Marcus Gunn jaw winking with trigemino-oculomotor synkinesis of the inferior division of the oculomotor nerve

First case of presumed trigemino-oculomotor synkinesis in a dog

An 11-year old, intact male Border Collie was referred with a history of subacute and progressive left eye exophthalmos and mydriasis associated with reduced pupillary light reflex, ventrolateral strabismus, and absence of physiologic nystagmus in the left eye. Neuroanatomical localization was consistent with a left oculomotor neuropathy, involving the general somatic and visceral parasympathetic efferent components. Computed tomography and magnetic resonance imaging of the head were performed. Imaging findings were consistent with an infectious-inflammatory process involving the left retrobulbar space and regional muscles, extending intracranially through the left orbital fissure. Cerebrospinal fluid (CSF) was collected from the cerebellomedullary cistern, and the analysis revealed albuminocytologic dissociation. The dog was treated with amoxicillin and clavulanic acid and prednisolone at anti-inflammatory dose; a significant improvement of neurologic status was observed afterward. However, 4 weeks after the initial presentation, the dog showed an abnormal, bilateral adduction of both eyes and third eyelid protrusion of the left eye while chewing the leash; the dog's mental status was normal, and the patient did not appear to be in discomfort during these episodes. A presumptive diagnosis of acquired trigemino-oculomotor synkinesis, induced by the intracranial inflammation was made. To the authors' best knowledge, this is the first case of presumed trigemino-oculomotor synkinesis reported in veterinary medicine.

Physiological oculo-auricular-facial-mandibular synkinesis elicited in humans by gaze deviations

Integrated motor behaviors involving ocular motion-associated movements of the head, neck, pinna, and parts of the face are commonly seen in animals orienting to a visual target. A number of coordinated movements have also been observed in humans making rapid gaze shifts to horizontal extremes, which may be vestiges of these. Since such integrated mechanisms point to a non-pathological co-activation of several anatomically separate cranial circuits in humans, it is important to see how the different pairs of integrative motor behaviors with a common trigger (i.e., ocular motion) manifest in relation to one another. Here, we systematically examined the pattern of eye movement-induced recruitment of multiple cranial muscles in humans. Simultaneous video-oculography and bilateral surface electromyograms of transverse auricular, temporalis, frontalis, and masseter muscles were recorded in 15 healthy subjects (8 females; 29.3±5.2 years) while they made head-fixed, horizontal saccadic, pursuit and optokinetic eye movements. Potential chin laterotrusion linked to contractions of masticator muscles was captured with a yaw-fixed accelerometer. Our findings objectively show an orchestrated aural-facial-masticatory muscle response to a range of horizontal eye movements (prevalence of 21-93%). These responses were most prominent during eccentric saccades. We further reveal distinctions between the various observed activation patterns in terms of their profile (transient or sustained), laterality (with respect to direction of gaze) and timing (with respect to saccade onset). Possible underlying neural substrates, their atavistic behavioral significance, and potential clinical applications for monitoring sensory attention and designing attention-directed hearing aids in the future are discussed.

Marcus Gunn Jaw-Winking Syndrome: a Case Report

Introduction:

Marcus Gunn syndrome is a rare phenomenon with very less number of cases reported in literature. It may be congenital or acquired.

Aim:

The aim of this case report was to report the clinical characteristics of Marcus Gunn patient from our Clinic.

Case report:

A comprehensive opthalmologic examination, CDVA (corrected distance visual acuity), fundus examination and photography, was conducted in Marcus Gunn patient. Clinical findings of patient presented as - chin positioned slightly upwards, extraocular motility normal on both eyes, cover test with normal findings, pupillary examination normal on both eyes. Left upper eyelid was in a lower position than the right one. On right eye, rima interpalpebrarum was 9 mm with upgaze of 13mm. On the left eye, rima interpalpebrarum was 5 mm with upgaze of 6 mm, and with open mouth, left rima interpalpebrarum was 10 mm. Visual acuity on both eyes was 1.0. Cycloplegic refraction on both eyes was +0,75 diopters (D), and Lang test was normal. In the differential diagnosis of patients with ptosis, Marcus Gunn jaw winking syndrome should be considered especially if it improves during feeding, sucking, chewing, smiling or any kind of mouth movement. In case of ptosis always do the jaw test. Have the infant bottle-feed. An older child can chew gum. Have the patient open the mouth, move the jaw from side to side, or protrude the jaw forward.

Conclusion:

Address first to treatment of any amblyopia if present - eyeglasses, patching etc., or strabismus. Think twice before deciding to operate.

Marcus Gunn Jaw-Winking Syndrome: A Comprehensive Review and Report of Four Novel Cases

PURPOSE

To report 4 cases of Marcus Gunn jaw-winking synkinesis (MGJWS) in the absence of ptosis.

METHODS

A retrospective review of patients with MGJWS and congenital ptosis was compiled from the public and private subspecialty adult and pediatric oculoplastic practices of the 2 senior authors (AAM, TGH). Clinical data collected on patients with MGJWS included visual acuity, stereopsis, ocular motility, side of jaw-wink, presence or absence of ptosis, levator function, clinical photographs and videos, and any management undertaken.

RESULTS

A total of 848 cases of congenital ptosis were seen. Of these, there were 72 consecutive patients with MGJWS, of which 4 cases (5.6%) had no ptosis. One patient had bilateral MGJWS, with ptosis on one side only. The authors found the incidence of MGJWS in our study population to be 8.5% of all congenital ptosis cases. When the authors excluded syndromic, neurogenic, and myopathic causes of congenital ptosis, the incidence was 12.1%. In addition, the authors found a trend toward females with simple congenital ptosis and MGJWS being affected on the left side, however this was not statistically significant.

CONCLUSIONS

The authors report the first case series of MGJWS in the absence of ptosis within the second largest series ever reported. These findings may help further our understanding of the etiology behind MGJWS.

Congenital third nerve palsy with synergistic depression on attempted adduction and trigemino-oculomotor synkinesis: Underpinnings of a spectral dysinnervation disorder

The authors describe a case of congenital partial pupil-sparing third cranial nerve palsy with absent adduction, synergistic depression of globe and widening of palpebral fissure on attempted adduction and synergistic elevation and adduction on mouth opening and sideways thrusting of jaw. The case illustrates trigemino-oculomotor synkinesis associated with congenital third nerve palsy. The possible mechanism of miswiring involving the medial longitudinal fasciculus and trigeminal nuclei is discussed. At least some cases of congenital third cranial nerve palsy may fall in the realm of congenital cranial dysinnervation disorders (CCDDs) sharing a much wider spectrum of presentation.