Congenital Brown Syndrome Research Articles

Superior oblique tendon trochlear passage syndrome : Causes, motility findings and treatment of acquired Jaensch-Brown syndrome

Acquired Jaensch-Brown syndrome is characterized by amechanical limitation of elevation in adduction, with orthophoria in downward gaze. It was first described by Jaensch in 1928 after orbital trauma in his case and has the same motility pattern as congenital Brown's syndrome. For this reason, in 1973 Brown differentiated between the "true" and "simulated" cases. Further clinical findings of the different etiological factors must be considered in order to differentiate between the two groups. The cause is an acquired restriction of the free passage of the superior oblique tendon through the trochlea. In most cases this is produced by apalpable swelling/nodule of the superior oblique tendon posterior to the trochlea. There are three possibilities to develop aswelling/nodule: 1.Shortly after birth due to an incomplete development at the time of birth of the sliding factors needed for afree passage. 2.An inflammation in combination with asystemic disease, such as rheumatism or idiopathic. 3.A blunt orbital trauma causing ahematoma of the superior oblique tendon. Additionally, the trochlear passage can be narrowed by asevere inflammation involving the trochlea, which is associated with aswelling and marked tenderness of the trochlear area and corresponds to stenosing tenosynovitis of the hand. The therapeutic management of these four variations differs significantly depending on the cause of the swelling. The swelling of the superior oblique tendon posterior to the trochlea explains the motility disorder in acquired Jaensch-Brown syndrome. There are three different causes for the swelling, which require different therapeutic management.

Superior oblique tendon thinning as a surgical treatment for Brown syndrome

To evaluate the results of a superior oblique thinning technique for the treatment of congenital Brown syndrome. 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. A total of 21 eyes of 20 consecutive patients (mean age, 5.8±2.5years) 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 3months postoperatively except for 1 patient who relapsed 9months after surgery and 1 patient who improved after 4years. 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.

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

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

Brown's atavistic superior oblique syndrome: etiology of different types of motility disorders in congenital Brown's syndrome

The congenital Brown syndrome is characterized by a mechanical limitation of elevation in adduction, with an orthophoria in down gaze. Brown postulated a shortened superior oblique tendon sheath as the cause of the limitation but this was disproved by Parks et al. in 1975 and the origin of Brown syndrome remains unclear. In recent years, acongenital dysinnervation has been discussed; however, this does not explain the full spectrum of abnormalities and especially contradicts the unlimited depression in adduction seen in Brown syndrome. Surgical exploration in Brown true typical cases reveals a fibrotic strand, typically located at the posterior margin of the superior oblique tendon. This strand originates from the trochlear area and has a common insertion with the superior oblique tendon posterior to the equator into the globe. It may represent an atavistic superior oblique muscle as described by Fink in various animals. They do not have a trochlea but a superior oblique muscle originating in the anterior superior nasal orbit. Afibrotic strand was also surgically revealed in two cases of atypical Brown syndrome. In the first case an elevation deficit-as in Brown true atypical cases-also present in abduction could be explained by an unusual insertion of the fibrotic strand anterior to the equator. The second case showed a fibrotic strand which was completely separated from the superior oblique tendon and inserted far posterior to the equator nasal to the superior rectus muscle. This finding had not been previously described and explained the total elevation restriction which was suddenly in > 30° adduction and the Y‑pattern exotropia which increased in adduction and decreased in abduction. A10 mm excision of the fibrotic strand from the insertion gives the best results from all procedures. The residual limitation of active elevation in adduction improved with gaze exercises mostly after more than 1year. The fibrotic strand, an atavistic superior oblique muscle, not only explains the typical Brown syndrome but also-by its variable insertion-different patterns of elevation deficits seen in atypical Brown syndrome. A10 mm excision of the strand gives good functional results of abnormal head position (immediate in most cases) and even elevation in adduction (after 1year in most cases).

Horizontal Deviations in Congenital Brown Syndrome.

To report the incidence of horizontal deviations requiring surgical correction in patients with congenital Brown syndrome. In a retrospective study, the medical records of all children who underwent a surgical correction of congenital Brown syndrome at Schneider Children's Medical Center of Israel from 1998 to 2016 were reviewed, analyzing the presence of preoperative primary position horizontal misalignment. Overall, 19 eyes (8 right and 11 left eyes) of 16 patients (7 males, 9 females; mean age: 4.2 ± 2.6 years) were included in this study. Fourteen patients (88%) had surgery for correction of a compensatory head position, including 8 patients (50%) with a head tilt and 6 patients (38%) with a chin-up position, and 2 patients had surgery for primary position hypotropia. All of them underwent a weakening procedure of the superior oblique tendon, by either Z-tenectomy (81%, n = 13) or suture elongation of the superior oblique tendon (19%, n = 3). Fifty-six percent of patients (n = 9) had primary position horizontal deviation before surgery, including 50% (n = 8) exodeviations, ranging from exophoria of 4 prism diopters (PD) to exotropia of 30 PD, and one esotropia of 14 PD. Fifty percent of patients (n = 8) had surgery to correct the horizontal deviation by a recession of either one (31%, n = 5) or two (19%, n = 3) muscles. Mean preoperative horizontal deviation (9.3 ± 3.4 PD) decreased significantly following surgery (1.7 ± 1 PD, P = .001) (paired t test). Significant horizontal misalignment is often present in patients with congenital Brown syndrome and its correction should be considered at the time of surgery. [J Pediatr Ophthalmol Strabismus. 2018;55(2):113-116.].

Combined Brown syndrome and superior oblique palsy without a trochlear nerve: case report

BackgroundCongenital Brown syndrome is characterized by limited elevation particularly during adduction. The pathogenesis of congenital Brown syndrome is still controversial.Case presentationA 6-year-old boy had been tilting his head to the left since infancy. He showed right hypertropia (RHT) of 2 prism diopters (Δ) in the primary position. He showed RHT 6Δ in right gaze, RHT 2Δ in left gaze, RHT 12Δ in right head tilt, and orthotropia in left head tilt. The right eye showed limitation of elevation and depression on adduction, and the left eye showed overdepression on adduction. MR images showed an absent right trochlear nerve with a hypoplastic ipsilateral superior oblique muscle.ConclusionsCongenital Brown syndrome may be associated with an absent trochlear nerve and hypoplastic superior oblique muscle suggesting an etiologic mechanism of congenital cranial dysinnervation disorder.

Aspects cliniques sensoriels et moteurs des syndromes de rétractions congénitaux : syndrome de Stilling-Duane et syndrome de Brown

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. Seventeen patients' records were retrospectively assessed for: the ocular deviation in primary position and in the 9positions of gaze, head tilt, visual acuity and binocular vision. Eleven patients with Stilling-Duane syndrome had a mean age of 12years, and monocular involvement, most frequently of typeI. The ocular deviation was variable; 16patients 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 6years. Three had a moderate form, 3had a severe form with vertical deviation in primary position, compensatory head position, amblyopia and binocular vision impairment. 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. Clinical motility and sensory assessment is essential, though difficult, to establish the diagnosis and the management of patients with retraction syndromes.

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

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). 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. 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. 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.

Considerations on the etiology of congenital Brown syndrome.

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

Magnetic resonance imaging in congenital Brown syndrome.

Our aim was to elucidate the etiology of Brown syndrome by evaluating the trochlea position, morphologic characteristics of the extraocular muscles including superior oblique muscle/tendon complex, and the presence of the cranial nerves (CN) III, IV, and VI using magnetic resonance imaging (MRI) in eight patients with unilateral congenital Brown syndrome and one patient with bilateral congenital Brown syndrome. Nine consecutive patients diagnosed with congenital Brown syndrome had a comprehensive ocular examination and MRI for the CN III, CN VI, and the extraocular muscles. Five of the nine patients underwent additional high resolution MRI for CN IV. The distance from the annulus of Zinn to the trochlea was measured. Normal sized CN III, IV, and VI, as well as all extraocular muscles, could be identified bilaterally in all patients with available MRI. The distance from the annulus of Zinn to the trochlea was the same in both eyes. The findings for our patients, particularly in those who underwent additional high resolution MRI, did not provide evidence of a lack of CN IV as a cause of Brown syndrome.

The Results of Brown Syndrome Surgery with Superior Oblique Split Tendon Lengthening

Purpose: To report the surgical outcome of superior oblique tendon split lengthening for management of patients with severe type of congenital Brown syndrome. Brown syndrome is characterized by hypotropia in primary position and limitation of elevation in adduction more than −4.Materials and methods: Fourteen consecutive patients with severe congenital Brown syndrome underwent superior oblique split lengthening surgery (10 mm). The amount of hypotropia in primary gaze and the degree of elevation in adduction were compared before and after the surgery. Any surgical complications were also recorded.Results: Surgery was performed on 15 eyes in 11 female and 3 male subjects. Mean postoperative follow-up time was 12.93 ± 1.79 months (ranging from 10 to 16 months). Average hypotropia in primary gaze improved from 16.2 ± 5.5 prism diopters (range: 10–25 prism diopters) preoperatively to 5.9 ± 4.0 prism diopters (range: 0–18 prism diopters) postoperatively recorded at final follow-up examination (p < 0.001). The limitation in adduction improved from −7.2 ± 4.5 (range: −6 to −8) preoperatively to −1.8 ± 1.3 (range: zero to −5) postoperatively (p < 0.001). No surgical complications were noted.Conclusion: Superior oblique split lengthening has a significant effect on reducing primary gaze hypotropia and improving elevation in adduction. This technique should be considered for the treatment of patients with severe congenital Brown syndrome.

Amblyopia and sensory features at initial presentation of Brown syndrome: an issue to recognize

To investigate the frequency of amblyopia and sensory features at initial presentation in patients who had unilateral congenital Brown syndrome (BS) and to identify the potential risk factors for amblyopia in BS. The study conducted with patients who had unilateral congenital BS. Patient demographics, visual acuity, refractive errors, amount of horizontal and vertical deviations, abnormal head position, fusion, and stereopsis were all reviewed. The main outcome measure was the frequency of amblyopia at initial presentation. The review identified 44 patients with BS (median age 5 years). The frequency of amblyopia was 15.9% (seven patients) in BS at initial presentation. Patient age (P=0.297), ocular alignment at primary position (P=0.693), anisometropia (P=0.184), and stereoacuity (P=0.061) were found to have no significant relation with amblyopia. The main associated risk factor was the absence of sensory fusion (P=0.013). Amblyopia may be encountered among patients with BS, and may be related to binocularity of the patient. Its recognition may be a critical step during the treatment planning and may determine presumably the success of future therapies.

Possible association of congenital Brown syndrome with congenital cranial dysinnervation disorders

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. 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. 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. 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).

Apport de l’IRM dans le syndrome de Brown congenital

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. 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. 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. 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.

This issue of Acta, printed and electronic

This issue of Acta, printed and electronic

Sequential presentation of bilateral Brown syndrome

Brown syndrome, characterized by a limitation of elevation in adduction and positive forced duction testing, is usually unilateral but occurs bilaterally in 10% of all cases. It may present as a congenital condition in one eye and develop in the other eye with no apparent cause. We present a case of bilateral Brown syndrome in which the right eye became involved within 1 year of surgery on the left eye for congenital Brown syndrome.

Absence of the fourth cranial nerve in congenital Brown syndrome

To elucidate the aetiology of congenital Brown syndrome. 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. 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. 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.

Superior oblique tendon expansion with Achilles tendon allograft for treating Brown syndrome

To report the results of treatment of Brown syndrome using Achilles tendon allograft as a superior oblique tendon expander. Achilles tendon allografts were prepared from the tissue bank. Five eyes of 3 patients with congenital Brown syndrome (mean age, 6 years) were enrolled in the study. Surgery was performed with a superotemporal conjunctival fornix approach. The superior oblique tendon was exposed and severed; then a 2- to 3-mm-wide strip of Achilles tendon (with a thickness of 1-2 mm) was trimmed and sutured between the cut ends using double-armed 5-0 Mersilene sutures. The length of the expander ranged from 7 mm to 8 mm, depending on the severity of the disease. The preoperative hypotropia in primary position ranged from 15(Δ) to 30(Δ), with abnormal head position in 1 patient. Nine months after the operation, 2 eyes with moderate Brown syndrome showed an improvement in the hypotropia to <3(Δ), and 2 eyes with severe disease had residual hypotropia of 5(Δ). Another eye with severe Brown syndrome had a residual hypotropia of 20(Δ). The elevation in adduction improved by 1 grade in 1 eye and resolved in the other 4 eyes. The amount of correction in the deviation improved with time. None of the patients developed secondary superior oblique palsy, rejection, infection, extrusion, prolonged ocular inflammation, or foreign body sensation. Superior oblique tendon elongation with Achilles tendon allograft had acceptable short-term results in 4 of 5 eyes treated for Brown syndrome.

Resultados del afilamiento del oblicuo superior en el tratamiento del síndrome de Brown 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.