Trochleitis
Encyclopedia
Trochleitis is inflammation
of the superior oblique tendon trochlea apparatus characterized by localized swelling, tenderness, and severe pain. This condition is an uncommon but treatable cause of periorbital pain. The trochlea is a ring-like apparatus of cartilage through which passes the tendon
of the superior oblique muscle. It is located in the superior nasal orbit
and functions as a pulley
for the superior oblique muscle
. Inflammation of the trochlear region leads to a painful syndrome with swelling and exquisite point tenderness in the upper medial rim of the orbit. A vicious cycle may ensue such that inflammation causes swelling and fraying of the tendon which then increases the friction of passing through the trochlea which in turn adds to the inflammation. Trochleitis has also been associated with triggering or worsening of migraine
attacks in patients with pre-existing migraines (Yanguela, 2002).
. Presentation is usually unilateral with palpable swelling over the affected area supranasal to the eye
. The trochlear region is extremely tender to touch. Pain is exacerbated by eye movements looking down and inwards, and especially in supraduction (looking up) and looking outwards, which stretches the superior oblique muscle
tendon. Notably, there is no restriction of extraocular movements, no diplopia
, and often no apparent ocular signs such as proptosis. However, occasionally mild ptosis
is found. The absence of generalized signs of orbital involvement is helpful in eliminating other more common causes of periorbital pain.
trochleitis), but it has been known to occur in patients with rheumatological diseases such as systemic lupus erythematosis, rheumatoid arthritis
, enteropathic arthropathy, and psoriasis
. In his study, Tychsen and his group evaluated trochleitis patients with echography
and CT scan to demonstrate swelling and inflammation. Imaging studies showed inflammation of superior oblique tendon/ trochlear pulley. It was unclear whether the inflammation involved the trochlea itself, or the tissues surrounding the trochlea.
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
of the superior oblique tendon trochlea apparatus characterized by localized swelling, tenderness, and severe pain. This condition is an uncommon but treatable cause of periorbital pain. The trochlea is a ring-like apparatus of cartilage through which passes the tendon
Tendon
A tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...
of the superior oblique muscle. It is located in the superior nasal orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
and functions as a pulley
Pulley
A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present...
for the superior oblique muscle
Superior oblique muscle
For the abdominal muscle see: Abdominal external oblique muscleThe superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit which abducts, depresses and internally rotates the eye...
. Inflammation of the trochlear region leads to a painful syndrome with swelling and exquisite point tenderness in the upper medial rim of the orbit. A vicious cycle may ensue such that inflammation causes swelling and fraying of the tendon which then increases the friction of passing through the trochlea which in turn adds to the inflammation. Trochleitis has also been associated with triggering or worsening of migraine
Migraine
Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...
attacks in patients with pre-existing migraines (Yanguela, 2002).
Symptoms
Patients with trochleitis typically experience a dull fluctuating aching over the trochlear region developing over a few days. Some may also feel occasional sharp pains punctuating the ache. In patients with migraines, trochleitis may occur simultaneously with headacheHeadache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
. Presentation is usually unilateral with palpable swelling over the affected area supranasal to the eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
. The trochlear region is extremely tender to touch. Pain is exacerbated by eye movements looking down and inwards, and especially in supraduction (looking up) and looking outwards, which stretches the superior oblique muscle
Superior oblique muscle
For the abdominal muscle see: Abdominal external oblique muscleThe superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit which abducts, depresses and internally rotates the eye...
tendon. Notably, there is no restriction of extraocular movements, no diplopia
Diplopia
Diplopia, commonly known as double vision, is the simultaneous perception of two images of a single object that may be displaced horizontally, vertically, or diagonally in relation to each other...
, and often no apparent ocular signs such as proptosis. However, occasionally mild ptosis
Ptosis (eyelid)
Ptosis is a drooping of the upper or lower eyelid. The drooping may be worse after being awake longer, when the individual's muscles are tired. This condition is sometimes called "lazy eye", but that term normally refers to amblyopia...
is found. The absence of generalized signs of orbital involvement is helpful in eliminating other more common causes of periorbital pain.
History
Trochleitis was first identified in 1984 by Tychsen, et al. in a study of thirteen patients with orbital pain and point tenderness over the trochlear region. Previously, the trochleitis syndrome had been included in the broad category of idiopathic orbital inflammation (also called orbital pseudotumor). From the study, Tychsen and his group surmised that trochleitis was a subtype of idiopathic orbital inflammation distinct from the larger category in that it produced little/ no discernible ocular signs (the eye looked normal) and did not cause restricted extraocular movement.Cause
The cause of trochleitis is often unknown (idiopathicIdiopathic
Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios + πάθος, pathos , it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease...
trochleitis), but it has been known to occur in patients with rheumatological diseases such as systemic lupus erythematosis, rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
, enteropathic arthropathy, and psoriasis
Psoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
. In his study, Tychsen and his group evaluated trochleitis patients with echography
Echography
Echography may refer to;* Sonography or Medical ultrasonography.* An Echograph, more commonly called Ultrasound Display....
and CT scan to demonstrate swelling and inflammation. Imaging studies showed inflammation of superior oblique tendon/ trochlear pulley. It was unclear whether the inflammation involved the trochlea itself, or the tissues surrounding the trochlea.