dizziness Flashcards
vertigo
peripheral vs central
Sensation of motion in the absence of actual motion
Exaggerated sense of motion in response to body movement
Peripheral
More common
“Inner ear”
Central
Worse pathology
Brain stem or cerebellar in origin
body orientation
visual:
spacial orientation
vestibular system: Indicates the body orientation relative to the gravity
proprioceptive: Relates body movements
Indicates the position of head relative to the body
vestibular system: otoliths are in the…
otolith organs
is a structure in the saccule of the inner ear
otholith organs: saccule and utricle
Utricle is sensitive to a change in horizontal movement
Saccule provides information about vertical acceleration
*if get stuck–>vertigo
semicircular canals
Sense orientation of movement
Filled with endolymph
Movement of endolymph results in sensory input
Dysfunction results in nystagmus
Abnormalities within the vertical canals (anterior or posterior) result in vertical/torsional nystagmus
Abnormalities within the horizontal canal (lateral) result in horizontal nystagmus
visual + vestibular
vestibulo-occular reflex (VOR) Maintains clear vision with movement Abnormality caused by aberrant stimulation Abnormality caused by lesion Results in vertigo / Nystagmus
nystagmus
Rhythmic movement of eyes
Fast and slow component
Direction is named by the fast component
Slow component is generated from the canals
( resulting in eye movement away from canals )
caloric reflex test
“COWS” ??
Test of the vestibulo-ocular reflex that involves irrigating cold or warm water external auditory canal.
caloric reflex test in pts w. cerebral damage
the fast phase of nystagmus will be absent as this is controlled by the cerebrum. As a result, using cold water irrigation will result in deviation of the eyes toward the ear being irrigated. If both phases are absent, this suggests the patient’s brainstem reflexes are also damaged and carries a very poor prognosis
COWS
Cold Opposite, Warm Same.Cold water = FAST phase of nystagmus to the side Opposite from the cold water filled earWarm water = FAST phase of nystagmus to the Same side as the warm water filled earIn other words: Contralateral when cold is applied and ipsilateral when warm is applied
peripheral vestibular disease
Three common peripheral vestibular disorders
Abrupt onset
Intense sensation of spinning
Worsened by rapid movement
Associated with nausea
Vestibular neuritis
Meniere disease
Benign paroxysmal positional vertigo
Meniere disease
Distention of the endolymphatic compartment Unknown cause ( head trauma, syphilis ) Vertigo ( minutes to hours ) Associated with hearing loss Tinnitus, fullness in ears
tx with diuretics, low salt
(enolymphatic hydrops)
Vestibular neuritis
Unknown cause ( Viral ) Intense vertigo (several days ) Positional nystagmus Very debilitating
tx: Supportive care
Diazepam
Meclizine* (nondrowsy dramamine)
(Vestibular suppressant
BPPV: benign paroxysmal positional vertigo
Inappropriate activation of semicircular canal Vertigo ( minutes ) *Provoked by head movement ( latency after movement ) Central lesions have no latency
central disease
Gradual onset More severe and debilitating Variable nystagmus Vertical / without latency *Worsened by rapid movement (with periph as well)
central causes
Cerebellar infarct
MS
neoplasm
vert. art. dissection
non vestibular dizzines
Imbalance
Syncope
Near syncope
syncope
transient loss of consciousness
near syncope
light headedness with concern of impending “transient loss of consciousness”
disequilibrium
feeling of unsteadiness, imbalance
dizzy hpi
Do not bias the patient’s response “leading questions” Describe the initial response Identify the onset Identify a noted trigger (med?) Describe the duration Review medication Review past medial history Identify the “type” of vertigo......
ask pt…
Onset CNS symptoms Tympanic membrane Pattern Hearing loss Tinnitus Increased by position Nystagmus Fatigue Associated with nausea / diaphoresis
see chart
slide 18
may have an affected, retracted TM in
peripheral
normal in central
older dizzy pt, eval. for ??
central disease: blood thinners (hemorrhage) HTN, hypotension (not enough CO) CV- arrhythmia: afib, vfib (wtws?, shockable rhythm) bradycardia SVT
e-lyte abnormalities: hyper/hypo?kalemia (transient paralysis)
hyponatremia
if hyper-dehydrated
hypoglycemia
hyperglycemia
PE: ear
OM
cholesteotoma
cholesteatoma
Destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear
two types: congenital and acquired.
Acquired cholesteatomas: more common, can be caused by pathological alteration of the ear drum leading to accumulation of keratin within the middle ear
-keratin should not be in middle ear, just EAC
tx. with microsurgery
PE: hearing
webber, rinne
webber
Identify unilateral conductive hearing loss (middle ear hearing loss) unilateral sensorineural hearing loss (inner ear hearing loss)
PE: neuro
Facial paresis Truncal ataxia cerebellar exam optic dix halpike
romberg: proprioception problem
The Romberg test is used to investigate the cause of loss of motor coordination (ataxia). A positive Romberg test suggests that the ataxia is sensory in nature, that is, depending on loss of proprioception. If a patient is ataxic and Romberg’s test is not positive, it suggests that ataxia is cerebellar in nature, that is, depending on localized cerebellar dysfunction instead.
dix-hallpike
The Dix–Hallpike test is performed with the patient sitting upright with the legs extended. The patient’s head is then rotated by approximately 45 degrees. The clinician helps the patient to lie down backwards quickly with the head held in approximately 20 degrees of extension. This extension may either be achieved by having the clinician supporting the head as it hangs off the table or by placing a pillow under their upper back. The patient’s eyes are then observed for about 45 seconds as there is a characteristic 5–10 second period of latency prior to the onset of nystagmus.
optho 1
nystagmus
goals of meds
Elimination of vertigo
Enhancement of vestibular compensation
Reduction of associated symptoms
antiemetics (peripheral)
hydroxyzine (reglan)
metoclopramide
benzos
diazepam
clonazepam
antihistamines
diphenhydramine
Ca2+ antags
nimodipine
anticholinergics
scopolamine
-motion sickness, chemo nausea, dementia pts: mild sedative
ancillary test for classic inducible peripheral vertigoGradual onset More severe and debilitating Variable nystagmus Vertical / without latency Worsened by rapid movement
Most patients do no require emergent laboratory work up, typ. don’t need lab testing
- exp: on diuretic
- do EKG
Detailed testing for ENT
CT/ MRI ( central disease )
PT
peripheral
Abrupt onset
Intense sensation of spinning
*Worsened by rapid movement
Associated with nausea
central
Gradual onset More severe and debilitating Variable nystagmus Vertical / without latency *Worsened by rapid movement
