Simulated superior oblique tendon sheath syndrome

[Click phenomenon in acquired Jaensch-Brown syndrome and trigger finger/thumb: the Notta syndrome]

CLINICAL FEATURES

The click phenomenon occurs when an acquired mechanical restriction of the elevation in adduction of the eye or of the extension of the finger/thumb, is forcefully overcome. The common cause is a nodule either of the superior oblique tendon posterior to the trochlea in the case of a Jaensch-Brown syndrome or of the digital flexor tendon anterior to the A1 annular pulley in the case of a trigger finger. Both locations share similar anatomical conditions for the development of the nodule and the pathomechanism of the click.

RESULTS

From these identical findings in the eye and the hand in small children it can be assumed that the results from the studies of the hand in newborns and infants with a trigger thumb/finger are also applicable to the situation of the eye. 1. This motility disorder is not congenital. This is most likely due to an incomplete development at the time of birth of the sliding factors needed for a free passage of the tendon through the trochlea and the A1 annular pulley. 2. A distinction must be made between stages 0-3: stage 0 = no more restriction of the motility and no click phenomenon; stage 1 = forced active extension/elevation possible; stage 2 = only passive extension/elevation, each with a click phenomenon; stage 3 = no extension/elevation possible and no click phenomenon. 3. In most cases in early childhood there is a spontaneous complete recovery (75% after 6-7 years). In the eye this spontaneous course can only limitedly be shortened with motility exercises in combination with segmental occlusion.

CONCLUSION

The click phenomenon is a symptom of stages 1 and 2 of an acquired mechanical restriction of the elevation in adduction of the eye or the extension of the finger/thumb. It should not be called a syndrome.

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

CLINICAL FEATURES

Acquired Jaensch-Brown syndrome is characterized by a mechanical 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.

ORIGIN

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 a palpable swelling/nodule of the superior oblique tendon posterior to the trochlea. There are three possibilities to develop a swelling/nodule: 1. Shortly after birth due to an incomplete development at the time of birth of the sliding factors needed for a free passage. 2. An inflammation in combination with a systemic disease, such as rheumatism or idiopathic. 3. A blunt orbital trauma causing a hematoma of the superior oblique tendon. Additionally, the trochlear passage can be narrowed by a severe inflammation involving the trochlea, which is associated with a swelling and marked tenderness of the trochlear area and corresponds to stenosing tenosynovitis of the hand.

TREATMENT

The therapeutic management of these four variations differs significantly depending on the cause of the swelling.

CONCLUSION

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.

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.