Advertisement

Brown’s syndrome during pregnancy: a case report and review of literature

      Brown’s syndrome is an uncommon strabismus characterized by restriction of elevation in adduction and can be congenital or acquired.
      • Brown H.W.
      Congenital structural muscle anomalies.
      • Wright K.W.
      Brown’s syndrome: diagnosis and management.
      Clinical features include mild impaired elevation on upgaze, minimal/no elevation deficit on abduction, and minimal/no superior oblique overaction.
      • Brown H.W.
      Congenital structural muscle anomalies.
      • Wright K.W.
      Brown’s syndrome: diagnosis and management.
      Acquired Brown’s syndrome can be due to superior oblique or trochlear etiology such as peritrochlear scarring in chronic sinusitis; tendon-trochlear inflammation in rheumatoid arthritis, often associated with superonasal orbital tenderness; superonasal orbital mass, such as neoplasm; or an inelastic superior oblique muscle as in thyroid disease. The differential diagnosis of deficient elevation in adduction includes monocular elevation deficiency, inferior oblique paresis, and superior oblique overaction.
      • Wright K.W.
      Brown’s syndrome: diagnosis and management.
      We report a rare case of Brown’s syndrome in pregnancy.
      A 34-year-old pregnant female presented to the emergency eye clinic with sudden-onset binocular vertical diplopia upon wakening with isolated right eye pain the previous day. She was 33 weeks pregnant with her second child. The current and previous pregnancies were both uncomplicated. Her medical history was significant for episodes of intermittent, nonerythematous, painful bilateral knee swelling 4 years prior with no definite diagnosis, controlled with oral nonsteroidal anti-inflammatory medications. Current medications were iron supplements. Her medical history was noncontributory, with no history of ocular trauma, rheumatoid arthritis, or sinusitis.
      On examination, visual acuity was 20/20 OU. Pupils were equal and reactive to light, with normal intraocular pressures. Ocular motility examination showed an elevation deficit OD in straight up gaze, −4 elevation deficit on adduction OD, and a slight right hypotropia in primary gaze (Fig. 1) and no compensatory head tilt. There was point tenderness over the right trochlea. Forced ductions showed marked restriction to elevation in adduction OD. Cranial nerves 2, 3, and 5–12 were intact bilaterally. Anterior and posterior segments were normal OU with no proptosis or palpable mass.
      Fig. 1
      Fig. 1Ocular motility examination at presentation showing an elevation deficit OD in straight up gaze, marked elevation deficit upon adduction OD; there was a slight right hypotropia in primary gaze (not shown).
      She was diagnosed with acute-onset right Brown’s syndrome of unknown etiology. After discussing treatment options with the patient and her obstetrician, a peritrochlear triamcinolone injection 10 mg was administered with no complications. Inflammatory work-up revealed normal complete blood count (apart from mild normocytic anemia) and normal c-anti-neutrophilic cytoplasmic antibody, antinuclear antibody, rheumatoid factor, syphilis, and Lyme serology. However, erythrocyte sedimentation rate (104 mm/h), C-reactive protein (CRP; 38.6 mg/L), and p-anti-neutrophil cytoplasmic antibody (200 AU/mL, normal range 0–99) were elevated.
      Over the following 2 weeks, her diplopia resolved and the elevation deficit on adduction also decreased considerably. On examination at 36 weeks of pregnancy in the adult strabismus clinic, she was orthotropic in all positions of gaze at distance, and near. She had a −2.5 limited elevation in adduction right eye, improved from initial presentation, with resolved tenderness over the right trochlea. Six weeks after her initial presentation, she underwent an uncomplicated labour, giving birth to a healthy baby.
      Two months postpartum she was orthotropic in all positions of gaze with resolved diplopia. The −2 elevation deficiency in adduction OD persisted, and a −1 elevation deficiency in adduction OS was detected. Her motility examination 16 months after initial presentation was unchanged. Systemically, she had recently developed right knee swelling and neck stiffness and was diagnosed with a seronegative spondyloarthritis. The significance of our patient’s elevated p-ANCA value is unclear. Follow-up with her rheumatologist found her to be HLA-B27 positive, with sacroiliitis and chronic synovitis. No systemic treatment or surgery has been required for symptom management.
      When a pregnant patient presents with diplopia, worrisome neurological disorders that affect ocular motility must be excluded, including parasellar and posterior fossa tumours, parasellar aneurysmal expansion, carotid-cavernous fistulas, and myasthenia gravis.
      • Grant A.D.
      • Chung S.M.
      The eye in pregnancy: ophthalmologic and neuro-ophthalmologic changes.
      Ocular motility disorders limited to the extraocular muscles with onset during pregnancy are rarely reported; we are aware of only 3 published reports in the literature, the details of which are summarized below.
      Jacobson
      • Jacobson D.M.
      Superior oblique palsy manifested during pregnancy.
      reported isolated superior oblique palsy in 3 pregnant women, with third-trimester onset, believed to be due to pregnancy-induced decompensation of a latent superior oblique palsy. Jacobson postulated that increases in extracellular fluid compartment during pregnancy caused sufficient expansion of the venous-filled cavernous sinus to exert mild compression or traction on the thin trochlear nerve residing in the lateral dural wall. Von Noorden
      • Von Noorden G.K.
      Chapter 19: Special forms of strabismus.
      reported a case of nonresolving Brown’s syndrome with onset during the first trimester, with no reported trochlear tenderness.
      Christiansen and Thomas
      • Christiansen S.P.
      • Thomas A.H.
      Postpartum Brown’s syndrome.
      described a case of postpartum Brown’s syndrome with no clinical evidence of systemic inflammatory disease, treated with oral prednisone followed by peritrochlear injection of dexamethasone.
      • Christiansen S.P.
      • Thomas A.H.
      Postpartum Brown’s syndrome.
      They suggested that pregnancy-associated fluid expansions, blood volume increase, and labour-associated Valsalva maneuvers might have exacerbated a previously subclinical trochlear stenosis or tenosynovitis.
      Our case is the first to report acute-onset Brown’s syndrome with diplopia in the third trimester of pregnancy with resolution of diplopia and improved ductions after peritrochlear steroid injection. The cause of our patient’s Brown’s syndrome is postulated to be a pregnancy-induced exacerbation of an underlying subclinical inflammatory process; the trochlear tenderness, response to steroids, elevated CRP,
      • Watts D.H.
      • Krohn M.A.
      • Wener M.H.
      • Eschenbach D.A.
      C-reactive protein in normal pregnancy.
      and seronegative spondyloarthritis support this hypothesis.
      In summary, Brown’s syndrome should be included in the differential diagnosis of new-onset diplopia in pregnancy. It may be the first presentation of an underlying inflammatory process warranting a referral to rheumatology. Treatment with peritrochlear steroids may resolve diplopia while limiting systemic exposure to medications that may affect the fetus.

      References

        • Brown H.W.
        Congenital structural muscle anomalies.
        in: Allen J.H. Strabismus Ophthalmic Symposium (1st ed.). Mosby, St. Louis1950: 205-236
        • Wright K.W.
        Brown’s syndrome: diagnosis and management.
        Trans Am Ophthalmol Soc. 1999; 97: 1023-1109
      1. Wright K.W. Strube Y.J. Pediatric Ophthalmology and Strabismus. 3rd ed. Oxford University Press, New York NY2012
        • Grant A.D.
        • Chung S.M.
        The eye in pregnancy: ophthalmologic and neuro-ophthalmologic changes.
        Clin Obstet Gynecol. 2013; 56: 397-412
        • Jacobson D.M.
        Superior oblique palsy manifested during pregnancy.
        Ophthalmology. 1991; 98: 1874-1876
        • Von Noorden G.K.
        Chapter 19: Special forms of strabismus.
        Binocular Vision and Ocular Motility. 4th ed. Mosby, St Louis, MO1990: 406
        • Christiansen S.P.
        • Thomas A.H.
        Postpartum Brown’s syndrome.
        Arch Ophthalmol. 1994; 112: 23-25
        • Watts D.H.
        • Krohn M.A.
        • Wener M.H.
        • Eschenbach D.A.
        C-reactive protein in normal pregnancy.
        Obstet Gynecol. 1991; 77: 176-180