Initial Approach to Dizziness
Categorize by Timing and Triggers, Not Symptom Quality
The initial approach to dizziness should immediately classify patients into one of three vestibular syndromes based on timing and triggers—Acute Vestibular Syndrome, Triggered Episodic Vestibular Syndrome, or Spontaneous Episodic Vestibular Syndrome—rather than relying on vague patient descriptions of "spinning" versus "lightheadedness," as this framework directly guides targeted physical examination and distinguishes benign peripheral vestibular disorders from dangerous central causes like stroke. 1, 2
The Three Vestibular Syndromes
1. Acute Vestibular Syndrome (AVS)
- Duration: Continuous severe vertigo lasting days to weeks 1, 2
- Key features: Constant symptoms with acute onset, nausea, vomiting, gait instability 1
- Differential: Vestibular neuritis (peripheral) vs. posterior circulation stroke (central) 1, 3
- Critical examination: Perform HINTS examination (Head Impulse, Nystagmus, Test of Skew) 1, 2
2. Triggered Episodic Vestibular Syndrome
- Duration: Brief episodes lasting seconds to <1 minute 1, 2
- Key features: Provoked by specific head position changes 1, 4
- Differential: BPPV (most common), superior canal dehiscence, perilymphatic fistula 4
- Critical examination: Perform Dix-Hallpike maneuver and supine roll test 1, 2
3. Spontaneous Episodic Vestibular Syndrome
- Duration: Episodes lasting minutes to hours without positional triggers 1, 2
- Key features: Unprovoked episodes 4
- Differential: Vestibular migraine, Ménière's disease, vertebrobasilar insufficiency, TIA 1, 4
- Critical history: Associated symptoms guide diagnosis 1
Essential History Components
- Onset and duration: Seconds (BPPV), minutes to hours (vestibular migraine, Ménière's), days to weeks (vestibular neuritis, stroke) 1, 2
- Triggers: Head position changes (BPPV), pressure changes (superior canal dehiscence), none (vestibular neuritis, stroke) 1, 2
- Associated symptoms: Auditory symptoms suggest peripheral causes; neurologic symptoms suggest central causes 1, 4
- Medication review: Essential, as medications are a leading cause of chronic vestibular syndrome, particularly antihypertensives, sedatives, anticonvulsants, psychotropic drugs 2
- Vascular risk factors: Age >50 with hypertension, diabetes, smoking increases stroke risk 4
Targeted Physical Examination
For All Patients
- Complete neurologic examination: Cranial nerves, cerebellar testing (finger-to-nose, heel-to-shin), gait assessment 1, 2
- Romberg test: If positive, indicates central pathology requiring imaging first—do not perform Dix-Hallpike 4
For Triggered Episodic Symptoms
- Dix-Hallpike maneuver: Gold standard for posterior canal BPPV (85-95% of BPPV cases) 2, 4
- Supine roll test: If Dix-Hallpike negative but history compatible, tests for lateral canal BPPV (10-15% of cases) 2, 4
For Acute Vestibular Syndrome
- HINTS examination (only if trained): 1, 2
- Head Impulse: Abnormal (corrective saccade) = peripheral; normal = central
- Nystagmus: Unidirectional horizontal = peripheral; direction-changing or vertical = central
- Test of Skew: Vertical misalignment = central
Critical Red Flags Requiring Urgent Evaluation
- Focal neurological deficits (even subtle) 2, 4
- Severe postural instability or inability to stand/walk 2, 4
- New severe headache accompanying dizziness 2, 4
- Sudden hearing loss 2, 4
- Downbeating nystagmus or other central nystagmus patterns 2, 4
- Failure to respond to appropriate vestibular treatments 2
Imaging Decisions
No imaging indicated for: 1, 2
- Brief episodic vertigo with typical BPPV features and positive Dix-Hallpike
- Acute persistent vertigo with normal neurologic exam and HINTS consistent with peripheral vertigo by trained examiner
MRI brain without contrast indicated for: 1, 2, 4
- Abnormal neurologic examination
- HINTS examination suggesting central cause
- High vascular risk patients with acute vestibular syndrome
- Unilateral or pulsatile tinnitus
- Asymmetric hearing loss
- Progressive symptoms suggesting mass lesion
CT head has very low yield (<1% diagnostic yield for isolated dizziness) and should not be used instead of MRI when stroke is suspected 1, 2, 4
Immediate Management Based on Diagnosis
BPPV
- Canalith repositioning procedures (Epley maneuver) as first-line treatment 1, 2
- Success rates: 80% after 1-3 treatments, 90-98% after repeat maneuvers 2
- No imaging or medication needed for typical cases 2
- Meclizine may be used for symptomatic relief of vertigo (25-100 mg daily in divided doses) but does not treat underlying BPPV 5
Vestibular Neuritis
Vestibular Migraine
Ménière's Disease
Posterior Circulation Stroke
- Activate stroke protocol immediately and urgent neurology consultation 1
Common Pitfalls to Avoid
- Assuming normal neurologic exam excludes stroke: 75-80% of patients with acute vestibular syndrome from posterior circulation infarct have no focal neurologic deficits 2, 4
- Relying on patient's description of "spinning" vs "lightheadedness" instead of focusing on timing and triggers 1, 2
- Performing Dix-Hallpike when Romberg is positive: This indicates central pathology requiring imaging first 4
- Ordering routine imaging for isolated dizziness: Low yield, most findings are incidental 2
- Using CT instead of MRI when stroke is suspected: CT misses many posterior circulation infarcts 1, 2
- Misdiagnosing central causes as BPPV: CNS disorders masquerading as BPPV found in 3% of treatment failures 4