Orbital Floor Fracture with Atypical Extraocular Muscle Entrapment Pattern and Intraoperative Asystole in an Adult

Abstract

).Extraocular muscle entrapment in the setting of orbital floor fractures, when precisely defined as muscle incarcerated in a nondisplaced fracture line, is rarely seen in adults. This is in contrast to herniation of extraocular muscles through a fracture defect, which is common. The oculocardiac reflex (OCR) is a sign that can be elicited in patients with entrapped muscle tissue and is typically defined as the triad of bradycardia, nausea, and syncope. We present an interesting case of muscle entrapment in a partially nondisplaced two-wall orbital fracture with accompanying preoperative bradycardia and intraoperative asystole in an adult. Case ReportA 27-year-old man was struck with a fist in the left periorbital area, and onset of binocular vertical diplopia and left orbital pain with eye movements was immediately noted. He was otherwise asymptomatic. Past medical history was notable only for asthma.On examination, best corrected visual acuity and intraocular pressures were within normal limits. There was no relative afferent pupillary defect. Extraocular movement of the right eye was normal, but demonstrated an 80% reduction of upgaze of the left eye (►Fig. 1). There was an elicited OCR with the patient's heart rate consistently dropping 33%, from 75 to 50 beats per minute during attempted upgaze with associated nausea and presyncopal symptoms. Horizontal motility was normal. There was 2 mm of enophthalmos of the left globe. Anterior and posterior segment exams of both eyes were within normal limits; no associated injuries were identified on the ED screening examination Noncontrast orbital CT scan demonstrated a comminuted left orbital floor fracture and an associated minimally displaced fracture of the left lamina papyracea and nasal bones. The shape of the inferior rectus muscle was distorted vertically and it appeared to be partially entrapped in the orbital floor fracture (►Fig. 2).Surgical exploration and fracture repair were conducted as soon as possible and within 24 hours of presentation. Forced duction testing performed intraoperatively confirmed restrictive strabismus. Upon exploration, the orbital floor fracture was identified and entrapped inferior rectus muscle tissue at the orbital floor fracture site identified. During release of the anterior portion of entrapped inferior rectus muscle, gentle Keywords ► orbital fracture ► extraocular muscle entrapment ► adult trapdoor fracture AbstractExtraocular muscle entrapment in a nondisplaced orbital fracture, although a wellknown entity in pediatric trauma, is atypical in adults. It can present with a triad of bradycardia, nausea, and in rare cases, syncope, and result in severe fibrosis of damaged and incarcerated muscle. We present a case of muscle entrapment in a partially nondisplaced two-wall orbital fracture with accompanying preoperative bradycardia and intraoperative asystole in an adult

Orbital Trauma

“…In extreme cases patients with entrapment can experience bradycardia, nausea, and syncope when attempting extraocular movements (the oculocardiac reflex), and immediate operative reduction with release of the entrapped muscle is of immediate importance. [15][16][17][24][25][26] The most common indication for repair is correction of enophthalmos, resulting from the loss of support of the orbital floor. A small amount of hypophthalmos can be tolerated both cosmetically and functionally; however, the degree of floor loss that does require repair is often debated.…”

Adult Orbital Fractures with Extraocular Muscle Entrapment

“…5 Most published cases appear to affect young adults in their late teens and 20's. [6][7][8][9][10][11][12][13][14][15] The oldest patient with confirmed extraocular muscle entrapment found in our literature review was 53 years old. 16 Similarly, we had 3 patients who were in their twenties and 2 patients aged 58 and 62, which to our knowledge represents the oldest patients with confirmed extraocular muscle entrapment.…”

Do Not Fall for This; Diagnostic Challenges in Orbital Floor Fractures With Extraocular Muscle Entrapment

“…Muscle and soft tissue entrapment happen when a fractured bone displaced by the fracturing force moves back towards its normal non-displaced position, trapping tissue into the fracture site. This so-called trapdoor style fracture is more common in pediatric patients due to the more malleable nature of younger bone [ 7 - 9 ], but it has also been reported in adults [ 10 , 11 ], including our patient in case #2. The symptoms most commonly reported by patients with extraocular muscle entrapment are diplopia and pain with eye movements (87.5%), nausea or vomiting (37.5%), and a heart rate of 60 bpm or less (50%) [ 12 ].…”