Should I order a stat (immediate) computed tomography (CT) scan for a patient who fell off a bike and hit their head last week, now presenting with feelings of fuzziness, but with normal neurological assessment results?

Head Injury One Week Ago with Current "Fuzziness" and Normal Neurological Exam

This patient does not need a stat CT scan, and likely does not need urgent imaging at all—this presentation represents delayed post-concussive symptoms rather than an acute intracranial emergency requiring immediate imaging. 1

Why This Is Not a Stat CT Situation

The critical distinction here is timing. This patient is presenting one week after the initial injury with new subjective symptoms ("fuzziness") but a completely normal neurological examination. This clinical picture does not meet criteria for emergent imaging because:

• Stat CT is reserved for acute presentations (within 0-7 days) where there is neurological deterioration, altered mental status, or high-risk features requiring immediate neurosurgical evaluation 2, 1
• Your patient has a normal neurological examination, which is the most important protective factor against clinically significant intracranial pathology 2
• The one-week delay between injury and symptom onset makes acute hemorrhagic complications (epidural hematoma, acute subdural hematoma) extremely unlikely, as these typically declare themselves within 24-48 hours 3

What "Fuzziness" Likely Represents

This vague cognitive symptom one week post-injury most likely represents post-concussive syndrome, which occurs in approximately 15% of patients with mild TBI even when initial CT scans are normal 2. These symptoms can include:

• Difficulty concentrating
• Mental fogginess
• Headache
• Fatigue
• Memory difficulties

2, 1

When You Would Order Urgent (Not Stat) Imaging

Consider urgent outpatient CT or MRI (within 24-72 hours, not emergently) if the patient develops any of the following:

• Neurological deterioration from baseline (new focal deficits, declining GCS, altered mental status) 2, 1
• Severe or worsening headache that is different from typical post-concussive headache 2
• Repeated vomiting (more than one episode) 1
• New seizure activity 2, 1
• Signs of basilar skull fracture on examination 2, 1

The Role of MRI in This Scenario

If symptoms persist beyond 2-4 weeks or worsen despite conservative management, MRI without contrast becomes the appropriate next step rather than CT, because:

• MRI is 27-30% more sensitive than CT for detecting subtle traumatic lesions (small contusions, microhemorrhages, diffuse axonal injury) that could explain persistent neurocognitive symptoms 2, 4
• MRI can detect non-hemorrhagic injuries that are invisible on CT but may have prognostic value for long-term outcomes 2
• CT after one week adds minimal value for detecting acute surgical lesions, while MRI better characterizes subacute/chronic changes 4

However, even MRI findings in this delayed setting rarely change acute management—they primarily serve prognostic rather than therapeutic purposes 2.

Critical Pitfalls to Avoid

• Do not assume vague symptoms one week post-injury require emergent imaging when the neurological exam is normal—this leads to unnecessary radiation exposure and healthcare costs 5
• Do not discharge without proper counseling about expected post-concussive symptoms and clear return precautions (worsening headache, vomiting, confusion, focal deficits) 1
• Do not rely solely on imaging to diagnose or exclude post-concussive syndrome—this is a clinical diagnosis, and up to 15% of patients with normal CT will have persistent symptoms 2, 1

Recommended Management Algorithm

For this specific patient:

1. Reassure that delayed cognitive symptoms are common after concussion and do not automatically indicate structural brain injury 2, 1
2. Provide written discharge instructions with specific warning signs requiring immediate return (severe headache, vomiting, confusion, weakness, seizure) 1
3. Recommend cognitive rest and gradual return to normal activities as tolerated 2
4. Schedule outpatient follow-up in 1-2 weeks to reassess symptoms 2
5. Consider outpatient MRI (not urgent) only if symptoms persist beyond 3-4 weeks or significantly worsen 2, 4

The key message: normal neurological examination one week post-injury with subjective symptoms does not warrant stat or even urgent CT imaging unless new objective findings develop 2, 1.