What is the initial workup for a patient presenting with dizziness?

Initial Workup for Dizziness

The initial workup for dizziness should focus on categorizing the presentation by timing and triggers into one of four vestibular syndromes—Acute Vestibular Syndrome, Triggered Episodic Vestibular Syndrome, Spontaneous Episodic Vestibular Syndrome, or Chronic Vestibular Syndrome—rather than relying on the patient's subjective description of symptoms, as this approach guides diagnostic testing and management more effectively. 1

History: Focus on Timing and Triggers

The most critical elements in the history are duration, onset, and specific triggers rather than vague descriptions like "spinning" versus "lightheadedness" 1, 2:

• Triggered episodic vertigo (seconds to minutes): Head movement-triggered episodes suggest Benign Paroxysmal Positional Vertigo (BPPV) 2, 3
• Acute persistent vertigo (days to weeks): Constant symptoms lasting days to weeks define Acute Vestibular Syndrome, which carries the highest stroke risk and requires differentiation between vestibular neuritis and posterior circulation stroke 4, 2
• Spontaneous episodic vertigo: Episodes without clear triggers may indicate vestibular migraine (especially with headache, photophobia, phonophobia) or Ménière's disease 2, 3
• Chronic vestibular syndrome: Persistent symptoms lasting months require evaluation for central pathology or persistent peripheral dysfunction 2

Associated symptoms provide critical diagnostic clues 1:

• Unilateral hearing loss or tinnitus suggests Ménière's disease 1, 3
• Sudden unilateral hearing loss with vertigo raises concern for labyrinthitis or anterior inferior cerebellar artery stroke 4
• Neurological symptoms (headache, diplopia, dysarthria, numbness, weakness) indicate central causes 1, 4

Physical Examination: Bedside Testing is Key

Observe for spontaneous nystagmus in all patients 1:

• Downbeating nystagmus or other central patterns indicate brainstem or cerebellar pathology 4, 2
• The pattern and direction of nystagmus help distinguish peripheral from central causes 3, 5

For triggered episodic vertigo, perform the Dix-Hallpike maneuver and supine roll test to assess for posterior and horizontal canal BPPV 1, 2:

• These bedside tests provide more diagnostic value than imaging in most cases 4
• Atypical responses increase risk of central pathology 4

For acute persistent vertigo, the HINTS examination (Head Impulse, Nystagmus, Test of Skew) is critical 2, 3:

• When performed by trained examiners, HINTS has 100% sensitivity for stroke, superior to early MRI (46% sensitivity) 4, 2
• Normal head impulse test in a patient with acute vertigo and nystagmus suggests central cause 4
• However, when performed by non-experts, results are less reliable 2

Complete the examination with 3, 6:

• Orthostatic blood pressure measurement 3, 6
• Full cardiac and neurologic examination 3, 6
• Thorough otologic examination 2

Imaging: Selective, Not Routine

Imaging is NOT routinely indicated for most cases of dizziness 1, 4:

• The diagnostic yield is extremely low for isolated dizziness with typical peripheral features, and most findings are incidental 4, 2
• Overuse of imaging in patients with clear peripheral causes should be avoided 1

MRI brain with diffusion-weighted imaging is indicated when 1, 2:

• Abnormal neurologic examination is present 2
• HINTS examination suggests central cause 1, 2
• High vascular risk patients present with acute vestibular syndrome 4, 2
• Focal neurological deficits are present 4
• Unilateral or pulsatile tinnitus is present (to exclude cerebellopontine angle tumors or vascular malformations) 4
• New severe headache accompanies dizziness 4
• Inability to stand or walk independently 4

CT head has limited utility 4, 2:

• CT misses many posterior circulation infarcts with sensitivity of only 20-40% for causative pathology in dizziness 4
• May be appropriate in acute settings before MRI when stroke is suspected, but should not replace MRI 2
• CT temporal bone may be used for suspected structural abnormalities of the ear 1

Laboratory Testing

Laboratory testing is usually not required or helpful 3, 6:

• Consider audiologic examination for patients with unilateral tinnitus, persistent symptoms, or associated hearing difficulties 2
• Other labs should be guided by specific clinical suspicion based on history and examination 6

Critical Red Flags Requiring Urgent Evaluation

A critical pitfall is that 75-80% of patients with acute vestibular syndrome from posterior circulation infarction have no focal neurologic deficits on standard examination 4:

• Do not assume a normal neurologic exam excludes stroke 2
• This is why the HINTS examination is so valuable in acute vestibular syndrome 4, 2

Red flags mandating immediate imaging and neurologic consultation 4, 2:

• Focal neurological deficits (diplopia, dysarthria, facial numbness, limb weakness, sensory changes) 4
• Inability to stand or walk independently 4
• New severe headache 4
• Sudden unilateral hearing loss with vertigo 4
• Downbeating or other central nystagmus patterns 4
• Abnormal HINTS examination in acute vestibular syndrome 4
• Failure to respond to appropriate treatment after adequate trials 4

Loss of consciousness is never a symptom of peripheral vestibular disorders and suggests cardiac, neurologic, or systemic causes 4

Common Pitfalls to Avoid

• Do not rely on patient descriptions of "spinning" versus "lightheadedness"—patients have difficulty describing symptom quality but can more consistently identify timing and triggers 4, 3
• Do not skip bedside testing—the Dix-Hallpike maneuver and HINTS examination provide more diagnostic value than imaging in most cases 4
• Do not use CT instead of MRI when stroke is suspected—CT misses many posterior circulation infarcts 4, 2
• Do not miss the 4% of isolated dizziness cases that are due to stroke 1
• Elderly patients may not manifest classic "spinning" vertigo even with serious pathology, instead describing vague dizziness 4