Medicine:Cogan syndrome

Cogan syndrome
Other names	Cogan's syndrome

Cogan syndrome (also Cogan's 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 person's 20s or 30s. The cause is not known. However, one theory is that it is an autoimmune disorder in which the body's 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 patient's 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, Ménière's 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.

Further reading

• "Cogan syndrome: studies in thirteen patients, long-term follow-up, and a review of the literature". Medicine 59 (6): 426–41. November 1980. doi:10.1097/00005792-198011000-00003. PMID 6969345. 
• "Cogan syndrome: a retrospective review of 60 patients throughout a half century". Mayo Clinic Proceedings 81 (4): 483–8. April 2006. doi:10.4065/81.4.483. PMID 16610568. 
• "Syndrome of nonsyphilitic interstitial keratitis and vestibuloauditory symptoms; a long-term follow-up". Archives of Ophthalmology 61 (5): 695–7. May 1959. doi:10.1001/archopht.1959.00940090697004. PMID 13636563. 
• "Neurologic manifestations of Cogan syndrome". Neurology 28 (3): 278–81. March 1978. doi:10.1212/wnl.28.3.278. PMID 305011. 
• "MR of the inner ear in patients with Cogan syndrome". American Journal of Neuroradiology 15 (1): 131–8. January 1994. PMID 8141044. 
• "Use of immunosuppressive agents in the treatment of severe ocular and vascular manifestations of Cogan's syndrome". The American Journal of Medicine 88 (3): 296–301. March 1990. doi:10.1016/0002-9343(90)90157-9. PMID 2309745. 
• "Cogan syndrome in childhood". The Journal of Pediatrics 97 (1): 96–8. July 1980. doi:10.1016/s0022-3476(80)80142-9. PMID 7381656. 

External links

Classification	D ICD-11: 4A44.Y ICD-10: M30.8 ICD-9-CM: 370.52 MeSH: D055952 DiseasesDB: 32705 SNOMED CT: 26018001
External resources	Medicine:GARD: cogans-syndrome Orphanet: 1467