What is the differential diagnosis for a patient with sudden onset rotatory dizziness and severe headache?

Differential Diagnosis for Sudden Onset Rotatory Dizziness with Severe Headache

Based on the MRI findings of a left frontal cavernous malformation, cerebellar atrophy, and the clinical presentation of continuous rotatory vertigo with severe frontal headache, unidirectional nystagmus, and bradycardia, the primary differential diagnoses are: cavernous malformation with possible hemorrhage or seizure activity, vestibular migraine, Ménière's disease, vestibular neuritis, and less likely but critical to exclude—posterior circulation stroke or spontaneous intracranial hypotension.

Critical Structural Pathology (Priority Given MRI Findings)

Cavernous Malformation

• The left frontal cavernous malformation identified on MRI is the most concerning finding and must be prioritized 1
• Cavernous malformations can cause seizures, hemorrhage, or focal neurological symptoms depending on location and size 1
• The continuous nature of symptoms over 6 days with severe headache (initially 10/10) raises concern for hemorrhage or seizure activity from this lesion 1
• The bradycardia (HR 54) could represent increased intracranial pressure from hemorrhage, though blood pressure is not elevated 1

Cerebellar Pathology

• Cerebrocerebellar atrophy noted on MRI may contribute to chronic imbalance but typically does not cause acute rotatory vertigo 1
• However, acute cerebellar stroke or hemorrhage must be excluded given the continuous vertigo and headache 2
• The normal finger-to-nose test and absence of dysdiadochokinesia argue against acute cerebellar dysfunction, but these tests have limited sensitivity 1

Peripheral Vestibular Causes

Vestibular Neuritis/Labyrinthitis

• Typically presents with sudden severe vertigo lasting >24 hours with profound nausea and vomiting 1, 3
• This patient's 6-day continuous rotatory vertigo fits the duration profile 1
• The unidirectional nystagmus supports a peripheral vestibular lesion 1
• However, vestibular neuritis typically does NOT cause severe headache, which makes this diagnosis less likely as the sole explanation 2, 1
• Previous hospitalization in 2020 for dizziness suggests possible recurrent vestibular pathology 1

Ménière's Disease

• Characterized by episodic vertigo lasting hours (not continuous for days) with fluctuating hearing loss, tinnitus, and aural fullness 2
• The continuous nature of this patient's vertigo over 6 days does NOT fit Ménière's disease, which features discrete attacks 2
• No documented hearing loss, tinnitus, or aural fullness in the presentation 2
• Ménière's attacks are spontaneous, not associated with severe persistent headache 2, 1

Benign Paroxysmal Positional Vertigo (BPPV)

• BPPV is effectively ruled out because symptoms last seconds to minutes (not continuous), are triggered by specific head positions, and this patient has continuous rotatory vertigo 2, 1
• The Dix-Hallpike maneuver was not documented but would be expected to be negative given the symptom pattern 4, 5

Central Vestibular Causes

Vestibular Migraine

• This is a strong consideration given the severe frontal throbbing headache combined with rotatory vertigo 2, 1
• Vestibular migraine attacks can last minutes to hours, or even >24 hours in 30% of patients, with some taking up to 4 weeks to fully recover 2
• The frontal throbbing headache is characteristic of migraine 2
• Maternal history of hypertension and diabetes (not migraine) makes familial migraine less likely but does not exclude it 2
• However, the continuous 6-day duration is atypical even for vestibular migraine 2
• Betahistine providing temporary relief is non-specific and does not distinguish between diagnoses 2

Posterior Circulation Stroke/TIA

• Must be excluded urgently despite normal neurological examination 1, 4, 6
• Stroke can present with vertigo lasting minutes with nausea, vomiting, and severe imbalance, often with visual blurring 2, 1
• The 9 pack-year smoking history is a vascular risk factor 6
• Five factors increase stroke risk in dizzy patients: sudden onset headache (present), nausea/vomiting (initially present), increasing systolic blood pressure (not present—BP 100/70), anticoagulant use (not present), and head trauma (not present) 6
• The sudden onset of symptoms 6 days prior fits stroke presentation 6
• However, the absence of focal neurological deficits, normal cranial nerve examination, 5/5 motor strength, and 100% sensory function make stroke less likely but do not exclude it 1, 4
• The unidirectional nystagmus that presumably lessens with visual fixation (not documented) would favor peripheral over central cause 1

Spontaneous Intracranial Hypotension (SIH)

• Typically presents with orthostatic headache (worse upright, better lying flat) 2
• This patient's headache is NOT described as orthostatic, making SIH unlikely 2
• SIH can present with thunderclap headache followed by orthostatic features 2
• Associated symptoms include nausea, neck pain, and auditory symptoms 2
• The MRI showed no evidence of brain sag or diffuse dural enhancement typical of SIH 2

Other Considerations

Medication/Toxic Causes

• Betahistine and Flanax (naproxen) are the only documented medications 1
• Occasional alcohol use is noted but no recent intoxication reported 1
• No ototoxic medications (aminoglycosides) documented 1

Infectious Causes

• Labyrinthitis would cause sudden severe vertigo with profound hearing loss lasting >24 hours 2, 1
• No fever, otalgia, or documented hearing loss 2
• The mucus retention cyst in right maxillary sinus is likely incidental 2

Cervicogenic Vertigo

• Would be provoked by cervical movement rather than posture 2
• No documented cervical pathology or reduced range of motion 2
• Not consistent with continuous symptoms 1

Diagnostic Algorithm

Immediate priorities:

1. Neurosurgical consultation for the cavernous malformation to assess hemorrhage risk and need for intervention 1
2. MRI brain with diffusion-weighted imaging (DWI) to exclude acute stroke, particularly in posterior circulation 1, 4
3. Formal audiometry to document any hearing loss that would support Ménière's disease or labyrinthitis 2, 1
4. Video-oculography or formal vestibular testing to characterize nystagmus and differentiate central from peripheral causes 1, 4
5. EEG if seizure activity suspected from the cavernous malformation 1

Key clinical features to monitor:

• Development of focal neurological deficits would indicate stroke or hemorrhage from cavernoma 1, 6
• Worsening headache with altered mental status could indicate increased intracranial pressure 2, 1
• The bradycardia (HR 54) requires monitoring—if associated with hypertension would suggest Cushing's triad 2

Common Pitfalls

• Do not assume isolated dizziness without focal deficits excludes serious central pathology—posterior circulation strokes can present with isolated vertigo 1, 4, 6
• Do not rely solely on symptom quality (rotatory vs non-rotatory) to differentiate peripheral from central causes—use timing, triggers, and associated symptoms instead 4, 5
• Do not dismiss the cavernous malformation as incidental—it requires neurosurgical evaluation regardless of whether it explains current symptoms 1
• Do not diagnose vestibular migraine without excluding structural lesions first, especially given the MRI findings 2, 1
• The previous hospitalization for dizziness in 2020 suggests recurrent pathology but does not clarify the current diagnosis 1