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 (nausea, hearing loss, tinnitus), 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 outlined in the clinical practice guideline for Ménière's disease 1.
Some key points to consider in the history and physical examination include:
- The nature of the onset (spontaneous or provoked) and duration of active vertigo (seconds, minutes, hours, or entire day)
- Concurrent otologic symptoms (fluctuating hearing, tinnitus, aural fullness) just before, during, or after the vertigo attack
- Whether the vertigo onset is provoked by head position (to rule out BPPV)
- If the patient is experiencing falls (i.e., drop attacks) during these episodes, as this could indicate a more serious condition such as stroke or ischemia 1.
Basic laboratory tests should include complete blood count, basic metabolic panel, and glucose measurement to rule out anemia, electrolyte disturbances, and hypoglycemia. An electrocardiogram is recommended, especially in older patients or those with cardiac risk factors, as suggested by the guidelines for the diagnosis and management of heart failure in adults 1. For patients with neurological signs, persistent symptoms, or concerning features like sudden onset severe headache, imaging studies such as CT or MRI of the brain may be indicated. Audiometry should be considered for patients with hearing symptoms. This systematic approach helps identify the underlying cause of dizziness, which is crucial for appropriate management, as treatment varies significantly depending on whether the etiology is peripheral vestibular, central, cardiovascular, or metabolic in nature.
From the FDA Drug Label
- 1 Drowsiness Since drowsiness may occur with use of meclizine hydrochloride tablets, patients should be warned of this possibility and cautioned against driving a car or operating dangerous machinery. 6 ADVERSE REACTIONS The following adverse reactions associated with the use of meclizine hydrochloride were identified in clinical studies or postmarketing reports Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Anaphylactic reaction, drowsiness, dry mouth, headache, fatigue, and vomiting.
The initial workup for a patient presenting with dizziness is not directly addressed in the provided drug label for meclizine hydrochloride tablets 2. However, dizziness can be related to the side effects of the medication, such as drowsiness.
- The drug label does mention drowsiness as a potential side effect, but it does not provide a specific workup for dizziness.
- It is essential to note that meclizine is indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults.
- When evaluating a patient with dizziness, it is crucial to consider the underlying cause and potential contributing factors, such as medication side effects, before initiating any treatment.
From the Research
Initial Workup for Dizziness
The initial workup for a patient presenting with dizziness involves a thorough history and physical examination to determine the underlying cause of the symptom.
- The history should focus on the timing and triggers of the dizziness, as well as any associated symptoms 3, 4.
- The physical examination should include orthostatic blood pressure measurement, a full cardiac and neurologic examination, assessment for nystagmus, and the Dix-Hallpike maneuver 3.
- The HINTS (head-impulse, nystagmus, test of skew) examination can help distinguish peripheral from central etiologies 3.
Diagnostic Approach
The diagnostic approach to dizziness can be divided into three key categories:
- Acute vestibular syndrome, where bedside physical examination differentiates vestibular neuritis from stroke 4.
- Spontaneous episodic vestibular syndrome, where associated symptoms help differentiate vestibular migraine from transient ischemic attack 4.
- Triggered episodic vestibular syndrome, where the Dix-Hallpike and supine roll test help differentiate benign paroxysmal positional vertigo from posterior fossa structural lesions 4.
Laboratory Testing and Imaging
Laboratory testing and imaging are not required and are usually not helpful in the initial workup for dizziness 3, 5, 6.