Brown Syndrome Differential Diagnoses

Updated: Jun 19, 2018
  • Author: Barbara L Roque, MD, DPBO, FPAO; Chief Editor: Edsel B Ing, MD, MPH, FRCSC, PhD, MA  more...
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DDx

Diagnostic Considerations

The following signs of superior oblique overaction help differentiate it from Brown syndrome (see Table below):

  • Mild limitation of elevation in adduction

  • No limitation of elevation in abduction

  • Common bilateral involvement

  • Superior oblique overaction

  • A-pattern, lambda-subtype with divergence in downgaze

  • Fundal examination reveals intorsion in primary position that increases in downgaze.

  • Negative forced ductions test

The following signs occur with inferior oblique paresis, differentiating it from Brown syndrome (see Table below):

  • Limitation of elevation in adduction occurs, with a large vertical deviation in primary position, usually more than 10 PD.

  • Marked superior oblique overaction

  • A-pattern, convergence in upgaze

  • Fundal examination reveals intorsion in primary position, which increases in upgaze.

  • Positive head-tilt test

  • Negative forced ductions test

Monocular elevation deficiency (double elevator palsy): In Brown syndrome, limitation of elevation in adduction is invariable; yet, this sign is also present in 70% of patients with double elevator palsy. However, with monocular elevation deficiency, there is also limited elevation in abduction.

Table 1. Differential Diagnoses: Clinical Features of Brown Syndrome, Inferior Oblique Paresis, and Superior Oblique Overaction (Open Table in a new window)

 

Brown syndrome (inelastic superior oblique muscle-tendon complex)

Primary superior oblique overaction

Inferior oblique paresis

Limitation of elevation in adduction

Usually severe (-3 to -4)

Usually mild

Usually severe (-3 to -4)

Limitation of elevation on abduction

Common (mild to moderate)

No

No

Bilateral involvement

Rare (5-10%)

Common

Unusual

Vertical deviation

None or small (< 10 PD)

Bilateral small (< 10 PD)

Unilateral large (>10 PD)

Superior oblique overaction

None or minimal

Yes, marked

Yes, marked

Pattern

None or V-pattern Y-subtype with divergence in upgaze

A-pattern Lambda-subtype with divergence in downward gaze

A-pattern, often convergence in upgaze

Fundus torsion

None in primary or downgaze, intorsion in upgaze

Intorsion in primary, increasing in downgaze

Intorsion in primary, increasing in upgaze

Head title test

Negative

Negative

Positive

Forced ductions

Positive

Negative

Negative

Differential Diagnoses