Brown Syndrome. predisposition to congenital Brown syndrome, however, most cases are sporadic in nature. In this particular case, horizontal muscle surgery or an expander may be more indicated, as suggested by Wright et al.[4]. If masked bilateral involvement or asymmetric involvement is suspected: Bilateral IO graded anteriorization + contralateral IR recession or bilateral graded IO anteriorization + Harada-Ito procedure on the more affected side. Trochlear nerve palsy can also occur as part of a broader syndrome related to causes like trauma, neoplasm, infection, and inflammation. HHS Vulnerability Disclosure, Help When it is primary (not related to a paresis of another vertical muscle), the head tilt- test is negative (the superior rectus and oblique muscles are working).[4]. [3] Idiopathic cases may improve or completely resolve over a matter of weeks. It can be caused by an adherence of the inferior rectus to the orbital floor following a traumatic fracture, giving rise to a muscle slack in front of the adherence. Further workup may be needed in acquired Brown syndrome and often depends on the suspected underlying etiology. Megha M, Tollefson, Mohney BG, Diehl N, Burke JP. After extensive further investigation, it was demonstrated that key clinical features were a V or Y pattern strabismus, divergence in upgaze, downdrift in adduction, and a positive forced duction test for ocular elevation in the nasal field. Duane1 introduced the concept of pattern in strabismus in 1897 when he described V pattern in bilateral superior oblique palsy. Microvascular disease can involve CN IV and usually in older patients with cardiovascular risk factors. There is a large differential for secondary causes of Brown syndrome, including inflammation, trauma, tendon cysts, previous sinusitis, orbital tumors, and iatrogenic causes such as orbital or strabismus surgery. 2004. Kim JH, Hwang JM. Gobin MH. Modified inferior oblique transposition considering the equator for primary inferior oblique overaction (IOOA) associated with dissociated vertical deviation (DVD). VS often limited to adduction, Y pattern in primary; V pattern in secondary, Over-depression in adduction. A relative afferent pupillary defect without any visual sensory deficit. Individuals. Unauthorized use of these marks is strictly prohibited. Following ocular surgery (Ex. This page has been accessed 158,873 times. Superior oblique runs anteriorly in the superomedial part of the orbit to reach the trochlea, a fibrocartilaginous pulley located just inside the superomedial orbital rim on the nasal aspect of the frontal bone 1,2. If there is a large hypotropia in upgaze even in the case of a <8PD deviation in primary position: IR recession and an additional contralateral asymmetrical IR recession or contralateral SR recession may be indicated. [4], Other features: Abduction and extorsion. If a big V-pattern, with >15DP esotropia in downgaze and >10 extorsion in primary position is present; reversing hypertropias in sidegaze: Bilateral Harada-Ito + bilateral medial rectus recessions with half-tendon width inferior transpositions or superior oblique tendon tuck + bilateral medial rectus recessions with half-tendon width inferior transpositions. Acquired Brown syndrome. Accessibility Disclaimer. 2018. doi:10.1016/j.ajo.2017.10.019, Purvin VA, Kawasaki A. There are several clinically significant features of the trochlear nerve anatomy. If superior rectus palsy: Superior transposition of half tendon lengths of medial and lateral recti or Knapp procedure. Specific methods for testing are detailed in the highlighted link above. 2004 Oct;8(5):507-8. doi: 10.1016/j.jaapos.2004.06.001. Oblique muscle weakening is the preferred approach in the presence of oblique muscle overactions. (Courtesy of Vinay Gupta, BSc Optometry), Figure 6. If due to restriction and minimal hypertropia in primary gaze: resection of the ipsilateral IR. Neurology. The superior oblique muscle is innervated by cranial nerve IV and the lateral rectus muscle by cranial nerve VI. Inferior Oblique Overaction Over-elevation of the eye in adduction Other features: If primary and bilateral, it gives rise to a Y-pattern, with divergence in upgaze; if secondary, i.e. Lueder GT, Scott WE, Kutschke PJ, Keech RV. : pseudo-Brown's syndrome), or following retinal surgery: Sometimes associated with a hypertropia in adduction, due to aberrant innervation of vertical muscles or a restrictive lateral muscle. In the case of a palsy, saccadic velocity and force generation are decreased. Kushner, Burton J. CN IV has the longest intracranial course and is vulnerable to damage, even with relatively mild trauma. Intraocular Pressure: Restrictions may lead to increase IOPs when the eye is moving against the restriction. Pseudo-Brown's syndrome as a complication of glaucoma drainage implant surgery. : Left inferior oblique paresis causes a right hypertropia on right and up gaze and head tilt to the right. Pseudo patterns must be ruled out by measuring the deviations after prescribing appropriate refractive correction or observing the deviation under cover to prevent fusion. Kushner BJ. 2013. doi:10.1212/WNL.0b013e3182a031ea, Wong AMF, Colpa L, Chandrakumar M. Ability of an upright-supine test to differentiate skew deviation from other vertical strabismus causes. : Slipped muscle; following tenotomy or tenectomy procedures), Trauma (The IV cranial nerves exit the midbrain very closely so that strong head traumas, or sometimes even small ones, frequently origin bilateral rather than unilateral palsies), Iatrogenic (ex. Instruction Courses and Skills Transfer Labs, Program Participant and Faculty Guidelines, LEO Continuing Education Recognition Award, What Practices Are Saying About the Registry, Provider Enrollment, Chain and Ownership System (PECOS), Subspecialty/Specialized Interest Society Directory, Subspecialty/Specialized Interest Society Meetings, Minority Ophthalmology Mentoring Campaign, Global Programs and Resources for National Societies, Patient-Reported Outcomes with LASIK Symptoms and Satisfaction, Steeper corneas and allergies may lead to faster keratoconus progression in kids, ROP treated with ranibizumab or low-dose bevacizumab may need re-treatment, Effect of Overminus Lens Therapy on Myopia Progression, Update on Atropine in Pediatric Ophthalmology, Peripheral Defocus Contact Lenses for Myopia Progression, International Society of Refractive Surgery. (Courtesy of Vinay Gupta, BSc Optometry), Figure 2. Clinical criteria for the assessment of disease activity in Graves' ophthalmopathy: a novel approach. If bilateral, even if asymmetric: Bilateral IO weakening procedures (myectomy, recession, anteriorization) should be performed, except if amblyopia is present (surgery on the good eye is discouraged). Patients with an acquired trochlear nerve palsy may respond to treatment of the underlying disease. If congenital: There is an indication for surgery if there is a vertical deviation in primary position with an important face turn. [4] A vertical deviation in primary position is more frequently associated with a unilateral or asymmetric SO paresis. Introduction. In Browns syndrome there is a Y-pattern, whereas a lambda pattern is present in SO overaction and an A pattern in IO paresis. More rarely, they are caused by abnormal positioning of the horizontal rectus muscles. 2019 American Academy of Ophthalmology. Brown syndrome due to inflammatory disease with associated pain may transiently benefit from injection of steroids to the trochlear area. Ex. It is seen in bilateral inferior oblique overaction, Brown syndrome, or Duane syndrome (DS). It has been proposed that congenital Brown syndrome is due to a dysgenesis of the muscle tendon, superior oblique tendon sheath or trochlea, and recent work suggests that some cases may be associated with congenital cranial dysinnervation disorders. The .gov means its official. Right inferior oblique muscle palsy. Walker JPS, Congenital absence of inferior rectus and external rectus muscles. Larson SA, Weed M. Brown syndrome outcomes: a 40-year retrospective analysis. Computed tomography (CT) scan is generally the first line imaging study in trauma but is often normal. Does the hypertropia worsen in left or right head tilt? In: StatPearls [Internet]. Prendiville P, Chopra M, Gauderman WJ, Feldon SE. Miller JE. -, Yang HK, Kim JH, Kim JS, Hwang JM. Orbital wall fracture with entrapment, orbital mass, and orbital or extraocular muscle inflammation can lead to vertical strabismus. For example, Brown's syndrome (superior oblique tendon sheath syndrome), which causes tethering of the superior oblique muscle, has a similar eye movement pattern to an inferior oblique paresis. The Academy uses cookies to analyze performance and provide relevant personalized content to users of our website. American Academy of Ophthalmology. Additional fourth step to distinguish from skew deviation. Pineles SL, Velez FG, Elliot RL, Rosenbaum AL. In: Rosenbaum AL, Santiago AP(eds). Subjects: We studied 33 eyes with oblique dysfunction (9 with presumed congenital superior oblique palsy [SOP], 13 with acquired SOP, 7 with Brown syndrome, and 4 with inverted Brown . This is a rare disorder described by Harold W. Brown in 1950 and first named as the "superior oblique tendon sheath syndrome.". JS Crawford, Surgical treatment of true Brown's syndrome, American journal of ophthalmology, 1976. J Pediatr Ophthalmol Strabismus, 1987; 24:10-7.. This procedure may cause iatrogenic Brown syndrome. Castro O, Johnson LD, Mamourian AC. Munoz M, Parrish Rk. A down movement of the eye on adduction may mimic superior oblique over-action with or without associated IO plasy. [4], Slight hypertropia in primary position as muscular function is preserved from upgaze to primary position, and a large hypertropia from primary position to downgaze. Determining if there worsening of the hypertropia in left or right head tilt can identify the involved muscle from the remaining two choices following steps 1 and 2 of the three step test. 20 However, results for pattern XT and with Duane syndrome-related upshoot were variable. The risk in this procedure is that the sutures may cut through the thin superior oblique tendon. Forced duction testing is very useful in the diagnosis of Brown syndrome, and will demonstrate restriction to passive elevation in adduction. Yang HK, Kim JH, Hwang JM. The 2 most commonly performed surgeries for correction of vertical incomitance in a horizontal strabismus are: Video 1: Inferior Oblique Recession Procedures. Pseudo A or V patterns may be seen in certain forms of strabismus in the absence of a true pattern. Bethesda, MD 20894, Web Policies In: StatPearls [Internet]. 1998;6(4):191-200. doi:10.1076/stra.6.4.191.620, Girkin CA, Perry JD, Miller NR. On version testing Brown syndrome might be confused with an inferior oblique muscle (IO) palsy. Reoperation was three times more likely to be necessary in traumatic cases than in congenital cases (35.0% vs 11.9%, p=0.02). The terminology regarding Brown syndrome has varied and was often confusing. Complications: Clinically significant Brown's Syndrome occurred in 43/72 (60%) of those cases who had undergone a superior oblique tuck. If >15DP hypertropia in primary position (or deviation bigger in downgaze): Ipsilateral graded inferior oblique anteriorization + contralateral inferior rectus recession (yoke muscle). Patients can present with binocular, vertical or torsional diplopia. Boyd TA, Leitch GT, Budd GE. adalimumab) have been used in refractory cases. In pseudo-inferior rectus palsy with hypertropia in primary position: Ipsilateral muscle slack reduction through a plication + contralateral IR recession. Management of Brown syndrome. Fever, headache, neck stiffness may be associated with meningitis. It frequently coexists with an underaction of the contralateral IR and intermittent exotropia. Apart from the basic strabismus work-up, the additional assessment needed in the presence of patterns is to look for: The management of pattern strabismus can be difficult. It manifests when binocular fusion is interrupted either by occlusion or by spontaneous dissociation. The degree of misalignment should be determined for at least primary, horizontal, and vertical gazes and in head tilt. Other features: Larger extorsion than in unilateral paresis (>10); esotropia increasing in down gaze (>10) V pattern of the ''arrow subtype''. Kushner BJ. 2004. In the case of a hypertropia, the diplopia is vertical. Relocate horizontal rectus muscle. Sagittalization of the oblique muscles as a possible cause for the A, V, and X phenomena. Additionally, the fourth cranial nerve exits dorsally, crosses the midline, and innervates the contralateral SOM. Greater than 50% change in vertical strabismus with position change from upright to supine is a positive test. Antielevation syndrome after bilateral anterior transposition of the inferior oblique muscles: incidence and prevention. Bilateral CN IV palsy may have large degree of bilateral excylotorsion (e.g., > 10 degrees) on the Double Maddox rod test. Other features: Chin elevation[2]and ipsilateral true or pseudo-ptosis. It is paramount to rule out a vertical pattern in every case of comitant strabismus, as our management would be defined by the same. [2] When bilateral, it frequently gives rise to lambda-pattern, with accentuated exotropia in downgaze.[4]. Other less commonly performed procedures are: Occurrence of a pattern in horizontal comitant strabismus is an interesting phenomenon. Nearly three fourths (71.4%) of the children had a IVth cranial nerve palsy, primary inferior oblique overaction, Brown syndrome, or a vertical tropia in the setting of an abnormal central nervous . Horizontal eye movement networks in primates as revealed by retrograde transneuronal transfer of rabies virus: differences in monosynaptic input to slow and fast abducens motoneurons. Stager DR Jr, Beauchamp GR, Wright WW, Felius J, Stager D Sr. Anterior and nasal transposition of the inferior oblique muscles. This patient had no abnormal neurologic findings. Wright KW, Brown's syndrome: diagnosis and management, Trans Am Ophthalmol Soc.
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