Cogan's syndrome is a chronic inflammatory disorder of unknown cause affecting mostly young adults. Two main observation of the disease are bilateral interstitial keratitis and vestibuloauditory dysfunction. Association between Cogan's syndrome and systemic vasculitis as well as aortitis are exist. The diagnosis of the disease is based upon the presence of inflammatory eye disease and vestibuloauditory dysfunction . In this article, the classic Cogan's syndrome has been reported in a 47-year-old woman. Two months prior to admission, the patient had been suffering from headache, vertigo, nausea, vomiting, right leg claudication, musculoskeletal pains, bilateral hearing loss and blindness. Ophthalmologic examination revealed that visual acuity was 0.1 bilaterally and on slit lamp examination, there was a conjunctival hyperemia, bilateral cataract and interstitial keratitis. Pure tone audiogram (PTA) and auditory brain stem response (ABR) showed bilateral sensorineural hearing loss. The patient was initially treated with pulse intravenous methylprednisolone and was followed by oral prednisolone and cyclophosphamide, which in follow-up showed partial improvement.
Addison’s disease is an uncommon autoimmune disease, characterized by chronic and insufficient functioning of the outer layer of the adrenal gland. The adrenal glands are located atop each kidney and produce vital glucocorticoid hormones. Because of this chronic under-functioning of the adrenal glands, persons with Addison’s disease have a deficiency in the production of glucocorticoid hormones. Glucocorticoid hormones are involved in how the body utilizes and stores carbohydrates, protein, fat and blood sugar.
The adrenal gland also plays a role in the immune response. A deficiency in glucocorticoid hormones causes an increase in the release of sodium and a decreased release of potassium in the urine, sweat, saliva, stomach and intestines. These changes can cause low blood pressure and increased water excretion that can in some cases lead to severe dehydration.
Although there are many underlying factors in the development of adrenal insufficiencies, including destruction of the adrenal cortex due to diseases such as tuberculosis, the growth of tumors, non-autoimmune diseases amyloidosis and adrenoleukodystrophy, and atrophy of the gland due to prolonged use of cortical steroids used in the treatment of other conditions and illnesses, most cases of Addison’s disease are thought to be autoimmune in nature.
Cogan syndrome is rare autoimmune-mediated rheumatic disorder characterized by recurrent cornea inflammation, fever, weight loss and hearing loss. It can lead the patient to blindness or deafness if not treated properly. In 1945 D.G. Cogan first described this term. People of 20s, 30s and children are mostly affected by Cogan syndrome.
What causes Cogan syndrome?
The exact cause of cogan syndrome is still unknown, but thought that it is an autoimmune disorder. Patients own antibody to inner ear and eye tissue causes the eye and ear inflammation. Infection with the bacteria Chlamydia pneumoniae has been demonstrated in some patients prior to the development of Cogan’s syndrome but not proved at.
Cogan’s syndrome is a rare autoimmune disorder characterized by nonsyphilitic interstitial keratitis and vestibuloauditory system involvement that primarily affects young adults, without a hereditary pattern. The syndrome of nonsyphilitic interstitial keratitis with audiovestibular dysfunction was first reported by Morgan and Baumgartner in 1934 (1,2). Cogan’s syndrome is classified into two groups. The presence of interstitial keratitis indicates typical Cogan’s syndrome and its absence indicates atypical Cogan’s syndrome. The term “atypical Cogan’s syndrome” is used when other types of inflammatory eye disease, including conjunctivitis, uveitis, scleritis, and choroiditis, are associated with the vestibuloauditory abnormalities (3,4). Vollertsen et al. showed that one-third of patients have other affected organs, in the cardiovascular, musculoskeletal, neurological, gastrointestinal or mucocutaneous systems. In addition, systemic vasculitis in any size vessel may be seen in approximately 10% of cases (5,6). Fluoro-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) has recently been used to diagnose infectious diseases with elevated intracellular glucose metabolism. It has been shown that activated inflammatory cells overexpress glucose transporters and accumulate increased amounts of glucose and structurally related substances such as FDG. Hence FDG-PET/CT is also introduced as a diagnostic way to assess involvement in vasculitis (7,8). In this study we aimed to show findings of FDG-PET/CT in Cogan’s syndrome and emphasize its importance in diagnosing vasculitis.