A 4-year-old child is noted to have a hypertropia of the left eye that is greater when the chin is elevated and when the head tilts to the left. He holds his head tilted to the right and chin down. The most likely diagnosis is:

• A Left superior oblique palsy (IV nerve palsy) ✓
• B Third nerve palsy with superior rectus paresis
• C Left inferior rectus palsy from orbital floor fracture
• D Dissociated vertical deviation (DVD)

Explanation

Left superior oblique (CN IV) palsy produces a characteristic hypertropia of the affected eye that worsens with gaze to the opposite side (right), with ipsilateral head tilt (left), and with chin elevation. The Bielschowsky head tilt test is positive—tilting the head toward the side of the paretic superior oblique increases the vertical deviation because the paretic muscle cannot intort the eye. The compensatory head posture (head tilt away from the affected eye, chin down) is pathognomonic. The Parks-Bielschowsky three-step test localises the paretic muscle.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.