Should a patient with a history of subdural (subdural hematoma) hematoma who has been undergoing physical therapy (PT) and now reports difficulty walking undergo a repeat head computed tomography (CT) scan?

Repeat Head CT is Indicated for a Patient with Subdural Hematoma Reporting New Difficulty Walking

A repeat head CT scan is strongly indicated for this patient with a history of subdural hematoma who is now experiencing new difficulty walking, as this represents a neurological deterioration that requires immediate evaluation. 1

Decision Algorithm for Repeat Imaging in Subdural Hematoma Patients

1. Assess for neurological changes:

   • New-onset difficulty walking represents a significant neurological change
   • This constitutes "neurologic deterioration" or "new-onset, progressive, or worsening symptoms" which is a Class I recommendation for repeat imaging 1

2. Consider timing since initial injury:

   • Patient had subdural hematoma in May 2025
   • Even months after initial injury, neurological deterioration warrants imaging
   • Subdural hematomas can expand, reaccumulate, or develop complications over time

3. Evaluate risk factors for hematoma progression:

   • Gait difficulty may indicate:
     • Expansion of existing hematoma
     • Development of new bleeding
     • Increased intracranial pressure
     • Mass effect on motor pathways

Evidence-Based Rationale

The American College of Radiology guidelines explicitly state that "follow-up NCCT is indicated for any trauma patient with neurologic deterioration (class I recommendation)" 1. This patient's new difficulty walking constitutes a neurological deterioration that requires immediate evaluation.

While routine repeat imaging for mild TBI with positive findings may not be necessary in all cases, the development of new neurological symptoms fundamentally changes the clinical scenario. The 2021 ACR Appropriateness Criteria specifically notes that this recommendation applies when "the patient's neurologic examination is stable or unchanged" 1, which is not the case here.

Important Clinical Considerations

• Timing of symptom onset: Subdural hematomas can expand or reaccumulate even weeks to months after the initial injury 2

• Mechanism of deterioration: Gait disturbances may indicate:

  • Expansion of existing hematoma
  • Development of delayed hematoma
  • Conversion to chronic subdural hematoma requiring drainage
  • Pressure on motor pathways

• Risk of delayed complications: Even patients with initially small subdural hematomas can develop significant complications requiring intervention 3

Pitfalls to Avoid

1. Attributing symptoms solely to physical therapy effects: While the patient has been undergoing PT, new gait difficulties should not be assumed to be PT-related without ruling out intracranial causes.

2. Delaying imaging in elderly patients: Older patients have higher risk for subdural hematoma expansion and poorer outcomes, requiring more vigilant monitoring 4.

3. Overlooking atypical presentations: Subdural hematomas can present with unusual neurological manifestations beyond classic symptoms 5.

4. Waiting for multiple symptoms: Difficulty walking alone is sufficient to warrant repeat imaging; additional symptoms like headache or altered mental status are not required to justify imaging.

Management Approach

1. Immediate head CT without contrast

   • First-line imaging modality for evaluating subdural hematoma changes 4
   • Rapidly assesses for hematoma expansion, mass effect, or new bleeding

2. Consider MRI if CT findings don't explain symptoms

   • MRI may detect subtle changes not visible on CT 1
   • Particularly useful for evaluating parenchymal injury

3. Neurosurgical consultation if hematoma has expanded

   • Surgical intervention may be needed for significant expansion or mass effect
   • Burr hole drainage is recommended for symptomatic hematomas with mass effect 4

4. Close monitoring after imaging

   • Even if initial repeat imaging is reassuring, continued observation is warranted
   • Serial imaging may be necessary if symptoms persist or worsen

The development of difficulty walking in a patient with a history of subdural hematoma represents a significant change requiring prompt evaluation with repeat head CT to guide appropriate management and prevent potential serious complications.