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Difficulty: HardInterpreting Imaging Results

A 7272-year-old man is brought to the emergency department by his daughter due to progressive confusion, frequent falls, and a slow, shuffling gait that has worsened over the past three weeks. His medical history includes hypertension, mild cognitive impairment, and coronary artery disease, for which he takes aspirin and lisinopril. Vital signs are within normal limits. Neurological examination reveals a delayed response to questions, mild left-sided hemiparesis, and a pronator drift in the left arm. A non-contrast head CT is performed. The preliminary interpretation by the radiology resident states 'no acute intracranial hemorrhage; normal age-related volume loss.' However, your careful review of the images reveals unilateral effacement of the cortical sulci over the right cerebral hemisphere, medial displacement of the gray-white matter junction, and a 55-mm leftward midline shift. The extra-axial space over the right convexity shares the exact same radiodensity (attenuation) as the adjacent cerebral cortex.

Based on your interpretation of these imaging findings, which of the following is the most appropriate next step in patient management?

  1. Consult neurosurgery for management of a subacute subdural hematomaAnswer
  2. B
    Order an emergent magnetic resonance imaging (MRI) of the brain to evaluate for ischemic stroke
  3. C
    Perform a high-volume lumbar puncture to assess for normal pressure hydrocephalus
  4. D
    Discharge the patient with a referral to physical therapy for age-related gait instability
  5. E
    Administer intravenous alteplase and admit to the neuro-intensive care unit

Answer

Consult neurosurgery for management of a subacute subdural hematoma
The correct answer is to consult neurosurgery for management of a subacute subdural hematoma. The patient's CT scan describes a classic isodense subdural hematoma, which typically occurs 11 to 33 weeks after an inciting event (often mild trauma in the elderly). Because the decomposing blood becomes isodense to the adjacent cerebral cortex, the fluid collection itself can be nearly invisible. The diagnosis relies heavily on recognizing secondary signs of mass effect, including unilateral sulcal effacement, medial displacement (buckling) of the gray-white matter junction, and midline shift. Given the patient's symptomatic presentation (hemiparesis, confusion) and significant mass effect, urgent neurosurgical consultation is required for possible evacuation.

Step-by-Step Solution

1
Analyze the clinical presentation.
A 72-year-old man presents with a 3-week history of progressive confusion, falls, and new-onset left-sided hemiparesis.
Establishes a subacute timeline and lateralizing neurological deficits pointing to a right-sided cortical or extra-axial lesion.
2
Interpret the specific CT head findings.
Unilateral right-sided sulcal effacement, a 5-mm leftward midline shift, and an extra-axial space that is isodense to the adjacent cortex.
Mass effect indicates a space-occupying lesion. The isodense nature of the extra-axial collection is the classic radiologic signature of a subacute hematoma.
3
Synthesize the clinical and radiologic data to form a diagnosis.
The patient has a symptomatic subacute right-sided subdural hematoma.
Subdural blood transitions from hyperdense (acute) to isodense (subacute, 1-3 weeks) to hypodense (chronic). The timeline and imaging perfectly align.
4
Determine the appropriate management.
Immediate neurosurgical consultation is required.
The patient is symptomatic with significant midline shift, indicating impending or actual risk of herniation, which may necessitate surgical evacuation.

Key Concept

Subacute subdural hematomas (1 to 3 weeks old) are isodense to the cerebral cortex on non-contrast CT and can be subtly identified by unilateral sulcal effacement, medial buckling of the gray-white matter junction, and midline shift.
Estimated Time:1m 30s
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Interpreting Imaging Results

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