We report ON the case of a female infant born in a general hospital. On her second day of life, her mother noticed repeated blinking of her right eye during feeding. This stopped on cessation of feeding. She was diagnosed later with Marcus Gunn jaw-winking syndrome.  

Case report

The baby was born at term by vacuum delivery. She is the first baby of non-consanguineous parents. On her second day of life her mother noticed repeated blinking of her right eye during feeding. 

Apparently this resolved on stopping of feed. There is a positive maternal history of congenital ptosis along with hypothyroidism. 

On examination the infant has no dysmorphic features. There is a right eye ptosis. She had normal eye movements, tone and deep tendon reflexes. Her primitive reflexes were also normal. She was investigated fully including FBC, CRP, bone, renal, liver and thyroid profile were normal. MRI brain and cranial ultrasound scan was unremarkable. 

She was referred to a paediatric neurologist for consultation. She was diagnosed with Marcus Gunn jaw-winking syndrome. Ophthalmology referral was arranged. Currently the baby is doing well. 

Discussion

In 1883, Marcus Gunn described a 15-year-old girl with a peculiar type of congenital ptosis that included an associated winking motion of the affected eyelid on the movement of the jaw. This synkinetic jaw-winking phenomenon now bears his name.^1,2

Patients with Marcus Gunn jaw-winking syndrome have variable degrees of blepharoptosis in the resting, primary position. Although Marcus Gunn jaw-winking syndrome is usually unilateral, it can present bilaterally in rare cases.

The wink phenomenon may be elicited by opening the mouth, thrusting the jaw to the contra lateral side, jaw protrusion, chewing, smiling or sucking. This wink phenomenon is often discovered early, as the infant is bottle feeding or breastfeeding. Although is usually unilateral, it can present bilaterally in rare cases.^2,3,4,5

Jaw-winking ptosis is almost always sporadic, but familial cases with an irregular autosomal dominant inheritance pattern have been reported.⁶ It is one of the more common congenital oculofacial synkinesis and accounts for approximately 5% of all congenital ptosis.

Marcus Gunn jaw-winking is thought to be a form of synkinetic ptosis. An aberrant connection appears to exist between the motor branches of the trigeminal nerve (CN V3) innervating the external pterygoid muscle and the fibres of the superior division of the oculomotor nerve (CN III) that innervate the levator superioris muscle of the upper eyelid.^7,8,9,10

A few authors have speculated that the jaw-winking is not due to a new aberrant pathway, but rather the disinhibition of pre-existing phylogenetically more primitive mechanisms.^1,2

This is thought to explain why individuals who are not affected will often open their mouths while attempting to widely open their eyes to place eye drops or to apply makeup.

It is associated with strabismus in 50-60% of cases.² Superior rectus palsy is found in 25% of cases² and double elevator palsy is found in another 25% of cases. Incidence of anisometropia among patients with Marcus Gunn jaw-winking syndrome is reported to be 5-25%.² Amblyopia occurs in 30-60% of patients with Marcus Gunn jaw-winking syndrome.² Prevalence is equal between male and female. This syndrome is usually evident at birth. The winking phenomenon is often first noted by the parents when the infant is feeding. 

Treatment

Treatment is usually unnecessary. In severe cases, surgery with a bilateral levator excision and frontalis brow suspension may be used (oculo plasty surgery).⁷

References

1. Gunn RM. Congenital ptosis with peculiar associated movements of the affected lid. Trans Ophthal Soc UK 1883; 3: 283-7 
2. Pratt SG, Beyer CK, Johnson CC. The Marcus Gunn phenomenon. A review of 71 cases. Ophthalmology 1984; 91(1):27-30 
3. Bradley WG, Toone KB. Synkinetic movements of the eyelid: a case with some unusual mechanisms of paradoxical lid retraction. J Neurol Neurosurg Psychiatry 1967; 30(6): 578-9 
4. Kirkham TH. Paradoxical elevation of eyelid on smiling. Am J Ophthalmol 1971; 72(1):207-8
5. Parry R. An unusual case of the Marcus Gunn syndrome. Trans Opthal Soc U K 1957; 77: 181-5 
6. Kirkham TH. Familial Marcus Gunn phenomenon. Br J Ophthalmol 1969; 53(4): 282-3
7. Beard C. Ptosis. 3rd ed. St. Louis: CV Mosby; 1981: 46-9
8. Duke Elder S. Normal and abnormal development; congenital deformities. In System of Ophthalmology. Vol 3, pt 2. St Louis: CV Mosby; 1963: 900-5
9. Pandey M, Baduni N, Jain A, Sanwal MK, Vajifdar H. Abnormal oculocardiac reflex in two patients with Marcus Gunn syndrome. J Anaesthesiol Clin Pharmacol 2011; 27(3): 398
10. Conte A, Brancati F, Garaci F, Toschi N, Bologna M, Fabbrini G et al. Kinematic and diffusion tensor imaging definition of familial Marcus Gunn jaw-winking synkinesis. PLoS One. 2012; 7(12): e51749