Mr. W, aged 57 years, presented to the ED complaining of severe dizziness. The man reported that the disequilibrium was with him when he woke up two days ago and was accompanied by vomiting. Mr. W thought the feeling of unsteadiness would go away, but it had not abated. Moving his head or opening his eyes made the dizziness worse.
Mr. W was not taking any medications. During consult, Mr. W noted recently battling sinus congestion and an accompanying headache behind his left eye. He had used a Neti pot for relief. No recent fever, ear problem or tinnitus were reported, and Mr. W had no history of dizziness or head or neck trauma. There was no family history of heart attack, stroke or diabetes.
Mr. W was afebrile, and his BP was normotensive (117/71 mm Hg). Pulse was 60 beats per minute and respiration 16 breaths per minute. Mr. W was alert and oriented. Ear, nose and throat all appeared normal. Cranial nerves II through XII were all intact. Horizontal nystagmus to the left was noted, and the Dix-Hallpike test was mildly positive. Finger-to-nose and heel-to-shin movements were normal. Mr. W had no pronator drift. Deep tendon reflexes were a normal 2+ throughout. Mr. W was able to stand at the side of the bed and had a negative Romberg test. Musculoskeletal strength was 5/5 in all four extremities with no numbness or tingling anywhere.
3. Diagnosis and treatment
Mr. W was given promethazine (Phenergan) to control the nausea and vomiting. Complete blood count and electrolytes came back normal 45 minutes later. Although Mr. W’s orthostatic vital signs were normal, a neurological exam was repeated, showing no real changes. As the Dix-Hallpike test was not convincing for vertigo, a CT scan of the head was ordered. The CT was negative for a bleed.
As Mr. W tried to walk, staff noticed that his gait was severely affected. A subsequent MRI revealed that Mr. W had an acute left cerebellar infarction. A magnetic resonance angiogram of the head and neck was ordered showing a vertebral artery dissection in the C1-C2 area. He was diagnosed with a cerebellar stroke causing acute vestibular syndrome (AVS).
Mr. W was admitted to telemetry and placed on aspirin. Lipids, carotids, and all other workups were negative. Mr. W was discharged two days later and able to walk without assistive devices after physical and occupational therapy. Within two weeks, Mr. W’s gait had returned to normal.
Dizziness is a common complaint in ambulatory care, comprising 4% to 5% of all visits. AVS is characterized by rapid onset of vertigo, nausea/vomiting, nystagmus and head-motion intolerance. Vertigo is a symptom, not a diagnosis. While this case study is only concerned with vestibular (32.9%) and neurologic (11.2%) causes of vertigo, other causes are cardiovascular (21%), respiratory (11%), metabolic (11%), injury/poisoning (11%), GI/genitourinary (12%) and infectious (2.9%).1
The best diagnostic approach is to ascertain the timing and triggers of a patient’s dizziness.1 This will help differentiate between peripheral and central causes of AVS.
There are three basic timing patterns of vertigo. Acute spontaneous vertigo slowly improves over days and weeks. The main differentiation here is between vestibular neuritis (peripheral) and a cerebellar or brainstem stroke (central); other concerns are multiple sclerosis, labyrinthitis, neoplasms and Chiari malformation. Episodic vertigo lasts from minutes to hours. The main differentiation here is between migrainous vertigo and vertebrobasilar transient ischemic attacks. Brief episodes of positional vertigo last from seconds to minutes. The usual cause of this is benign positional vertigo (BPV).
With vertigo, a prime concern is to not overlook causes that could be fatal. Not all patients with cerebellar infarction will present with focal neural deficits. A study of persons with cerebellar infarcts identified 10.4% who presented only with symptoms of isolated vertigo.2 The remainder had more neurologic symptoms, which led to a diagnosis of a cerebellar infarct. We can identify the roughly 10% of patients who have isolated vertigo with the HINTS (Head Impulse, Nystagmus, Test of Skew) tests.3 These simple, bedside tests are more accurate than an MRI within the first 48 hours. Abnormal results can be remembered by the acronym INFARCT (Impulse Normal, Fast-phase alternating, Refixation on Cover Test).3 Lastly, the Dix-Hallpike test should be performed because despite its low sensitivity, this test does direct to the diagnosis of BPV.
If a radiologic exam is necessary, an MRI is first choice, followed by thin-slice CT. A recent study showed that MRI is superior to CT for detection of acute ischemia and for suspected acute stroke.4 Do not completely rely on the diffusion-weighted MRI; one study reported up to a 31 % false-negative rate in the first 24 hours of a stroke, with posterior and brainstem strokes representing the majority missed.5
The causes of dizziness run the gamut from a small infection to stroke. AVS can safely be worked up to determine whether the cause is central or peripheral. Once you have determined that the patient has a peripheral AVS, the Dix-Hallpike test can be useful in diagnosing BPV despite a 70% sensitivity rate.
If there is a central cause to the AVS, then an MRI is the radiologic tool of choice, with the caveat that sensitivity improves with time, especially after 48 hours.
Sigfried Emme, NP-C, CEN, CCRN, is a family nurse practitioner specializing in emergency care at McKee Medical Center in Loveland, Colo.
1. Newman-Toker DE, Cannon LM, Stofferahn ME, et al. Imprecision in patient reports of dizziness symptom quality: a cross-sectional study conducted in an acute care setting. Mayo Clin Proc. 2007;82:1329-1340.
2. Lee H, Sohn SI, Cho YW, et al. Cerebellar infarction presenting isolated vertigo: frequency and vascular topographical patterns. Neurology. 2006;67:1178-1183.
3. Kattah JC, Talkad AV, Wang DZ, et al. HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging. Stroke. 2009;40: 3504-3510.
4. Chalela JA, Kidwell CS, Nentwich LM, et al. Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison. Lancet. 2007;369:293-298.
All electronic documents accessed March 5, 2012.