BPPV Flashcards
what is the normal function of the SCCs and ampulla
fluid filled canals detecting rotation of the head
* rotation causes deflection of sensory hairs in crista ampullaris
* hair cells embedded w/i gelatinous membrane (cupula)
what can happen to otoconia when they degenerate w age
get more brittle, have more fissures
* more likely to break off matrix
how do the hair cells in the SCC work with the CN VIII’s excitation/inhbition
deflection away from kinocilium = inhibits
towards kinocilium = excites
why is the situation of the SCC planes significant
key for positional testing
what is the pathophys behind BPPV
mechanical disorder of inner ear caused by abnormal stim of 1 or more of 3 SCC w/i the ear
* otoconia break free from macula of utricle
* misplaced otoconia fall into SCC, change canal response to gravity
what is the most common etiology of BPPV
idiopathic (58%)
can have correlations to other disorders
18.2% post-traumatic
8.5% viral neurolabyrinthitis
what questionnaire do you use w someone you suspect of BPPB
Dizziness Handicap Inventory (DHI)
what is significant prior medical hx to screen for in BPPV
vestib co-morbidities
* migraines
* inner ear
what are 4 types of special dx tests
neurologic tests
general med tests
x-rays
otologic tests
what are 6 vestibular co-morbidities for BPPV
- otological hx
- diabetes
- osteopenia/porosis, Vit D deficiency
- concussion
- migraine
- thryoid
why we not utilize Brandt-Daroff or self-CRP exercises
there aren’t any exercises we can do to prevent recurrence
Brandt-Daroff can also result in multi-canal involvement
may use brandt-daroff for habituation purposes
what is the clinical implication for the growing support for a correlation b/w DM2 and BPPV
screen for BPPV in those w DM2 and dizziness
additional research is needed to determine if this data is clearly meaningful
what is the thought behind why someone w DM2 and BPPV might also have HTN
HTN –> dec blood flow to labyrinth –> otolith dislodgement
if a woman is having recurrent BPPV what might be a nutritional recommendation and why
Vit D and calcium supplements
lower bone mineral density and low serum Vit D may be a risk factor for BPPV
most notable in post-menopausal women
why is there thought to be a seasonality to BPPV
BPPV cases highest in months when serum Vit D levels lowest
* incidence is higher in autumn and winter over spring and summer
a migraine comorbity is most common in what BPPV etiology
idiopathic BPPV
3-4x more common in idiopathic BPPV than post traumatic
what autoimmune condition is most commonly associated w BPPV
thyroid dysfunction / hashimoto’s thyroiditis
what is the hypothesis for why autoimmune conditions may be correlated w BPPV
diffusion of immune-complexes in inner ear could change composition of endolympathic fluid exerting a mechanical stim of receptors and provoking typical vertigo
what are functional mvmts that if triggering may indicate BPPV vertical canal involvement
- looks up (PC)
- gets out of bed
- moves head quickly
- rolls over in bed
- bends over
- bends forward to read (AC)
what are functional mvmts that if triggering may indicate BPPV horizontal canal involvement
- turning head in horizontal plane
- bending forward in pitch plane
what is key to accurately dx BPPV
targeted hx
thorough clinical exam
why would you test for BPPV in an elderly pt w poor balance w/o classic BPPV subjective reports
elderly often don’t complain of true vertigo - “feel off”
* they also might move slow, so when they roll, they aren’t generating a robust response w positional changes to have a classic BPPV subjective report
what is cupulolithiasis
otoconia adhere to cupula itself inc the density of the particle –> producing inappropriate deflection of cupula in head when in provoking position
long duration
* otoconia adhere or hang down
what is canalithiasis
otoconia from utricle float into long arm of SCC
* when in provoking position, otoconia pulled by gravity to most dependent part of canal –> mvmt of otoconia overcomes the inertia of endolymph –> causes deflection of cupula
short duration sx, little latency
* otoconia move and create ripples, then settles