How should I assess and manage a 35‑year‑old woman (G3P2) with sudden severe throbbing vertex headache, rotational dizziness on standing, seven episodes of clear vomiting, intense epigastric pain, normal vital signs and neurologic exam, no past medical history, and unknown last menstrual period?

Assessment and Plan

This patient requires urgent neuroimaging with MRI brain without contrast and neurologic consultation to rule out subarachnoid hemorrhage or posterior circulation stroke, given her sudden-onset severe vertex headache (10/10), rotatory vertigo, and severe vomiting—all red flags for life-threatening intracranial pathology.

Immediate Assessment

Critical Red Flags Present

• Sudden severe headache (10/10 intensity) with vertex location represents a "thunderclap headache" pattern that mandates immediate investigation for subarachnoid hemorrhage (SAH), which occurs in 11.3% of patients presenting with sudden-onset severe headache 1
• Seven episodes of vomiting with severe epigastric pain suggest increased intracranial pressure or posterior fossa pathology 2
• Rotatory vertigo on standing combined with severe headache raises concern for posterior circulation stroke, which accounts for 25% of acute vestibular syndrome presentations 3

Differential Diagnosis Priority

Life-Threatening Causes (Rule Out First):

• Subarachnoid hemorrhage—most critical diagnosis given sudden severe headache 2, 4, 1
• Posterior circulation stroke—particularly with combined vertigo and headache 3
• Cerebral venous sinus thrombosis—young woman of childbearing age with severe headache and vomiting 5
• Meningitis—though less likely with normal neurologic exam 1

Secondary Considerations:

• Vestibular migraine with severe attack—14% of vertigo cases, but typically not this severe on first presentation 3
• Acute vestibular neuritis—but would not explain the severe vertex headache 3

Immediate Diagnostic Workup

Neuroimaging (URGENT)

MRI brain without IV contrast is the required first-line imaging for this presentation 6, 3:

• MRI with diffusion-weighted imaging has 4% diagnostic yield vs <1% for CT in isolated dizziness, and is essential for detecting posterior circulation infarcts 3
• Do not rely on CT head alone—CT has only 20-40% sensitivity for posterior circulation stroke and misses most cases 3
• If MRI is unavailable or significantly delayed, obtain CT head without contrast first, but understand it may miss critical pathology 4, 1

Lumbar Puncture

• Required if CT/MRI is negative to definitively exclude SAH, as CT sensitivity decreases after 6 hours and imaging can miss 2% of SAH cases 4, 1
• Perform CSF spectrophotometry (not just visual inspection) to detect xanthochromia 4

Bedside Examination

While awaiting imaging, perform:

• HINTS examination (Head Impulse, Nystagmus, Test of Skew)—though this patient's presentation is too concerning to rely on HINTS alone given the severe headache component 3
• Repeat vital signs including orthostatic measurements
• Fundoscopic examination for papilledema

Management Plan

Acute Symptom Management

For Severe Headache:

• Ketorolac 60 mg IM is appropriate for severe migraine-type headache with rapid onset and 6-hour duration, with low rebound risk 6
• Avoid opioids (meperidine, butorphanol) unless other treatments fail, as they can cause dependency and rebound headaches 6

For Nausea/Vomiting:

• Metoclopramide 10 mg IV or prochlorperazine 10 mg IV—both treat nausea and provide synergistic analgesia for migraine 6
• Use non-oral route given seven vomiting episodes 6

Critical Caveat: Do not administer symptomatic treatment until after neuroimaging rules out life-threatening causes, as symptom relief may mask deterioration.

If Imaging Rules Out Emergent Pathology

Only after SAH and stroke are excluded, consider:

• Dix-Hallpike maneuver to evaluate for BPPV (though vertex headache is atypical) 3
• Trial of migraine-specific therapy if vestibular migraine is suspected 6

Disposition

• Admit for observation until imaging complete and SAH/stroke definitively excluded
• Neurology consultation regardless of imaging results given severity of presentation
• If imaging negative and symptoms resolve, consider outpatient neurology follow-up within 1 week with repeat imaging if symptoms recur 1

Common Pitfalls to Avoid

• Never assume "just migraine" with first-time sudden severe headache—11.3% have SAH 1
• Do not rely on normal neurologic exam to exclude stroke—75-80% of posterior circulation infarcts have no focal deficits 3
• Do not skip lumbar puncture if imaging is negative—CT misses 2% of SAH cases 4, 1
• Do not use patient's description of "dizziness" alone—focus on timing, triggers, and associated symptoms 3
• Avoid treating symptoms before excluding life-threatening causes—symptom relief may mask deterioration

Documentation Requirements

Document specifically:

• Exact time to peak headache intensity (critical for SAH diagnosis) 4
• Duration of each symptom
• Any trauma history
• Medication use including oral contraceptives (thrombosis risk)
• Last menstrual period to assess pregnancy status before imaging