Emergency Department Care
First, distinguish true vertigo from disequilibrium and other forms of dizziness. Ascertaining this history from patients sometimes requires patience and persistence. Once the presence of vertigo or disequilibrium has been confirmed, consider a central cause. Evaluate on the basis of a careful history and physical examination and liberal use of imaging studies of the posterior fossa.
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Therapy usually targets the etiology of the symptoms. However, a variety of medications may be used to reduce symptoms of central vertigo, including antihistamines and benzodiazepines.
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Regardless of the vertigo's etiology, attempt to alleviate the patient's suffering.
Place intravenous lines to rehydrate patients.
Allow patients to lie still in bed as desired.
Administer parenteral medicines for symptomatic relief.
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If clinical and radiologic evaluation suggest an acute ischemic stroke, consider thrombolytic therapy after thorough evaluation and consultation.
Thrombolytic therapy is administered with an intra-arterial catheter close to the clot [19] , or intravenously, if within 3 hours of the onset of symptoms and no other contraindications exist. [20]
Prior to using thrombolytic therapy, consider several issues, especially the risk of intracerebral bleeding. Emergency physicians should be familiar with contraindications such as major surgery within the previous 10 days, severe hypertension, evidence of acute bleed or edema on CT scan, and rapidly improving symptoms.
The decision to administer thrombolytic therapy preferably is made with direct neurologic consultation and only after the patient has received a thorough explanation of the procedure and given informed consent. This therapy is discussed further in other articles (see Stroke, Ischemic and Thrombolytic Therapy).
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Lethargic patients or those with altered level of consciousness require vigilance and close supervision, including direct visual, ECG, and pulse oximetry monitoring.
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Do not administer anticoagulant medicine, including aspirin, until intracranial hemorrhage has been ruled out by imaging.
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Imaging studies should be performed expeditiously, and the patient never should be left unattended by clinical personnel in the imaging suite.
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Patients with altered consciousness and a deteriorating course in the ED may require emergent interventions to minimize edema and brainstem compression.
As the posterior fossa is a relatively small and nonexpandable space, hemorrhage or edema can lead to rapid compression and compromise of vital medullary functions, obstructive hydrocephalus, or herniation of the medullary tonsils.
Invasive actions may include endotracheal intubation to protect the airway, control breathing, and allow therapeutic hyperventilation.
Consider elevating the head of the bed, performing diuresis with mannitol or furosemide, and administering dexamethasone.
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Preliminary evidence suggests that recombinant activated factor VII may be useful for acute hemorrhagic stroke when administered within 4 hours of symptom onset. [21] The data supporting the use of this therapy for hemorrhagic cerebellar stroke is too limited thus far to make a therapeutic recommendation, but further results are expected to clarify its utility and adverse effect profile.
Consultations
Obtain neurologic consultation for patients with central vertigo, and consider neurosurgical consultation for all patients with space-occupying lesions or hydrocephalus.
The emergency physician should seek immediate neurosurgical consultation for patients with hemorrhage, brainstem compression, or edema, as surgical decompression via suboccipital craniectomy or ventriculostomy may be lifesaving.
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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.
