What is the best approach to manage a 40-year-old woman with persistent dizziness for 3 days, who is unable to complete orthostatic vitals due to dizziness, has normal sitting and one-minute standing vitals, a normal Electrocardiogram (EKG), and no neurological abnormalities?

Approach to Persistent Dizziness in a 40-Year-Old Woman

This patient requires urgent MRI brain without contrast to exclude posterior circulation stroke, as she has persistent continuous vertigo for 3 days with severe postural instability (inability to complete orthostatic vitals), which are red flags for central pathology despite a normal neurologic exam. 1

Critical Red Flags Present

This case contains multiple concerning features that mandate urgent evaluation:

• Severe postural instability with inability to complete 3-minute standing vitals is a cardinal red flag for central causes, particularly vertebrobasilar insufficiency and cerebellar lesions 2
• Persistent continuous vertigo lasting 3 days places this in the "acute vestibular syndrome" category, where approximately 25% of patients have cerebrovascular disease 2
• Normal neurologic exam does NOT exclude stroke - approximately 75-80% of patients with acute vestibular syndrome from posterior circulation infarct have no focal neurologic deficits on standard examination 1, 2

Immediate Diagnostic Approach

Perform HINTS Examination (If Trained)

• The HINTS examination (Head-Impulse, Nystagmus, Test of Skew) has 100% sensitivity for detecting posterior circulation stroke when performed by trained practitioners, compared to only 46% for early MRI 1
• However, HINTS is less reliable when performed by non-experts 1
• If HINTS suggests central cause, proceed immediately to imaging 1

Obtain MRI Brain Without Contrast

• MRI is the imaging modality of choice for posterior circulation infarcts, with significantly higher diagnostic yield (4-16%) compared to CT 1
• CT head has very low sensitivity (20-40%) for causative pathology in dizziness and particularly poor detection of posterior circulation infarcts 1, 3
• Do not rely on CT - it misses many posterior circulation infarcts that MRI will detect 1

What This Is NOT

BPPV is Excluded

• BPPV causes brief episodes lasting seconds to minutes, not continuous dizziness for 3 days 1
• BPPV is triggered by specific head movements and resolves between episodes 4
• This patient has persistent continuous symptoms, which is incompatible with BPPV 1

Orthostatic Hypotension is Unlikely

• Sitting and 1-minute standing vitals were normal 4
• True orthostatic hypotension requires sustained BP drop of ≥20/10 mmHg within 3 minutes of standing 4
• The inability to complete testing was due to dizziness severity, not documented hypotension 4

Differential Diagnosis for Acute Persistent Vertigo

The most critical diagnoses to consider:

• Posterior circulation stroke (25% of acute vestibular syndrome cases) 2
• Cerebellar infarction or hemorrhage (presents with severe postural instability) 2
• Vestibular neuritis (benign peripheral cause, but diagnosis of exclusion after ruling out central causes) 5
• Vertebrobasilar insufficiency (especially with severe postural instability) 2

Management Algorithm

1. Immediate neuroimaging with MRI brain without contrast 1, 2
2. Neurology consultation if imaging shows stroke or other central pathology 2
3. Continuous cardiac monitoring to document any arrhythmias correlating with symptoms 2
4. If MRI is negative and HINTS suggests peripheral cause, consider vestibular neuritis and treat with vestibular suppressants short-term plus early vestibular rehabilitation 5

Medications to Consider (Only After Excluding Central Causes)

• Meclizine is FDA-approved for vertigo associated with vestibular system diseases 6
• However, avoid vestibular suppressants if BPPV is suspected (which it is not in this case) as they do not address the underlying cause 3
• Limit vestibular suppressant use to 2-3 days maximum as they impede central compensation 3

Common Pitfalls to Avoid

• Do not assume normal neurologic exam excludes stroke - this is the most dangerous assumption in acute vestibular syndrome 1, 2
• Do not order CT instead of MRI when stroke is suspected - CT misses many posterior circulation infarcts 1
• Do not attribute symptoms to anxiety or benign causes without first excluding central pathology in a patient with severe postural instability 1
• Do not perform Dix-Hallpike maneuver in a patient with continuous symptoms lasting days - this is not BPPV 1
• Do not rely on patient's description of "spinning" vs "lightheadedness" - focus on timing (continuous for 3 days) and severity (cannot stand for 3 minutes) 1

Follow-Up After Imaging

• If MRI shows stroke or central lesion: immediate neurology consultation and stroke protocol 2
• If MRI is negative: likely vestibular neuritis, treat with short course of vestibular suppressants followed by vestibular rehabilitation therapy 5
• Reassess within 1 week to document resolution or persistence of symptoms 1