Causes of dizziness Flashcards
What is the difference between vertigo and dizziness?
Vertigo is a type of dizzy which is related to spinning
What motion is the lateral semicircular canal responsible for?
Left to right movement
What motion is the posterior semicircular canal responsible for?
Moving head to shoulder
What motion is the superior semicircular canal responsible for?
Nodding
What is the basics of the vestibularoccular reflex?
Means to focus on a point even when head not directly looking at it
In what way can the eye affect balance?
Cataracts
Diabetes Mellitus
How can joints affect balance?
Arthritis may make it mechanically difficult to stand
What neurological impairments affect the balance system?
Migraines
MS
Space occupying lesions
Where exactly in the SCC is the vestibulooccular reflex set up?
The cupula in the crista ampullaris
What is the mechanism for the vestibule-ocular reflex?
Calcium carbonate crystals on the cupula activate hair cells to make APs when the endolymph causes the crystals to move
If the vestibulo-ocular reflex isn’t working, what might occur?
Nystagmus
In what direction does the nystagmus move?
Away from the affected ear.
E.g. if right ear then will point towards nose
Why might anxiety lead to dizziness?
Hyperventilation
What would you do on examination if dizzy was PC?
Otoscopy
Neurological exam
BP
Audiometry
What is BPPV?
Benign positional paroxysmal vertigo
What is the pathophysiology of BPPV?
Otoconia are displaced into the SCC causing the hair cells in the SCC to become depolarised unnecessarily
What is the difference between BPPV and vertebrobasilar insufficiency?
VBI needs other symptoms e.g. visual disturbance, weakness or numbness
When are vertigo symptoms often seen?
Looking up
Turning in bed
Getting out of bed in morning
Rising from bending
True or False
There is tinnitus associated with BPPV
False
What is Hallpike’s test?
Lie on couch so head is off the back and turn head away from affected side and to 45degrees
What is Hallpike’s test for?
Nystagmus
What is important to note about repeating Hallpike’s test?
Doesn’t give as accurate results the second time around
What manoeuvre can be done to treat BPPV?
Epley manouevre
What is the Epley manoeuvre?
Manual exercise involving turning the patient to move the otoconia from the SCC to the utricle
What is vestibular neronitis?
Inflammation of vestibular nerve
What symptoms does vestibular neuronitis present with?
Prolonged vertigo
NO tinnitus/hearing loss
What causes labyrynthitis?
Virus
What is different about labyrinthitis in terms of presentation as compared with vestibular neuronitis?
Labyrinthitis is associated with tinnitus or hearing loss
What is the pathophysiology of Meniere’s disease?
Too much endolymph
What is a classic history of Meniere’s disease?
Periodic vertigo with pro-drome
Hearing loss
Tinnitus
Aural pressure
What kind of hearing loss is present in Meniere’s disease?
Sensory-neural
What is conductive hearing loss?
Gap between bone conduction and that in air
What is an example of conductive hearing loss?
OME
Where is the problem is sensorineural hearing loss?
Cochlea
What is the management for Meniere’s disease?
Tinnitus therapy
Hearing Aids
Tx during episodes
What symptomatic management is available for Menieres disease?
Betahistine
Anti-emetics
Why is a low salt diet and diuretics prescribed for Meniere’s disease?
To reduce levels of fluid (endolymph)
What role does gentamicin play in Meniere’s disease?
Destroys OHC so no sensation of falling
