Brown's syndrome

Clinical features and refractive profile of Brown syndrome

CLINICAL SIGNIFICANCE

Understanding the refractive profile, amblyopia prevalence, binocular status, and head position in patients with Brown syndrome help clinicians become more familiar with this syndrome.

BACKGROUND

Brown syndrome is identified as an active and passive restricted elevation of the eye in adduction. There is little information on clinical features, including refractive status, amblyopia, abnormal head posture (AHP), and types of deviation in these patients.

METHODS

This study retrospectively evaluated records of 100 Brown syndrome patients from 2015 to 2022 at Farabi Eye Hospital, Iran.

RESULTS

The mean age was 6.99 ± 6.33 years, including 48 (48%) males. A congenital source was found in 74 (74%) and 96 (96%) patients had unilateral involvement. The mean CDVA for the affected and non-affected eyes were 0.05 ± 0.11 and 0.03 ± 0.06 logMAR, respectively (P = 0.31). In unilateral cases, hyperopia, myopia, and emmetropia were observed in 55 (57.29%), 2 (2.08%), and 39 (40.63%) affected eyes, respectively. The most common type of deviation was pure hypotropia, which was found in 53 (53%) cases, followed by 'combined exotropia and hypotropia' observed in 26 (26%) patients. The mean angle of hypotropia and horizontal deviation in the primary position at distance was 12.10 ± 8.50 and 8 ± 13.20 prism dioptre, respectively. A V-pattern was found in 76 (76%) patients. Amblyopia was observed in 13 (21.67%) of 60 cooperative patients, and AHP was noticed in 66 (66%) patients, in which "combined chin up and contralateral face turn" was the most common type.

CONCLUSION

About 75% of cases were congenital, 50% had pure hypotropia, 75% showed V-pattern, 20% had amblyopia, and AHP was observed in 67% of patients. The remarkable prevalence of amblyopia alongside the high occurrence of AHP should alert clinicians to carefully assess patients with Brown syndrome for sensory fusion and amblyopia.

Orbital Fibrotic Band as Cause of Monocular Elevation Deficiency

Monocular elevation deficiency is a congenital, unilateral inability of elevation. It is classified as innervational, restrictive, or combine types. Here, we report a rare case of monocular elevation deficiency who had 60 PD left hypotropia and left ptosis with limited elevation (-5) both on abduction and adduction. Orbital MRI revealed a hypointense fibrotic band between the superior oblique and superior rectus muscles extending obliquely in the superonasal direction between the sclera and orbital roof. She was successfully treated after severing the fibrotic band between the sclera and bony orbit.

Brown syndrome: a literature review

The current data on various aspects of Brown syndrome are limited and sporadic. This review provides a coherent and comprehensive review of basic features, etiology, classification, differential diagnosis, and different management strategies of patients with Brown syndrome. In this topical review, PubMed, Scopus, and Google Scholar search engines were searched for papers, published between 1950 and January 2023 based on the keywords of this article. The related articles were collected, summarized, categorized, assessed, concluded, and presented. Brown syndrome is identified by restricted passive and active elevation of the eye in adduction. The condition is divided into congenital and acquired causes. The clinical features result from a restricted motion of the superior oblique tendon sheath through the trochlea while trying to look up in adduction. The newest explanation of the underlying pathophysiology has been explained as the presence of a fibrotic strand in the superior oblique muscle tendon with variable insertion sites which creates various elevation deficits seen in Brown syndrome. The most common clinical features include the presence of an abnormal head posture, V-pattern strabismus, and hypotropia in the primary position. Management of Brown syndrome includes watchful observation, surgical, and non-surgical procedures. Some cases might resolve spontaneously without any intervention; however, some acquired cases might require systemic and/or intra-trochlear steroid administration to treat the underlying causes. Surgical procedures such as superior oblique tenectomy and using a silicon tendon expander are indicated in the presence of hypotropia and significant abnormal head posture in the primary position.

Case Report: Acquired Brown Syndrome after COVID-19 Vaccination

SIGNIFICANCE

Brown syndrome, or superior oblique tendon sheath syndrome, is characterized by limitation of elevation on adduction. The disorder is thought to involve the trochlea/superior oblique tendon complex through traumatic, surgical, and inflammatory mechanisms. It could be an indication of multiple underlying immunological or rheumatological disorders.

PURPOSE

This study aimed to report an unusual strabismus after receiving the first dose of a live attenuated coronavirus disease 2019 (COVID-19) vaccine.

CASE REPORT

A 31-year-old female patient presented with painful vertical diplopia and tenderness of the left trochlear area 3 days after the first dose of COVID-19 vaccination. She had a compensatory chin elevation and face turn to the right, as well as a left 10-prism-diopter hypotropia in the primary position, which increased to 15 prism diopters in the right gaze and disappeared in the left gaze. Ocular motility revealed the limitation of elevation on adduction. The patient denied any history of ocular trauma and was consequently investigated for dysthyroid disease and various immunological and rheumatological disorders, which were excluded. A Hess chart was obtained to document the motility disorder.

CONCLUSIONS

We report a case of acquired Brown syndrome in a 31-year-old otherwise healthy woman shortly after COVID-19 vaccination. It is possible that the patient may have developed trochleitis and/or superior oblique tenosynovitis brought on by cross-reacting antibodies generated by the immune response to the vaccine. In the age of the widest vaccination campaign in human history, it is highly likely that we will continue to observe many unexpected potential adverse effects of these vaccines in our clinical practice.

Acquired Brown Syndrome After a Fist Punch: A Case Report

A 15-year-old male presented with double vision in the left and upward gaze following a hit in the right orbital region. The orthoptic assessment revealed -2 limitation of elevation in the adduction position of the right eye and right hypotropia of 20 prism diopter (PD) in the left gaze and right hypotropia of 10 PD in the upward gaze. He was diagnosed with traumatic Brown syndrome and planned for superior oblique lengthening surgery for the right eye. Two months postoperatively, the patient has a normal extra-ocular motor function with the elimination of diplopia and significant improvement of elevation of the right eye in the adduction position. Herein, we discuss the clinical features, etiologies, tailored evaluation, and management for the patient with traumatic Brown syndrome.

Whole tendon disinsertion of superior oblique for the treatment of Brown syndrome: a comparative study with multiple techniques

PURPOSE

To evaluate the results of a temporal whole superior oblique (SO) tendon disinsertion technique compared with other SO tendon-weakening procedures.

METHODS

The medical records of patients who underwent an SO procedure at University of Health Sciences Beyoğlu Eye Research and Training Hospital from January 2008 to January 2018 for treatment of Brown syndrome were reviewed retrospectively. Patients with follow-up of at least 12 months were included. The following data were included in our analysis: pre- and postoperative ocular ductions, versions, and vertical deviations; presence of abnormal head position (AHP); complications; and success rates of procedures.

RESULTS

The record review identified 158 patients, of whom 52 patients had nasal tenotomy, 6 had nasal tenectomy, 48 had SO tendon elongation by suture spacer and 6 by silicone spacer, and 46 patients had temporal tendon disinsertion of the SO. The rate of AHP decreased from 91.3% to 4.3% postoperatively, and the preoperative mean limitation of elevation in adduction and hypotropia decreased from -3.60^Δ ± 0.65^Δ and -2.26^Δ ± 4.28^Δ to -0.47 ± 0.79 and -0.34 ± 2.67^Δ postoperatively, respectively, in the temporal tendon disinsertion group. SO palsy was not observed after temporal disinsertion surgery, but undercorrection, overcorrection, and adhesion were seen in 8.7%, 8.7%, and 4.3% of patients, respectively, and a second surgery was needed for 17.4% of patients because of vertical deviations. The success rate of temporal tendon disinsertion technique was not significantly different from those of the other SO procedures (P = 0.91).

CONCLUSIONS

Temporal disinsertion of the SO tendon may be as effective as other SO-weakening procedures.

Sequential Presentation of Bilateral Brown Syndrome: Report of a Case with an Interesting Imaging Finding

Purpose

To present a case of bilateral Brown syndrome who presented as a unilateral disease and then showed the disease in the fellow eye in an older age.

Methods

A 4-year-old girl presented with congenital Brown syndrome of the left eye and underwent a superior oblique weakening procedure in that eye, but then developed Brown syndrome in the right eye which required two more surgeries on the right eye to attain an acceptable alignment.

Results

Her orbital computed tomography scan revealed that the distance between the annulus of Zinn and trochlea (Z-T distance) was 41.2 mm in both sides, which was comparatively longer than her age- and sex-matched cases. This finding can suggest a possible mechanism of Brown syndrome development in some patients.

Conclusion

Bilateral Brown syndrome can present as a sequential disease, and its radiologic finding may be associated with increased Z-T distance.

Superior oblique tendon thinning as a surgical treatment for Brown syndrome

PURPOSE

To evaluate the results of a superior oblique thinning technique for the treatment of congenital Brown syndrome.

METHODS

The medical records of consecutive patients at a single institution who were diagnosed with congenital Brown syndrome and underwent superior oblique thinning were retrospectively reviewed. In all cases, the prism cover test was used to assess ocular alignment. Standardized nine-gaze photographs were used to evaluate ocular rotations. Ocular torsion was measured using fundus retinography. Intraoperatively, all patients showed a positive forced duction test for elevation from adduction that became negative after a strongly maintained traction test maneuver.

RESULTS

A total of 21 eyes of 20 consecutive patients (mean age, 5.8 ± 2.5 years) were included. Preoperatively, 16 patients were orthotropic in primary position; 4, hypotropic. Postoperatively, all patients were orthotropic in primary position. Limitation of elevation in adduction improved from -3.4 ± -0.6 (range, -2 to -4) to 0.6 ± 1 (range, 0 to -3; P < 0.01). Fundus retinography showed >1° change in ocular torsion after surgery in 3 of 6 patients (P > 0.5). Superior oblique underaction or hypertropia did not occur. No superior oblique palsy appeared in any patient. There were no changes beyond 3 months postoperatively except for 1 patient who relapsed 9 months after surgery and 1 patient who improved after 4 years.

CONCLUSIONS

Superior oblique thinning is effective in improving elevation in adduction and hypotropia in primary position in patients with Brown syndrome associated with a thickened superior oblique tendon.

The rate of superior oblique surgery in children and adolescents with Brown syndrome according to claims data

PURPOSE

To determine the rate of superior oblique surgery and how often it is combined with surgery on other extraocular muscles or associated with subsequent strabismus surgeries in children and adolescents with Brown syndrome.

METHODS

This was a population-based retrospective cohort study using the Optum deidentified Clinformatics Data Mart Database (2004-2018) for patients ≤18 years of age diagnosed with Brown syndrome who underwent superior oblique surgery as their first strabismus surgery and had at least 6 months of continuous enrollment. We assessed sex, age, and the number of included patients by year and by age. Combined and subsequent strabismus surgeries were also investigated.

RESULTS

Of 1,007 patients diagnosed with Brown syndrome, 115 (11.4%) underwent superior oblique surgery. The rate of superior oblique surgery was relatively constant between 2004 to 2018. The superior oblique surgery rate was highest in children ≤2 years of age with a decreasing rate as age increased. In 45 of 115 patients (39.1%), other extraocular muscles were operated on in addition to the superior oblique muscle. Of 88 patients who underwent superior oblique surgery without concurrent vertical muscle surgery as the first operation, 11 patients (12.5%) subsequently underwent an additional vertical muscle surgery because of newly developed or worsening vertical misalignment.

CONCLUSIONS

In this study cohort, superior oblique surgery was performed on 11.4% of children and adolescents with Brown syndrome. The number of patients with Brown syndrome and the rate of superior oblique surgery decreased as age increased to age 10 years.

Superior oblique split tendon elongation for Brown's syndrome: Long-term outcomes

PURPOSE

To report the outcomes of superior oblique split tendon elongation in Brown's syndrome.

METHODS

Charts of 17 consecutive Brown's syndrome patients who underwent superior oblique split tendon elongation were reviewed and clinical data regarding preoperative, intraoperative, and postoperative data were collected.

RESULTS

About 17 eyes of 17 children with congenital Brown's syndrome underwent superior oblique split tendon elongation between January 2012 and March 2020 by a single surgeon. Mean age at surgery was 5.47 ± 2.82 (range 1.50-13.2). Eight (47.1%) were female. Preoperative deficit of elevation in adduction was -4 in all children. At the end of surgery, all eyes were freely elevated on adduction, on forced duction test. Mean follow-up time of 26.24 ± 11.22 (range 11-53) months. In 15 of 17 children (88.2%), motility improved, orthotropia in primary position was achieved, and head posture eliminated (p < 0.001). Superior oblique palsy occurred in two children, who after reoperation, achieved an acceptable outcome. No intraoperative complications were recorded.

CONCLUSION

The superior oblique split tendon elongation procedure is a useful surgical technique with stable and satisfying outcomes for the treatment of severe congenital Brown's syndrome.

Acquired Brown Syndrome in Head Trauma: Does Fixation of Associated Nasal and Frontal Bone Fractures Provide a Cure?

A 43-year-old gentleman presented with vertical double vision following nasal and frontal bone fractures resulting from blunt trauma to the glabella. Orthoptic assessment revealed a diagnosis of traumatic Brown syndrome affecting the right eye. The fractures were fixed with open reduction internal fixation via a coronal flap nine days after the injury was sustained. Evidence of resolution of the syndrome became apparent clinically within 15 days following surgery, which was confirmed with a later orthoptic evaluation. This case demonstrates that prompt surgical intervention of fractures associated with traumatic Brown syndrome may lead to resolution without the need to resort to extraocular muscle surgery.

Innovative techniques for the treatment of adult strabismus

Adult strabismus is often characterized by surgical complexity. In recent years, several innovative techniques for the management of complex strabismus have been developed. Strabismus surgeons should understand the indications for various strabismus surgical techniques in the management of these difficult cases. This workshop describes several new surgical techniques to manage complex strabismus, including small-angle incomitant and very large-angle strabismus, torsional diplopia, and restrictive, paralytic, and secondary strabismus. Because strabismus surgery is an ever-evolving field, it is important to continue to refine our surgical armamentarium. Strabismus surgeons may wish to add these techniques to their surgical repertoire for select cases.

Acquired Pediatric Brown Syndrome Secondary to Sinusitis

Acquired pediatric Brown syndrome is rarely associated with sinusitis. Children may present with diplopia, elevation deficiency in adduction, and a head tilt or chin-up position. Magnetic resonance imaging can confirm the diagnosis. Antibiotic treatment is often insufficient for resolution. Surgical correction can effectively prevent amblyopia and restore binocular vision. [J Pediatr Ophthalmol Strabismus. 2019;56:e17-e19.].

[Brown's syndrome]

Brown's syndrome is related to an abnormality of the superior oblique muscle: it is manifested by an oculomotor disorder with active and passive limitation of elevation in adduction, the field of action of the inferior oblique muscle. The origin is congenital or acquired secondary to multiple causes - inflammatory-infectious, traumatic or iatrogenic. The clinical and paraclinical signs are suggestive. Cerebral and orbital imaging including CT and magnetic resonance imaging (MRI) is essential for the diagnosis and management of congenital or acquired Brown's syndrome. The course may yield improvement (spontaneous or after etiological treatment) or a steady state. Treatment is rarely surgical. The indication for surgery requires specific functional and clinical signs: torticollis, hypotropia in primary position, associated strabismus and impaired binocular vision; the long-term results of the various surgical techniques are variable.

Intratrochlear steroid injections in acquired Brown syndrome-a case series

PURPOSE

To present our experience in the treatment of children with acquired Brown syndrome by means of intratrochlear injection of betamethasone.

METHODS

The medical records of patients treated with intratrochlear betamethasone in 2016 at the Aravind Eye Hospital, Madurai, were reviewed retrospectively. The following data were collected: pre- and postoperative orthoptic work-up, blood work, and neuroimaging. Betamethasone injection was administered 2-8 weeks following onset of symptoms.

RESULTS

Five children (4 girls), 1.5-15 years of age, were included. During the postoperative period, abnormal head posture and elevation in adduction improved in 4 subjects but did not resolve completely. The median vertical deviation was 11.5^Δ preoperatively and reduced to 3.5^Δ postoperatively. A significant reduction in deviation was demonstrable on diplopia and Hess charting in 2 of the older children. Subject 2, who did not show improvement after injection, was prescribed prism glasses and became diplopia free.

CONCLUSIONS

In this case series, children with acquired Brown syndrome of idiopathic or presumed inflammatory etiology showed significant reduction in deviation and symptoms following intratrochlear injection of betamethasone. We recommend that this treatment be considered for children affected by acquired Brown syndrome, especially those in the amblyogenic age group.

Double vision in adults

PURPOSE

To determine the patient characteristics, patterns in presentation and incidences of the various etiologies in adult patients with the chief complaint of double vision.

DESIGN

Retrospective review.

SUBJECTS

All persons greater than 18 years of age who presented to a single provider (DG) in a nonacademic private practice over a 2-year period, from 2011 to 2013, with the chief complaint of double vision. The provider is part of a multispecialty eye care group practice with both ophthalmologists and optometrists. This group practice provides a large adult referral base.

METHODS

Examination for each patient included refraction, versions, alignment in different positions of gaze at distance and at near, binocular sensory testing, neuro-ophthalmologic examination, and dilated fundus examination if not recently documented. Alignment was measured with cover-uncover testing and alternate cover testing with prism bars or free prisms, using Snellen letters for fixation. Appropriate refractive correction was ensured. Alignment was measured in the primary position at distance and in gaze directed 20 degrees L, R, up, and down. The near deviation was measured in the reading position with the large letters on a near card for fixation. Sensory testing was performed with the Worth 4-dot at distance and near and with the Titmus stereopsis test. Vectograph testing was also performed at distance on many patients, particularly those with small-angle deviations. The prismatic correction necessary to correct diplopia subjectively at distance in the primary position and at near in the reading position was also recorded.

PRIMARY OUTCOME

Ocular alignment and etiology of diplopia. Management, response to treatment, and outcome were also recorded.

RESULTS

A total of 125 patients were included in the analysis. Subjects ranged from 18 to 93 years of age. Most cases of idiopathic strabismus were in the elderly, but the age range varied with category of underlying strabismus. Small-angle HT was the most common type of strabismus, comprising 21% of all subjects. ET, usually of the divergence insufficiency type (20%); XT (14%); and palsies not including trochlear palsy (12%) and trochlear palsy (8%) were the next most common etiologies. No strabismus was found in 11% of subjects.

CONCLUSIONS

Most cases of diplopia in adults presenting as an outpatient can be classified into a few categories based on their type of strabismus. These categories of strabismus share typical age ranges and features. While diplopia in adults is usually idiopathic, diplopia can be the presenting sign of serious underlying pathology. Thus, a thorough history; examination; and, in some cases, diagnostic testing is necessary.

Congenital Brown's Syndrome: Clinical and Surgical Approach

Brown's syndrome is a well-recognized clinical disorder of ocular motility consisting mainly of a restriction of active and passive elevation in adduction. We report a series of 17 patients with true Brown's syndrome and discuss the clinical features and results of surgical intervention. Surgery should be considered carefully for the treatment of this syndrome as reoperation may be necessary and spontaneous resolution is seen during long-term follow-up of some patients.

MRI of acquired Brown syndrome: a report of two cases

Brown syndrome is characterized by upward gaze impairment while the eye is in adduction. It is caused by abnormalities involving the superior oblique tendon-trochlea complex. Imaging can help confirm the diagnosis, shed light on its etiology, and determine the best course of treatment. However, reports of magnetic resonance imaging findings of acquired Brown syndrome are scarce in the literature. Here, we describe magnetic resonance imaging features of 2 cases of acquired Brown syndrome.

[Sensory and motor clinical presentation of congenital retraction syndromes: Stilling-Duane and Brown syndrome]

INTRODUCTION

Congenital Brown syndrome and Stilling-Duane syndrome, two rare causes of strabismus are caused by fibrosis of one or more extraocular muscles. This series aims to report the clinical sensory and motor features of patients with Brown or Stilling-Duane syndrome.

METHODS

Seventeen patients' records were retrospectively assessed for: the ocular deviation in primary position and in the 9 positions of gaze, head tilt, visual acuity and binocular vision.

RESULTS

Eleven patients with Stilling-Duane syndrome had a mean age of 12 years, and monocular involvement, most frequently of type I. The ocular deviation was variable; 16 patients had an abnormal head position, while 50 % presented with amblyopia, and only 37 % achieved fusion in the compensatory head posture. Six patients presented with congenital Brown syndrome at mean age of 6 years. Three had a moderate form, 3 had a severe form with vertical deviation in primary position, compensatory head position, amblyopia and binocular vision impairment.

DISCUSSION

The motility impairments depend highly on the identified syndrome, its classification and its severity. Therefore, these two retraction syndromes present some common features. Strabismus in primary position may lead to amblyopia and binocular vision impairment.

CONCLUSION

Clinical motility and sensory assessment is essential, though difficult, to establish the diagnosis and the management of patients with retraction syndromes.

Acquired Brown Syndrome Treated With Traction of Superior Oblique Tendon

Brown syndrome is a rare strabismic disease characterized by a limited elevation in adduction of the eye. The lengthening/weakening of superior oblique muscle is the main way of surgical intervention for this disease. A 7-year-old boy was diagnosed as having acquired Brown syndrome in his right eye after injury in his face. We experienced successful release of this Brown syndrome through mere pulling outward of superior oblique tendon during surgical exploration. We briefly discuss why this manipulation of superior oblique tendon that we performed was successful.

Size of the Oblique Extraocular Muscles and Superior Oblique Muscle Contractility in Brown Syndrome

PURPOSE

This study employed magnetic resonance imaging (MRI) to investigate possible size and contractility changes in the superior oblique (SO) muscle, and possible isometric hypertrophy in the inferior oblique (IO) muscle, resulting from abnormal mechanical loading in Brown syndrome (BrS).

METHODS

High resolution orbital MRI was obtained in 4 congenital and 11 acquired cases of BrS, and compared with 44 normal subjects. Maximal cross-section areas and posterior partial volumes (PPVs) of the SO were analyzed in central gaze, supraduction, and infraduction [corrected] for the SO, and in central gaze only for the IO.

RESULTS

In congenital BrS, mean maximum SO cross-sectional areas were 24% and 20% less than normal in affected and unaffected eyes, respectively (P = 0.0002). Mean PPV in congenital BrS was also significantly subnormal bilaterally (29% and 34% less in affected and unaffected eyes, respectively, P = 0.001). However, SO muscle size and volume were normal in acquired cases. The SO muscle did not relax in supraduction in BrS, although there was normal contractile thickening in infraduction. The IO muscle had normal size bilaterally in BrS.

CONCLUSIONS

Congenital BrS may be associated with SO hypoplasia that could reflect hypoinnervation. However, unique isometric loading of oblique extraocular muscles due to restrictive hypotropia in adduction in BrS is generally not associated with changes in muscle bulk or in SO contractility. Unlike skeletal muscles, the bulk and contractility of extraocular muscles can therefore be regarded as independent of isometric exercise history. Restriction to elevation in BrS typically arises in the trochlea-tendon complex.

Brown's syndrome with ocular albinism: Case report of a rare presentation and literature review

We report a rare case of Brown's syndrome associated with ocular albinism in a 10-year-old boy. This report highlights the importance of further analysis of cases of Brown's syndrome and throws some light on the etiology and association of this rare condition.

Considerations on the etiology of congenital Brown syndrome

PURPOSE OF REVIEW

Brown syndrome is an ocular motility disorder characterized by limited volitional and passive elevation of the eye in adduction. Although originally thought due to abnormalities in the trochlea or tendon sheath (limiting the free movement of the tendon through the trochlea), recent evidence suggests that some cases of congenital Brown syndrome may be related to neurodevelopmental abnormalities of the extraocular muscles (congenital cranial dysinnervation disorders, CCDD).

RECENT FINDINGS

CCDD is a term encompassing congenital abnormalities of eye movements caused by congenital innervational abnormalities. The abnormal development of cranial nerve nuclei or abnormalities in cranial nerve axonal transport affects the development of the extraocular muscle(s). Currently, congenital fibrosis of the extraocular muscles, Duane syndrome, Moebius syndrome, Horizontal gaze palsy and progressive scoliosis, and synergistic divergence are included as CCDDs. In addition, congenial ptosis, Jaw Wink ptosis, and congenital superior oblique palsy are also included. Recently, it has been suggested that some cases of congenital Brown syndrome and congenital superior oblique paresis are related, and these entities may be part of the CCDDs spectrum.

SUMMARY

Important findings regarding the cause of congenital Brown syndrome will be reviewed.

Clinical progression of untreated bilateral Brown syndrome

PURPOSE

To present the natural history of bilateral Brown syndrome in patients without surgical intervention.

METHODS

The medical records of cases of bilateral Brown syndrome not treated surgically with long-term follow-up from 1987 to 2012 were retrospectively reviewed.

RESULTS

A total of 9 cases were included. The majority of patients in this series had idiopathic Brown syndrome, were diagnosed in early childhood, and had minimal ophthalmic sequelae. Of the 9 patients, 8 were diagnosed with bilateral Brown syndrome at their first ophthalmologic assessment. The age range at first diagnosis was 3-6 years of age. The mean follow-up period was 7.9 years; the median, 5 years (range, 1-20 years). At the most recent follow-up visit, 6 patients remained orthophoric in primary position; 1 patient had a micro-esotropia; 1 had developed an exotropia of 30 D; and 1 had developed a right hyperphoria. All patients without concurrent horizontal strabismus developed normal stereopsis and visual acuity, with minimal or no compensatory head position or downshoot in adduction.

CONCLUSIONS

Patients in this case series show minimal, if any, long-term visual impairment.

Trochlea surgery for acquired Brown syndrome

PURPOSE

To describe surgical treatment of acquired Brown syndrome by trochlea reconstruction and trochlea adhesiotomy.

METHODS

The medical records of patients with acquired Brown syndrome who underwent intraoperative forced duction testing under direct view of the trochlea from 2010 to 2012 were retrospectively reviewed. In all cases, the site of restricted movement was identified, after which either the trochlea was reconstructed or the trochlear adhesion was removed. Surgical results were assessed by means of the pre- and postoperative Hess chart scores and binocular single vision test scores.

RESULTS

Six eyes of 6 patients were included. In 4 patients the trochlea was reconstructed; in 2, the adhesion was removed. A significant improvement in the Hess chart scores was observed postoperatively in 5 of the 6 patients (P = 0.047). Binocular single vision test scores also significantly improved in 4 of 5 patients (P = 0.019). No iatrogenic superior oblique muscle paresis was observed in any of the patients.

CONCLUSIONS

Our technique of isolating the source of limitation of elevation and treating with trochlea reconstruction or adhesion removal successfully treated acquired Brown syndrome in these patients.

Fourth cranial nerve palsy and Brown syndrome: two interrelated congenital cranial dysinnervation disorders?

Based on neuroimaging data showing absence of the trochlear nerve, congenital superior oblique palsy is now classified as a congenital cranial dysinnervation disorder. A similar absence of the abducens nerve is accompanied by misinnervation to the lateral rectus muscle from a branch of oculomotor nerve in the Duane retraction syndrome. This similarity raises the question of whether some cases of Brown syndrome could arise from a similar synkinesis between the inferior and superior oblique muscles in the setting of congenital superior oblique palsy. This hypothesis has gained support from the confluence of evidence from a number of independent studies. Using Duane syndrome as a model, we critically review the accumulating evidence that some cases of Brown syndrome are ultimately attributable to dysgenesis of the trochlear nerve.

Possible association of congenital Brown syndrome with congenital cranial dysinnervation disorders

BACKGROUND

Congenital cranial dysinnervation disorders (CCDDs) are known to arise from abnormal development of individual and multiple cranial nerve nuclei or abnormalities in cranial nerve axonal transport. We report our findings for several patients with Brown syndrome in association with other known abnormalities characteristic of CCDDs.

METHODS

The medical records of patients presenting during a 4-year period with congenital Brown syndrome were retrospectively reviewed. Patients with Brown syndrome confirmed by forced ductions were included in the study if the Brown syndrome was associated with either an abnormal development of the superior oblique muscle or superior oblique paresis, ptosis, Duane syndrome, or other known CCDDs.

RESULTS

A total of 9 patients with Brown syndrome were identified. Of these, 3 also demonstrated a contralateral superior oblique palsy; 2, a contralateral Duane syndrome; 1, an ipsilateral congenital ptosis; and 3, a moderate to severely hypoplastic ipsilateral superior oblique muscle.

CONCLUSIONS

Some patients with congenital Brown syndrome are associated with and possibly in the spectrum of CCDDs. We propose that Brown syndrome may be due to abnormal development of the trochlear nerve, which results in physical changes in the superior oblique muscle-tendon-trochlea complex. This results in a tendon that is either long and lax, absent, or abnormally inserted (ie, superior oblique paresis) or a tendon that is restricted in its movements through the trochlea (Brown syndrome).

[MRI in congenital Brown's syndrome: report of 16 cases]

INTRODUCTION

Superior oblique retraction syndrome or Brown's syndrome is one of the so-called restrictive syndromes causing anatomic strabismus. It is characterized by active and passive limitation of upward gaze in adduction in the field of action of the superior oblique muscle (SO). The etiology of this congenital syndrome remains unknown. The purpose of this prospective study is to analyze brain and orbital magnetic resonance imaging (MRI) in patients with congenital Brown's syndrome.

PATIENTS AND METHODS

Sixteen children (19 months - 9 years) underwent complete ophthalmologic evaluation followed by brain/orbital MRI with attention to the superior oblique muscle. Average age at time of MRI was 4.2 years old. Among patients included were eight girls and eight boys. MRI was performed on a 1.5T (Symphony TIM, Siemens, Erlangen) to visualize the orbit and specifically the SO.

RESULTS

Of 16 eyes, 13 demonstrated radiologic abnormalities of the SO muscle; six demonstrated tendon-trochlea complex hypertrophy, four demonstrated complete SO hypertrophy (tendon-trochlea-muscle belly), one demonstrated trochlear hypertrophy, and two demonstrated abnormalities solely of the tendons, of which one was longer and one was thinner with fibrosis.

CONCLUSION

MRI shows a high frequency of SO radiologic abnormalities in congenital Brown's syndrome. MRI permits the analysis of not only the tendon, but also the trochlea and muscle belly, whereas surgery only allows visualization of the tendon. MRI proved to be an interesting tool for investigation of these patients and for a better understanding of the pathogenesis.

A 6-year-old girl with restricted upward gaze of her right eye

Brown syndrome is an incomitant strabismus syndrome characterized by inability of the eye to elevate during adduction. • Primary Brown syndrome is thought to occur due to the inability of the superior oblique tendon to stretch.However, there are many secondary causes of this condition that must be ruled out. • Despite significant misalignment of the eyes during upgaze, patients with Brown syndrome usually do not have decreased vision or diplopia with primary gaze. • Unlike paralytic strabismus, forced duction tests demonstrate restriction and a Parks’ three-step test does not demonstrate a paralytic muscle. Spontaneous resolution is frequent, and surgical management typically is not indicated because of the high incidence of postoperative symptomatic superior oblique palsy.

Hypertropia following Spontaneous Resolution of Brown's Syndrome

Purpose

To report a case of bilateral Brown's syndrome with unilateral spontaneous resolution causing hypertropia and significant head tilt.

Case Report

A 3 ½-year-old girl presented with bilateral typical Brown's syndrome and orthophoria in the primary position; she presented with unilateral resolution of right Brown's syndrome 6 months later, causing right hypertropia and gradually deteriorating left head tilt. She benefited from right superior rectus muscle recession to help correct her head posture.

Conclusion

This is the first report of a patient presenting with known bilateral Brown's syndrome with subsequent documented unilateral resolution causing a significant hypertropia of the resolved side and contralateral head tilt. Our case provides evidence in support of Clark and Noël's [Can J Ophthalmol 1993;28:213–216] hypothesis that patients who present with unilateral Brown's syndrome and contralateral inferior oblique muscle overaction might originally have had bilateral Brown's syndrome with spontaneous resolution of 1 side only.

Absence of the fourth cranial nerve in congenital Brown syndrome

PURPOSE

To elucidate the aetiology of congenital Brown syndrome.

METHODS

Four consecutive patients diagnosed with unilateral congenital Brown syndrome had a comprehensive standardized ocular motility examination. Any compensatory head posture was measured. Brain magnetic resonance imaging (MRI) with regard for the IV cranial nerve (CN) was performed in all patients. Orbital MRI was performed in 2/4 patients, with images acquired in eight directions of gaze and superior oblique (SO) muscle areas compared.

RESULTS

CN IV could not be identified bilaterally in two patients, but was absent only on the side of the Brown syndrome in the two other patients. On the normal side, orbital MRI revealed a smaller SO muscle area in upgaze than in downgaze, demonstrating normal actions of this muscle. On the side of the Brown syndrome, the SO area remained the same in upgaze and in downgaze and approximately symmetric to the area of SO in downgaze on the normal side.

CONCLUSIONS

These cases add further anatomical support to the theory of paradoxical innervation in congenital Brown syndrome. CN IV was absent in two patients on the side of the Brown syndrome, but without muscle hypoplasia. SO muscle size did not vary in up- and downgaze, which we interpreted as a sign of constant innervation through branches of CN III.

Monocular partial/sector occlusion therapy: a procedure to inhibit diplopia in Brown syndrome

BACKGROUND

Brown syndrome is recognized clinically as an absence or restriction of elevation in adduction. It often causes intermittent diplopia.

CASE REPORT

This article includes discussion of a child, age 3 years, 11 months, who underwent surgery of the right eye for a left hypertropia. By age 5 years, he complained to his mother of daily, intermittent diplopia, eye pain in both eyes (OU), and frontal headaches. Additional strabismus surgeries OU were done at ages 6¾ years and 8¼ years. At age 10½ years, the ophthalmologist first noted suspicion of acquired right Brown syndrome, which was definitively diagnosed at age 14. At that time, the original complaints remained unresolved, and his mother was hesitant to allow a fourth surgery. Thus, a procedure was devised to partially occlude a precise sector of the spectacle lens for the noninvolved eye in Brown syndrome. This successfully inhibited the daily, intermittent diplopia while allowing fusion and normal stereopsis in primary and down gaze. Also, it resolved the associated eye pain OU and headaches.

CONCLUSION

Monocular partial/sector occlusion therapy to inhibit intermittent diplopia in Brown syndrome offers a sensible alternative to surgery for those with normal or near-normal alignment, fusion, and stereopsis in primary and down gaze. For those who contemplate surgery, had failed surgery, or require treatment of underlying disease, monocular partial/sector occlusion therapy can serve as an excellent adjunct. Also, it may be attempted in other incomitant strabismic deviations with bothersome diplopia limited to specific positions of gaze.

[Superior oblique sharpening surgery in the treatment of Brown syndrome plus]

PURPOSE

To describe superior oblique sharpening in congenital Brown syndrome plus.

MATERIAL AND METHODS

A retrospective study of 17 Brown syndrome cases that were treated with oblique superior sharpening from 1997 to 2007. Vertical deviation in primary position was classified as + to +++, head tilt as: mild (< 10°), moderate (10-20°) and severe (≥ 20°); elevation in adduction from -1 to -4. A good postoperative result was considered if last elevation limitation in adduction was zero or -1, without head tilt and vertical deviation in primary position.

RESULTS

Mean age was 4.9 years. Limitation elevation in adduction which was -3 in 8 cases (47.1%) and -4 in 9 (52.9%), which improved completely after surgery in 6, -1 in 9 and -3 in 2 patients. Preoperative hypotropia in 15 cases (13 mild, 1 moderate and one severe) was resolved in 13 after surgery. Of 14 patients with torticollis (3 mild, 10 moderate and one severe) it was surgically corrected in 11. Success was achieved in 14 (82.4%), 2 were under corrected (11.8%) and one was overcorrected (5.88%). Mean follow-up was 60.71 months.

CONCLUSIONS

Oblique superior sharpening as treatment for Brown syndrome plus is an effective procedure. The incidence of secondary oblique palsies has been very low.

Late spontaneous resolution of congenital Brown syndrome

Brown syndrome is characterized by restricted elevation in adduction. Congenital Brown syndrome usually is diagnosed during early childhood. It is believed to be caused by an abnormality of the superior oblique tendon as it passes through the trochlea. The natural history of Brown syndrome is poorly characterized. Many patients with congenital Brown syndrome undergo strabismus surgery during childhood in an attempt to correct the problem surgically. This report describes spontaneous regression of congenital Brown syndrome in an adult.

Palmaris longus tendon as an autogenous expander for Brown's syndrome: a novel technique

INTRODUCTION

The palmaris longus tendon (PLT) is one of the most commonly used donor tendons in orthopedic and reconstructive surgery. We present a new surgical technique using this autogenous tissue for lengthening the superior oblique tendon in cases of moderate to severe Brown syndrome.

METHODS

Four children with Brown syndrome were selected, and consent was obtained. Preoperative motility assessment and intraoperative forced duction tests confirmed the diagnosis. PLT harvesting was performed under general anesthesia. Follow-up ranged from 12 to 21 months.

RESULTS

Preoperatively all patients demonstrated hypotropia of 16Delta to 30Delta with an abnormal head posture. Postoperatively all patients showed an improvement in hypotropia to <3Delta, with complete resolution of abnormal head posture. Improvement of elevation in adduction did not match that of the vertical deviation, but all patients had less restriction of elevation in adduction after surgery. No patients developed any of the complications encountered with a silicone expander (eg, extrusion, tendon-related inflammation, foreign body sensation, or consecutive superior oblique palsy), and none needed further surgery. Wrist function was completely normal in all patients postoperatively.

CONCLUSIONS

PLT is an autogenous tissue that allowed for controlled weakening of the superior oblique tendon, with minimal complications observed in four patients. More studies comparing PLT tendon expansion with other published methods are warranted.

Incidence of calcification of the trochlear apparatus in the orbit

Purpose

To quantify the incidence of asymptomatic incidental trochlear calcifications and to describe their clinical features.

Methods

We retrospectively reviewed orbital computed tomography (CT) scans of 216 patients to identify the presence of trochlear calcifications. We analyzed the prevalence, age distribution, and gender preponderance of trochlear calcifications. We also examined age-specific prevalence rates for trochlear calcifications, as well as their relationship to systemic disease.

Results

The mean age of patients was 26.8 years. Trochlear calcifications were observed in 35 (16%) of the 216 patients, and 18 of the 35 patients had bilateral calcifications. The rate of trochlear calcification was higher in males; 32 (20.9%) of 153 male patients had trochlear calcifications, compared with 3 (4.8%) of 63 female patients. Age, hypertension, diabetes mellitus, and thyroid disease were not significantly associated with the incidence of trochlear calcifications.

Conclusions

Incidental asymptomatic orbital calcification is more commonly observed on CT images than we expected and occurs predominantly in male patients. Understanding this to be a relatively common, benign finding may help us to rule out foreign bodies and other pathologic conditions.

A case of acquired Brown syndrome after surgical repair of a medial orbital wall fracture

A case of acquired Brown syndrome caused by surgical repair of medial orbital wall fracture is reported in the present paper. A 23-year-old man presented at the hospital with right periorbital trauma. Although the patient did not complain of any diplopia, the imaging study revealed a blow-out fracture of the medial orbital wall. Surgical repair with a calvarial bone autograft was performed at the department of plastic surgery. The patient was referred to the ophthalmologic department due to diplopia that newly developed after surgery. The prism cover test at distant fixation showed hypotropia of the right eye, which was 4 prism diopters (PD) in primary gaze, 20 PD in left gaze, while orthophoric in right gaze. Eye movement of the right eye was markedly limited on elevation in adduction with normal elevation in abduction with intorsion in the right eye present. Forced duction test of the right eye showed restricted elevation in adduction. Computerized tomography scan of the orbits showed the right superior oblique muscle was entrapped between the autografted bone fragment and posterior margin of the fracture. When repairing medial orbital wall fracture that causes Brown syndrome, surgeons should always be careful of entrapment of the superior oblique muscle if the implant is inserted without identifying the superior and posterior margin of the orbital fracture site.

Brown syndrome in one pair of dizygotic twins: a case report

Introduction

Brown syndrome is a rare ocular movement abnormality. This syndrome is characterized by an inability to elevate the affected eye in adduction. Most cases are sporadic but the occurrence in Monozygotic twins has suggested the possible autosomal dominant inheritance in Brown syndrome.

Case presentation

A 4-year-old girl (one pair of dizygotic twins) was referred to our pediatric ophthalmology clinic to assess her abnormal eye movement noticed by her mother. Visual acuity of both eyes was 20/20 with Snellen chart. Ocular motility showed mild exotropia in primary position with marked divergence in upward gaze (V pattern), mild hypotropia in adduction, and limitation of elevation in adduction of both eyes (Fig. 1A). We also examined her sister, all ocular evaluations including visual acuity, slit lamp examination, funduscopy and ocular motility (Ductions & Versions) were normal without any limitation.

We also review the related articles that previously have reported Brown syndrome in twins.

Conclusion

Although there are few case reports of Brown syndrome in twins, combination of these reports may elucidate the genetic basis of this disease.