USMLE Step 2 CK: Neurology – Headache, Migraine, Cluster, Tension, SAH, Temporal Arteritis, Red Flags

What This Is and Why It Matters for USMLE

Headache: Migraine, Cluster, Tension, SAH, Temporal Arteritis is a high-yield topic for Step 1, Step 2 CK, and Step 3. It appears in basic science, clinical, and ethics/management contexts, particularly in neurology and emergency medicine. Understanding the pathophysiology, clinical presentation, diagnostic approach, and management of these conditions is crucial for diagnosing and treating patients effectively.

High-Yield Facts (What You Must Memorize)

• Pathophysiology:
  • Migraine: vasodilation, serotonin release, and inflammation.
  • Cluster headache: vasodilation and inflammation of the trigeminal nerve.
  • Tension headache: muscle tension and stress.
  • SAH: subarachnoid hemorrhage due to aneurysm rupture.
  • Temporal arteritis: giant cell arteritis, inflammation of the temporal artery.
• Classic presentation and physical exam findings:
  • Migraine: unilateral headache, photophobia, and nausea.
  • Cluster headache: severe, unilateral orbital pain, ptosis, and miosis.
  • Tension headache: bilateral headache, muscle tension, and stress.
  • SAH: sudden, severe headache, often described as "the worst headache of my life."
  • Temporal arteritis: scalp tenderness, jaw claudication, and visual disturbances.
• Diagnostic approach:
  • Labs: complete blood count, erythrocyte sedimentation rate (ESR), and blood cultures.
  • Imaging: non-contrast CT, MRI, or angiography.
• First-line treatment and management:
  • Migraine: triptans, ergots, and anti-emetics.
  • Cluster headache: oxygen therapy, triptans, and ergots.
  • Tension headache: acetaminophen, NSAIDs, and stress management.
  • SAH: immediate imaging, blood pressure management, and neurosurgical consultation.
  • Temporal arteritis: corticosteroids, temporal artery biopsy, and ophthalmologic evaluation.
• Red flags, complications, and follow-up:
  • SAH: increased intracranial pressure, hydrocephalus, and vasospasm.
  • Temporal arteritis: visual loss, aortic aneurysm, and blindness.

Clinical Pearls & Buzzwords

• Migraine: "Migraine aura" (visual, sensory, or motor symptoms).
• Cluster headache: "Cluster headache syndrome" (recurrent, severe headaches).
• Tension headache: "Tension headache variant" (bilateral, muscle tension).
• SAH: "Subarachnoid hemorrhage" (blood in the subarachnoid space).
• Temporal arteritis: "Giant cell arteritis" (inflammation of the temporal artery).

Step-by-Step Clinical Reasoning

1. Identify the syndrome or presentation.
2. Generate a differential (most likely and must-not-miss):
   • Migraine, cluster headache, tension headache, SAH, and temporal arteritis.
3. Order appropriate initial tests:
   • Labs (CBC, ESR, blood cultures) and imaging (non-contrast CT, MRI, or angiography).
4. Interpret results:
   • SAH: non-contrast CT or MRI showing blood in the subarachnoid space.
   • Temporal arteritis: ESR, temporal artery biopsy, and ophthalmologic evaluation.
5. Initiate treatment and monitoring:
   • SAH: immediate imaging, blood pressure management, and neurosurgical consultation.
   • Temporal arteritis: corticosteroids, temporal artery biopsy, and ophthalmologic evaluation.

Common Mistakes & Exam Traps

• The mistake: Missing SAH or temporal arteritis due to lack of red flags.
• Why it happens: Misunderstanding or overlooking key symptoms and signs.
• How to avoid it: Verify the presence of red flags, such as sudden, severe headache or scalp tenderness.

• Exam board insight: The examiners will penalize you for missing critical diagnoses.

• The mistake: Overlooking tension headache variant due to bilateral symptoms.

• Why it happens: Rushing through the exam or misreading the question.
• How to avoid it: Take your time, read the question carefully, and consider all possible diagnoses.

• Exam board insight: The examiners will reward you for considering all possibilities.

• The mistake: Not ordering indicated tests for SAH or temporal arteritis.

• Why it happens: Lack of knowledge or experience with these conditions.
• How to avoid it: Review the high-yield facts, practice with case scenarios, and seek guidance from experienced clinicians.
• Exam board insight: The examiners will penalize you for not following established protocols.

How It’s Tested on USMLE

• Step 1: Basic science vignette (e.g., molecular mechanism, pathology slide, pharmacology).
• Step 2 CK: Clinical vignette (e.g., "A 45-year-old with chest pain...").
• Step 3: Similar to Step 2 CK, plus prognosis, risk factors, and occasionally CCS management.

CCS (Step 3) Relevance (If Applicable)

• Initial orders: non-contrast CT or MRI for SAH, ESR and temporal artery biopsy for temporal arteritis.
• Monitoring and follow-up: blood pressure management, neurosurgical consultation for SAH, and ophthalmologic evaluation for temporal arteritis.
• Common mistakes: not ordering indicated tests, delaying treatment.

Practice Questions (3-5 single-best-answer)

Question 1: A 35-year-old woman presents with a sudden, severe headache, often described as "the worst headache of my life." Which of the following is the most likely diagnosis? A) Migraine B) Cluster headache C) SAH D) Temporal arteritis

Answer: C) SAH Explanation: The patient's sudden, severe headache is a classic presentation for SAH. The presence of blood in the subarachnoid space on non-contrast CT or MRI confirms the diagnosis.

Question 2: A 60-year-old man presents with scalp tenderness, jaw claudication, and visual disturbances. Which of the following is the most likely diagnosis? A) Migraine B) Cluster headache C) SAH D) Temporal arteritis

Answer: D) Temporal arteritis Explanation: The patient's symptoms, including scalp tenderness, jaw claudication, and visual disturbances, are characteristic of temporal arteritis. The elevated ESR and temporal artery biopsy confirm the diagnosis.

Question 3: A 45-year-old woman presents with a bilateral headache, muscle tension, and stress. Which of the following is the most likely diagnosis? A) Migraine B) Cluster headache C) SAH D) Tension headache

Answer: D) Tension headache Explanation: The patient's bilateral headache, muscle tension, and stress are characteristic of tension headache. The absence of red flags, such as sudden, severe headache or scalp tenderness, makes this diagnosis more likely.

Quick Reference Card (60-Second Summary)

• SAH: sudden, severe headache, blood in the subarachnoid space on non-contrast CT or MRI.
• Temporal arteritis: scalp tenderness, jaw claudication, visual disturbances, elevated ESR.
• Migraine: unilateral headache, photophobia, nausea, aura.
• Cluster headache: severe, unilateral orbital pain, ptosis, miosis.
• Tension headache: bilateral headache, muscle tension, stress.

If You Get Stuck on Test Day

• Eliminate obviously wrong answers by considering the patient's symptoms and signs.
• Use the "next best step" hierarchy (least invasive, most specific) to approach the diagnosis.
• For Step 3 CCS, order basic labs, vitals, and IV access when unsure.

Related USMLE Topics

• Stroke: connects to SAH, temporal arteritis, and cerebral vasculitis.
• Neuroimaging: connects to SAH, temporal arteritis, and cerebral vasculitis.
• Neurology: connects to SAH, temporal arteritis, and cerebral vasculitis.