Dizziness, an NIHSS of 2, and a Premature Discharge Plan
A 58-year-old woman with hypertension and a 30-pack-year smoking history presents at 09:20 with sudden onset at 07:45 of 'the room spinning,' two episodes of vomiting, double vision, and veering to the right when she walks. She is pale and diaphoretic. BP 168/94 mmHg. She is alert and oriented, speech is fluent, and she follows commands. Examination shows direction-changing horizontal nystagmus, impaired right finger-to-nose and right heel-to-shin, gait ataxia, and decreased pinprick on the left arm. NIHSS is scored as 2 (ataxia, right arm and leg only). Glucose 104 mg/dL. She takes no anticoagulants, has no bleeding history, and has no contraindications to fibrinolysis. Noncontrast head CT is normal. The ED resident documents 'peripheral vertigo, likely vestibular neuritis' and asks you to cosign discharge with meclizine.
1. What is wrong with the resident's assessment, and what is your immediate plan?
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This is a posterior circulation stroke until proven otherwise, and the low NIHSS is a trap.
Errors in the plan:
- Direction-changing (bidirectional) nystagmus is a central finding on the HINTS exam; peripheral lesions produce unidirectional, suppressed-by-fixation nystagmus. The resident apparently did not perform or interpret HINTS.
- Crossed findings - right-sided limb and gait ataxia with left-sided pinprick loss - localize to the brainstem (lateral medulla or pons), not the labyrinth.
- New double vision and gait ataxia are disabling deficits that the NIHSS scores poorly in posterior circulation disease. An NIHSS of 2 does not mean a small or benign stroke.
Immediate actions:
- Call it a stroke alert. Obtain CTA of the head and neck to assess the vertebrobasilar system (basilar occlusion is a reperfusion emergency).
- She is 95 minutes from onset with no contraindications: give IV thrombolysis for disabling deficits, after BP <185/110. Do not wait for MRI.
- Admit to a stroke unit, keep NPO until a swallow screen, and start a repeat NIHSS and serial cranial nerve checks.
- Cancel the meclizine-and-discharge plan; document the reasoning in the chart.
2. The noncontrast CT is completely normal. How does that affect your decision, and what does an early MRI add?
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A normal noncontrast CT does not change the decision to treat.
- In the first hours, CT is used to exclude hemorrhage, not to confirm ischemia. Posterior fossa infarcts are especially poorly seen because of beam-hardening artifact from the skull base.
- MRI DWI is more sensitive, but in acute vestibular syndrome, HINTS performed by a trained examiner is more sensitive than early DWI within the first 24–48 hours for distinguishing central from peripheral causes. A negative DWI in the first day does not exclude a small brainstem stroke.
- Therefore MRI is useful for confirmation, for characterizing the extent of the infarct, and for later etiologic workup, but it should not delay thrombolysis.
- If imaging is repeated and remains negative but the exam is central, manage her as a stroke: telemetry, swallowing screen, vascular imaging, echocardiogram, and risk factor treatment.
3. Ninety minutes after arrival her symptoms have fully resolved and NIHSS is 0. Does she still receive thrombolysis? What is the plan?
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No - and the plan changes, but does not become discharge.
- Fibrinolysis is indicated for disabling deficits. With complete resolution, there is no deficit to treat, and the bleeding risk is not justified.
- Transient brainstem symptoms with a normal CT are a TIA/minor stroke until proven otherwise - high early recurrence risk, particularly for vertebrobasilar disease. Admit, obtain MRI and CTA/MRA, and start telemetry.
- If imaging confirms a minor nondisabling infarct or high-risk TIA, short-term dual antiplatelet therapy (aspirin plus clopidogrel, 21 days) is reasonable, along with high-intensity statin therapy and blood pressure management.
- Screen swallowing, mobilize with assistance, and do not discharge from the ED on meclizine.