Dizziness Flashcards
Signs of peripheral vs. central vertigo:
Onset differences?
Severity differences?
Are there CN findings?
Is there a latent period?
Nystagmus Differences?
Possible etiologies of each?
CENTRAL PERIPHERAL
Onset slow rapid
**Severity ** mild worse
CN findings + -
Latency - +
Nylen-Barany* nystagmus persists nystagmus extinguishes
(* positive if nystagmus present, fast phase toward affected ear = ear closest to ground)
Etiologies brain stem ischemia acoustic schwannoma
posterior fossa tumors Meniere’ disease
multiple sclerosis labyrinthitis (infection)
drugs: anticonvulsants, benign positional vertigo
PCP, ethanol trauma (endolymphatic fistula)
labyrinthine concussion
Most likely diagnosis if there is vertigo that recurs and abates every few hours:
Peripheral Cause
Most likely diagnosis if vertigo is violent and severe:
Peripheral Vertigo
Diagnosis if vertigo has gradual onset, constant and not affected by movement:
Vertigo with central cause
What to think if there are symptoms including dysphasia, dysphonia, ataxia, diplopia, miosis or bilateral blurred vision:
Central Vertigo or possible cerebellar abnormality
Dx with acute onset vertigo not affected by movement, along with cranial nerve findings:
Acute Ischemic Cause of Central Vertigo
Dx with vertigo + acute hearing loss
acute labyrinthitis: typically after URI’s, otitis media
Dx for vertigo + hearing loss + tinnitus
classic triad of Meniere’s disease
Patient presentation of Meniere’s disease:
Classic triad of: vertigo, hearing loss, and tinnitus
Often occurs in middle age, can recur and symptoms increase with each recurrence until peaks and slowly decrease in intensity, hearing loss typically persists between episodes
DDx of vertigo associated with trauma:
Perilymphatic fistula: results in leakage of endolymph from the round or oval window into the middle ear. These patients complain of acute worsening of dizziness when middle ear pressure increases during coughing, sneezing or straining.
Post-Concussive Syndrome: Nonspecific dizziness may be seen as part of post-concussive syndrome but the increase in symptoms with coughing is not seen.
Labyrinthine concussion: may include vertigo, postural imbalance, hearing loss, tinnitus, nausea, vomiting, or some combination of these after head trauma.
**Post-traumatic positional vertigo: **easily recognized based on the pattern of dizziness that is elicited only when the head is placed in certain positions–caused by particles within endolymph following trauma.
Components of physical exam for patient with vertigo:
Where to perform exam and why?
Features of peripheral vs. central nystagmus:
Key is a good neurologic examination particularly the cranial nerves, cerebellar function, nystagmus and positional testing.
Nystagmus is seen in both peripheral and central causes of vertigo. Best observed in dark room because if the patient has something to fixate their vision on, any peripherally-induced nystagmus can be extinguished.
That’s why its helpful to “look at the horizon” (i.e., a stationary object) when you have “sea sickness.”
Peripheral nystagmus is rotatory or horizontal.
Centrally-induced nystagmus can be vertical or dysconjugate.
Nylan-Barany maneuver (aka Dix-Hallpick)
Pt is sitting near top of gurney. Have them rapidly lay down and extend their neck 45 degrees below horizontal and 45 degrees to left. If this induces nystagmus, then the test is positive. Fast phase is towards affected ear (the ear closest to the ground is being tested)
Define Syncope:
. Symptoms may be better referred to as a near faint due to decreased cerebral blood flow. We have all experienced near syncope when we stand after crouching for a prolonged period, particularly if in the sun.
Causes of Syncope:
Anything that altered the body’s normal vascular reflexes to maintain central perfusion can cause this including:
drugs esp. antihypertensives and ethanol
hypovolemia
rarely poor cardiac output secondary to a dysrhythmia or aortic stenosis
Questions to ask syncopal patient about episodes:
Why?
“Do you ever feel dizzy while sitting? How about while standing? How about while lying down.”
If they only get dizzy with standing, I ask about postural changes or exertion.
