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An Approach to Oculomotor Anomalies in a Child
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
The three ocular motor nerves innervate the six extraocular muscles as well as the levator palpebrae superioris (LPS) and the pupillary constrictors. The oculomotor nerve innervates the LPS, superior rectus (SR), inferior rectus, medial rectus, inferior oblique, and the pupillary constrictors. The trochlear nerve innervates the superior oblique muscle, and the abducens nerve innervates the lateral rectus muscle. The pathways involved in supranuclear control of the ocular motor nerves descend from the cerebral cortex and terminate in the brainstem in the omnipause neurons (for horizontal saccades) and the rostral interstitial nucleus of the medial longitudinal fasciculus of the midbrain (vertical saccades).
Thyroid ophtalmopathy manifesting as superior oblique paralysis
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
V. Oğuz, M. Yolar, H. Pazarli, S. Özkan
It is known that the oblique muscles are rarely involved in thyroid ophtalmomyopathy, and the studies investigating the involvement of these muscles are also rare [8,9,13–15]. Additionally, there are only a few studies about the cases who present with a paralysis of the superior oblique simulating the superior oblique involvement as an initial sign of the thyroid ophthalmopathy [9]. In this study the cases arising as a paralysis of the superior oblique muscle and at the same time showing an involvement of the inferior oblique were evaluated. The relationship between the paralysis of the superior oblique and the thyroid ophtalmopathy can be explained in 5 different ways [9]. The most plausible explanation is that probably the paralysis of the superior oblique precedes Graves disease rather than being a result of this disorder. It becomes symptomatic by the diminution of fusion due to the Graves disease [13]. In our 7 patients whose history did not include any cause of the paralysis of the 4th nerve, the most acceptable assumption is the preceding asymptomatic paralysis of the superior oblique that becomes symptomatic after decompensation by diminution in fusion related to the disease.
The nervous system
Published in Peter Kopelman, Dame Jane Dacre, Handbook of Clinical Skills, 2019
Peter Kopelman, Dame Jane Dacre
The abducens nerve innervates the lateral rectus and the trochlear nerve innervates the superior oblique muscle. All the other external ocular muscles, the sphincter pupillae (muscle of accommodation) and the levator palpebrae are supplied by the oculomotor nerve. A simple way to remember the muscle innervation is LR6SO4 – Remainder 3: lateral rectus = abducens (cranial nerve no. 6), superior oblique = trochlear (cranial nerve no. 4) and the remainder = oculomotor ( cranial nerve no. 3).
Normative orbital measurements in an Australian cohort on computed tomography
Published in Orbit, 2023
Khizar Rana, Valerie Juniat, Wen Yong, Sandy Patel, Dinesh Selva
The superior oblique muscle was measured on a coronal plane perpendicular to the muscle belly. The inferior oblique was measured on a coronal plane and a quasi-sagittal plane parallel to the orbital axis, below the centre of the inferior rectus tendon. Similarly, by using high-resolution CT orbit studies, we were able to reconstruct the quasi-sagittal plane and measure the inferior oblique muscle under the centre of the inferior rectus tendon. Previous MRI studies measuring the inferior oblique muscle have used quasi-sagittal sequences with a higher 2–3 mm slice thickness.16,17 A 2–3 mm slice thickness would make standardisation of the slice under the inferior rectus tendon less reliable. Additionally, dedicated quasi-sagittal MRI sequences are not widely available and are limited to specific indications.18
Concomitant Unilateral Duane Retraction Syndrome and Contralateral Brown’s Syndrome
Published in Journal of Binocular Vision and Ocular Motility, 2023
Arash Mirmohammadsadeghi, Mohammad Reza Akbari, Sahel Soltani Shahgholi
Bagheri and Repka described a 5-year-old boy with right Brown and left Duane syndrome, like our patient. They performed two strabismus surgeries for the case.6 Karsenti et al. described another patient of DRS and contralateral Brown syndrome with auriculo-temporal nerve syndrome and other congenital systemic anomalies.12 Ellis et al. published a case series of 9 patients with Brown syndrome.4 In these cases, three demonstrated contralateral superior oblique palsy; 2 demonstrated contralateral DRS (similar to our case); one demonstrated ipsilateral congenital ptosis; and three demonstrated hypoplastic ipsilateral superior oblique muscle.4 They suggested that Brown syndrome may be induced by abnormal development of fourth nerve and some of the Brown syndrome cases can be classified in CCDD category.4 On the other hand, Parsa and Robert suggested that fibrin clots and resultant focal vascular insults to sixth and fourth nerves in fetus may be the etiology of DRS and Brown syndromes, respectively.13 The concomitant presentation of both syndromes in one case may support the theory of vascular insult.
Nasal insertion of the superior oblique tendon presenting as Brown syndrome
Published in Strabismus, 2022
Ahmed Awadein, Ahmed Adel Youssef, Jylan Gouda
The normal superior oblique muscle passes posterolateral beneath the superior rectus muscle, to be inserted temporal to the superior rectus muscle. Sagittalization of superior oblique muscle occurs when the muscle courses directly posteriorly parallel to the sagittal suture and gets attached nasal to the superior rectus muscle.1 Both patients reported here showed nasal insertion of the superior oblique tendon. The anterior fibers were much shorter, inserting nasal to the superior rectus insertion. We postulate that this abnormal insertion of the superior oblique muscle restricts the elevation of the globe in adduction, and that this effect is further enhanced by the tightness and shortness of the tendon and creates a tethering similar to what is seen in Brown syndrome. Following superior oblique lengthening, the tethering effect was reduced and the elevation in adduction improved in all three eyes.