Diagnosis of Vertigo
It is important to diagnose the cause of vertigo, or dizziness, as quickly as possible to rule out serious conditions such as cardiovascular disease, stroke, hemorrhage, or tumor. Diagnosis includes clinical history, physical and neurological examination, blood tests, and imaging tests (e.g., CT scan, MRI scan).
Important considerations include the following:
- What triggers the vertigo?
- What other symptoms occur?
- How long does the dizziness last?
- What improves or worsens symptoms?
Physical examination includes measuring blood pressure and heart rate. Neurological examination includes testing facial and vestibular nerves and muscles, strength, coordination, balance, and walking (gait).
The positional vertigo test is used to help distinguish peripheral from central vestibular disorders. In this test, the patient sits on a table with the head turned to the side. The physician then supports the head and lowers it gently below the table while the patient lies back. The patient reports symptoms of vertigo while the physician looks for circular movement of the eyes (called nystagmus).
A delay between the onset of nystagmus and the sensation of vertigo usually indicates a peripheral vestibular disorder. Lack of a delay may indicate a central vestibular disorder. The test is repeated with the head turned in the opposite direction.
Electronystagmography (ENG) is a neurological test used to evaluate the vestibular system. It involves testing hearing in both ears (audiometry tests), testing eye movements, and evaluating responses to changes in posture and position.
Blood tests include a complete blood count (CBC) and kidney and thyroid panels to rule out systemic diseases (e.g., kidney disease, hypothyroidism). If the patient is taking medication, drug levels are obtained.
Imaging tests may be used to detect brain abnormalities (e.g., stroke, tumor). Computed tomography (CT scan) produces x-ray images of the brain and magnetic resonance imaging (MRI scan) uses a magnetic field to produce detailed images of brain tissue and arteries in the neck and brain.