What are the other Names for this Condition? (Also known as/Synonyms)

• Mixed Malformation of the Brain
• MM of the Brain

What is Mixed Vascular Malformation of the Brain? (Definition/Background Information)

• Mixed Vascular Malformation of the Brain is a term used to describe the existence of more than one subtype of vascular malformations of the brain. The exact prevalence of Mixed Vascular Malformation of the Brain is not known
• Vascular malformations of the brain (VBM) is a collective term designated to describe abnormalities in the formation and structure of the blood vessels, and their subsequent malfunction in the brain
• There are 6 subtypes of vascular malformations of the brain and these include:
  • Arteriovenous malformation (AVM)
  • Cavernous malformation (CCM)
  • Venous malformation (VM)
  • Capillary telangiectasia (CTS)
  • Vein of Galen malformation (VOGM)
  • Mixed malformation (MM)
• Most often, AVM and CTS are the 2 conditions that coexist and form a mixed malformation. An arteriovenous malformation is the presence of abnormal arteries and veins in the brain that are enlarged and twisted, and a capillary telangiectasia is a term used for clusters of dilated capillaries formed in some areas of the brain, interspersed with normal brain tissue
• The specific risk factors for Mixed Vascular Malformation of the Brain are not known. Being a male and having a family history of Osler-Weber-Rendu syndrome may increase the risk for AVM and CTS respectively
• The exact cause of arteriovenous malformation is not known. They may occur owing to abnormal development of blood vessels during gestation, and thus, may be present at birth. The weakened, abnormal blood vessels can burst, leading to bleeding in the brain. Most cases of AVMs are not inherited. A gene mutation leading to AVMs has been suggested, although no strong evidence exists to support this theory
• If capillary telangiectasia is associated with Osler-Weber-Rendu syndrome, the condition is heritable and caused by gene mutations. The inheritance pattern is autosomal dominant, in which a single copy of a defective gene is sufficient to cause the condition
• The symptoms of Mixed Vascular Malformation of the Brain include headaches, numbness, weakness, and seizures. CTS may not contribute significantly to the set of symptoms noted
• A healthcare professional may perform a physical examination, assess symptoms, and evaluate the medical history of an individual to aid in the diagnosis. Imaging studies, such as CT or MRI scan and cerebral arteriography, may be conducted to arrive at a final diagnosis. Capillary telangiectasia is usually diagnosed incidentally
• Some potential complications of Mixed Vascular Malformation of the Brain include bleeding in the brain, stroke, loss of vision, memory problems, difficulties with speech, and damage to the brain. Pregnant women can experience hemorrhaging
• The treatment option is determined by the size and location of the malformations. The affected individual may be prescribed medication for headaches and seizures. The abnormality may also be removed surgically, where possible. The capillary malformations are generally not treated
• At the present time, no guidelines or methods exist to prevent the formation of Mixed Vascular Malformation of the Brain. If a genetic basis is known, the prospective parents may benefit from genetic counseling before planning for a baby
• The prognosis of Mixed Vascular Malformation of the Brain depends on the size and location of the malformations. There is a possibility that bleeding in the brain can cause permanent injury/paralysis, and be fatal as well. If no complications arise, the outcome is generally positive

Who gets Mixed Vascular Malformation of the Brain? (Age and Sex Distribution)

• Mixed Vascular Malformations of the Brain are rare, and less than 2% of the world population are possibly affected
• The condition can occur at any age. However, the typical age of onset is between 20-40 years
• Both male and female genders can be affected; although males are more prone to AVM
• MM of the Brain can occur in people belonging to all races and ethnic backgrounds

What are the Risk Factors for Mixed Vascular Malformation of the Brain? (Predisposing Factors)

The risk factors for Mixed Vascular Malformation of the Brain may include:

• Being a male
• If the condition is associated with Osler-Weber-Rendu syndrome, then a family history of the disorder can be a risk factor

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Mixed Vascular Malformation of the Brain? (Etiology)

In majority of cases, the cause of Mixed Vascular Malformation of the Brain is not known. In some cases, the following may be noted:

• Malformations in arteries and veins of the brain have been observed, without any family history of the disorder
• Accidents causing injury to the brain
• If the condition is associated with Osler-Weber-Rendu syndrome, then mutation(s) in the ACVRL1, ENG and SMAD4 genes have been observed
  • These genes code for proteins that interact with growth factors and play a role in the formation of blood vessels
  • The pattern of inheritance is autosomal dominant, in which a single copy of a defective gene is sufficient to cause disease. Affected individuals inherit the condition from an affected parent

What are the Signs and Symptoms of Mixed Vascular Malformation of the Brain?

The signs and symptoms of Mixed Vascular Malformation of the Brain may include:

• Headaches
• Weakness
• Hemorrhage
• Double vision
• Dizziness, vertigo
• Ringing in the ears (tinnitus)
• Hearing loss
• Speech impediment
• Uncoordinated movements
• Exaggerated reaction to external stimuli (hyperflexia)
• Numbness, tingling, burning or other sensations in various parts of the body (paresthesia)

How is Mixed Vascular Malformation of the Brain Diagnosed?

The diagnosis of Mixed Vascular Malformations of the Brain is made by the following tools:

• A thorough physical examination and an assessment of symptoms
• An evaluation of the affected individual’s personal and family medical history
• Cerebral arteriography:
  • This test provides information on the location and characteristics of the feeding arteries and draining veins, as well as blockages
  • A thin tube is threaded up towards the brain and inserted into an artery in the groin; a dye is injected through this thin tube. The dye provides a contrast for X-ray analysis of the affected organ/area
• Computerized tomography (CT) scans of the brain; it may include CT angiogram that may be performed with a dye injection
• Magnetic resonance imaging (MRI) of the brain; it may include MRI angiogram with an injected dye

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Mixed Vascular Malformation of the Brain?

The following are some potential complications of Mixed Vascular Malformation of the Brain:

• Hemorrhage
• Stroke
• Difficulty in speaking
• Loss of vision
• Unsteadiness that may be very severe
• Hydrocephalus (fluid build-up in the skull, pushing the brain tissue towards the skull)

How is Mixed Vascular Malformation of the Brain Treated?

The treatment options for Mixed Vascular Malformation of the Brain may include the following:

• Medications for seizures and headaches
• Surgical removal of arteriovenous malformation
• Endovascular embolization: Introduction of small particles to block the flow of blood, with the help of a catheter introduced in a leg artery
• Stereotactic radio surgery: Use of radiation to destroy tangled vessels, which makes the vessels clot gradually over a period of time
• If capillary telangiectasia is in a critical area of the brain, the risk of complications due to treatment outweigh the benefits. In such cases, a ‘wait and watch’ approach may be considered

In some instances, the malformation may be very complex, which may limit the treatment options.

How can Mixed Vascular Malformation of the Brain be Prevented?

• Presently, there are no known methods or guidance available for the prevention of Mixed Vascular Malformation of the Brain
• If the condition runs in the family, genetic counseling may help prospective parents understand the risks and plan for a child accordingly
• Routine monitoring and follow-up of the condition is highly recommended

What is the Prognosis of Mixed Vascular Malformation of the Brain? (Outcomes/Resolutions)

• The prognosis of Mixed Vascular Malformation of the Brain is dependent upon the size and location of the individual subtypes (generally arteriovenous malformation and capillary telangiectasia). The outcome is good, if no complications arise
• If there are complications, or if bleeding in the brain that can cause paralysis is noted, then the condition may be fatal

Additional and Relevant Useful Information for Mixed Vascular Malformation of the Brain:

• Dandy-Walker malformation (DWM) is a rare, congenital malformation of the brain that includes the cerebellum and the fluid filled spaces around it

The following link may help you find useful additional information on Dandy-Walker malformation:

http://www.dovemed.com/diseases-conditions/dandy-walker-malformation/