NUR 560 Module 7 Milestone Two Example

Milestone Two: Sudden Vertigo in a 61-Year-Old Man, and Why the Head Impulse Test Decided

[Student Name]

Southern New Hampshire University

NUR 560: Advanced Health Assessment and Clinical Reasoning

Milestone Two

[Instructor Name]

[Date]

The organization, setting and figures below are a composite written as a model document. No real employer, client, colleague or patient is described.

Milestone Two: Sudden Vertigo in a 61-Year-Old Man, and Why the Head Impulse Test Decided

Dizziness is among the most common reasons adults seek urgent care, and most causes are benign. A small share are strokes in the posterior circulation, which can look almost exactly like an inner-ear disorder at the bedside and are among the most frequently missed strokes. This milestone examines a composite 61-year-old man with sudden, continuous vertigo. It argues that his presentation is an acute vestibular syndrome, that his vascular risk and a normal head impulse test make stroke the leading diagnosis despite a normal CT and no limb weakness, and that a structured bedside examination outperforms early imaging in this setting.

History

The spinning started when he woke before dawn. The vertigo has been continuous for ten hours, worse with head movement but present at rest. He has vomited four times and cannot walk without holding the wall. He denies hearing loss, tinnitus, ear fullness, headache, double vision, slurred speech, trouble swallowing, facial numbness or limb weakness. He has had no previous episodes and no recent viral illness. His history includes hypertension, type 2 diabetes and 40 pack-years of smoking.

Three features of the history mattered most. The vertigo is continuous rather than brief and triggered, which moves the problem away from benign positional vertigo. It began suddenly and has lasted hours, which fits both vestibular neuritis and stroke. And his vascular risk profile raises the prior probability of stroke well above that of a younger patient without risk factors.

Naming the Syndrome

Vertigo that starts suddenly and persists for at least a day, together with nausea or vomiting, gait unsteadiness, nystagmus and intolerance of head motion, is called the acute vestibular syndrome. Most cases are caused by vestibular neuritis, but a meaningful minority are posterior circulation strokes, usually in the cerebellum or lateral medulla (Tarnutzer et al., 2011). Naming the syndrome is useful because it tells the clinician which bedside tests have been validated. The HINTS examination was studied in exactly this group and should not be applied to brief, triggered dizziness, in which a normal head impulse is expected and meaningless.

Examination

Blood pressure is 172/94 mm Hg, heart rate 84 and regular, and glucose 168 mg/dL. He is alert and speaks clearly. Cranial nerves are intact apart from the eye findings, strength and sensation are normal in all limbs and finger-to-nose testing is accurate. He cannot stand without support, and when seated upright without his hands he leans to the left.

The three HINTS steps gave the following. Head impulse: when his head was turned quickly to each side while he fixed on the examiner's nose, his eyes stayed on target with no corrective saccade in either direction. Nystagmus: he had left-beating nystagmus in primary gaze that became right-beating on right gaze. Test of skew: on alternate cover testing, the left eye made a small vertical correction.

Interpreting HINTS

Each of his three findings points centrally. In vestibular neuritis the damaged nerve cannot drive the reflex that holds the eyes steady, so a quick head turn toward the affected side produces a catch-up saccade; a normal head impulse in a patient with continuous vertigo is therefore a warning sign, because it suggests the peripheral reflex is intact and the problem lies in the brain. Nystagmus that changes direction with gaze is a central sign, since peripheral nystagmus beats in one direction. Skew deviation, a vertical misalignment, also points to a brainstem lesion.

In the original study of high-risk patients with the acute vestibular syndrome, a HINTS pattern suggesting a central cause was 100% sensitive and 96% specific for stroke, and it outperformed early MRI with diffusion-weighted imaging, which was falsely negative in 12% of strokes when performed in the first 48 hours (Kattah et al., 2009). A later systematic review reached the same conclusion and found that the general neurological examination was not enough on its own, because many of these strokes produce no limb weakness or speech changes (Tarnutzer et al., 2011). His severe truncal ataxia, the inability to sit or stand unsupported, added further weight.

Summary Statement and Ranked Differential

Summary statement: a 61-year-old man with hypertension, diabetes and heavy smoking who has an acute vestibular syndrome of ten hours with a normal head impulse test, direction-changing nystagmus, skew deviation and severe truncal ataxia but no limb findings.

1. Posterior circulation stroke, most likely cerebellar or lateral medullary. For: vascular risk, all three central HINTS findings, severe truncal ataxia. Against: normal limb examination and normal CT, neither of which excludes it.

2. Vestibular neuritis. For: sudden continuous vertigo without hearing loss is its usual pattern. Against: normal head impulse, direction-changing nystagmus and skew.

3. Labyrinthitis. Against: no hearing loss or tinnitus, and the same central findings.

4. Vestibular migraine. Against: no migraine history, no headache, first episode at 61.

5. Benign paroxysmal positional vertigo. Against: vertigo is continuous and present at rest rather than brief and triggered by position.

Why the CT Did Not Settle It

A noncontrast CT of the head, done before the HINTS examination, was normal. CT is useful to exclude hemorrhage but sees early infarcts in the posterior fossa poorly, because bone near the brainstem and cerebellum obscures the image. Treating that normal CT as reassurance would have been a framing error: the scan answered whether there was a bleed, not whether there was an infarct. Recognizing what a test can and cannot answer is central to diagnostic reasoning (Bowen, 2006). Here, the bedside findings carried more information than the first image.

Plan and What Would Change It

He is treated as a suspected posterior circulation stroke. The stroke team is activated, with urgent MRI with diffusion-weighted imaging and vascular imaging of the vertebral and basilar arteries, and a decision on acute treatment based on timing and eligibility. He is kept nil by mouth until a swallow screen is completed, monitored closely for drowsiness or new brainstem signs, because swelling after a cerebellar infarct can compress the brainstem, and given antiemetics. If an early MRI is negative while the central HINTS findings persist, the clinical diagnosis stands, and repeat imaging is considered. A corrective saccade on repeat head impulse testing, unidirectional nystagmus and no skew would favor vestibular neuritis, while new hearing loss would widen the differential to include an infarct of the inner ear's blood supply.

His MRI later that day showed an acute infarct in the left cerebellar hemisphere.

Conclusion

This man's continuous vertigo, vomiting and inability to walk were an acute vestibular syndrome, and his normal limb examination and normal CT could easily have led to a diagnosis of an inner-ear disorder. The three-step HINTS examination, applied to the group for which it was validated, pointed firmly to a central cause, and imaging confirmed a cerebellar stroke. The milestone shows why defining the syndrome, understanding what each test answers and trusting validated bedside findings can prevent one of the most commonly missed strokes.

References

Bowen, J. L. (2006). Educational strategies to promote clinical diagnostic reasoning. New England Journal of Medicine, 355(21), 2217-2225. https://doi.org/10.1056/NEJMra054782

Kattah, J. C., Talkad, A. V., Wang, D. Z., Hsieh, Y.-H., & Newman-Toker, D. E. (2009). HINTS to diagnose stroke in the acute vestibular syndrome: Three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging. Stroke, 40(11), 3504-3510. https://doi.org/10.1161/STROKEAHA.109.551234

Tarnutzer, A. A., Berkowitz, A. L., Robinson, K. A., Hsieh, Y.-H., & Newman-Toker, D. E. (2011). Does my dizzy patient have a stroke? A systematic review of bedside diagnosis in acute vestibular syndrome. Canadian Medical Association Journal, 183(9), E571-E592. https://doi.org/10.1503/cmaj.100174