What is the diagnosis for someone experiencing dizziness?

Differential Diagnosis of Dizziness

Dizziness encompasses a broad differential diagnosis that must be systematically categorized by timing and triggers—not by the patient's subjective description—into four distinct vestibular syndromes: Acute Vestibular Syndrome (days to weeks of continuous symptoms), Triggered Episodic Vestibular Syndrome (seconds to minutes, positionally triggered), Spontaneous Episodic Vestibular Syndrome (minutes to hours, unprovoked), and Chronic Vestibular Syndrome (weeks to months or longer). 1, 2

Primary Diagnostic Categories by Timing and Triggers

Triggered Episodic Vestibular Syndrome (Brief, Positional)

• Benign Paroxysmal Positional Vertigo (BPPV): Most common cause of peripheral vertigo, characterized by vertigo lasting less than 1 minute (typically seconds) triggered by specific head position changes 1
• Perilymphatic fistula: Triggered by pressure changes or Valsalva maneuvers 1
• Superior canal dehiscence syndrome: Triggered by loud sounds or pressure changes 1
• Central paroxysmal positional vertigo: Rare central mimic of BPPV requiring neuroimaging 1

Acute Vestibular Syndrome (Continuous, Days to Weeks)

• Vestibular neuritis: Viral infection causing severe rotational vertigo lasting 12-36 hours with decreasing disequilibrium over 4-5 days, without hearing loss, tinnitus, or aural fullness 1
• Labyrinthitis: Sudden severe vertigo with profound hearing loss lasting >24 hours 1
• Posterior circulation stroke: Critical diagnosis requiring urgent identification; 75-80% have no focal neurologic deficits on standard examination 3
• Demyelinating diseases: Multiple sclerosis or related conditions 1
• Posttraumatic vertigo: Following head trauma 1

Spontaneous Episodic Vestibular Syndrome (Minutes to Hours, Unprovoked)

• Vestibular migraine: Episodes lasting minutes to >24 hours with photophobia, phonophobia, and often a migraine history; hearing loss less likely than Ménière's disease 1, 3
• Ménière's disease: Spontaneous vertigo attacks lasting 20 minutes to 12 hours with fluctuating hearing loss, tinnitus, and aural fullness occurring before, during, or after attacks 1
• Posterior circulation transient ischemic attack: High-risk patients with vascular risk factors; approximately 4% of isolated dizziness cases are due to stroke 2, 3
• Medication side effects: Antihypertensives, sedatives, anticonvulsants, psychotropic drugs 2, 3

Chronic Vestibular Syndrome (Weeks to Months or Longer)

• Anxiety or panic disorder: Common cause requiring psychiatric screening 2, 3
• Medication side effects: Leading reversible cause; review antihypertensives, sedatives, anticonvulsants, psychotropic drugs 2, 3
• Posttraumatic vertigo: Persistent symptoms following head trauma with vertigo, disequilibrium, tinnitus, headache 2, 3
• Posterior fossa mass lesions: Vestibular schwannoma, cerebellar tumors; typically present with chronic imbalance and asymmetric hearing loss rather than episodic vertigo 1, 2
• Cervicogenic vertigo: Variable presentation 1

Critical Distinguishing Features

Otologic Symptoms as Diagnostic Clues

• Hearing loss, tinnitus, or aural fullness: Strongly suggests Ménière's disease, labyrinthitis, or vestibular schwannoma 1, 2
• Unilateral or pulsatile tinnitus: Warrants MRI with contrast to exclude vestibular schwannoma or vascular malformation 2, 3
• No otologic symptoms: Suggests vestibular neuritis, BPPV, vestibular migraine, or central causes 1

Neurologic Red Flags Requiring Urgent Evaluation

• Focal neurological deficits: Dysarthria, dysphagia, dysphonia, diplopia, numbness, weakness 2, 3
• Sudden hearing loss: Requires urgent evaluation 3
• Inability to stand or walk: Suggests cerebellar or brainstem pathology 3
• New severe headache: Mandates immediate imaging and neurologic consultation 3
• Downbeating nystagmus or other central nystagmus patterns: Indicates central pathology 3

Common Diagnostic Pitfalls to Avoid

• Do not rely on patient descriptions of "spinning" versus "lightheadedness": Patients have difficulty accurately describing symptom quality; focus instead on timing, triggers, and duration 1, 2, 4
• Do not assume normal neurologic examination excludes stroke: 75-80% of patients with posterior circulation infarct have no focal neurologic deficits on standard examination 3
• Do not confuse presyncope with vestibular disorders: Loss of consciousness is never a symptom of Ménière's disease or other vestibular disorders 1, 4
• Do not order routine imaging for typical BPPV: Imaging is unnecessary for BPPV with positive Dix-Hallpike testing and no atypical features 2, 3
• Do not use CT instead of MRI when stroke is suspected: CT has only 20-40% sensitivity for posterior circulation infarcts and misses most causative pathology 3

Essential Bedside Diagnostic Maneuvers

• Dix-Hallpike maneuver: Gold standard for BPPV diagnosis; positive test shows 5-20 second latency, torsional upbeating nystagmus toward affected ear, symptoms resolving within 60 seconds 2, 3
• HINTS examination (Head Impulse, Nystagmus, Test of Skew): 100% sensitivity for detecting stroke in acute vestibular syndrome when performed by trained practitioners (versus 46% for early MRI) 2, 3
• Orthostatic blood pressure measurement: Evaluates for postural hypotension 1, 5
• Assessment for spontaneous nystagmus: Should be performed in all dizzy patients 2