From the Guidelines
The recommended imaging approach for patients presenting with dizziness is to prioritize MRI of the brain with contrast over CT, especially in cases where stroke is suspected, and to consider temporal bone CT or MRI for inner ear pathology, while minimizing unnecessary imaging to reduce healthcare costs and radiation exposure. When evaluating patients with dizziness, it is crucial to consider the clinical presentation and suspected underlying cause to determine the most appropriate imaging strategy. For patients with isolated dizziness without focal neurological deficits, imaging may not be necessary as the initial step, as many cases are due to benign peripheral causes such as vestibular neuritis or labyrinthitis, which do not have associated findings on CT imaging 1. However, in acute settings where stroke is suspected, a non-contrast CT may be performed first for rapid assessment, followed by MRI if available, as MRI provides better visualization of the posterior fossa, brainstem, and inner ear structures 1. The HINTS examination, which includes Head-Impulse, Nystagmus, and Test-of-Skew testing, can help distinguish between central and peripheral vertigo patterns and guide the need for imaging 1. Doppler ultrasonography of the carotid and vertebral arteries might be considered when vascular causes are suspected, and the timing of imaging should be prioritized in patients with acute onset severe dizziness accompanied by headache, neurological deficits, or risk factors for cerebrovascular disease 1. Ultimately, the selection of imaging should be guided by the patient's history, physical examination findings, and the distinction between central and peripheral vertigo patterns to avoid unnecessary imaging and its associated costs and radiation exposure 1. Key considerations include the patient's risk factors for cerebrovascular disease, the presence of neurological deficits, and the results of the HINTS examination, which can help identify patients who require urgent imaging to rule out stroke or other central causes of vertigo 1. By adopting a thoughtful and evidence-based approach to imaging in patients with dizziness, clinicians can optimize patient outcomes while minimizing unnecessary testing and radiation exposure.
From the Research
Imaging Approach for Dizziness
The recommended imaging approach for patients presenting with dizziness is not always clear-cut and depends on various factors, including the underlying cause of dizziness.
- Laboratory testing and imaging are usually not required but can be helpful in certain cases 2.
- A directed approach to the dizzy patient can help identify key factors on which a directed evaluation could be based, including a standardized history, physical examination, and basic laboratory evaluation 3.
- The timing and triggers diagnostic approach for the acutely dizzy patient offers the potential to reduce misdiagnosis while simultaneously decreasing diagnostic test overuse, unnecessary hospitalization, and incorrect treatments 4.
Key Considerations
When evaluating patients with dizziness, it is essential to consider the following:
- The differential diagnosis is broad and includes peripheral and central causes 2, 5.
- Serious causes of dizziness, such as stroke, are more prevalent than expected in some patient populations 6.
- A new approach to diagnosis that emphasizes different aspects of the history to guide a focused physical examination can help differentiate benign peripheral vestibular conditions from dangerous posterior circulation strokes 4.
Diagnostic Tests
The following diagnostic tests may be useful in evaluating patients with dizziness:
- Orthostatic blood pressure measurement 2.
- Full cardiac and neurologic examination 2.
- Assessment for nystagmus 2.
- Dix-Hallpike maneuver (for patients with triggered dizziness) 2, 4.
- HINTS (head-impulse, nystagmus, test of skew) examination when indicated 2.
- Imaging studies, such as MRI or CT scans, may be necessary in certain cases, especially if a central cause is suspected 6, 4.