Cogan's Syndrome: 18 Cases and a Review of the Literature RANDALL S. VOLLERTSEN, M.D.  Mayo Clinic Proceedings  Volume 61, Issue 5, Pages 344-361 (May 1986) DOI: 10.1016/S0025-6196(12)61951-X Copyright © 1986 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 1 Ophthalmologic findings in patients with Cogan's syndrome. Top Left, In retroillumination, the cornea shows a diffuse spotty opacity, typical of Cogan's interstitial keratitis. Top Right, Slit-lamp examination demonstrates diffuse episcleral injection and a slight midstromal corneal opacity in the inferior slit beam. The opacity was evanescent. Bottom Left, Close-up view shows injected perilimbal vessels and midstromal opacity in upper part of cornea. Bottom Right, Dilated tortuous veins are shown in association with a few small retinal hemorrhages inferiorly. Mayo Clinic Proceedings 1986 61, 344-361DOI: (10.1016/S0025-6196(12)61951-X) Copyright © 1986 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 2 Audiogram and caloric test results (arrows indicate relative duration of nystagmus; normal result surpasses the second large vertical mark) from one of our patients with Cogan's syndrome before (at left) and 3 months after (at right) therapy with prednisone (initial dosage, 40 mg daily; decreased to 20 mg daily at time of second study). The initial audiogram shows profound, bilateral sensorineural deafness and nearly absent caloric responses to both cold (30°C) and warm (44°C) water. A bolus of cold water elicited minimal response in right ear and no response in left ear. Three months after therapy, the pure-tone audiogram demonstrated substantial improvement, and corresponding improvement was noted in speech discrimination. At that time, caloric responses approached normal. ANSI = American National Standards Institute. Mayo Clinic Proceedings 1986 61, 344-361DOI: (10.1016/S0025-6196(12)61951-X) Copyright © 1986 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 3 Vascular changes in patient with Cogan's syndrome. A, Diffuse narrowing of right external iliac artery (arrow) and both internal iliac arteries (arrowheads). Also, aorta is stenotic and left common femoral artery is occluded. B, Segmental narrowing of main left renal artery (arrow) and focal stenosis of upper primary branch (arrowhead). C, Diffuse narrowing of anterior tibial artery (arrowhead) and slight narrowing of peroneal artery (arrow). Mayo Clinic Proceedings 1986 61, 344-361DOI: (10.1016/S0025-6196(12)61951-X) Copyright © 1986 Mayo Foundation for Medical Education and Research Terms and Conditions

Fig. 4 Biopsy specimens from patients with Cogan's syndrome. A, Small muscular artery from femoral region. Dense transmural inflammation is most prominent in region of internal elastic membrane, a feature similar to giant cell arteritis. (Hematoxylin and eosin; x64.) B, Higher magnification of A, demonstrating an infiltrate consisting of mononuclear and polymorphonuclear cells without giant cells. (Hematoxylin and eosin; x250.) C, Femoral artery specimen from another patient, demonstrating inflammation throughout adventitia and outer media. Inner media and intima are uninvolved. (Hematoxylin and eosin; x64.) D, Higher magnification of C, showing internal elastic membrane as inner border of the mononuclear inflammation. (Hematoxylin and eosin; x250.) Mayo Clinic Proceedings 1986 61, 344-361DOI: (10.1016/S0025-6196(12)61951-X) Copyright © 1986 Mayo Foundation for Medical Education and Research Terms and Conditions