Vertigo & BPPV Flashcards
Define vertigo
Sensation that there is movement between the patient and their environment.
May feel they are moving or that the room is moving.
Often this is a horizontal spinning sensation.
What are the 3 sensory inputs responsible for maintaining balance & posture?
1) vision
2) proprioception
3) signals from vestibular system
Vertigo is caused by a mismatch between these sensory inputs.
What is the vestibular apparatus?
Located in the inner ear.
Consists of 3 loops (semicircular canals) that are filled with endolymph.
These semicircular canals are oriented in different directions to detect various movements of the head.
Describe how the vestibular system lets the brain know that the head is moving in a particular direction.
1) Head turns and endolymph fluid shifts within semicircular canals
2) Fluid shift is detected by tiny hairs (stereocilia) found in the ampulla (a section of the canal)
3) Sensory input of shifting fluid is transmitted to the brain by the vestibular nerve
4) The vestibular nerve carries signals from the vestibular apparatus to the vestibular nucleus in the brainstem and the cerebellum
Vertigo can be caused by peripheral or central problems.
What are problems with the peripheral system usually affecting?
Central?
Peripheral problem - usually affecting the vestibular system
Central problem - usually involving the brainstem or the cerebellum
Give 5 major causes of peripheral vertigo
1) Viral labyrinthritis
2) Vestibular neuronitis
3) BPPV
4) Meniere’s disease
5) Acoustic neuroma
What is BPPV characterised by?
Sudden onset dizziness and vertigo triggered by changes in head position .
Average age of onset of BPPV?
> 55 y/o
Prognosis of BPPV?
BPPV has a good prognosis and usually resolves spontaneously after a few weeks to months.
Features of BPPV?
1) vertigo triggered by change in head position (e.g. rolling over in bed or gazing upwards)
2) may have nausea
3) episodes last 10-20 seconds
How long do BPPV attacks last?
10-20 seconds
Does BPPV cause hearing loss or tinnitus?
No
Cause of BPPV?
Crystals of calcium carbonate (otoconia) become displaced into the semicircular canals.
The crystals disrupt the normal flow of endolymph through the canals, confusing the vestibular system.
Head movement creates the flow of endolymph in the canals, triggering episodes of vertigo.
What manoeuvre can be used to diagnose BPPV?
The Dix-Hallpike manoeuvre
(Dix for dx - diagnosis)
Describe the Dix-Hallpike manoeuvre
Involves moving the patient’s head in a way that moves endolymph through the semicircular canals and triggers vertigo in patients with BPPV.
What should you check before performing the Dix-Hallpike?
Ensuring they have no neck pain or pathology.
How to perform the Dix-Hallpike?
1) The patient sits upright on a flat examination couch with their head turned 45 degrees to one side (turned to the right to test the right ear and left to test the left ear)
2) Support the patient’s head to stay in the 45 degree position while rapidly lowering the patient backwards until their head is hanging off the end of the couch, extended 20-30 degrees
3) Hold the patient’s head still, turned 45 degrees to one side and extended 20-30 degrees below the level of the couch
4) Watch the eyes closely for 30-60 seconds, looking for nystagmus
5) Repeat the test with the head turned 45 degrees in the other direction
What is a positive result of Dix-Hallpike?
In patients with BPPV, the Dix-Hallpike manoeuvre will trigger rotational nystagmus and symptoms of vertigo.
The eye will have rotational beats of nystagmus TOWARDS the affected ear (clockwise with left ear and anti-clockwise for right ear BPPV).
Most common semicircular canal to be affected by crystals in BPPV?
Posterior semicircular canal
What manoeuvre is used to treat BPPV?
Epley manoeuvre
The idea is to move the crystals in the semicircular canal into a position that does not disrupt endolymph flow.
Describe the Epley manouevre
1) Follow the steps of the Dix-Hallpike manoeuvre, having the patient go from an upright position with their head rotated 45 degrees (to the affected side) down to a lying position with their head extended off the end of the bed, still rotated 45 degrees
2) Rotate the patient’s head 90 degrees past the central position
3) Have the patient roll onto their side so their head rotates a further 90 degrees in the same direction
4) Have the patient sit up sideways with the legs off the side of the couch
5) Position the head in the central position with the neck flexed 45 degrees, with the chin towards the chest
6) At each stage, support the patient’s head in place for 30 seconds and wait for any nystagmus or dizziness to settle