Diagnostic Approach to Vertigo

Classification and Initial Evaluation

• The American Academy of Otolaryngology-Head and Neck Surgery recommends classifying vertigo into four vestibular syndromes based on timing and triggers, followed by targeted physical examination maneuvers and selective imaging 1
• Patients with triggered episodic vertigo (<1 minute) may have BPPV, superior canal dehiscence, or perilymphatic fistula, characterized by brief episodes provoked by specific head position changes 1
• Spontaneous episodic vertigo (minutes to hours) may suggest Ménière's disease, vestibular migraine, or vertebrobasilar insufficiency, with unprovoked episodes lasting 20 minutes to hours 1
• Acute vestibular syndrome (days) may indicate vestibular neuritis, labyrinthitis, or posterior circulation stroke, with continuous severe vertigo lasting days 1
• Chronic vertigo (weeks to months) may suggest anxiety disorder, medication effects, or posterior fossa mass, with persistent symptoms 1

Differentiation of Peripheral and Central Causes

• The American Academy of Otolaryngology-Head and Neck Surgery suggests that peripheral vertigo indicators include auditory symptoms, episodes triggered by specific head movements, and no neurologic symptoms beyond vertigo 1
• Central vertigo red flags include severe postural instability, cranial nerve deficits, and age >50 with vascular risk factors 2, 3, 4
• The HINTS examination (Head Impulse, Nystagmus, Test of Skew) has 92.9% sensitivity and 83.4% specificity for central causes when performed by trained clinicians 4

Imaging Strategy

• The American College of Radiology recommends urgent MRI brain without and with IV contrast for patients with vertigo and positive Romberg test, central warning signs on HINTS examination, severe postural instability, or focal neurologic deficits 4, 5
• MRI head and internal auditory canal without IV contrast is first-line for persistent vertigo with neurologic symptoms, while MRA head and neck can detect vertebrobasilar insufficiency in episodic vertigo 5, 6
• CT head without contrast is inadequate for detecting CNS pathology in isolated vertigo and misses posterior fossa strokes in the acute phase 4, 5

Common Pitfalls

• Assuming a normal neurologic examination excludes stroke, as up to 75-80% of posterior circulation strokes causing vertigo may lack focal neurologic deficits initially 3, 4
• Misdiagnosing central causes as BPPV, as CNS disorders masquerading as BPPV are found in 3% of treatment failures 2
• Relying solely on the patient's description of "spinning" instead of focusing on timing and triggers, which are more diagnostically useful 1
• Performing Dix-Hallpike when Romberg is positive, which indicates central pathology requiring imaging first 4

Diagnostic Approach to Vertigo

Physical Examination Maneuvers

• The American Academy of Otolaryngology-Head and Neck Surgery recommends performing the Dix-Hallpike maneuver to test for posterior canal BPPV, which is the most common type of BPPV, and may need to be repeated at a separate visit to avoid false-negative results 7
• The Dix-Hallpike maneuver is also used to diagnose BPPV, and if the history is compatible with BPPV but the Dix-Hallpike is negative, the Supine Roll Test can be performed to diagnose lateral canal BPPV, which accounts for 10-15% of BPPV cases 7
• The Supine Roll Test is used to diagnose lateral canal BPPV, and the patient should be observed for geotropic (most common) or apogeotropic nystagmus 7

Imaging Strategy

• The American College of Radiology recommends ordering urgent MRI brain without and with IV contrast for patients with persistent vertigo and neurologic symptoms, as it can detect acute brain lesions and reveal central causes of vertigo 8
• MRI head and internal auditory canal is the first-line imaging modality for persistent vertigo with neurologic symptoms, and can detect acute brain lesions in 11% of patients with acute persistent vertigo and no focal neurologic deficits 8
• MRA head and neck can be used to detect vertebrobasilar insufficiency in patients with episodic vertigo that cannot be confidently categorized as peripheral 8
• CT temporal bone without IV contrast can be used to detect structural inner ear pathology in patients with episodic peripheral vertigo and auditory symptoms 8

Laboratory Testing for Vertigo

Introduction to Vertigo Diagnosis

• The American Academy of Otolaryngology-Head and Neck Surgery guidelines do not recommend routine blood tests, such as complete blood count and serum chemistry, as standard practice for diagnosing benign paroxysmal positional vertigo (BPPV), which accounts for 85-95% of vertigo cases, due to the clinical nature of the diagnosis 9, 10

Diagnostic Approach

• The diagnosis of vertigo is fundamentally clinical, based on symptom timing, triggers, and targeted physical examination rather than laboratory values, with audiometry considered when there are auditory symptoms suggesting Ménière's disease or other inner ear pathology 9, 10

Specific Clinical Scenarios

• For suspected Ménière's Disease, no specific labs are required for diagnosis, which is made clinically based on episodic vertigo lasting 20 minutes to 12 hours with fluctuating hearing loss, tinnitus, or ear fullness, but labs may be useful to exclude other conditions when the presentation is atypical 11
• In cases of suspected autoimmune causes, such as progressive fluctuating bilateral hearing loss that may be steroid-responsive, especially with concurrent vision, skin, or joint problems, consider autoimmune panels 11
• For suspected infectious causes, such as Lyme disease or otosyphilis, presenting with vertigo and severe otalgia, fever, or sudden bilateral hearing loss, order appropriate serologic testing 11

Appropriate Use of Laboratory Tests

• Laboratory tests should be reserved for specific clinical scenarios where the history suggests systemic or infectious causes, rather than being ordered routinely 9, 10
• The American Academy of Otolaryngology-Head and Neck Surgery explicitly lists blood tests among diagnostic interventions considered but not recommended as standard practice for BPPV 9, 10

Clinical Evaluation and Imaging Recommendations for Vertigo

Diagnostic Approach

• The evaluation of vertigo should be primarily clinical, using bedside positional maneuvers (Dix‑Hallpike and supine roll) and reserving laboratory or imaging studies only for patients with red‑flag features suggesting central pathology, as recommended by the American Academy of Otolaryngology‑Head and Neck Surgery (AAO‑HNS). 12

Bedside Positional Maneuvers

Dix‑Hallpike (Posterior Canal BPPV)

• Perform the Dix‑Hallpike maneuver bilaterally on every patient presenting with positional vertigo. 13
• A positive test is characterized by torsional up‑beating nystagmus with a latency of 5–20 seconds, a crescendo‑decrescendo pattern lasting less than 60 seconds, fatigability on repeated testing, and accompanying subjective vertigo. 13
• The maneuver demonstrates a sensitivity of approximately 82 % and a specificity of 71 % for posterior‑canal BPPV; a negative result does not exclude the diagnosis and may require repeat testing at a later visit. 13
• If the Dix‑Hallpike is negative, the clinician should proceed to the supine roll test to assess for lateral‑canal BPPV, per AAO‑HNS guidance. 12

Supine Roll Test (Lateral Canal BPPV)

• Conduct the supine roll test when the Dix‑Hallpike is negative or produces horizontal nystagmus, rotating the patient’s head 90° to each side while supine. 14
• Lateral‑canal BPPV accounts for roughly 10–15 % of all BPPV cases and is frequently missed if the supine roll test is omitted. 13
• Look for geotropic nystagmus (fast phase toward the ground) as the most common pattern, or apogeotropic nystagmus (fast phase away from the ground). 13

Imaging Indications

• Routine radiographic imaging or vestibular testing is not indicated for patients who meet BPPV diagnostic criteria with typical nystagmus on Dix‑Hallpike and lack additional concerning symptoms, according to AAO‑HNS recommendations. 15
• CT head has a diagnostic yield of < 1 % for isolated dizziness and frequently misses posterior‑fossa strokes in the acute phase (American College of Radiology, ACR). 14
• MRI provides a diagnostic yield of only 4 % in patients with isolated dizziness without neurologic findings (ACR). 14
• Urgent MRI of the brain with diffusion‑weighted imaging is mandatory in the presence of severe postural instability with falling (ACR). 14
• CT temporal bone without contrast is reserved for conductive hearing loss evaluation (e.g., otosclerosis, ossicular erosion, superior semicircular canal dehiscence) and is not a routine study for vertigo assessment (ACR). 14

Audiometric Testing

• Routine audiometry is not recommended for patients with a confirmed diagnosis of BPPV, per AAO‑HNS guidance. 15

Follow‑up Protocol

• Reassess all patients within 1 month after the initial observation or treatment to verify symptom resolution or to identify persistent BPPV or underlying peripheral/central vestibular disorders, as advised by AAO‑HNS. 12