33: 28-year-old woman with dizziness

Question 1

There are three categories to differentiate between when a patient presents with dizziness: presyncope, disequilibrium, and vertigo.

Answer 1

1. Presyncope - Feeling light-headed or faint, as opposed to actually passing out. Sometimes patients with presyncope feel worse when they stand up quickly.
2. Disequilibrium - A feeling of being off balance.
3. Vertigo - A sensation of the room spinning

Question 2

Presyncope Symptoms, Etiologies, and Management

Answer 2

inadequate cardiac output due to “pump failure”: myocardial infarct

inadequate cardiac output due to decreased filling time: atrial fibrillation
»Rate control in atrial fibrillation is achieved through pharmacologic or electric cardioversion or use of calcium-channel blockers, beta blockers, or digoxin if cardioversion is contraindicated or ineffective.

inadequate cardiac output due to decreased filling time: tachycardia of thyroid storm
»Treatment of dizziness due to tachycardia caused by thyroid storm is focused on treatment of the underlying hyperthyroidism and cardiac rate control with beta blockers.

inadequate cardiac output due to decrease heart rate: bradyarrhythmias
»Medications are a frequent cause of bradyarrhythmias, and treatment is simply withdrawal of the medication. Symptomatic bradyarrhythmias frequently require a pacemaker.

inadequate cardiac output due to obstruction:
valvular heart disease
»For example, aortic stenosis is a common valvular lesion in the elderly that may be asymptomatic; however, once syncope develops, valve replacement may be indicated.

1. inadequate cardiac output due to decreased preload due to volume depletion
2. poor cerebral oxygenation due to inadequate hemoglobin concentration
   »acute blood loss such as gastric ulcer bleed
   Replacing volume and raising hemoglobin concentration are the mainstays of management.

Question 3

Orthostatic Hypotension

Answer 3

1. A drop in systolic blood pressure of ≥ 20 mmHg or
2. A drop in diastolic blood pressure of ≥ 10 mmHg
   »when changing position from supine to standing
   »accompanied by feelings of dizziness or light-headedness

Question 4

Common Causes of Vertigo in Primary Practice

Answer 4

1. Most common cause:
   »Benign paroxysmal positional vertigo (BPPV)
2. Second-most common causes:
   »Vestibular neuritis results when a viral (or, less commonly, bacterial) infection of the inner ear causes inflammation of the vestibular branch of the eighth cranial nerve.
   »Acute labyrinthitis occurs when an infection affects both branches of the nerve resulting in tinnitus and/or hearing loss as well as vertigo.

Question 5

Head Thrust Test

Answer 5

Observation of nystagmus is essential to differentiating between peripheral and central vertigo. The head thrust test is used to demonstrate a likely peripheral lesion.

Normally, when you face your pt and ask them to keep looking at your nose, his eyes will stay fixed on your nose if you move his head suddenly to the side. If there is a peripheral lesion in the vestibular system, the vestibular ocular reflex will be disrupted and his eyes will move with the head and then saccade back to center when his head is moved in the direction of the lesion. A normal head thrust test in the presence of vertigo means the peripheral vestibular system is intact and that the lesion is central.

Question 6

uncomplicated otitis media

Answer 6

According to American Academy of Pediatrics and American Academy of Family Physicians guidelines, children over two years old with uncomplicated acute otitis media may be treated with additional observation without prescribing antibiotics; children less than six months should be treated with antibiotics; and those between six months and two years with uncomplicated unilateral otitis media may be cautiously observed first - depending on the certainty of the diagnosis, social supports, and clinical picture.

Question 7

Maxillary sinusitis

Answer 7

Maxillary sinusitis is usually preceded by an upper respiratory infection. Signs and symptoms include facial pain in the area of the maxillary sinuses, purulent nasal discharge, post nasal drip, and tenderness to palpation or percussion of the sinuses. A recent Cochrane review concluded that in otherwise uncomplicated maxillary sinusitis, the beneficial effect of antibiotics is minimal and does not justify the use. This systematic review excluded studies of sinusitis complicated by involvement of multiple sinuses, severe systemic signs and symptoms, acute isolated frontal sinusitis, recurrent sinusitis, or sinusitis with known anatomic defect.

Question 8

When Neuroimaging is Indicated for Patients with Vertigo

Answer 8

There are multiple reasons to be concerned about a central lesion and possible infarct in this patient. Her age puts her at risk as does her hypertension. Her physical exam shows nystagmus that changes direction and that does not inhibit with focus . Both of these findings are consistent with a central lesion. She needs an urgent MRI.

This patient has a classic history of benign paroxysmal positional vertigo (BPPV). In addition, the positive Dix-Hallpike maneuver confirms the diagnosis. Neuroimaging is not required.

The triad of recurrent episodes of vertigo, tinnitus, and hearing loss is characteristic of Meniere’s disease which is a peripheral lesion. A positive head thrust test reassures that the lesion is peripheral.

Unidirectional nystagmus that disappears with fixation and recurs with loss of fixation implies a peripheral lesion. In the absence of other neurological signs and symptoms in an otherwise well young woman, neuroimaging is not needed since the likelihood of a central lesion is minimal.

A normal head thrust test in the face of constant and new vertigo combined with a history of migraines indicates a possible central lesion. Neuroimaging is needed.

Question 9

Differential of Dizziness: Most Likely Diagnoses

Answer 9

Vestibular neuritis
»Commonly associated with a recent URI.
»Nystagmus caused by a peripheral lesion such as this does not change direction with gaze.

Benign paroxysmal positional vertigo (BPPV)
»Causes acute onset vertigo that can be associated with nausea and vomiting and intact hearing.
»Vertigo in BPPV is thought to be caused by calcium carbonate debris in the semicircular canals.
»BPPV typically causes episodic rather than constant vertigo that is triggered by positional change as calcium debris moves within the semicircular canals. Symptoms usually resolve several seconds to minutes following position change in BPPV.

Vestibular migraine
»Vestibular migraine is a variant of migraine that can cause central vertigo.
»Most patients will give a history of previous migraine headaches. However, at the time of a vestibular migraine, many patients do not have a headache.

Question 10

Peripheral vs. Central Vertigo

Answer 10

periph nystagmus:

• unidirectional (usually horizontal and rotational) and does not change direction
• inhibited by fixating on a point and intensifies when fixation is withdrawn
• Frenzel glasses prevent fixation and bring out the nystagmus

ctl nystagmus:

• purely horizontal, vertical, or rotational
• does not lessen when the patient focuses gaze
• persists for a longer period