What is the differential diagnosis for vertigo that began after a head injury from a fall?

Differential Diagnosis for Post-Traumatic Vertigo

The differential diagnosis for vertigo after head trauma includes benign paroxysmal positional vertigo (BPPV) as the most common cause, followed by labyrinthine concussion, perilymphatic fistula, temporal bone fracture with otic capsule involvement, cervicogenic vertigo, otolithic dysfunction, delayed endolymphatic hydrops, and central causes including posterior fossa hemorrhage or infarction.

Primary Post-Traumatic Vestibular Disorders

Peripheral Causes (Most Common)

Benign Paroxysmal Positional Vertigo (BPPV)

• Occurs in approximately 18-22% of patients with mild to moderate head trauma 1, 2
• Posterior semicircular canal involvement is most frequent (68.2%), followed by horizontal canal (27.3%) 2
• Post-traumatic BPPV differs from idiopathic BPPV: more frequently involves multiple canals, requires repeated repositioning maneuvers, and has variable recurrence patterns 1
• Diagnosis confirmed by Dix-Hallpike maneuver (posterior canal) or supine roll test (horizontal canal)
• Critical pitfall: Atypical or absent nystagmus on Dix-Hallpike testing should raise suspicion for central causes mimicking BPPV 3

Labyrinthine Concussion

• Direct mechanical injury to the inner ear structures without temporal bone fracture 4
• Presents with acute vertigo, nausea, and possible hearing loss
• Can occur even without radiological evidence of fracture 5

Perilymphatic Fistula

• Rupture of round or oval window membranes 4, 6
• Presents with vertigo triggered by Valsalva maneuvers, loud sounds, or pressure changes
• May have associated hearing loss
• Requires high index of suspicion as imaging is often normal

Temporal Bone Fracture

• Classification: "otic capsule sparing" (OCS) versus "otic capsule violating" (OCV) 5
• OCV fractures have worse prognosis for vestibular and auditory function
• Look for indirect signs: hemotympanum, CSF otorrhea, facial nerve palsy, Battle's sign 5
• Imaging is often insufficient in emergency settings; consequences frequently underestimated 5

Otolithic Dysfunction

• Disruption of utricle or saccule function 4, 1
• May present with imbalance and spatial disorientation rather than classic spinning vertigo
• Often coexists with BPPV

Cervicogenic Vertigo

• Results from whiplash-type injury to cervical structures 4, 6
• Associated with neck pain and restricted cervical range of motion
• Diagnosis of exclusion after ruling out other vestibular pathology

Secondary/Delayed Disorders

Delayed Endolymphatic Hydrops

• Can develop weeks to months after initial trauma 4
• Presents with episodic vertigo similar to Menière's disease
• May have fluctuating hearing loss and tinnitus

Post-Concussive Dizziness/Persistent Postural-Perceptual Dizziness (PPPD)

• Functional vestibular disorder that develops when symptoms persist beyond expected recovery 5, 7
• Characterized by chronic non-vertiginous dizziness, unsteadiness, and hypersensitivity to motion
• Important: Consider PPPD if vertigo worsens over time rather than improving 5

Central Causes (Ominous)

Central Positional Vertigo (CPPV)

• Mimics BPPV clinically but has central pathology 3
• Causes include: posterior fossa hemorrhage, cerebellar infarction, mass lesions, demyelinating disease
• Red flags: Atypical nystagmus patterns, negative Dix-Hallpike with persistent symptoms, neurological deficits, severe headache
• In one study, 11% of patients with episodic positional vertigo and atypical Dix-Hallpike had acute brain lesions on MRI 3

Brainstem/Cerebellar Injury

• Direct trauma to posterior fossa structures 6
• Associated with other neurological signs: ataxia, dysmetria, cranial nerve deficits

Imaging Considerations

When to Image 3, 8:

• Atypical features: lack of nystagmus on Dix-Hallpike or lack of response to Epley maneuver
• Neurological deficits present
• Severe or progressive symptoms
• Elderly patients or those with vascular risk factors
• Short-term symptom recurrence despite treatment

Imaging Modality:

• MRI brain is superior to CT for detecting central causes (11% vs 6% detection rate for acute lesions) 3
• CT head without contrast is appropriate for acute trauma evaluation but has inferior soft tissue contrast 8
• Temporal bone CT may be needed if fracture suspected, but often insufficient for detecting otic capsule injury 5

Clinical Approach Algorithm

1. Immediate assessment: Perform Dix-Hallpike and supine roll tests

   • Typical BPPV pattern with appropriate nystagmus → Proceed with repositioning maneuvers
   • Atypical or absent nystagmus → Consider imaging for central causes 3

2. Assess for temporal bone fracture indicators: hemotympanum, CSF leak, facial palsy, Battle's sign 5

   • If present → CT temporal bone and neurosurgical consultation

3. Evaluate for perilymphatic fistula: Valsalva-induced symptoms, hearing loss, pressure sensitivity 4

   • If suspected → ENT referral for possible surgical exploration

4. Check for central red flags: severe headache, ataxia, diplopia, dysarthria, focal weakness

   • If present → Urgent MRI brain 3

5. If symptoms persist beyond 1-3 months despite appropriate treatment: Consider delayed hydrops, PPPD, or missed structural pathology 5, 4

Common Pitfall: Assuming all post-traumatic positional vertigo is benign BPPV without performing proper positional testing and assessing for atypical features that suggest central pathology 3.