Laboratory Studies
See the list below:
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Laboratory studies may be useful for patients who do not complain strictly of vertigo.
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Rule out anemia, pregnancy, and derangement of serum glucose or electrolytes, if relevant, in patients who complain of lightheadedness or disequilibrium.
Imaging Studies
See the list below:
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Imaging of the posterior fossa is necessary if the clinician suspects a central lesion.
Magnetic resonance imaging (MRI) is the preferred modality to detect infarction, [18] hemorrhage, tumor, [5] and the white matter lesions of multiple sclerosis.
If MRI is unavailable, computed tomography (CT) scan with fine cuts through the posterior fossa may be used. Unfortunately, CT scan is limited by poorer resolution than MRI and bony artifact.
Intra-arterial angiography is used traditionally to diagnose occlusions in the vertebrobasilar system. CT angiography (CTA), noninvasive magnetic resonance angiography (MRA), and Doppler ultrasonography are steadily supplanting it. This may be particularly important as early thrombolysis becomes more established as a therapy.
See the images below.
CT scan of a patient with an acute spontaneous cerebellar hemorrhage. The hemorrhage in the right lobe of the cerebellum is partly obscured by bony artifact.
MRI of a patient with an acute cerebellar hemorrhage less than 24 hours after presentation. MRI allows better resolution than CT scan without bony artifact. MRI is preferred over CT scan for imaging lesions in the posterior fossa.
Other Tests
See the list below:
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Electrocardiography (ECG) is necessary to assess for atrial fibrillation, other dysrhythmias, or evidence of acute myocardial infarction (AMI).
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AMI, particularly involving the anterior wall of the left ventricle, can lead to a stiffened ventricle with poor wall movement and secondary stasis. This may serve as a cardioembolic source for cerebral thromboembolism.
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The consulting neurologist may perform caloric testing and electronystagmography (ENG) to help localize the lesion in the vestibular apparatus or vestibular nerve nuclei; audiometry and brainstem auditory evoked potentials (BAER) also may be performed.
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CT scan of a patient with an acute spontaneous cerebellar hemorrhage. The hemorrhage in the right lobe of the cerebellum is partly obscured by bony artifact.
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MRI of a patient with an acute cerebellar hemorrhage less than 24 hours after presentation. MRI allows better resolution than CT scan without bony artifact. MRI is preferred over CT scan for imaging lesions in the posterior fossa.
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CT scan of a patient with a large acoustic neuroma on the right side of the brainstem. The scan was performed after injection of intravenous contrast, which is critical for identifying tumors with CT imaging.
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A CT slice through the brain of a patient with an acoustic neuroma. This slice reveals a level of the brain higher than the acoustic neuroma. The dilated third and lateral ventricles provide gross evidence of obstructive hydrocephalus due to pressure exerted by the tumor on the brainstem. A ventriculostomy, seen as a white circle in the right lateral ventricle, has been placed in an attempt to drain cerebrospinal fluid and relieve the excessive pressure above the brainstem.
