Dizziness Flashcards
define dizziness
a feeling of spinning or light headedness, without loss of consciousness, and may or may not be associated with falls
what is the term describing a sensation of the environment
exteroception
what is proprioception
internal sense of body/ limb position
the utricle senses
horizontal acceleration
the saccule senses
vertical linear acceleration
canals and otolith organs are innervated by the
vestibular nerve
describe some PNS changes with age
degeneration of ampullae of the semicircular canals and otolith organs
describe CNS changes with age
decreased vestibular hair and nerve cells, loss of cerebellar purkinje cells
what are some disease related factors that cause somatosensory changes
arthritis
joint replacements
peripheral neuropathy
Sensation of motion when there is none (false sense of motion) or an exaggerated moving sensation to normal daily activities
vertigo
Feeling of unsteadiness, imbalance, or insecurity without rotation
disequilibrium
feeling of losing consciousness, impending fainting, blacking out
presyncope
Swimming, floating, giddy, or swaying sensation in the head or room
Vague sx- possibly feeling disconnected with the environment
lightheadedness
list some points of pt assessment to hit when assessing dizziness
clarify terms
what is the specific sensation
timing- onset/ pattern
triggers and progression
med and trauma hx
blood work
diagnostic imaging- CT, MRI head
physical exam to reproduce dizziness
med hx- ototoxic drugs? hypotensives?
what is the goal of the physical exam in dizziness? what is the specific maneuver to assess called?
to reproduce the dizziness
Dix-Hallpike Maneuver
3 approaches to treating dizziness
disease spec tx
symptomatic tx
rehab
match the following sx to central or peripheral vertigo
1. mild-mod
2. abrupt onset
3. chronic and continuous
4. more prominent movement illusions
5. gets worse with movement
6. has neurologic signs
7. hearing loss present
8. no N/V
9. severe imbalance
- mild-mod = central
- abrupt onset = peripheral
- chronic and continuous = central
- more prominent movement illusions = peripheral
- gets worse with movement = peripheral
- has neurologic signs = central
- hearing loss present = peripheral
- no N/V = central
- severe imbalance = central
list 3 central causes of dizziness
brainstem ischemia
cerebellar hemorrhage
normal pressure hydrocephalus
MS
space occupying lesions
3 approaches for treating central vertigo
manage/ reverse underlying condition
vestibular rehab
rehab with physio F3mths
describe presyncope clinical presentation
fainting or near fainting, seconds to minutes, can be accompanied by diaphoresis, nausea, blurred vision, pallor
presyncope is
1. red flag that requires assessment ASAP
2. may be accompanied by movement difficulties and hearing loss
3. may be managed by canalith repositioning
4. is most often caused by volume overload in the ear
5. often slower onset and lead up to syncope
1
causes/ origin of presyncope include
cardiac origin mostly/ decreased perf to brain- OH, volume depletion, carotid stenosis, arrhythmia, reflex, MI, autonomic failure
3 classes of medications that can cause presyncope/ syncope
cardiac- any antihypertensive or vasodilator
CNS- psychotropic drugs, anticonvulsants, dopaminergic, skeletal muscle relaxants
uroloogic drugs- anticholinergics, PDE5i
what is the guideline definition of orthostasis
SBP decrease of at least 20 mmHg or DCP decrease of at least 10 mmHg within 3 minutes of standing
what is a nonpharm tx for vertigo
pressure stockings
syncope/ presyncope pharm tx (list 3)
midodrine
fludrocortisone
caffeine
erythropoetin
desmopressin
pseudoephedrine
n disequilibrium, we are most concerned about
1. standing from sitting
2. standing to laying down
3. holding posture against gravity for long time
4. quick movements
4
disequilibrium can be assessed by
observing gait and full neuro exam
3 caues of lightheadedness
psychiatric
hyperventilation
hypoxia
how to manage light headedness
manage underlying conditions
optimize anxiety
BPPV is a form of
peripheral vertigo
BPPV onset is usually
50-70yrs old
what is the clinical course of BPPV
sx resolve in 6-20d, up to 2mths in some cases
describe the etiology of BPPV
debris from utricle circulate, otoliths (CaCO3) detach, settle in dependent portion of inner ear = tells brain the body is in a position it’s not in = disorientation
BPPV is diagnosed with the
Dix Hallpike
2 nonpharm tx for BPPPV
canalith repositioning
vestibular rehab
which of the followign is false
1. canalith repositioning is up to 95% effective in BPPV
2. vestibular rehabilitation may be used in lightheadedness
3. vestibular rehab is usually a 3mth trial
4. vestibular suppressants are used in BPPV when nonpharm fails
2
describe vestibular rehab
exercises that improve central compensation for peripheral deficit
Maneuvers (Semont, Brandt-Daroff, Gans)- direct the otoconia back to the utricle where it is absorbed
canalith repositioning
how long should vestibular suppressants be used for
3-7d
why should the duration of vestibular suppressants be limited
inhibit the brains natural abiltiy to compensate for vertigo over time
list the 3 classes of vestibular suppressants
anticholinergics
antihistamines
BZDs
how do anticholinergics work in vertigo
suppresses firing in vestibular nucleus neurons
how do BZDs work in vertigo
GABA modulators that act centrally to potentiate GABA and suppress vestibular responses
which BZD is used in vertigo
lorazepam
what is an alternative tx that directly suppresses vestibular activity in vertigo
flunarizine
2 investigational tx in vertigo
vit D
calcium
onset of meniere’s disease is usually
30-60yrs
describe the presentation of meniere’s disease
No specific precipitant
Usually starts unilaterally, but over time both ears are affected
Symptoms remit and reoccur (episodic)
Episodes can last 20 min to few hours
which of the following accurately describes Meniere’s disease
1. is caused by inflammation of endolymphatic system
2. has no specific precipitant
3. may be caused from external fluid entering ear
4. does not result in hearing loss
2
4 classic sx of meniere’s disease
Aural fullness + pressure
Vertigo lasting minutes to hrs - often with N/V
Tinnitus
Hearing loss (unilateral at first)
describe the pathophys of meniere’s disease
Dilation (ballooning) of the endolymphatic system
↑↑ production of endolymph
↓reabsorption
acute tx of meniere’s disease
Vestibular suppressants (Ex- meclizine)
Antinauseants (Ex- prochlorperazine)
often resolves before med kicks in
refractory intervention for meniere’s disease
intratympanic CS or gentamicin
vestibular neurectomy
labyrinthectomy
name 3 prophylactics to use in meniere’s
changing diet: low salt, avoid caffeine, alcohol
diuretics: HCTZ, triamterene, acetazolamide
betahistine
diet changes for meniere’s includes
low salt, avoid caffeine, alcohol
which 3 diuretics are used in meniere’s?
HCTZ, triamterene, acetazolamide
betahistine MOA
H1 agonist, strong H3 antagonist = vasodilation peripherally
3 sites of action: ↑ cochlear blood flow, ↑ CNS and vestibular histamine turnover, ↓ vestibular input in peripheral vestibular system
T or F: evidence for betahistine use in meniere’s disease is strong
F- v weak
CI for betahistine
PUD
what might betahistine be used for
prophylactic tx for meniere’s
presentation of vestibular neuritis
sudden/ severe vertigo, N/V
Auditory sx usually absent (no hearing loss)
select all the following that have hearing loss
1. BPPV
2. vestibular neuritis
3. labryinthitis
4. meniere’s disease
3,4
select all the following that are episodic
1. BPPV
2. vestibular neuritis
3. labryinthitis
4. meniere’s disease
1, 4
tx for vestibular neuritis
bedrest
corticosteroids for 10 days if debilitating (methylprednisolone) then vestibular rehab after acute phase (2-3d after onset)
3 causes of vestibular neuritis
viral infection
head injury
extreme stress
what is the cause of labyrinthitis
inflammation of inner ear canals, may result from prior infections or ototoxic drugs
labyrinthitis presentation
severe vertigo, hearing loss, N/v, fever
labyrinthitis tx
hospitalization, IV antibiotics, possible surgical drainage and debridement
