vestibular disorders Flashcards
Vertigo
most common
False perception of movement of self or surroundings
Both central and peripheral causes
Due to imbalance of vestibular signals
nystagmus
Involuntary rapid and repetitive eye movements
More severe in peripheral than central disorders
peripheral-habituation
Central- no change
Unbalanced inputs, vestibular, ocular reflex circuits
disequilibrium
perception of imbalance
difficulty of suppressing the stream of visual information that occurs with movement through the environment
unsteadiness and disorientation
Central lesion
Vestibular nuclei, brain stem, cerebellum
Connections within brain
Brain cannot process incoming information
Milder symptoms
nystagmus is frequently present and may be vertical directional or multi direction
Cochclear nerve symptoms are uncommon
Brainstem region signs - may have motor or sensory deficits Babinski sign, dysarthria, limb ataxia, hyperreflexia
mild nausea or vomiting
Severe oscillopsia
Peripheral lesion
cranial nerve eight vestibular portion
Diminishes sensory information coming into the brain
Nystagmus is almost always present typically unidirectional not vertical
Cochlear Nerve symptoms may have tinnitus or decreased hearing
no brainstem region sign
Moderate severe nausea or vomiting
Mild oscillopsia unless the lesion is bilateral
Hallpike positional testing peripheral
delayed onset of nystagmus
Habituation is there
Horizontal or rotatory not vertical
Does not change directions
Prominent nystagmus only if vertigo as well
Hallpike positional testing central
immediate or delayed onset of nystagmus
No habituation
Horizontal rotatory or vertical
Does not change directions
Prominent nystagmus may occur in absence of vertigo
Peripheral vestibular disorders results in
recurrent vertigo
Severe nausea
Nystagmus always present with peripheral vertigo
Frequent tinnitus and diminished hearing
Types of peripheral vestibular disorders
benign paroxymal positional vertigo
Vestibular neuritis
Ménière’s disease
Traumatic injury
perilymph fistula
BPPV
most common cause of vertigo
Inner ear disorder
Acute onset of vertigo and nystagmus
Provoked by changes in head position
subsides in less than two minutes
Caused by otoconia displaced from macula and inside semicircular canal, most often the posterior canal
Maneuver stimulates the movement of otoconia and subsides when the endolymph stops moving
Vestibular neuritis
vestibular nerve inflammation
Second, most common cause of vertigo
Caused by reactivation of latent herpes simplex virus type one HSV one infection
Virus damages the vestibular ganglion and interrupts the signals to the brain
symptoms
Disequilibrium
Spontaneous nystagmus
Nausea
Hearing unaffected
Ménière’s disease
Associated with abnormal fluid pressure in the inner ear
Unknown cause
More prevalent in females
sensation of fullness in the ear
Tinnitus
Severe acute vertigo
Nausea
Vomiting
Hearing loss
30 minutes to 24 hours
The disease lifespan is about seven years
Some have mild hearing loss and a few episodes
Most have multiple episodes and progressive hearing loss
Treatment includes
diuretics
low Sodium diet
gentamicin injection to damage labyrinth to control, nausea and vomiting
Surgically severe the vestibular nerve
perilymph fistula
perilymph is the fluid between bone and membranous labyrinth
this condition is the fluid leak between the inner and middle ear
Causes abrupt hearing loss, tinnitus, and vertigo
Most cases secondary to trauma
Central vestibular disorders may involve
damage to vestibular nuclei or their connection to the brain
Central vestibular disorders symptoms
milder than peripheral disorders
May produce brainstem signs like sensory and motor loss, double vision and dysarthria
Three days of continuous, severe vertigo with nausea and vomiting, indicates to CNS lesion
common causes of central vestibular disorders
Vertebrobasilar ischemia
brainstem or cerebellar tumor
cerebellar degeneration
multiple sclerosis
Arnold chiari malformation
Migraine
Unilateral vestibular loss
problems with posture, eye movement control, and nausea
Imbalance of signals from damaged side with intact side
VestibuloSpinal system affected
-fall or lean towards side of lesion
Nystagmus beats away from side of lesion
bilateral vestibular loss
Loss of internal sense of gravity
Spatial orientation requires visual and proprioceptive cues
Difficulty walking on uneven services or in the dark with eyes closed
No vertigo
No asymmetric vestibular information coming in
Can have a failure of the VOR reflex
- allusion of the objects moving as you walk or causing blurriness in vision as you move your head because you can’t stabilize the gaze
Is hearing typically affected with vestibular neuritis?
No
