About
- Free floating particles in semicircular canals = Canalithiasis
- Usually small particles of calcium carbonate from the utricle
- Seen in those age 50-70 and the older population
Aetiology
- Free floating endolymph particles in the posterior semicircular canal
- They settle in the dependent posterior canal and render it sensitive to gravity.
- 5% involve the lateral horizontal canal but they tend to settle quicker
Different types
- Posterior semicircular canals 80%
- Horizontal semicircular canals
- Anterior semicircular canals
Clinical
- Acute vertigo with head movements and changing positions
- Does it get worse "turning over in bed"
- What if any head/body movements preceded onset.
- Each attack lasts usually less than one minute
- There may be a history of head injury
- BPPV is the commonest cause of dizziness or vertigo and nystagmus
Diagnosis is clinical
- CT/MRI head if concerns that there is brainstem or cerebellar disease or acoustic neuroma - in these causes vertigo is longer lasting and less positional. BPPV has a somewhat classical story.
- Dix-Hallpike test - Video showing tests: This induces the symptoms and nystagmus
Differential
- BPPV: repeated short episodes ( less than 1 minute) of vertigo which is brought on by positional head changes with positive Dix Hallpike
- Labyrinthitis: Sudden severe attacks. Recent ENT infection or inner ear infections. Also can be due to toxic drugs.
- Meniere: Tinnitus, hearing loss, clusters of attacks with gaps
- Vestibular neuronitis: lasts several days with some positional vertigo
- Acoustic neuroma: Increasing vertigo, hearing loss and tinnitus
- Stroke: sudden onset over seconds/minutes persisting vertigo and ataxia. Eye signs/long tract signs. May persist or be progressive.
- MS: slower onset hours/days. Vertigo/ataxia/INO and eye signs and long tract signs. May be progressive.
- Vestibular migraine: common, aura, headache, repeated. Resolves between attacks.
Dix-Hallpike
- Explain test to patient so they are aware. Patient sits upright so
that when they lie back their head will lie over the end of the bench.
- Stand behind the patient and turn their head 45 degrees to one side.
- Support the neck and lie the patient back with head handing over edge to 30 degrees below horizon.
- Inspect for eyes movements of nystagmus for at least 30 seconds.
- If no nystagmus is observed, the test is then complete for that side and you should carefully help the patient sit back up.
- The test should be repeated on the other side, turning the patient’s head in the opposite direction
Management
- Very short term - Cinnarizine or Betahistine or hyoscine but definitive Epley manoeuvre is recommended by ENT referral
- Most patients can be treated with the Epley manoeuvre that moves the particles back into the utricle. Also called the particle repositioning, canalith repositioning procedure
- Patient should not drive home after in case there is further vertigo or if driving brings on disabling symptoms
Epley manoeuvre
- Each step allow the patient to remains still until full resolution of symptoms and nystagmus has been achieved for at least 30-60 seconds:
- This is often done after a positive Dix-Hallpike test. So the patient is lying on couch with room to allow head over side of bed.
- Rotate patient’s head 90 degrees to the contralateral side to 45 degrees past the midline while maintaining neck extension over the bed. Keep the patient in this position for 30-60 seconds.
- Whilst holding this position of the patient’s head, ask the patient to roll onto their shoulder (on the side their head is currently turned towards).
- As soon as patient is on their side, rotate the patient’s head so that they are looking directly towards the floor. Maintain this position for 30-60 seconds.
- Allow patient to sit up sideways, whilst maintaining head rotation.
- Once the patient is sitting upright, the head can be re-aligned to the midline and the neck can be flexed so that the patient is facing downwards (chin to chest). Maintain this position for 30 seconds.
- This procedure can be repeated 2-3 times if needed, however, this will depend on whether the patient is able to tolerate further manoeuvres (as they often precipitate vertigo).
References