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

Inpatient Workup for Dizziness

The appropriate inpatient workup for dizziness should be guided by categorizing the patient's symptoms based on timing and triggers, with MRI being the preferred imaging modality when indicated, rather than CT which has low diagnostic yield for most causes of dizziness. 1

Initial Assessment Framework

Step 1: Categorize the Dizziness Pattern

Categorize the patient's dizziness into one of these syndromes based on timing and triggers:

1. Acute Vestibular Syndrome (AVS): Continuous dizziness lasting days to weeks

   • Key features: Nausea, vomiting, gait instability, nystagmus, head-motion intolerance
   • Main concerns: Vestibular neuritis (benign) vs. posterior circulation stroke (serious)

2. Triggered Episodic Vestibular Syndrome (t-EVS): Brief episodes triggered by position changes

   • Key features: Vertigo triggered by specific head movements, lasting <1 minute
   • Main concern: BPPV (benign) vs. central positional vertigo (serious)

3. Spontaneous Episodic Vestibular Syndrome: Recurrent episodes without clear triggers

   • Key features: Episodes lasting minutes to hours
   • Main concerns: Vestibular migraine, Ménière's disease, TIA

4. Chronic Vestibular Syndrome: Persistent dizziness lasting weeks to months

   • Main concerns: Medication side effects, anxiety, posterior fossa mass lesions

Step 2: Focused Physical Examination

• For AVS: Perform HINTS examination (Head-Impulse, Nystagmus, Test of Skew)

  • When performed correctly, HINTS is more sensitive than early MRI for detecting stroke (100% vs 46%) 1
  • Normal HINTS exam suggesting peripheral cause: positive head impulse, direction-fixed horizontal nystagmus, no skew deviation

• For t-EVS: Perform Dix-Hallpike maneuver and supine roll test

  • Observe for characteristic nystagmus pattern of BPPV
  • Atypical nystagmus may suggest central pathology

• For all patients: Complete neurological examination to identify focal deficits

Diagnostic Testing Algorithm

1. Laboratory Testing

• Basic metabolic panel: Assess for electrolyte abnormalities and renal function
• Blood glucose: Recommended for all dizzy patients 2
• Complete blood count: Only if indicated by history (suspected anemia, infection)
• Thyroid function tests: If symptoms suggest thyroid dysfunction
• Drug levels: If on medications with vestibulotoxic potential

2. Imaging Studies

For AVS with normal neurologic exam and HINTS exam suggesting peripheral cause:

• Imaging generally not required 1

For AVS with any of these red flags:

• Abnormal HINTS exam suggesting central cause
• Neurologic deficits
• Vascular risk factors
• Age >45 years with first episode
• Recommended imaging: MRI brain with DWI (not CT) 1
  • CT has very low yield (<1%) for detecting relevant pathology in isolated dizziness 1
  • MRI with DWI is significantly more sensitive for early posterior circulation infarcts

For t-EVS with typical BPPV pattern on Dix-Hallpike:

• Imaging not indicated 1

For t-EVS with atypical features:

• Recommended imaging: MRI brain without and with contrast 1
  • Acute brain lesions reported in 11% of patients undergoing MRI for central positional vertigo 1

For chronic or recurrent dizziness with hearing loss:

• Recommended imaging: MRI head and internal auditory canal to evaluate for acoustic neuroma

Management Considerations

• BPPV: Perform canalith repositioning procedures (Epley maneuver) rather than medication
• Vestibular neuritis: Consider short course of corticosteroids
• Stroke: Urgent neurological consultation and stroke protocol
• Medication-induced dizziness: Review and adjust medication regimen

Common Pitfalls to Avoid

1. Relying solely on symptom quality descriptions (vertigo, lightheadedness) rather than timing and triggers for diagnosis 3
2. Overuse of CT imaging which has very low yield for isolated dizziness 1
3. Failure to perform the HINTS examination in patients with AVS, which is more sensitive than MRI for stroke detection when performed correctly 1
4. Premature diagnosis of BPPV without performing Dix-Hallpike testing
5. Missing posterior circulation strokes which can present with isolated dizziness without other neurological symptoms in 75-80% of cases 1

Remember that while most cases of dizziness are benign peripheral vestibular disorders (43% in one study) 2, the most concerning cause to exclude is posterior circulation stroke, which can present with isolated dizziness and normal neurological examination in many cases.