Charles Bonnet syndrome is a neurologic syndrome that causes visual hallucinations. Damage to the anterior or posterior visual pathway causes the hallucinations, but the patient does not perceive them as real. If vision can be improved with glasses or surgery, symptoms may completely resolve.
What is Charles Bonnet syndrome?
Charles Bonnet syndrome is a neurological psychiatric symptom complex. At first glance, the symptoms resemble those of mentally ill individuals. In the actual sense, however, the affected persons are not mentally ill, but neurologically damaged. The leading symptom for the syndrome is visual hallucinations. The hallucinations are even limited exclusively to the visual system. There are no auditory or tactile phenomena. Patients with Charles Bonnet syndrome also do not usually develop delusions. They perceive the complex and sometimes moving hallucinations for several minutes with unclouded consciousness before they subside again. The natural scientist Charles Bonnet first described the syndrome. The phenomenon mainly affects older people. However, corresponding cases have also been observed in children.
Causes
Meanwhile, medicine suspects damage to the visual pathways and the slow loss of vision behind CB syndrome. Both damage in the anterior portion and that in the posterior portion of the visual pathways can cause the hallucinations. For this reason, the syndrome can occur, for example, in the context of diseases such as macular degeneration, diabetic retinopathy or cataracts, which often affect older people in particular. Brain infarctions or brain tumors are also possible primary causes. The hallucinations occur mainly in the blind area of the visual field. Therefore, medicine suspects a connection to the association cortex, which is tied to the visual system. If not only the visual pathways are damaged, but also the visual hallucination cortex, hallucinations cannot occur. However, in most defects of the visual pathways, the cortex is preserved as well as the visual imagination.
Symptoms, complaints, and signs
The leading symptom of CB syndrome is visual hallucinations that occur in the absence of previous mental illness and with perfectly clear consciousness and are not accompanied by hallucinations from other perceptual systems. These hallucinations are stereotypical visual hallucinations that the patient experiences from a distance. He doubts the authenticity of the images. Therefore, delusional experience with actual involvement in the hallucinatory world does not occur. Therefore, the images cannot actually be called hallucinations, but rather illusions and pseudohallucinations. If an involvement is present, a mental illness is the more likely cause and the clinical picture can no longer be summarized as CB syndrome. Typically, illusions in CB syndrome correspond to light apparitions, geometric figures with clear outlines, distortions of objects just seen or fantasy figures, and doppelganger hallucination.
Diagnosis and course
Charles Bonnet syndrome must be differentiated by differential diagnosis, especially from conditions such as Lewy body dementia, hallucinatory migraine attacks, the side effects of certain medications, and the effects of hallucinogenic drugs. In making the diagnosis, an inspection of the visual pathways, in addition to the medical history, can provide crucial clues. As a rule, however, the causative visual pathway damage is diagnosed well before the first hallucinations. Therefore, the medical history is usually sufficient for the physician to make a diagnosis of CB syndrome. Up to nearly 60 percent of all individuals with reduced visual acuity are said to have Charles Bonnet syndrome. The prognosis depends on the potential for vision improvement in each individual case. Although the syndrome is a harmless disease in and of itself, it can affect patients’ quality of life.
When should you see a doctor?
In Charles Bonnet syndrome, a doctor should be consulted when the affected person suffers from hallucinations. However, the patient can usually determine for himself that the hallucinations are not real and distinguish them from reality.The doctor should be consulted especially if these complaints occur after an accident or after a blow to the head. Severe migraine and other pains in the head may also indicate Charles Bonnet syndrome and should be examined. In many cases, the patient sees a double or different light apparitions in his hallucinations, but he doubts their authenticity. Decreased vision is also suggestive of Charles Bonnet syndrome and should definitely be investigated. Diagnosis and treatment can be performed by a psychologist. Eye complaints can usually be improved by surgery or by wearing glasses. Whether there will be a positive course of the disease cannot be universally predicted.
Treatment and therapy
Medications include substances such as the antipsychotics melperone and risperidone, anticonvulsants such as carbamazepine and clonazepam, and serotonin antagonists such as ondansetron to relieve symptoms. However, this symptomatic treatment is rarely used. In connection with drug therapies, the benefits and risks to the patient are weighed first. For example, since CB syndrome is not threatening in and of itself, the physician may also advise against medicinal steps from the outset. Since a causal therapy is available for CB syndrome, this therapy usually corresponds to the primary treatment. The treating physician aims at an improvement of the vision. For this purpose, glasses or surgery are usually used instead of medication. Lens surgery can completely reduce visual hallucinations in some syndromes. If the symptoms of the syndrome are limited in their occurrence to darkness, adequate lighting is often sufficient to attenuate the hallucinations. In some cases, causative therapy does not make the hallucinations disappear completely. However, a reduction in intensity is usually achieved. Supportive therapy may also be appropriate to accompany the causal treatment. The patients’ suffering is thus alleviated and their quality of life improves. Since socially isolated people suffer from CB syndrome all the more frequently, supportive therapy with social connection can even aim to improve the symptoms. At the very least, those affected have the opportunity to talk about their suffering in settings such as support groups.
Outlook and prognosis
A general prognosis cannot usually be given for Charles Bonnet syndrome. The further course depends on the exact cause of the syndrome and on its severity. If the vision of the affected person can be improved, the symptoms of Charles-Bonnet syndrome can be completely overcome in most cases. The vision is improved mainly by interventions with a laser or by wearing glasses. In these cases there is a positive course of the disease without complications. Since the symptoms of the syndrome often occur only in the dark, they can be alleviated by suitable lighting, so that there are no particular restrictions in the everyday life of the affected person. Since the affected person does not perceive the hallucinations as real, they can often go about an ordinary life, even if the condition cannot be completely alleviated. The treatment of Charles Bonnet syndrome with the help of medication is very rarely successful, so that it is usually dispensed with. The syndrome does not have a negative effect on the life expectancy of the affected person. The further course depends here, however, strongly on the underlying disease.
Prevention
Charles Bonnet syndrome can be prevented in many cases by providing appropriate visual aids.
Follow-up care
Follow-up care for Charles Bonnet syndrome usually begins following therapy with psychotropic drugs or after lens surgery. This often involves the use of glasses, which are designed to improve vision. Depending on when the syndrome mainly occurs, it can be helpful to adjust the lighting. But there are also cases when the hallucinations continue to occur. At least they can be reduced with bright lighting. As a support and aftercare, this solution to increase the quality of life is quite simple. Often, affected patients are relatively isolated individuals.Therefore, aftercare therapy with increased social connection is helpful. The symptoms no longer occur as often and as violently. This aftercare includes, for example, participation in a self-help group. Here, patients feel less alone and can share ideas about possible methods to alleviate vision symptoms. In such a support group or with the doctor, they learn that it is a physical defect and not a special form of mental illness. The medications that the doctor prescribes usually do not lead to complete success, but with the right approach, patients have no problems coping with everyday life.
What you can do yourself
To better cope with the disease in everyday life, it is important for the patient and especially his social environment to internalize that Charles Bonnet syndrome is not a mental illness. Those affected are not mentally ill, but suffer from a purely physical defect. In self-help groups, which are active on the Internet and in larger cities also locally, those affected learn to cope better with their hallucinations and the often discriminatory or even humiliating reactions of their social environment. These groups also provide information material with which the close social environment, especially the employer and work colleagues, can be educated about the disease. In this way, prejudices resulting from ignorance can be reduced. In addition, those affected should seek professional medical care. Charles Bonnet Syndrome is a rather rare disease. It is therefore important that the affected person seeks out a specialist who is experienced in treating the syndrome. Information on appropriately qualified physicians is provided by the medical associations and the health insurance companies. The causes of the disease have not yet been conclusively clarified, but treatment successes are nevertheless already being achieved. A sufferer should therefore seek comprehensive information about all medical options to alleviate his or her suffering.
