What is the appropriate inpatient workup for a patient presenting with dizziness?

Inpatient Dizziness Workup: A Structured Clinical Approach

The workup for hospitalized patients with dizziness should be driven by clinical phenotyping using timing and triggers, not routine imaging—with bedside examination determining whether imaging is needed and what type to obtain. 1

Initial Clinical Stratification

The first critical step is categorizing the dizziness presentation into one of several clinical syndromes, as this determines the entire diagnostic pathway:

1. Brief Episodic Vertigo (Triggered by Head Movement)

• Perform Dix-Hallpike maneuver immediately at bedside
• If typical nystagmus pattern consistent with BPPV: No imaging required 1
• If atypical or negative Dix-Hallpike with persistent symptoms (central paroxysmal positional vertigo): MRI brain without contrast is indicated to exclude mass, stroke, or demyelination 1

2. Acute Vestibular Syndrome (AVS)

This is persistent vertigo with nausea/vomiting, gait instability, nystagmus, and head-motion intolerance:

Without Focal Neurologic Deficits:

• HINTS examination (Head Impulse, Nystagmus, Test of Skew) is more sensitive than early MRI for posterior circulation stroke (100% vs 46% sensitivity) 1
• If HINTS performed by trained examiner and consistent with peripheral vertigo: No imaging needed 1
• If HINTS unavailable or concerning for central cause: MRI brain with DWI (diffusion-weighted imaging) is the study of choice 1
• CT head has very low yield (<1%) and should be avoided unless MRI contraindicated 1

Critical pitfall: 11% of patients with acute persistent vertigo and no focal neurologic signs have acute infarct on imaging, and 75-80% of AVS patients with posterior circulation stroke lack focal neurologic deficits 1. The absence of neurologic findings does NOT exclude stroke.

With Focal Neurologic Deficits:

• MRI brain with DWI immediately—diagnostic yield increases to 12% with neurologic symptoms present 1
• Consider MRA or CTA if vascular dissection or vertebrobasilar insufficiency suspected 1

3. Chronic Recurrent Vertigo

With Hearing Loss or Tinnitus:

• Suspect Menière disease 1
• MRI brain and internal auditory canals (IAC) with contrast to exclude vestibular schwannoma or other mass

With Brainstem Neurologic Deficits:

• Suspect vertebrobasilar insufficiency 1
• MRI brain with MRA or CTA of neck vessels
• Conventional angiography reserved for specific cases where positional insufficiency needs dynamic evaluation 1

4. Chronic Disequilibrium with Cerebellar Ataxia

• MRI brain without contrast to evaluate for cerebellar degeneration, mass, or structural lesions 1
• Consider genetic testing for spinocerebellar ataxia if family history present

5. Chronic Disequilibrium with Sensory/Proprioceptive Ataxia

• MRI cervical and thoracic spine without contrast to evaluate dorsal columns 1
• Consider B12, copper levels, syphilis testing for metabolic/infectious causes

6. Nonspecific Dizziness (No Vertigo, Ataxia, or Neurologic Deficits)

• Imaging has extremely low yield: CT <1%, MRI DWI ~4% 1
• Do not routinely image these patients 1
• Focus on orthostatic vital signs, cardiac evaluation, medication review
• Consider autonomic dysfunction, dehydration, vasovagal, anxiety 1

Key Diagnostic Principles

Imaging yield is directly proportional to clinical risk stratification:

• Overall CT positivity in ED dizziness: ~2% 1
• Isolated dizziness without neurologic signs: <1% CT yield 1
• AVS with neurologic signs: 12% MRI yield 1
• Cerebrovascular disease prevalence in AVS: 25% (up to 75% in high vascular risk patients) 1

When imaging IS indicated, MRI with DWI is superior to CT for posterior fossa pathology, which is the most common serious cause of central dizziness 1, 2. CT misses small brainstem and cerebellar infarcts.

Bedside Examination Essentials

Every hospitalized dizzy patient requires:

• Orthostatic vital signs (standing BP at 1 and 3 minutes)
• Dix-Hallpike maneuver if any positional component
• HINTS examination if AVS present (requires training for accuracy) 1, 3
• Gait assessment for ataxia
• Cranial nerve examination focusing on ocular motility, nystagmus, skew deviation
• Romberg test for sensory ataxia

Common Pitfalls to Avoid

1. Over-reliance on CT imaging: CT has poor sensitivity for posterior fossa stroke and most causes of dizziness 1, 2
2. Assuming normal neurologic exam excludes stroke: Up to two-thirds of posterior circulation strokes present without focal findings 1
3. Performing HINTS incorrectly: Sensitivity drops significantly when performed by non-experts 1
4. Imaging everyone with dizziness: This is costly and low-yield without proper clinical phenotyping 1, 4, 2
5. Missing vertebral artery dissection: Consider in younger patients with neck pain and vertigo—needs vascular imaging 1

Laboratory Testing

Not routinely indicated unless specific clinical suspicion:

• CBC, BMP if dehydration/electrolyte abnormality suspected
• Cardiac enzymes if syncope component
• B12, copper, RPR if sensory ataxia present
• Thyroid function if chronic symptoms

The most cost-effective approach is clinical phenotyping first, selective imaging second, with MRI (not CT) when central pathology is suspected. 1