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.
Work-up for Syncope:
ABCs / Telemetry / EKG / Possibly fluids
Ask about postural Changes in Symptoms
Assess for volume loss
Assess for any profound or new symptoms associated with episode (chest pain, headaches, etc)
Orthostatic Vital Sings
Look for murmurs
Other studies might include echocardiography, head / neck / chest CT
Things to look for / consider in syncopal patient with the below associated symptoms:
- Acute Headache
- Acute Abdominal Pain
- SAH
- Increased vagal tone from perforated bowel, ruptured AAA, ruptured ectopic pregnancy.
Definition of dysequilibrium:
gait disturbance
General causes of dysequilibrium:
Sensory loss surrounding positional information:
vision
propioception
light touch
Dx in patient losing dizziness when holding onto the gurney:
dysequilibrium
What to look for on exam in patient with dysequilibrium:
visual acuity, fundoscopic exam for cataracts, retinal disease
complete neurologic examination but focus on light touch, pin prick, proprioception in lower ext.
Patients may have a wide based or stumbling gait but not ataxic – can test cerebellar function with finger-nose-finger and rapid alternating movements in upper extremities.
Must be careful to do a good neurologic examination to evaluate for true weakness or ataxia.
Specific Etiologies of Dysequilibrium:
poor vision
diabetic or ethanol induced neuropathy
B12 deficiency
tabes dorsalis
motor gait disorders due to cerebellar degeneration or Parkinson’s dz but the neuro exam will help differentiate.
Define “Ill-defined lightheadedness”
category of dizziness for patients without a specific etiology elicited from the H&P.
What patients often complain of with ill-defined lightheadedness:
What to be highly suspicious of with strange explanations of lightheadedness in otherwise healthy patients:
Conditions to consider in patients appearing at least slightly ill or with multiple medical problems:
“it feels like my head is full of air”, “I just feel strange,” or they may describe feeling of being distant from the environment or others, derealization or depersonalization respectively.
If anyone describes their symptoms to you like this strongly suggests depression as an etiology (PSYCH). The etiology of this nonspecific feeling may be difficult to identify but hyperventilation, anxiety, depression, and medications should be very high on the list in otherwise healthy patients.
However in patients who are slightly ill appearing or who have multiple medical problems, hyperCa, hyperMg, uremia, anemia, chronic subdural hematoma, and myocardial ischemia can all present with this nonspecific complaint.
Main features of exam for patient complaining of ill-defined light-headedness:
typically have a normal physical examination
but pay attention to more subjective findings of flat affect and other clues to depression or stressors.
Look for evidence of anemia with pale conjunctiva or under tongue (frenulum)
Diagnostic Studies for Dizziness:
- FSBG
- ECG (unless patient has acute vertigo)
- lab levels of any quantifiable therapeutics the patient may be on (e.g., anticonvulsants, ethanol)
- CT/MRI (if symptoms are vertiginous but possibly central in etiology or if any localizing weakness is identified).
- The older the patient and the more nonspecific the symptoms, esp. in patients with dysequilibrium and lightheadedness, the greater number of tests should be done: CBC, lytes w/ Ca, Mg, Phos, renal function
General Management of Vertigo?
Specific Medications?
- Treat any dehydration with isotonic fluids
- Antiemetics for any vomiting
- If central, then probably admit (unless drug related)
- If peripheral, then treat etiology:
- To ENT if traumatic perilymphatic fistula
- ABX if otitis media
- Reassurance and symptomatic treatment
- Tell patients to sit rather than lay down so that they can fixate on an object
- Tell patients to move slowly
- Advise not to drive
- Advise to elevate on a few pillows and take medications just prior to lying down to improve sleep
Medications (one not better than the other):
- Meclizine (Antivert) 25-50 mg TID (antihistamine)
- Scopolamine transdermal Q 3 days (anticholinergic)
- Diazepam 5-10 mg BID (benzodiazepine)
- Proclorpherazine 5-10 mg PO TID or 25 mg PR (antiemetic).
- These should only be used for 3 days because, while this blunts the symptoms they also slow the resetting of the vestibular system.
- Inform patients that recurrence over the next 3-4 days is expected but if it persists, recommend reevaluation
Management of Dysequilibrium:
improve home environment (not an easy task)
glasses or ophthalmologic care
rehabilitation to train patients how to walk
NO MEDICATIONS! Remember that many of these can cause sedation and actually worsen these symptoms
