Central vertigo is a clinical condition in which an individual experiences hallucinations of motion of their surroundings, or a sensation of spinning, while remaining still, as a result of dysfunction in the central nervous system (CNS).
Central vertigo may occur as a result of hemorrhage or ischemia in the cerebellum, brainstem, or vestibular nuclei. Additional causes include infection, trauma, multiple sclerosis, and CNS tumors (e.g., acoustic neuroma involving cranial nerve (CN) VIII).
In the United States, there are approximately 500,000 individuals per year, that experience a stroke. Of these, about 85% are ischemic (rather than hemorrhagic) strokes, 1.5% of which affect the cerebellum primarily. Of all patients with an isolated cerebellar infarction, approximately 10% will have a major complaint of vertigo or imbalance.
Additional causes of vertigo include multiple sclerosis, which has an incidence of approximately 10 to 80 cases per 100,000 individuals in the United States per year, and acoustic neuromas, of which there are approximately 3000 cases diagnosed per year.
Men tend to experience cerebrovascular disease more frequently than women, at a rate of about 2:1. Multiple sclerosis, on the other hand, affects twice as many women than it does men.
There is an increased incidence of cerebrovascular disease (e.g., cerebrovascular accident (CVA), stroke) with increasing age. Approximately 50% of cerebellar infarctions occur in patients aged 60 to 80 years, with the mean age being 65 years.
The vertebrobasilar arterial (VBA) system supplies blood to the brainstem, cerebellum, and peripheral labyrinths. Occlusion of the system, therefore, can result in either central or peripheral vertigo, depending on the specific artery affected. Occlusion can occur as a result of an embolism (e.g., cardioembolism or plaque from the vertebral arteries) and may result in an ischemic infarct.
Due to the level of anastomoses and retrograde blood flow via the posterior communicating arteries and the Circle of Willis, even complete occlusion of a large artery in the VBA system will not result in death.
Temporary vertebrobasilar insufficiency or ischemia (VBI) may occur as a result of decreased blood flow to the posterior circulation (VBA system). This may occur as a result of a sudden or temporary drop in blood pressure, heat or dehydration, a mechanical force on the neck, turning the neck to extreme angles (e.g., overextension), sudden postural changes or certain leg exercises. VBI may present as either a migraine or a transient ischemic attack (TIA).
Vertigo may occur in the setting of multiple sclerosis as well, generally with a waxing and waning course as a result of demyelination in the brainstem.
Acoustic neuromas, or Schwann cell tumors of the vestibular portion of CNVIII, have also been associated with central vertigo, particularly as they expand and compress surrounding structures along the brainstem.
Central vertigo is also commonly seen in the setting of trauma particularly as a result of shearing forces in the brain stem and resultant petechial hemorrhages in the vestibular nuclei.
A patient presenting with central vertigo will complain of an abnormal sensation of rotation or movement of him or herself or the environment while remaining still. Patients may additionally complain of difficulties maintaining balance or an upright posture.
Patients with central vertigo may present similarly to those with peripheral vertigo with nausea, vomiting, and auditory symptoms (e.g., tinnitus or hearing loss). Central vertigo, however, is often more gradual in onset than peripheral vertigo, and the symptoms are usually much less severe.
It is important to determine whether there are any additional symptoms present, along with the sensation of vertigo, as these may help point toward an underlying disease or cause.
The Dix-Hallpike maneuver may help differentiate between whether a patient is experiencing central versus peripheral vertigo. With the help of a physician, this test involves 45-degree rotation of the head of the patient, to one side, while he or she is helped to lie down quickly, with the neck extended slightly. If this elicits rotational nystagmus (e.g., slow eye movement in one direction followed by rapid movements in the opposite direction), the test is considered positive for peripheral vertigo. If the test is negative, it is more likely that a patient is experiencing central vertigo as a result of central nervous system (CNS) dysfunction.
Central vertigo is more commonly associated with vertical nystagmus (rather than rotational) and is typically worse with attempted gaze fixation. Peripheral vertigo often improves with gaze fixation. Additionally, dizziness associated with central vertigo is multidirectional and may change with altered gaze direction, while peripheral vertigo-associated nystagmus is unidirectional.
Aside from the Dix-Hallpike maneuver, one can elicit symptoms of vertigo with the Valsalva maneuver, sudden turning when walking, head turn standing with the eyes open, or hyperventilation for three minutes.
When a patient presents with symptoms of central vertigo, a thorough cardiac and neurological examination is warranted, especially if there are signs of altered level of consciousness. Lethargy is often the first sign of brainstem compression, but may also be associated with infarction within the brainstem or occlusion in the posterior circulation. Cardiac examination (e.g., electrocardiogram (ECG), echocardiogram) may help point toward a potential source for an embolus or other irregularities such as atrial fibrillation or bradycardia.
If a central lesion is suspected, magnetic resonance imaging (MRI) is the imaging modality of choice for visualization of a potential infarction, tumor, hemorrhage, or evidence of demyelination that would be associated with multiple sclerosis. Although, computed tomography (CT) may be employed if MRI is unavailable. Intra-arterial angiography has been classically employed to detect any occlusions in the VBA system, though less invasive techniques (e.g., CT, angiography, magnetic resonance angiography (MRA), and Doppler ultrasonography) are becoming more popular modalities of choice.
Finally, laboratory studies may be helpful in ruling out other potential causes of disequilibrium or light-headedness (e.g., anemia, pregnancy, serum electrolyte imbalances, hypoglycemia).
The initial step in approaching a patient complaining of vertigo is to determine whether they are in fact experiencing vertigo and not another form of dizziness from a migraine, medication, or alcohol. Once a diagnosis of central vertigo has been established, treatment is aimed at resolving the underlying cause. Medications like antihistamines or benzodiazepines may be used to help alleviate symptoms. Additionally, patients are encouraged to lie still in bed, while they receive rehydration and medication for symptomatic relief.
Imaging studies should be done as soon as possible with a patient complaining of vertigo, and the patient should not be left unattended until a thorough examination is complete and a diagnosis is made.
Thrombolytic therapy may be considered if the patient is suffering from an acute ischemic stroke, although it is critical to be aware of any contraindications (e.g., recent surgery, severe hypertension, evidence of acute hemorrhage or edema, or rapidly improving symptoms).
Anticoagulant medication should not be administered until the potential for intracranial hemorrhage has been completely ruled out.
Patients with an altered level of consciousness warrant an ECG, pulse oximetry, and extremely close supervision. If a patient continues to deteriorate, emergent interventions may be required to decreased intracranial pressure (ICP) and minimize compression of the brainstem These interventions may include endotracheal intubation with or without hyperventilation, aggressive diuresis, and corticosteroids.
Finally, a neurologic consultation is warranted for a patient complaining of vertigo, and a neurosurgical consultation is necessary if an underlying hemorrhage, edema, or brainstem compression is discovered, as surgical decompression (e.g., ventriculostomy or craniectomy) may be required.