Cogan’s syndrome (CS) is the combination of hearing loss, vertigo, and inflammation in the eyes of uncertain cause, which can be associated with a large-, more often than medium-, size vessel vasculitis in 10-15% of patients. It is not clear that Cogan’s syndrome is a primary vasculitis. Large vessel vasculitis predominates in the aorta and its branches and resembles Takayasu’s arteritis. Inflammation of the proximal aorta (aortitis) may occur in 10% of patients. Medium vessel vasculitis often can involve many organs, as is seen in polyarteritis nodosa (PAN).
CS can occur in people of any age and race, and it most frequently starts in young adults in their late 20’s or early 30’s. It can start with eye inflammation (red and painful eyes irritated by the light), with hearing loss and vertigo, or with both within a one month period of time. The hearing loss can be profound and is frequently associated with the sensation of pressure in the ear. Vertigo can also be severe. Vasculitis signs and symptoms can be present at presentation or may develop later in the course of the syndrome. Large vessel vasculitis and aortitis symptoms often include the heart sounds of a leaky aortic heart valve diminished pulses, and peripheral claudication (pain in muscles with use from poor blood flow). Medium vessel vasculitis symptoms are non-specific and are similar to those seen in PAN. The eye and ear disease have never been pathologically documented to be secondary to vasculitis.
Permanent hearing loss occurs in almost all patients with CS and is profound in up to two-thirds. Vertigo is more severe with the initial episodes than later attacks, tending to improve with time. A vague unsteadiness can persist in some patients and evidence of vestibular damage can be found in all patients (abnormal electronystagmography). Permanent eye damage and visual loss are rare. Aortitis can lead to aortic insufficiency and congestive heart failure.
Most patients have an elevated erythrocyte sedimentation rate (ESR) and leukocytosis (elevated white blood count) at presentation. Anemia is present, initially, in one-third of patients, and about 20% have cryoglobulinemia (cold precipitating proteins in the blood) or eosinophilia (increased number of eosinophil white blood cells in the blood).
The diagnosis of CS requires the presence of eye inflammation and inner ear dysfunction that is not explained by another illness. Other major illnesses with similar symptoms include infections (Lyme disease, syphilis, Chlamydia, and Whipple’s disease), other systemic inflammatory diseases (Crohn’s, Behcet’s, Relapsing polychondritis, rheumatoid arthritis, sarcoidosis, Sjogren’s syndrome, systemic lupus, vasculitis, and Vogt-Koyanagi-Harada syndrome), cancers (central nervous system lymphoma and chronic lymphocytic leukemia), antiphospholipid antibody syndrome and multiple sclerosis. The diagnosis of vasculitis is suspected based on the symptoms above and proven in patients with CS via echocardiography, angiography, and/or biopsy of affected tissues.
Glucocorticoid therapy should be started early in the course of CS, topically for the eye inflammation and orally for decreased hearing. Eye-dilating drops (mydriatics) are used with inflammation in the front part of the eye to prevent the iris (colored part of the eye) from becoming stuck to the cornea (clear part of the eye). Hearing loss may respond to early oral glucocorticoid therapy beginning at 1 mg/kg/day of prednisone or equivalent. Patients failing to respond to glucocorticoid therapy in 7-10 days can be considered for additional immunosuppressive therapy (methotrexate, azathioprine, or other), although the effectiveness of such therapy is unclear. Additional immunosuppressive drugs can be considered for steroid-sparing effects in patients where the glucococorticoids are unable to be tapered to a dose of less than 10 mg/day prednisone equivalents. Anti-tumor necrosis factor (TNF) therapy has been effective in some patients with recurrent hearing loss.
Recurrent drops in hearing can be secondary to recurrent inner ear inflammation or the changes in swelling due to damage done to the inner ear, called cochlear hydrops. If hearing loss is associated with eye inflammation or fails to improve after 3-5 days, increased doses of glucocorticoids should be considered.
Proven aortitis and/or vasculitis should be treated with glucocorticoids and immunosuppressive therapy. Cyclosporine, cyclophosphamide, and methotrexate have all been effective initial agents in patients with aortitis and/or large vessel vasculitis. Medium-size vessel vasculitis is treated similarly to the approach taken with PAN. Symptomatic aortic valve disease may lead to the need for aortic valve replacement, chronically or sub-acutely. Peripheral ischemia can require balloon dilatation and/or vascular by-pass procedures in the rare patient.
Adverse effects of glucocorticoids are well known and include glucose intolerance, diabetes, easy bruising, increased infections, rounded faces, loss of calcium from bones, central nervous system effects (particularly at high dose), and thinning of skin. Immunosuppressive drugs can lower blood counts, increase likelihood of infections, damage the liver, cause urinary bleeding, and increase the risk of malignancies.
The Vasculitis Foundation would like to acknowledge Dr. Rex McCallum, University of Texas Medical Branch and Dr. E. William St. Clair, Duke University Medical Center, for their expertise and contribution in developing this informational brochure.