Marcus Gunn Phenomenon: differential diagnosis of palpebral ptoses in children

Abstract

This report is an alert to pediatricians regarding the presence of this largely unknown phenomenon, making it possible for pediatricians to identify the phenomenon, refer the patient to an ophthalmologist, and establish differential diagnosis from other, more severe forms of ptosis, requiring more aggressive treatment.

The rare phenomenon of Marcus-Gunn jaw winking without ptosis: Report of 14 cases and review of the literature

“…Although lid elevation is commonly associated with chewing or sucking movements, it has been reported with other movements such as lateral mandibular movement, yawning, smiling, sternocleidomastoid contraction, tongue protrusion, Valsalva maneuver, or even during inspiration. [ 10 11 12 ] We did not analyze different maneuvers triggering lid elevation, and since there were no remarks regarding any rare maneuver triggering it we presume that most of them were associated with chewing, sucking and jaw movement. There were no dental anomalies associated with our subset of patients; however, there have been a few case reports that describe malocclusion, proclined upper anterior teeth, severe lower crowding and mandibular micrognathia associated with MGJWP.…”

Marcus Gunn syndrome without ptosis

“…Variations can be observed not just in ptosis grade -mild, moderate and severe, but in the magnitude of jaw-winking -from mild (< 2 mm) and moderate (2-5 mm) elevation to severe eyelid retraction (≥ 5 mm) triggered by jaw movement (9). The elevation of the affected eyelid is triggered by chewing, suction, lateral mandible movement, smiling, but also by sternocleidomastoid contraction, protrusion of the tongue, Valsalva maneuver, and even by breathing (10). It is evident at birth and parents are the first that detect the jawwinking during infants' feeding (3).…”

“…Different theories have been discussed regarding the etiology and pathogenesis of the phenomenon. Classic theory denotes anomalous connections between the mandibular branch of the trigeminal nerve and the superior branch of the oculomotor nerve (10). Thus the upper eyelid levator receives double innervation.…”

“…Patients often have associated ophthalmological abnormalities including amblyopia, strabismus, anisometropia, paralysis of the rectus superior, double elevator palsy (3,10). Rarely, associated systemic anomalies such as congenital pathology of the extremities, spina bifida, renal calculi and congenital renal anomalies, cleft lips, etc.…”

Marcus Gunn Phenomenon

“…First described more than 100 years ago by Scottish ophthalmologist Robert Marcus Gunn, this condition is characterized by ptosis associated with synkinetic "winking" movement of the upper eyelid and masticating movements of jaw. 1 The etiology of MGP is not understood. It is thought to result from an abnormal branch of the trigeminal nerve, which has been misdirected congenitally to the oculomotor nerve supplying the levator muscle, but other theories have been suggested, including genetic predisposition and phylogenetic atavism.…”