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Introduction References
Case Outcome Annotated
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the World Turns: Vertigo in the Emergency Department Case Presentation A 67 year-old man rolled over in bed early in the morning and suddenly developed severe nausea as well as the unpleasant sensation that the room was spinning around him. The spinning resolved within 30 seconds but recurred again in the opposite direction when he rolled back to his original position. This had never happened to him before. The patient denied tinnitus, hearing loss, recent viral illness, or head trauma. The patient's past medical history was remarkable only for hypertension for which he took atenolol. Surgical history was unremarkable. He did not smoke, drank only occasionally, and denied illicit drug use. Family history was non-contributory. He had no known drug allergies. Vital signs
revealed a temperature of 37.2, pulse of 70, BP of 140/85, respirations
of 12/minute, and oxygen saturation of 98%. The head, eyes, ears, neck,
and cardiac examinations were unremarkable. A detailed neurological
examination, including mental status, cranial nerves, motor function,
sensory function, and cerebellar function, was normal. A Hallpike (aka
Nylan-Barany) test was performed and showed torsional nystagmus in the
right head-hanging position, along with reproduction of the patient's
symptoms.
As the World Turns: Vertigo in the Emergency Department Introduction Benign Paroxysmal Positional Vertigo Background, Risk Factors and Epidemiology Evaluating the dizzy patient can be difficult, since dizziness is a nonspecific symptom and is difficult to objectively measure. The four major causes of dizziness are vertigo, near-syncope, disequilibrium, and psychogenic dizziness (1,2). Vertigo is the most common cause of dizziness, and benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo. Vertigo, which is an illusion of motion, is classically described as "the room is spinning." However, it is important to realize that patients may use alternative descriptions, such as rocking, tilting, somersaulting, and descending in an elevator. All that matters is that there is an illusion of motion. BPPV is usually a disease of the elderly (3). Younger patients may also develop BPPV, especially if there is a history of head trauma. Many ED physicians treat vertigo with an antiemetic and intravenous fluids, and then discharge the patient with meclizine (Antivert). Unfortunately, the prescription of meclizine tends to be a knee-jerk reaction to the chief complaint of dizziness. Although useful in patients with vertigo, this medication may actually worsen symptoms in patients who have one of the other causes of dizziness. In BPPV, the need for meclizine may be moot as the disease can often be cured with a simple bedside maneuver.
The labyrinth of the inner
ear is composed of the vestibule (made up of the sac-like utricle and
saccule) and the 3 semicircular canals. These structures are interconnected
and are filled with endolymph. Receptors are located in each structure
which inform the brain about the head's position in space. In addition
to endolymph, the utricle is unique in that it also contains calcium oxalate
crystals called otoliths or otoconia. These otoliths are attached to ciliary
hairs on top of a membrane. Since the otoliths are denser than the surrounding
endolymph, they are pulled down by gravity. When the head is tilted up
or down, the otoliths bend the hair cells and trigger linear receptors,
which inform the brain about head-tilt position in space.
The BPPV patient typically moves his head and develops nausea and vertigo after a few seconds delay. This usually resolves in less than one minute once the head stops moving. If the patient then turns his head to the original position, the otoliths reverse direction and the room will seem to spin in the opposite direction. Most BPPV patients are nauseated and some may vomit. Patients quickly learn to avoid head positions which provoke the vertigo. The neurological examination is completely nonfocal. This is a useful distinguishing feature that differentiates peripheral from central vertigo. In central vertigo, either the cerebellum or vestibular nuclei within the brainstem are affected. Since the vestibular nuclei are so closely located to other nuclei and various axonal tracts, it would be extremely unlikely for a central nervous system lesion to affect only the vestibular nuclei and not other systems as well. All vertigo patients should receive a Hallpike (also known as Nylan-Barany) test. In this diagnostic test, the patient is sat upright in the gurney with the head turned 45 degrees to either side. The examiner grasps the patient's head and gently lays the patient down to the supine position with the head hanging over the edge of the bed. The patient is told to keep his eyes open. The examiner looks for signs of torsional or rotatory nystagmus and asks the patient if his symptoms recur. The patient is returned to the upright position and the test is repeated with the head turned in the opposite direction. Only one side is usually symptomatic, and it is this side that serves as the starting point for the Epley maneuver (to be discussed in the procedure section).
If the history is classic and the patient has a positive Hallpike test (defined as torsional or rotatory nystagmus along with reproduction of symptoms while in the head-hanging position), then the ED physician can be confident that he is treating BPPV. No laboratory tests are mandatory in such a case, with the exception of checking electrolytes if the patient has had prolonged vomiting. Other laboratory tests may be ordered if the diagnosis is in doubt. For example, a dizzy diabetic patient should have a blood sugar level to rule out hypoglycemia. A hemoglobin or hematocrit can also be checked to rule out anemia as a cause of dizziness.
If the examiner is confident that the diagnosis is BPPV, then no further imaging studies need to be performed. If the examiner is not confident of the diagnosis or if the patient has a focal neurological examination, then a non-contrast cranial CT should be performed as an initial screening test.
The Epley maneuver, also known as the canalith repositioning maneuver, was first described in 1992 (5). Multiple trials suggest that it is an effective treatment for BPPV (6,7). Epley originally pretreated patients and used a mastoid oscillator. Most clinicians perform a modified version (no pretreatment, no mastoid oscillation), and this is described as follows: the patient's head is turned 45 degrees to the side that demonstrated nystagmus and reproduction of symptoms during the diagnostic Hallpike test. As in the Hallpike test, the patient is guided to the supine position with the head hanging over the edge of the gurney. The head is then rotated 90 degrees in the opposite direction with the face upwards, maintaining a dependent position. The patient is then asked to roll onto his side and rotate his head so that he is looking straight to the ground. The patient is then raised to a sitting position while maintaining head rotation. Finally, the head is rotated to a central position and moved forward 45 degrees. The patient should be warned that he will become symptomatic with each turn of the head. Each position should be held at least 30 seconds, or until nystagmus and reproduction of symptoms has resolved. It is not clear whether the Epley maneuver should be repeated multiple times. Epley himself performs the maneuver up to approximately 5 times (personal communication). Other experts perform the maneuver only one time since they feel that the particles will just continually reintroduce themselves into the canals if the procedure is repeated. The Epley maneuver takes approximately 2-3 minutes to perform and is done at the patient's bedside. Aside from the expected reproduction of symptoms and occasional vomiting, there have been no reported adverse events from performing the Epley maneuver. Contrary to popular belief, each part of the Epley maneuver does not need to be done rapidly. After the maneuver, patients are generally advised to stay in an upright position. Once the otoliths re-enter the utricle, they need time to reattach to the hair cells and membrane. The time required for this process is not clear, but it is generally advised that at least 8 hours are needed before the patient can assume a supine position. Contraindications to performing the Epley maneuver include unstable heart disease, high grade carotid stenosis, ongoing CNS disease (stroke or TIA), and severe neck disease (8). Relative contraindications include pregnant women beyond the 24th week gestation (to avoid the supine hypotension syndrome).
What is convenient about BPPV is that no laboratory tests or imaging tests are usually needed. In addition, the patient often does not require the placement of an intravenous line unless he is actively vomiting or is dehydrated. Instead, the ED physician physically lays his hands on the patient and "cures" him right at the bedside. This is extremely gratifying to both the patient and the physician performing the maneuver. If the Epley maneuver fails or if the patient needs medication immediately for acute vomiting, then one of 3 classes of vestibular suppressants should be used. The sensory conflict theory states that when there is a mismatch of information from any 2 of the 3 inputs (vestibular, visual, proprioceptive), then in the acute phase nausea and emesis result, but with time, habituation occurs. There are 3 main neurotransmitters that regulate this system: GABA agonists, anticholinergics, and antihistaminics. Intravenous promethazine (Phenergan) is felt by many to be the most appropriate medication in the ED setting. This medication works quickly to relieve vomiting and vertigo through both its antihistaminic and anticholinergic effects. This medication is, however, somewhat sedating. Scopalamine, which is recommended in several textbooks, has a delayed onset of 4-6 hours and hence is not appropriate for the acute treatment of BPPV in the ED. Intravenous benzodiazepines also have some benefit, but many experts avoid them since they can prevent the process of vestibular rehabilitation.
In general, most patients with BPPV respond to the Epley maneuver and can be discharged home. Those with persistent vomiting and vertigo, or those who cannot ambulate may need to be admitted to the hospital. Consultation with a neurologist or otolaryngologist may be appropriate if the diagnosis is in doubt or if the patient is not responding to the Epley maneuver. These patients often have an alternative diagnosis, such as vestibular neuritis.
As the World Turns: Vertigo in the Emergency Department Case Outcome Diagnosis: Benign paroxysmal positional vertigo (BPPV) Given a classic history,
a nonfocal neurological examination, and a positive Hallpike test (torsional
nystagmus and reproduction of symptoms in the right head-hanging position),
it was felt that the patient had BPPV. The patient received the Epley
maneuver with complete resolution of symptoms. His length of stay was
only 20 minutes, and he did not require laboratory work, imaging studies,
or even an intravenous line. He was extremely pleased with his care
in the ED.
1. Answer e. 2. Answer e. 3. Answer b. 4. Answer d 5. Answer a |