry mouth, confusion).
4. CGRP Monoclonal Antibodies (Erenumab, Galcanezumab): Monthly subcutaneous injections that target CGRP or its receptor, offering high efficacy and low side-effect profiles, reserved for refractory cases.