Benign Paroxysmal Positional Vertigo

Definition & Epidemiology - What's Shakin'?

• BPPV: Sudden, brief (<1 min) rotational vertigo, triggered by specific head position changes.
• Pathophysiology: Otoconia (canaliths) dislodged from the utricle, migrating into semicircular canals.
• Epidemiology:
  • Most common cause of recurrent vertigo; lifetime prevalence ~2.4%.
  • Incidence ↑ with age (peak 50-60 yrs); F:M ratio ~2:1.

  ⭐ Posterior semicircular canal is the most frequently affected (85-95% of cases).

Pathophysiology - Canalith Chaos

• Otoconia (calcium carbonate crystals) dislodged from utricular macula.
• Become free-floating debris (canaliths) within semicircular canal (SCC) endolymph - Canalithiasis theory.
• Posterior SCC most commonly affected (~85-95%); Lateral SCC (5-15%); Anterior SCC (rare).
• Head movements → gravity-dependent canalith movement → abnormal endolymphatic flow.
• This inappropriately deflects the cupula → transient vertigo & nystagmus.
• ⭐ > Cupulolithiasis: a rarer mechanism where otoconia adhere to the cupula, leading to more persistent vertigo.

Clinical Features - Dizzy Spells

• Sudden, brief (seconds to <1 min) rotatory vertigo.
• Triggered by head position changes:
  • Rolling in bed, lying down.
  • Looking up, bending over.
• Nausea, vomiting common during spells.
• No auditory or neurological symptoms (e.g., hearing loss, weakness).
• Latency (1-5 sec) & fatigability with provocative maneuvers (e.g., Dix-Hallpike).

⭐ BPPV spells are intense but brief, often <30 seconds, and are characteristically fatigable.

Diagnosis - Head Games

• Dix-Hallpike Maneuver: Key for posterior canal BPPV (commonest).
  • Positive: Latency (~1-30s), torsional upbeating nystagmus, fatigable, reverses on sitting.
• Supine Roll Test (Pagnini-McClure): For lateral canal BPPV.
  • Geotropic (to ground): Canalithiasis (affected side down).
  • Apogeotropic (to ceiling): Cupulolithiasis (affected side up).
• Anterior Canal BPPV: Rare; downbeating nystagmus (Dix-Hallpike/head hanging).
• Nystagmus: Purely vertical/non-fatigable suggests central cause. 📌

⭐ BPPV nystagmus: Latency (~1-30s), duration <60s, fatigable, and reverses direction upon returning to upright position.

Management - Canalith Repositioning

• Goal: Reposition free-floating otoconia from affected semicircular canal (SCC) back to the utricle.
• Posterior Canal (PC-BPPV):
  • Epley maneuver (gold standard).
  • Semont maneuver (alternative).
• Horizontal Canal (HC-BPPV):
  • Lempert (BBQ) roll (360° turn).
  • Gufoni maneuver (for geotropic/apogeotropic variants).
• Anterior Canal (AC-BPPV):
  • Deep head-hanging maneuver (Yacovino maneuver).
  • Reverse Epley.
• Post-maneuver instructions: Maintain upright posture for several hours; avoid sleeping on affected side for a few days.

⭐ Epley maneuver for PC-BPPV boasts success rates of ~80-95% with one to two maneuvers, making it highly effective.

Differential Dx & Complications - Not Just BPPV

• DDx (Red flags?):
  • Central Positional Vertigo (CPV): Vertical/non-fatiguing nystagmus, neurological signs.
  • Vestibular Migraine: Migraine Hx, aura.
  • Meniere's Disease (atypical): Hearing loss, tinnitus.
  • Vertebrobasilar Insufficiency (VBI): Vascular risks, neuro deficits.
• Complications:
  • Falls (esp. elderly).
  • Recurrence: Common (15-20%/year).
  • Canal conversion (e.g., posterior to lateral canal).

⭐ Central Positional Vertigo (CPV) is a key differential, often presenting with nystagmus that is purely vertical, non-fatiguing, and may change direction with gaze, unlike typical BPPV's torsional-upbeating nystagmus.

High‑Yield Points - ⚡ Biggest Takeaways

• BPPV is the most common cause of peripheral vertigo.
• Caused by otoconia (canaliths) in semicircular canals, typically the posterior canal (PSC).
• Characterized by brief vertigo episodes (<1 minute) with specific head position changes.
• Dix-Hallpike maneuver diagnoses PSC BPPV, eliciting latency and geotropic rotatory nystagmus.
• Treatment: Canalith Repositioning Maneuvers (CRM), like Epley maneuver for PSC.
• BPPV nystagmus is transient, fatigable, with torsional component towards the affected ear.