Internuclear ophthalmoplegia caused by subdural hematoma

Area of Science:

• Neuroscience
• Neurology
• Ophthalmology

Background:

• Internuclear ophthalmoplegia (INO) is a clinical sign resulting from lesions in the median longitudinal fasciculus (MLF).
• INO typically indicates primary intraaxial brain disorders, such as multiple sclerosis in younger individuals and infarction in older adults.
• Rarely, extraaxial disorders can cause INO through brainstem compression.

Observation:

• This report details two cases of INO in patients with subdural hematoma causing transtentorial herniation.
• These patients presented with INO as a neurological manifestation of their extraaxial condition.

Findings:

• The findings suggest that INO, while a reliable sign, is not pathognomonic for intraaxial lesions.
• Subdural hematomas with transtentorial herniation represent a rare but significant extraaxial cause of INO.

Implications:

• Recognizing INO in the context of potential extraaxial masses like subdural hematomas is crucial for timely diagnosis and management.
• This expands the differential diagnosis for INO, prompting consideration of extrinsic brainstem compression.
• Further investigation into rare causes of INO can improve patient outcomes by avoiding diagnostic delays.