To report a case of pediatric medial wall blowout fracture with entrapment of medial rectus muscle which can be easily misdiagnosed as a cerebral lesion.

A 16-year-old male visited our clinic with headache, severe restriction of his right eye movement, and diplopia after a head injury due to falling occurring 1 day before evaluation. The patient was inebriated at the time of the accident and could not recall the event but occipital hematoma was palpable. Periorbital ecchymosis or edema was not observed with minimal soft tissue injury except mild conjunctival injection on slit-lamp examination. The patient had an 18 prism diopter exodeviation at primary position and severe medial and mild lateral gaze limitation in his right eye. Brain magnetic resonance imaging (MRI) showed no specific cerebral findings although trapdoor orbital medial wall fracture with incarceration of soft tissue and medial rectus muscle at the medial wall fracture site of his right eye was observed. Within 48 hours from the first evaluation, the blowout fracture was repaired and 50 days postoperatively, right eye gaze limitation and diplopia were nearly recovered.

A case of pediatric blowout fracture with uncertain injury location, periocular ecchymosis, or edema absent could be misdiagnosed as a cerebral lesion. If a pediatric patient is experiencing gaze limitation, diplopia, nausea, or vomiting after trauma, neurological examination as well as evaluation for blowout fracture should be performed.