When should a repeat head (Computed Tomography) CT scan be done for a possible brain bleed if symptoms are worsening?

Repeat Head CT Timing for Worsening Symptoms in Possible Brain Bleed

A repeat head CT scan should be performed immediately when symptoms are worsening in a patient with possible brain bleed, regardless of the time since the initial scan. 1

Timing Based on Type of Brain Bleed

Spontaneous Intracerebral Hemorrhage (ICH)

• Hemorrhage expansion (HE) occurs early after ICH and is an independent predictor of mortality and poor functional outcome 1
• Most HE occurs within the first 6 hours after ICH onset, with decreasing frequency between 6-24 hours 1
• Follow-up CT scans at approximately 6 and 24 hours after onset are adequate to exclude HE and document final ICH volume in patients with stable examination 1
• Delayed intraventricular hemorrhage (IVH) can occur in 21% of patients with no initial IVH, sometimes beyond 24 hours 1

Traumatic Brain Injury (TBI)

• Repeat head CT is strongly indicated for any patient with neurologic deterioration, regardless of the time since injury (Class I recommendation) 1
• For moderate to severe TBI, routine follow-up CT is supported regardless of neurological status (Class I recommendation) 1
• For mild TBI with positive initial CT findings, repeat imaging may be guided by clinical factors rather than routine protocols 1, 2
• Patients on anticoagulation therapy with initial CT abnormalities have a 3-fold higher risk of bleeding progression (26% vs 9%) and should have follow-up imaging 1, 3

Algorithm for Repeat Head CT Based on Clinical Scenario

1. Immediate repeat CT (within minutes to hours):

   • Any neurological deterioration or worsening symptoms 1
   • New onset of severe headache, vomiting, or altered mental status 1
   • Decline in Glasgow Coma Scale (GCS) score 4, 5

2. Early repeat CT (within 6 hours):

   • Spontaneous ICH within first 6 hours of symptom onset (highest risk period for expansion) 1
   • Moderate to severe TBI (GCS ≤12) 1
   • Patients on anticoagulation therapy with positive initial CT 1, 3

3. 24-hour repeat CT:

   • Stable spontaneous ICH to document final hemorrhage volume 1
   • Patients with subfrontal/temporal intraparenchymal contusions (53% progression rate) 2
   • ICH volume >10 ml on initial scan 2
   • Elderly patients (>65 years) with ICH 2

Special Considerations

Anticoagulation

• Patients on anticoagulants have higher risk of hemorrhage progression and require closer monitoring 1, 3
• Factor Xa inhibitors like apixaban have lower incidence of intracranial hemorrhage compared to warfarin (2.6% vs 10.2%), but still higher than patients without anticoagulation 3

Mild TBI with Negative Initial CT

• Routine repeat CT is not supported for patients with mild TBI and negative findings on initial CT (Class III recommendation) 1, 6
• For patients on DOACs with negative initial CT, the risk of developing delayed traumatic ICH is very low (0.5%, 95% CI [0.06%, 1.7%]) 6

Predictors of Clinical Deterioration

• Decline in GCS (OR 8.64) and polytrauma (ISS >15; OR 3.32) are stronger predictors of need for surgical intervention than CT findings alone 5
• Age >65 years (OR 2.06) is associated with higher likelihood of requiring medical intervention 5

Common Pitfalls to Avoid

• Delaying repeat imaging when neurological deterioration occurs, regardless of time since initial scan 1
• Assuming that small hemorrhages on initial CT will not progress (subfrontal/temporal contusions have 53% progression rate) 2
• Relying solely on imaging findings without correlating with clinical examination (negative predictive value of normal neurologic examination is 100% in some studies) 7
• Performing unnecessary repeat imaging in stable patients with mild TBI and negative initial CT (changes management in only 2.3-3.9% of cases) 1