Bonnet-Dechaume-Blanc Syndrome – Causes, Symptoms & Treatment


Bonnet-Dechaume-Blanc syndrome is the name of a very rare disease that is congenital. The condition becomes noticeable through arteriovenous malformations in the retinal blood vessels and facial changes.

What is Bonnet-Dechaume-Blanc Syndrome?

In medicine, Bonnet-Dechaume-Blanc syndrome is also known as congenital retinocephalofacial vascular malformation syndrome ( CRC syndrome ) or Wyburn-Mason syndrome . The French ophthalmologist Paul Bonnet (1884-1959) was one of the namesakes.

Bonnet-Dechaume-Blanc syndrome is congenital and extremely rare. It is caused by a developmental disorder that occurs during embryogenesis . The typical features of the syndrome include unilateral artervio-venous malformations (malformations) in the retinal blood vessels of the eye, malformations in the cerebral and head blood vessels and changes in the face.

So far, many physicians have found it difficult to precisely classify the Bonnet-Dechaume-Blanc syndrome. The disease is often classified as a neurocutaneous syndrome . The rare Bonnet-Dechaume-Blanc syndrome has been known since the 19th century. Partial aspects were described by the German neuropathologist Hugo Spatz (1888-1969).

The first detailed case reports were made in the 1930s. The term Bonnet-Dechaume-Blanc syndrome came about in 1937 through a case report by the French physicians Paul Bonnet, Jean Dechaume and Emile Blanc. A case report by Roger Wyburn-Mason came from 1943, so that he was also used as the eponym for the syndrome.

How many people have Bonnet-Dechaume-Blanc syndrome could not be determined exactly. By 2009 there were 132 known cases of the disease. The syndrome appears equally in both sexes.


The reason for the development of the Bonnet-Dechaume-Blanc syndrome is a developmental disorder during the 7th week of pregnancy. However, what causes this disorder is still unknown. Arteriovenous malformations (AVM) represent shunts that occur between the venous and arterial vasculature.

The vessels are often arranged in the form of a tangle and form a connection between the high and low pressure systems. Pressure increases blood flow to the vessels and expands them. The vascular bed is continuously remodeled. Since the vascular wall is affected, this leads to complications such as narrowing and rupture of the vessels.

Symptoms, Ailments & Signs

The Bonnet-Dechaume-Blanc syndrome becomes noticeable through different changes in the face, the eyes and the intracranial blood vessels, which depend on the form of the syndrome. In the case of a complete syndrome, in addition to the arteriovenous malformations of the retina and the cerebral vessels, there are also unilateral facial changes.

These are mostly forehead, cheek or conjunctival vessels, some of which protrude. In addition, the lid vessels change. Sometimes the nose, ears or lips are also affected. Changes in the eyes occur in incomplete Bonnet-Dechaume-Blanc syndrome and isolated malformations of the retina. Almost 50 percent of all patients go blind on the affected side of the body.

There is also a risk of optic nerve atrophy (atrophy of the optic nerve cells) and secondary glaucoma. Hemorrhages in the vitreous body or the retina also sometimes occur. A cerebral arteriovenous malformation can result in squinting (extropia), nystagma, or abnormal ocular motility .

Around two-thirds of patients have arteriovenous malformations within the orbit. In addition to cerebral malformations of the vessels, one-sided protrusion of an eyeball from the orbit is possible. It is not uncommon for the optic nerve to be affected as well.

In the case of a complete or incomplete Bonnet-Dechaume-Blanc syndrome, malformations of the cerebral vessels appear, which are primarily located in the supply region of the middle cerebral artery (arteria cerebri media). A third of the patients suffer from altered vessels in the cerebral visual pathway section.

In some cases, the vascular changes do not cause any symptoms. In other patients, on the other hand, there is a risk of various forms of cerebral hemorrhage , increased intracranial pressure or symptomatic epilepsy . Furthermore, a paralysis of the facial nerve ( facial paralysis ) is possible.


If there is a suspicion of Bonnet-Dechaume-Blanc syndrome, the attending physician will carry out a neurological examination. Also of importance are ophthalmological examination methods such as perimetry (visual field measurement) or ophthalmoscopy (eye reflection). Digital subtraction angiography, computed tomography (CT), or magnetic resonance imaging (MRI) can be used to image an arteriovenous malformation .

Magnetic resonance imaging is considered to be the best examination method, as it provides the most data on the extent of the disease. The course of Bonnet-Dechaume-Blanc syndrome depends on the extent of the damage and the part of the body where it occurs.


Characteristic of the Bonnet-Dechaume-Blanc syndrome are pronounced malformations of the face, the blood vessels in the brain and the eyes. If the patient suffers from the complete syndrome, malformations of the retina and the cerebral vessels as well as unilateral facial changes are classic symptoms.

In many cases, conjunctival, cheek, and forehead vessels protrude. Other complications are changes in the lid vessels. Noses, ears and lips can also be affected by this developmental disorder. In the case of incomplete Bonnet-Dechaume-Blanc syndrome and isolated malformations of the retina, the characteristic eye changes occur.

Every second patient goes blind on the affected side of the body. Other complications include loss of optic nerve cells and secondary glaucoma. Hemorrhages in the retina or in the vitreous are potential side effects. Malformed blood vessels in the brain can lead to various forms of strabismus and the unilateral protrusion of the eyeball from the orbit.

The malformed cerebral vessels are predominantly located in the supply area of ​​the middle cerebral artery. Two-thirds of patients suffer from changes in the blood vessels within the orbits, often affecting the optic nerve. The cerebral portion of the visual pathway may also be involved.

Some patients do not notice any symptoms, while others develop complications such as increased intracranial pressure , cerebral hemorrhage, paralysis of the facial nerve or symptomatic epilepsy . The success of treatment and the prognosis depend on the extent of the disease and the body parts involved.

When should you go to the doctor?

In most cases, Bonnet-Dechaume-Blanc syndrome is diagnosed immediately after birth or in the first few months after birth, so that a visit to the doctor for diagnosis is not necessary. Those affected suffer from various changes and malformations, which occur primarily in the face of the affected person. However, it cannot be predicted how severely the affected person will be affected by this syndrome. In many cases, patients are dependent on various treatments that can make everyday life easier.

A doctor must be consulted, especially in the case of epileptic seizures caused by Bonnet-Dechaume-Blanc syndrome. However, paralysis of the face or cerebral hemorrhage can also occur as the disease progresses. Here, too, a visit to a doctor is necessary in any case, since otherwise, in the worst case, the patient may die.

As a rule, the Bonnet-Dechaume-Blanc syndrome is diagnosed directly by a general practitioner or a pediatrician. The further treatment of the syndrome is then carried out by the respective specialists. As a rule, not all complaints can be completely restricted. The patient’s life expectancy may also be reduced by Bonnet-Dechaume-Blanc syndrome.

Treatment & Therapy

Management of Bonnet-Dechaume-Blanc syndrome in arteriovenous malformation should be performed by a vascular anomaly specialist. In babies or children, however, therapy is rarely considered appropriate. While treatment is discouraged for silent arterial lesions, intracranial impairment can be treated with embolization or proton beams.

If the malformations show up in other parts of the body, embolization is possible, which is followed by an operation. However, there is also the option of embolization alone or a single surgical intervention. During embolization, the supplying vessels are closed.

Some patients cannot be operated on. In such cases, only embolizations take place. The neuroradiological surgeon glues the arteriovenous shunts together. For this purpose, he uses a catheter as part of an arteriography . However, there is a risk of skin necrosis with this procedure. In the case of a diffuse AVM, treatment with medication is an alternative.

Outlook & Forecast

The prospect of a cure is almost hopeless in Bonnet-Dechaume-Blanc syndrome. The disease, with all its side effects, represents a significant burden for the patient throughout life. Therapy and medical care are made more difficult by the uncertainty of the cause. To this day, researchers and scientists have not been able to adequately prove the reasons for the developmental disorder. Therefore, the Bonnet-Dechaume-Blanc syndrome is treated according to the individually occurring symptoms and complaints.

The refusal of medical care is associated with numerous complications and should be avoided. The deformities in the face and also the visual disturbance reduce the general well-being and the quality of life to a considerable extent. If cerebral hemorrhage occurs, the patient may also die.

Conventional medicine offers the patient opportunities to improve their health in a comprehensive treatment plan. The serious sequelae of Bonnet-Dechaume-Blanc Syndrome are treated gradually and according to urgency. The additional complications from surgical procedures further worsen the prognosis.

Nevertheless, the patient can experience an alleviation of his symptoms when corrections to the vascular changes have been initiated. In addition to the current treatment, the treatment plan also includes further check-ups. These should enable early detection of possible critical states of the patient in order to treat possible bleeding or increased intracranial pressure in good time.


There are no preventive measures against Bonnet-Dechaume-Blanc syndrome. The triggering causes of the congenital malformations have so far remained unclear.

You can do that yourself

Bonnet-Dechaume-Blanc syndrome cannot be treated causally. The therapy focuses on surgical interventions and physiotherapeutic measures as well as cognitive training, whereby the therapeutic measures can be supported at home.

Parents of affected children should start cognitive training early and discuss this with the responsible specialist. The physiotherapeutic measures can be supported by moderate sport. Depending on the age of the child, swimming, walking or targeted muscle training can be used.

Since the Bonnet-Dechaume-Blanc syndrome can occur in a wide variety of types and forms, the measures must first be planned by a doctor so that the child’s state of health can be improved in a targeted manner. A change in diet is also recommended . For example, avoiding certain foods can reduce the risk of epileptic seizures.

Lastly, parents should watch their child carefully as there is an increased risk of accidents. In the event of a fall, the emergency services must be called. Failure to do so can result in serious complications such as vitreous hemorrhage or intraocular bleeding. In addition to the measures mentioned, comprehensive therapeutic support is always necessary.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.