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
