Cogan syndrome
Cogan syndrome (also Cogans syndrome) is a rare disorder characterized by recurrent inflammation of the front of the eye (the cornea) and often fever, fatigue, and weight loss, episodes of vertigo (dizziness), tinnitus (ringing in the ears) and hearing loss. It can lead to deafness or blindness if untreated. The classic form of the disease was first described by D. G. Cogan in 1945.

Signs and symptoms
Cogan syndrome is a rare, rheumatic disease characterized by inflammation of the ears and eyes. Cogan syndrome can lead to vision difficulty, hearing loss and dizziness. The condition may also be associated with blood-vessel inflammation (called vasculitis) in other areas of the body that can cause major organ damage in 15% of those affected or, in a small number of cases, even death. It most commonly occurs in a persons 20s or 30s. The cause is not known. However, one theory is that it is an autoimmune disorder in which the bodys immune system mistakenly attacks tissue in the eye and ear.

Causes
It is currently thought that Cogan syndrome is an autoimmune disease. The inflammation in the eye and ear are due to the patients own immune system producing antibodies that attack the inner ear and eye tissue. Autoantibodies can be demonstrated in the blood of some patients, and these antibodies have been shown to attack inner ear tissue in laboratory studies. Infection with the bacteria Chlamydia pneumoniae has been demonstrated in some patients prior to the development of Cogan syndrome, leading some researchers to hypothesize that the autoimmune disease may be initiated by the infection. C. pneumoniae is a common cause of mild pneumonia, and the vast majority of patients who are infected with the bacteria do not develop Cogan syndrome.

Diagnosis
While the white blood cell count, erythrocyte sedimentation rate, and C-reactive protein tests may be abnormal and there may be abnormally high levels of platelets in the blood or too few red blood cells in the blood, none of these findings is a reliable indicator of the disease. A slit-lamp examination is essential. Recent work has suggested that high-resolution MRI and antibodies to inner ear antigens may be helpful. Cogan syndrome can occur in children, and is particularly difficult
to recognize in that situation.

Treatment
For more severe disease, oral corticosteroids may be necessary to reduce the inflammatory response. When large amounts of steroids are required or if the disease is severe and is not responding to steroid therapy, other immunosuppressive medications often are recommended. These immunosuppressive drugs include methotrexate, cyclophosphamide, cyclosporine or azathioprine. In some cases, combinations of these medicines are prescribed. Occasionally, if the disease has damaged blood vessels in the ear, cochlear implantation may be used to restore some sense of hearing.Cinnarizine is mainly used to treat nausea and vomiting associated with motion sickness, vertigo, Ménières disease, or Cogan syndrome. Studies have shown it to produce significant improvement in hearing loss in some patients.

History
In 1945, the ophthalmologist David Glendenning Cogan (1908–1993) first described the "nonsyphilitic interstitial keratitis and vestibuloauditory symptoms" that would later bear his name. In 1963, the atypical form of Cogan syndrome, also known as "Logan Syndrome" was first described.

References
Further reading
Haynes BF, Kaiser-Kupfer MI, Mason P, Fauci AS (November 1980). "Cogan syndrome: studies in thirteen patients, long-term follow-up, and a review of the literature". Medicine. 59 (6): 426–41. doi:10.1097/00005792-198011000-00003. PMID 6969345.
Gluth MB, Baratz KH, Matteson EL, Driscoll CL (April 2006). "Cogan syndrome: a retrospective review of 60 patients throughout a half century". Mayo Clinic Proceedings. 81 (4): 483–8. doi:10.4065/81.4.483. PMID 16610568.
Norton EW, Cogan DG (May 1959). "Syndrome of nonsyphilitic interstitial keratitis and vestibuloauditory symptoms; a long-term follow-up". Archives of Ophthalmology. 61 (5): 695–7. doi:10.1001/archopht.1959.00940090697004. PMID 13636563.
Bicknell JM, Holland JV (March 1978). "Neurologic manifestations of Cogan syndrome". Neurology. 28 (3): 278–81. doi:10.1212/wnl.28.3.278. PMID 305011. S2CID 22367876.
Casselman JW, Majoor MH, Albers FW (January 1994). "MR of the inner ear in patients with Cogan syndrome". American Journal of Neuroradiology. 15 (1): 131–8. PMC 8332073. PMID 8141044.
Allen NB, Cox CC, Cobo M,  et al. (March 1990). "Use of immunosuppressive agents in the treatment of severe ocular and vascular manifestations of Cogans syndrome". The American Journal of Medicine. 88 (3): 296–301. doi:10.1016/0002-9343(90)90157-9. PMID 2309745.
Kundell SP, Ochs HD (July 1980). "Cogan syndrome in childhood". The Journal of Pediatrics. 97 (1): 96–8. doi:10.1016/s0022-3476(80)80142-9. PMID 7381656.


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