Head CT in an Elderly Patient with Acute Confusion
An 82-year-old woman is brought to the emergency department by family after 12 hours of confusion and a fall at home. She takes warfarin for a mechanical mitral valve (INR 2.8 today) and has a history of hypertension. On examination she is drowsy but arousable, follows simple commands, and has a mild left pronator drift. There is a small scalp hematoma over the right parietal region. Noncontrast head CT shows a hyperdense crescentic collection over the right cerebral convexity, approximately 8 mm thick, with mild effacement of the right sulci but no midline shift. There is also a small hypodense focus in the right frontal white matter consistent with chronic microvascular disease. She is admitted for observation.
1. What is the diagnosis and what does the imaging pattern tell you about acuity and mechanism?
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The hyperdense crescentic extra-axial collection over the convexity is an acute subdural hematoma. The crescent shape reflects blood spreading in the subdural space, which is not constrained by sutures. Hyperdensity on noncontrast CT indicates acute hemorrhage. The absence of midline shift and the mild sulcal effacement suggest a modest volume without significant mass effect at this time.
The mechanism in an elderly patient on anticoagulation is typically bridging vein injury from minor trauma (the fall), and the frontal white matter hypodensity reflects chronic small-vessel disease, which is a risk factor for falls and for hematoma expansion. The mild pronator drift indicates some cortical dysfunction, so this is not a purely incidental finding.
The critical judgment: a subdural hematoma in a patient on warfarin with a therapeutic INR is at high risk for delayed expansion, even if the initial CT looks modest. Observation alone with a single CT is not sufficient.
2. What immediate management and imaging follow-up would you recommend?
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- Reverse anticoagulation: give vitamin K (10 mg IV) and prothrombin complex concentrate (PCC) to correct the INR urgently, given the intracranial hemorrhage. Fresh frozen plasma is an alternative if PCC is unavailable. The target is rapid INR correction to <1.4.
- Hold warfarin. Coordinate with cardiology regarding the mechanical mitral valve - the thrombotic risk of stopping anticoagulation must be balanced against the hemorrhagic risk, and bridging with heparin is generally deferred until the hematoma is stable.
- Neurosurgical consultation: the hematoma is small and there is no midline shift, so evacuation is not immediately indicated, but the patient needs serial neurologic exams.
- Repeat noncontrast head CT within 6–12 hours (or sooner if neurologic deterioration) to assess for expansion. A follow-up CT in 24 hours is also standard.
- Admit to a monitored bed; avoid antiplatelet agents and NSAIDs.
The judgment point is that anticoagulation reversal is the priority and should not wait for the repeat scan, and that a "small" subdural in an anticoagulated elderly patient is a high-risk lesion requiring serial imaging, not a discharge diagnosis.