From the Guidelines
The initial workup for a patient presenting with dizziness should begin with a thorough history and physical examination to distinguish between vertigo, presyncope, disequilibrium, and lightheadedness. Ask about onset, duration, triggers, associated symptoms (hearing loss, tinnitus, nausea, vomiting), and medication use. Vital signs should be measured, including orthostatic blood pressure readings (supine, then standing after 1-3 minutes). A complete neurological examination is essential, including cranial nerves, cerebellar function, and special tests like the Dix-Hallpike maneuver for benign paroxysmal positional vertigo (BPPV) and the head impulse test for vestibular dysfunction, as recommended by 1.
Key Components of the Initial Workup
- History: onset, duration, triggers, associated symptoms, medication use
- Physical examination: vital signs, neurological examination, special tests (Dix-Hallpike, head impulse test)
- Laboratory tests: complete blood count, electrolytes, glucose, thyroid function tests
- Cardiovascular examination: assess for arrhythmias or murmurs
- ECG: to rule out cardiac causes
Additional Testing for Persistent or Concerning Symptoms
For patients with persistent or concerning symptoms, additional testing might include:
- Audiometry
- Vestibular function tests
- Brain imaging (CT or MRI) if central causes are suspected, as discussed in 1 and 1
Importance of Bedside Tests
Bedside tests like the HINTS examination have been developed to distinguish between acute brain lesions and benign causes of vertigo, as mentioned in 1. These tests can help in clinical decision making, including the need for subsequent imaging.
Limitations and Considerations
It's essential to note that the positivity rate of head CT in the emergency department for patients presenting with dizziness is low, and the diagnostic yield of MRI increases when associated neurologic findings are present, as discussed in 1 and 1. Therefore, a systematic approach that includes a thorough history, physical examination, and selective use of laboratory tests and imaging is crucial for differentiating between peripheral vestibular disorders, central nervous system disorders, cardiovascular issues, or metabolic causes, and allowing for appropriate treatment planning.
From the FDA Drug Label
Meclizine hydrochloride tablets are indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults. The FDA drug label does not answer the question.
From the Research
Initial Workup for Dizziness
The initial workup for a patient presenting with dizziness involves a thorough medical history, physical examination, and assessment of the timing and triggers of the dizziness 2, 3.
- The physical examination may include:
- Orthostatic blood pressure measurement
- A full cardiac and neurologic examination
- Assessment for nystagmus
- The Dix-Hallpike maneuver (for patients with triggered dizziness)
- The HINTS (head-impulse, nystagmus, test of skew) examination when indicated
Laboratory Testing and Imaging
Laboratory testing and imaging are usually not required but can be helpful in certain cases 2, 3.
- Orthostatic vital sign measurement (OVSM) can be used to diagnose orthostatic intolerance (OI) 4
- Autonomic function tests (AFTs) can be used to diagnose postural orthostatic tachycardia syndrome (POTS) 5
- Magnetic resonance imaging (MRI) brain can be used to rule out central causes of dizziness 5, 6
Differential Diagnosis
The differential diagnosis for dizziness is broad and includes peripheral and central causes 2, 3.
- Peripheral etiologies can cause significant morbidity but are generally less concerning
- Central etiologies are more urgent and require immediate attention
- Common causes of dizziness include:
- Benign paroxysmal positional vertigo (BPPV)
- Meniere disease
- Vestibular neuritis
- Orthostatic hypotension (OH)
- Postural orthostatic tachycardia syndrome (POTS)
- Vasovagal syncope
- Fluid and electrolyte disorders
- Circulatory/pulmonary causes
- Central vascular causes 6