Dizziness and Vertigo Flashcards
Define “dizziness’
extremely common yet complex
neurologic symptom that reflects a disturbance of normal balance perception and spatial orientation.”
Name 4 broad categories of dizziness
Vertigo- illusion of motion, often described as the room spinning
Near syncope- feeling faint or light headed
Disequilibrium- sense of unsteady gait
Non-specific dizziness-often related to polysensory d/o with component of anxiety
Define Vertigo
illusion of motion “room spinning”
**not all patients with vertigo have acute vestibular syndrome.
Define acute vestibular syndrome
- A clinical condition in which dizziness develops ACUTELY, is CONSTANT, and persists longer than 24 HOURS.
- Acute vestibular syndrome is, by definition, accompanied by nausea, vomiting, unsteady
gait, nystagmus, and intolerance to head motion.
What 4 systems are involved in maintenance of equilibrium?
How many systems need to be involved to affect
- vision
- vestibular system
- Proprioceptive system
- Cerebellum
A loss or mismatch of any (2) of these can cause the perception of vertigo
Trace the neuronal impulse from the vestibular apparatus to the
muscle endplate
- Vestibular apparatus
- Cranial Nerve VIII
- Brainstem
o Below the pons and anterior to the cerebellum - Cerebellum
- Vestibular Brainstem Nuclei
o (4) exist - Medial longitudinal fasciculus and vestibulospinal tract
- Motor neurons
- Synapse
- Muscle end-plate
Define nystagmus and its variants
Rhythmic beating of the eyes caused by asymmetrical stimulation of the extraocular
muscles
- Upbeat
- Downbeat
- Horizontal
- Torsional
- Mixed
List five peripheral causes of vertigo
● BPPV
● Vestibular neuritis
● Labrynthitis
● Foreign body in ear canal
● Acute otitis media
● Perilymphatic fistula
● Trauma (labyrinth concussion)
● Motion sickness
● Acoustic neuroma
● Meniere’s
List five central causes of vertigo
● Vertebrobasilar artery insufficiency
● Cerebellar hemorrhage or infarction
● Tumor
● Migrainous vertigo
● MS
● Post-traumatic injury (temporal bone fracture, post-concussive syndrome)
● Infection
○ Encephalitis
○ Meningitis
○ Brain abscess
● Temporal lobe epilepsy
● Subclavian steal syndrome
Differentiate between central and peripheral vertigo based on onset; intensity; duration; direction of nystagmus; effects of head position; associated neurologic findings; Associated auditory findings
Peripheral
Onset-sudden
Intensity
- Severe initially, often decreasing over
time
Duration
- Intermittent episodes lasting seconds
to less than one minute for BPPV; continuous and lasting for hours to
days for vestibular neuritis
Direction of Nystagmus
- (posterior canal BPPV) torsional and up beating
-Horizontl canal BPPV - horizontal; horizontal torsional with vestibular neuritis and labrynthitis
Effects of head position:
-BPPV > induces vertigo
-vestibular neuritis > worsens vertigo
Associated ND:
- none
Auditory findings:
- +/- tinnitus (meniers) +/- hearing loss (labrynthitis)
Central
Onset: gradual or sudden
Intensity:
- mild (can be severe in stroke and MS)
Duration: continuous or minutes (vascular cause ie TIA)
Nystagmus direction:
Vertical, spontaneous, torsional, direction changing on lateral gaze, down beating
Effect of head position:
- less likely to cause effect
Associated ND: usually present
Auditory findings: rare
Describe the Dix Hallpike Test
** used to confirm posterior canal BPPV. use with caution in patients with acute vestibular syndrome
**If vertigo continuous> not inkeeping with BPPV
lie the patient down so their head is just off the edge of
the gurney
○ Then sit them up.
○ Turn head 45º to one side
○ Lay patient down quickly with head overhanging edge of gurney
○ Ask about symptoms and look for nystagmus +/- wipe vomit off your shoes
○ Bring patient back upright
○ Then repeat on other side.
● Positive test, ie confirmatory of BPPV = latent onset of vertigo and nystagmus (10-30
seconds)
● nystagmus (up beating and ipsilateral torsional/top pole beats to downward ear.
What are components of the HINTS exam?
Head impulse Test - rapid, passive rotation of head while patient fixates on nose ofexaminer.
○ Central - no findings (no saccade)
○ Peripheral - catchup saccade present
● Nystagmus
○ Central = bilateral, direction changing horizontal nystagmus or vertical nystagmus
○ Peripheral = unilateral, horizontal nystagmus
● Test of Skew = cover/uncover test of each eye while patient fixates on nose
○ Central - refixation present after uncover
○ Peripheral = no refixation
What is a HINTS exam ?
“Head Impulse, Nystagmus, Test of Skew”
used to differentiate between central and peripheral causes of the acute
vestibular syndrome, i.e. CONSTANT VERTIGO >24h (in most cases, vestibular neuritis
vs. posterior stroke are the main differentials)
Peripheral HINTS
unilateral positive HIT + unilateral horizontal nystagmus+
absent skew deviation
Central HINTS
negative HIT
bidirectional horizontal/vertical nystagmus,
positive test of skew
INFARCT (impulse normal, fast phase alternating, refixation on cover test)
Sensitivity and specificity of HINTS exam for posterior stroke
Sensitivity- 96-100%
Specificity- 85-98%
What is the Epley maneuver and what pathology does it treat?
Used to treat posterior semicircular canal BPPV
Describe the Barbecue Roll Test and what pathology does it treat?
horizontal canal variant of BPPV
Head turns 90º to affected side. Then rotated in 45 degree intervals away from the involved side.
Each position is held until the nystagmus and vertigo resolves, approximately 30 seconds.
The maneuver is complete when the head is back in the original starting position.
