Sturge–Weber syndrome

The Sturge -Weber syndrome, also under the synonyms of Sturge -Weber- Krabbe syndrome, meningofaciale angiomatosis, encephalotrigeminale angiomatosis or angiomatosis known encephalofacialis, is an inherited progressive disease from the group of neurocutaneous phakomatoses. It is characterized by hohlräumige benign vascular tumors ( angiomas ) in the facial area, in the meninges, in the ipsilateral pia mater ( leptomeninges ) and the choroid of the eye ( choroid ); often with subsequent ocular signs.

Externally visible vascular malformations are usually on a capillary vascular malformation in the form of a mostly one-sided reddish port wine-colored nevus flammeus ( port-wine stain ) in the face of affected children, this always includes the eyelid.

History

It has been described from a scientific point for the first time in 1879 by William A. Sturge ( 1850-1919 ). He reported on a young girl with nevus flammeus on the face, neck and upper body, an existing on the same side eyes magnification ( Buphthalmus ), epileptic seizures and hemiplegia ( hemiparesis ). Frederick Parkes Weber (1863-1962) was able to demonstrate the intracranial calcifications ( calcifications inside the skull ) in 1922 by X-ray examinations.

Frequency and cause

The syndrome is rare and has an incidence of about 1:20,000 to 1:50,000 live births in on. For a long time a somatic mutation was suspected as the cause, which was finally confirmed by a DNA sequencing study. In 23 of 26 American patients (88%) was found in the studied biopsies a somatic mosaic mutation with replacement of one base pair ( Single Nucleotide Polymorphism: c.548G → A, on chromosome 9q21 p.Arg183Gln ) in the gene GNAQ, the protein that Gαq encoding a protein of the q- class of G -protein α - subunit, which serves to further effector for intracellular signal transduction by G- protein-coupled receptors. Arginine at position 138 is conserved in all twenty human G -protein α - subunits. It is the GTP - binding site and plays an important role in the hydrolysis of GTP. By mutation of the GTPase activity is reduced and it results in an increased signal - GTP activity.

The same activating somatic mutation in GNAQ gene was also found in 92 % of the skin biopsies from non- syndromic wine stains. And similar GNAQ mutations were also found in blue nevi and at Ota's nevus. Melanocytic nevi are found in the same place like a birthmark, it is a Phakomatosis pigmentosum vascularis, which was originally described in association with Sturge -Weber syndrome.

Since it is a somatic mutation, abnormal familial clustering were not described.

Symptoms

Is determined the classical picture of the syndrome by vascular malformations of the skin and in the brain ( meninges and choroid participation of ). The expression of the resulting symptoms can be very different, but which are characterized in most cases by neurological and ophthalmological features; about 45 out of 100 affected children get epileptic seizures (lightning - Nick - Salaam seizures) and glaucoma.

Most children are significantly developmentally delayed. The anatomical vascular malformations show up mostly of skin and meninges through a port-wine stain on the face area of ​​the forehead and eyelids.

Due to the changes in the meninges often occurs already during the first year after giving birth to relatively difficult to treat epileptic seizures (heaped example, West syndrome ). A brain atrophy, associated with developmental delays to cognitive impairment due to cerebral blood flow disturbances caused by calcification of the angiomas can occur. Many affected people have repeated migraine headaches.

It often occurs in childhood to a half- side paralysis of the body ( hemiparesis ), with the risk of underdevelopment or reduced size growth ( hypertrophy ) of affected limb (s ).

Eye diseases ( eg glaucoma ) may occur as neurologically induced visual field defects.

Diagnosis

The Angioma of the face are present at birth and change the size proportional to the growth of the child. They are easy to recognize in the rule of their reddish color. Fading is described as well as discoloration in dark red -violet tones. You can stand out from the skin also structurally.

The radiograph of the skull shows a scalloped Doppelkonturierung the Gefäßkalzifizierungen in Parietocccipitalregion. Computed tomography can see the tissue shrinking in the brain ( cerebral atrophy ). In order to clarify the presence of vascular malformations in the pia mater, a magnetic resonance imaging performed with contrast medium; However, occasionally corresponding changes show until after the first year of life.

The presence and, if possible, already a classification of epilepsy is carried out by measuring the electrical activity in the brain by an EEG.

Ophthalmologic monitoring is recommended as requiring treatment eye diseases occur more frequently. Described are glaucoma, choroidal hemangiomas, enlargement and tortuosity of the vessels of the conjunctiva (conjunctiva ), the iris ( iris) and the retina ( retina). As a rule, ocular signs on the side is to determine where the angioma is the face.

Differential diagnosis Klippel Trenaunay - syndrome and Ruvalcaba - Myhre -Smith syndrome in question.

Therapy

Methods for causal curative treatment of Sturge -Weber syndrome are not known. Therefore, the treatment consists of treating the symptoms; (recommended at least one inspection every year), for example, periodic review of the eyes.

The most important with a view to developing the child's prognosis therapeutic intervention is the treatment of epilepsy: Depending on the origin of the seizures is the medical setting, the procedure of choice or surgical intervention can be made.

The dyed and cosmetically perceived as more or less disturbing nevus flammeus can with little scarring by special laser procedures are treated largely in most multiple sessions, with a complete disappearance is usually not achieved. The brighter the discoloration, the more satisfactory are the therapeutic success; therefore treatment should already be taken in childhood, before it eventually comes to a dark tint. Where appropriate, the prevention of mental disorders due to the psychological impact of the psychotherapeutic help Gesichtsangiom be availed.

Often to support the physical development physiotherapy (physical therapy and occupational therapy) are necessary.

Forecast

The estimation of prognosis is individually made. It is in the context of epilepsy, to a large extent depends on the severity of the neurological deficits and cognitive development possibilities of the. The range of development ( physically and cognitively ) ranges from regular equitable development to severe disability of the child.