brown's syndrome

has anyone heard of this visual difficculty. I have a 4yr old who has it?

> has anyone heard of this visual difficculty. I have a 4yr old who has it?
annie<

Annie: Never heard of it, but here's one result of a web search
(http://www.smbs.buffalo.edu/oph/ped/browns.htm). If Friday Night is Music
Night, then Wednesday Night is fast becoming Syndrome Night! As I expected,
lots of medical information about the syndrome and absolutely nothing about
the educational implications.

David Wilson

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BROWN SYNDROME

This ocular motility disorder, characterized by an inability to elevate the
adducted eye actively or passively, was first described by Brown. It has
since become recognized that there is a variety of causes, that the
condition may be congenital or acquired, and that the defect can be
permanent, transient, or intermittent. 

Clinical Manifestations Brown syndrome is characterized by a deficiency of
elevation in the adducting position. Improved elevation is usually apparent
in the midline, with normal or near-normal elevation in abduction. There is
occasional widening of the palpebral fissure on attempted elevation in
adduction. With lateral gaze in the opposite direction, the involved eye
may depress in adduction, although no overdepression simulating overaction
of the superior oblique muscle occurs on duction testing. Exodeviation (V
pattern) often occurs as the eyes are moved upward in the midline. Many
patients are orthophoric in the primary position, although with time
hypotropia may develop with a compensatory face turn toward the opposite
eye. In some cases, there is discomfort on attempted elevation in
adduction, the patient may feel or even hear a click under the same
circumstances, and there may be a palpable mass or tenderness in the
trochlear region. A positive forced duction test is the hallmark of Brown's
syndrome. 

Pathogenesis Brown subsequently redefined the syndrome, recognizing that it
is more complex than originally proposed. He initially believed that the
simulated inferior oblique palsy was due to an innervational disturbance to
this muscle, with secondary contracture of the anterior sheath of the
superior oblique tendon. Catford and Hart, using electromyography,
demonstrated electrical silence on recording from the superior oblique
muscle and maximal activity from the inferior oblique muscle in patients
with Brown syndrome who attempted elevation in adduction. Metz reported
normal upward saccades in adduction, confirming the restrictive nature of
the problem. 

Brown attributed the syndrome to congenital shortening of the sheath
surrounding the reflected tendon of the superior oblique muscle. However,
several investigators were unable to substantiate Brown's theory of a
primary congenital anomaly of the anterior sheath of the superior oblique
tendon. Crawford was the first to prove that the cause of the syndrome is a
tight superior oblique tendon. By cutting the tendon or excising a portion
of it, the restricted elevation of the involved eye was cured. 

Acquired Brown syndrome has been attributed to a variety of causes,
including superior oblique surgery, scleral buckling bands, trauma, focal
metastasis to the superior oblique, and following sinus surgery and
inflammation in the trochlear region. An identical motility pattern, as
seen in Brown syndrome, can be acquired by patients with juvenile or adult
rheumatoid arthritis. It appears that this form of Brown's syndrome
represents a stenosing tenosynovitis of the trochlea and shares similar
characteristics to inflammatory disorders that affect the tendons of the
fingers. 

Treatment If patients with Brown syndrome are orthophoric in primary
position and without an anomalous head posture, surgery is not necessary.
Such patients may experience diplopia when elevating the involved eye in
adduction, but will learn to avoid this position of gaze. However, if the
eye is hypotropic in primary position or if a head turn is cosmetically
significant, surgery is indicated to attempt to restore binocular function
in the primary position. 

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