What is the best approach to diagnose and manage acute dizziness?

Best Approach to Diagnosing Acute Dizziness

The best approach to diagnosing acute dizziness is to categorize it based on timing and triggers rather than relying on the patient's subjective description, as this classification system leads to more accurate diagnosis and appropriate management. 1, 2

Initial Classification of Dizziness

• Categorize dizziness into one of four vestibular syndromes based on timing and triggers 3, 1:
  • Acute Vestibular Syndrome (AVS): acute persistent continuous dizziness lasting days to weeks with nausea, vomiting, and head motion intolerance 3
  • Triggered Episodic Vestibular Syndrome: episodic dizziness triggered by specific actions (usually position changes), lasting <1 minute 3
  • Spontaneous Episodic Vestibular Syndrome: episodic dizziness without triggers, lasting minutes to hours 3
  • Chronic Vestibular Syndrome: dizziness lasting weeks to months or longer 3

Focused History

• Determine exact timing of symptoms (onset, duration, frequency) 1, 2
• Identify specific triggers (positional changes, pressure changes, etc.) 1
• Document associated symptoms 4:
  • Hearing loss, tinnitus, or aural fullness (suggesting Ménière's disease)
  • Headache, photophobia (suggesting vestibular migraine)
  • Neurological symptoms (diplopia, dysarthria, numbness - suggesting central causes)

Physical Examination

• Perform a complete otologic examination 1
• Observe for spontaneous nystagmus 2
• For suspected BPPV, perform the Dix-Hallpike maneuver and supine roll test 1, 2
• For Acute Vestibular Syndrome, perform the HINTS examination (Head Impulse, Nystagmus, Test of Skew) 3, 5:
  • Normal HINTS exam consistent with peripheral vertigo has 100% sensitivity for ruling out stroke 3
  • Abnormal HINTS exam is more sensitive than early MRI for detecting stroke (100% vs 46%) 3

Diagnostic Testing

• Laboratory testing is generally not required in the initial workup unless specific medical conditions are suspected 1
• Imaging studies are not routinely indicated for most cases of dizziness 3, 2
• MRI brain with diffusion-weighted imaging is preferred over CT when neuroimaging is indicated 3, 2
• Consider MRI when there are:
  • Focal neurological deficits 3
  • Atypical presentation or red flags 1
  • HINTS examination suggesting central cause 3

Common Diagnoses by Category

• Acute Vestibular Syndrome 3:

  • Vestibular neuritis
  • Labyrinthitis
  • Posterior circulation stroke
  • Demyelinating diseases

• Triggered Episodic Vestibular Syndrome 3:

  • Benign paroxysmal positional vertigo (BPPV)
  • Postural hypotension
  • Superior canal dehiscence syndrome

• Spontaneous Episodic Vestibular Syndrome 3:

  • Vestibular migraine
  • Ménière's disease
  • Posterior circulation TIA

Management Considerations

• For BPPV: canalith repositioning procedures (e.g., Epley maneuver) 4
• For vestibular neuritis: steroids 6
• For Ménière's disease: salt restriction, diuretics, intratympanic treatments 4
• For vertigo symptoms: meclizine is indicated for vertigo associated with diseases affecting the vestibular system 7

Red Flags and Common Pitfalls

• Red flags requiring urgent evaluation 1, 4:

  • Focal neurological deficits
  • Sudden hearing loss
  • Inability to stand or walk
  • Downbeating nystagmus or other central nystagmus patterns

• Common pitfalls to avoid 1, 2:

  • Relying solely on the patient's description without clarifying the exact nature of symptoms
  • Failing to perform appropriate positional testing
  • Overreliance on CT imaging
  • Assuming absence of focal neurologic deficits rules out central causes
  • Missing stroke in patients with isolated dizziness (4% of isolated dizziness cases are due to stroke) 2