Cogan-I syndrome, as a clinical picture, is the combination of inflammation of the cornea of the eyes (keratitis) and a disorder of the sense of balance due to irritation of the 8th cranial nerve. Cogan I syndrome, often referred to simply as Cogan syndrome, is a rare condition.
What is Cogan I syndrome?
Cogan-I syndrome was first described in 1945 by the American ophthalmologist Cogan. The clinical picture was also known before that time, but it was mistakenly thought to be Meniere’s disease with an atypical course. The symptoms of both diseases are similar, but Meniere’s disease has completely different causes. Cogan I syndrome is also known as oculovestibuloauditory syndrome in medical parlance. Eyes and ears are mainly affected by Cogan I syndrome. What often complicates the diagnosis in medical practice is the fact that many other organs and organ systems may also be affected, and as a result, may present with many different symptoms. Cogan I syndrome is further subdivided into so-called typical and atypical Cogan I syndrome. In addition, a therapeutic distinction must also be made from Cogan II syndrome, which has no parallels to Cogan I syndrome. In Cogan II syndrome, the ability to coordinate actions and movements of the eyes is disturbed. Cogan II syndrome is therefore a congenital form of oculomotor apraxia.
Causes
The cause of Cogan I syndrome remains unknown to date. Because it is a rare condition, research into the cause of Cogan I syndrome is not pursued to the extent that would be required to clearly identify the cause, due to lack of funding. However, this is a general problem in the cause research of rare and very rare diseases. It is assumed that inflammatory processes underlie the occurrence of Cogan I syndrome. It can be assumed that the actual cause is due to an autoimmune process in the course of which fine connective tissue structures become chronically inflamed and then trigger the symptoms of the disease. In the case of Cogan I syndrome, this is likely to involve so-called vascular and interstitial inflammatory processes in the narrower sense. On the one hand, the inner walls of the vessels are altered by the chronic inflammatory processes, and on the other hand, the interstitial tissue is also altered. Depending on the severity of the inflammatory changes, Cogan I syndrome can occur in episodes, with almost symptom-free intervals. However, beyond a certain degree of cellular damage, symptoms persist permanently.
Symptoms, complaints, and signs
The 4 leading symptoms of Cogan I syndrome are keratitis, sensorineural hearing loss, tinnitus, and vertigo. These complaints usually occur in both forms, i.e., typical and atypical Cogan I syndrome, in varying degrees of intensity individually or together. The course of the disease and the occurrence of the symptoms can be acute or over a longer period of time, also in the form of relapses. All patients diagnosed with Cogan I syndrome experience a more or less pronounced loss of hearing during the course of the disease. After all, the increasing hearing loss leads to complete deafness in about half of the patients. Agonizing dizziness, vertigo, and ringing in the ears, tinnitus, are frequent accompanying symptoms in most patients. The most frequent symptom of the eyes is keratitis, and scleritis or panuveitis have been described as occurring in parallel. In Cogan I syndrome, the pathological changes of the eyes always occur in both eyes and can vary considerably in duration, treatability and severity. Despite the severe inflammatory changes in the eyes, a so-called visual loss does not usually occur. Patients also do not lose their eyesight, because the retina is typically not affected by Cogan I syndrome. In addition to the ears and eyes, the entire rest of the body can be affected by vasculitides. If the heart, aorta, central nervous system or kidneys are affected, it is also called generalized vasculitis, as a result of which about 10 percent of patients with Cogan I syndrome die. Generalized lymph node swelling, joint inflammation, and fever may also occur in the chronic course of the disease.
Diagnosis and course
Diagnosis of Cogan I syndrome is based solely on symptoms and findings.Due to the inflammatory changes in the blood, acute phase proteins play a central role in the diagnosis. If there are significant ocular signs, the diagnosis does not cause any problems for the specialist, but if these are missing, the disease is still not correctly recognized for years. In the absence of ocular findings, the exact differentiation from Meniere’s disease is also difficult. Cogan I syndrome is characterized by a chronic recurrent and relapsing course.
Complications
In Cogan I syndrome, the patient’s ears are primarily affected. In most cases, affected individuals develop severe hearing loss and tinnitus. Both symptoms extremely limit the patient’s daily life and can also lead to psychological problems and depression. Due to the beeping in the ear, sleep disturbances and headaches often occur. The quality of life is greatly reduced by the symptoms. Likewise, dizziness occurs, leading to coordination problems. The symptoms do not have to be permanent, but can also disappear on their own in the course of life and suddenly reappear. In the worst case, Cogan I syndrome results in complete hearing loss. In severe cases, other organs are also affected, such as the kidneys and heart. If Cogan I syndrome is not treated, death usually results. Sufferers often complain of swelling and inflammation of joints and high fever. Specific treatment and cure of the symptom is not possible. For this reason, the loading of Cogan I syndrome aims at minimizing the symptoms. Immunosuppressants are administered. There are usually no further complications, but the affected person’s life is very limited by the deafness.
When should you see a doctor?
As a rule, a doctor should be consulted for Cogan I syndrome whenever the affected person suffers from discomfort in the ears. This may involve pain in the ear or sensorineural hearing loss. Tinnitus can also occur with Cogan I syndrome and significantly reduce the quality of life of the affected person. If the tinnitus persists for a long time and does not disappear on its own, an ENT specialist should be consulted. Medical treatment is also very useful and advisable in the case of an episodic occurrence of these complaints. In the worst case, deafness may result. In many cases, Cogan I syndrome also leads to psychological complaints or depression. If these complaints occur together with fever or with swelling of the lymph nodes, an examination is also advisable. In case of psychological problems, a psychologist should be consulted. The diagnosis of this disease can be made by the general practitioner or the otolaryngologist. However, further treatment takes place by the respective specialist and is strongly dependent on the severity of the complaints.
Treatment and therapy
A cure for Cogan I syndrome is not possible to date because of the unknown causes. However, anti-inflammatory and immunosuppressive therapy can greatly alleviate the symptoms or temporarily cause them to disappear altogether. Affected patients often have to undergo therapy for the rest of their lives. If the symptoms occur only in the eyes and ears, the general life expectancy is not reduced. However, if the vasculitides occur in other organs and organ systems, the lethality increases significantly. In addition to the use of high-dose immunosuppressants such as cyclophosphamide or cortisone, hearing aids or so-called cochlear implants are used to compensate for the inner ear hearing loss. In progressive cases, bilateral deafness cannot be prevented despite therapy. The severe side effects of the drugs used are also a problem.
Outlook and prognosis
There is no complete cure for Cogan I syndrome. In this case, the syndrome can only be treated symptomatically, since causal therapy is not possible. In some cases, however, it is possible to limit the symptoms completely, although these limitations are often short-lived. The success of the treatment, however, depends very much on the exact manifestation of the Cogan I syndrome, so that a generally valid prediction is not possible here. Patients are thus often dependent on lifelong therapy in order to improve their quality of life.Since the complaints usually only occur in the ears and eyes, the patient’s life expectancy is not negatively affected. In other regions of the body, however, the complaints can reduce the quality of life. Hearing loss can be limited with the help of hearing aids. Furthermore, those affected are also dependent on taking strong medications, which are associated with many side effects. If no treatment is given for Cogan I syndrome, the quality of life is significantly reduced and there are severe limitations in everyday life. Often, the symptoms continue to worsen. Possibly it comes thereby also prematurely to the death of the concerning.
Prevention
Cogan I syndrome occurs equally in all age groups and in both sexes. Because prophylaxis is not possible, prognosis depends mainly on making the diagnosis as early as possible, which in most patients occurs in early adulthood. Only prompt bilateral cochlear implantation can prevent otherwise progressive deafness.
Follow-up
Cogan I syndrome is a multisystem disorder. This requires careful follow-up because of diverse affected areas in the organism. However, the problem with all diseases that occur so rarely is that medical science knows too little about them so far. The lack of research also affects treatment and follow-up. In both typical and atypical Cogan I syndrome, various sequelae occur. These require symptomatic treatment. For this, and for follow-up, different physicians or interdisciplinary approaches may be considered. Disease sequelae such as keratitis, sensorineural hearing loss or tinnitus, and vertigo must be treated. If deafness increases, fitting a cochlear implant may become necessary. Increasing eye problems also require careful follow-up in Cogan I syndrome. What is difficult is that generalized vasculitis can occur as a result of inflammatory processes. About ten percent of all affected patients with Cogan I syndrome with chronic courses die from it. Even good follow-up care cannot prevent this. It is also problematic that many physicians do not recognize this multisystem disease. If Cogan I syndrome is correctly recognized, only symptomatic treatment and an equal amount of follow-up care can be provided due to the lack of meaningful therapeutic concepts.
What you can do yourself
Cogan I syndrome is a very rare disease whose causes are still unknown. Therefore, the patient cannot take any self-help measures that are causative. However, there are some measures that can help to cope better with everyday life. Typical symptoms of the disease are severe dizziness, tinnitus and a disturbance of the sense of balance. The latter in particular can severely restrict the mobility of those affected and greatly increase the risk of accidents. Patients should not be afraid to use walking aids and, if necessary, a wheelchair to help them avoid falls and improve their mobility. In many sufferers, hearing also deteriorates. Hearing aids or implants usually help here. However, complete loss of hearing cannot always be prevented despite these aids. If complete deafness is on the horizon, those affected should learn sign language as early as possible so that they can still communicate after hearing loss. Teaching is easier as long as the affected person still understands spoken instructions. Although Cogan I syndrome is a very rare disease, a self-help group has now formed in German-speaking countries, which is also active on the Internet. Patients and their relatives should take advantage of the opportunity to exchange information with other affected persons.
