List three red flags that would prompt urgent neuroimaging in a patient with new diplopia.

List three red flags that would prompt urgent neuroimaging in a patient with new diplopia.

• A. Acute onset with neurologic signs (weakness, ataxia, aphasia); pupil-involving cranial nerve palsy; severe headache with neck stiffness or signs of brainstem involvement.
• B. Diplopia that improves with rest and wears off quickly.
• C. Chronic gradual diplopia with no neurologic signs.
• D. Diplopia only at distance.

Answer: (D)

Recognize red flags that signal possible acute intracranial or brainstem pathology when a patient presents with new diplopia. Urgent neuroimaging is warranted when there is sudden onset of diplopia accompanied by neurologic signs such as weakness, impaired coordination (ataxia), or aphasia, because these point to a central process rather than a simple binocular misalignment. A pupil-involving cranial nerve palsy is particularly concerning, as it can reflect a compressive lesion (for example, a posterior communicating artery aneurysm) or other mass effect that requires prompt evaluation. Severe headache with neck stiffness or signs suggesting brainstem involvement also raises the possibility of dangerous conditions such as meningitis, hemorrhage, or acute stroke, which need rapid imaging and further workup. The other described patterns fit more with non-urgent or non-central causes of diplopia. Diplopia that improves with rest or resolves quickly is more typical of a non-acute binocular issue, not a brain or brainstem process. A chronic, gradual diplopia with no neurologic signs suggests a more stable, non-emergent cause like a longstanding strabismus or ocular motility issue. Diplopia occurring only at distance could be related to refractive or accommodative factors or a non-acute misalignment, without indications of acute CNS involvement. So the first scenario aligns with urgent imaging due to the combination of acute onset and neurologic or brainstem–level red flags.

Recognize red flags that signal possible acute intracranial or brainstem pathology when a patient presents with new diplopia. Urgent neuroimaging is warranted when there is sudden onset of diplopia accompanied by neurologic signs such as weakness, impaired coordination (ataxia), or aphasia, because these point to a central process rather than a simple binocular misalignment. A pupil-involving cranial nerve palsy is particularly concerning, as it can reflect a compressive lesion (for example, a posterior communicating artery aneurysm) or other mass effect that requires prompt evaluation. Severe headache with neck stiffness or signs suggesting brainstem involvement also raises the possibility of dangerous conditions such as meningitis, hemorrhage, or acute stroke, which need rapid imaging and further workup.

The other described patterns fit more with non-urgent or non-central causes of diplopia. Diplopia that improves with rest or resolves quickly is more typical of a non-acute binocular issue, not a brain or brainstem process. A chronic, gradual diplopia with no neurologic signs suggests a more stable, non-emergent cause like a longstanding strabismus or ocular motility issue. Diplopia occurring only at distance could be related to refractive or accommodative factors or a non-acute misalignment, without indications of acute CNS involvement.

So the first scenario aligns with urgent imaging due to the combination of acute onset and neurologic or brainstem–level red flags.