Wednesday, August 1, 2007

Seizures


drawing by Marguerita

Seizures are caused by abnormal electrical discharges in the brain. Symptoms may vary depending on the part of the brain that is involved, but seizures often cause unusual sensations, uncontrollable muscle spasms, and loss of consciousness.
Some seizures may be the result of a medical problem. Low blood sugar, infection, a head injury, accidental poisoning, or drug overdose can cause a seizure. A seizure may also be due to a brain tumor or other health problem affecting the brain. In addition, anything that results in a sudden lack of oxygen to the brain can cause a seizure. In some cases, the cause of the seizure is never discovered.
There is also another cause,an IVM,which is an arterio venous malformation.,which is only discovered,after the ocurrence of a stroke,and a cat scan or a MRI is performed,then an angiogram to investigate the exact cnfiguration and condition of the brain,after the ocurrence.
An angiogram is an x-ray movie of the blood flowing through the blood vessels. It is made by injecting contrast into the arteries going into the head and taking a series of x-rays films.

An Arterio-Venous Malformation or Avm,is an abornormal collection of blood vessels.
Normally, oxygenated blood is pumped by the heart through branching tubes called arteries to the brain, where it enters a fine network of tiny vessels called capillaries. It is in these capillary beds where the blood nourishes the tissues. The “used” (deoxygenated) blood then passes back to the heart through branching thin walled tubes called veins. Arterial-Venous Malformations are areas that lack the tiny capillaries. The location of the connection between the artery and the vein is called the shunt. The area of tissue is called a nidus of the AVM. An AVM can be thought of as a "Short Circuit" where the blood does not go to the tissues but is pumped through the shunt and back to the heart without ever giving nutrients to the tissues.
We don't know what causes most AVMs. People are born with AVMs although they do not appear to be hereditary. AVMs occur about equally in both sexes and in different races. An estimation of 3 million people in the United States are born with vascular malformation, 10% of which are AVMs. AVMs may be caused by a rupture or clotting of a blood vessel during fetal development. It is usually not associated with any other problems at birth.

Numbness and tingling are abnormal sensations that can occur anywhere in your body, but are often felt in your hands, feet, arms, or legs.How well a patient does depends on the size of the hematoma and the amount of swelling.

Recovery may occur completely,
or there may be some permanent loss of brain function.
Death is possible, and may quickly occur despite prompt medical treatment.

Medications, surgery, or other treatments may have severe side effects.

A cerebral arteriovenous malformation is a birth defect
in which there is an abnormal connection between the arteries and veins in the brain.The cause of cerebral arteriovenous malformation (AVM) is unknown. The condition occurs when arteries in the brain connect directly to nearby veins without having the normal vessels (capillaries) between them.
Arteriovenous malformations vary in their size and location within the brain.
There are often no symptoms until the AVM ruptures. This results in sudden bleeding in the brain (hemorrhagic stroke). In more than half of patients with AVM, hemorrhage is the first symptom.
Depending on the location and the severity of the bleed, the hemorrhage can be very disabling or even deadly.
Symptoms of an AVM rupture are similar to a stroke, and occur because of a lack of blood flow to the brain. Symptoms may also occur when large AVMs press on the brain tissue, which can cause nerve damage and blood flow problems.
Cerebral arteriovenous malformations occur in less than 1% of people. Although the condition is present at birth, symptoms may occur at any age. Hemorrhages occur most often in people aged 15 - 20, but can also occur later in life. Some patients with an AVM also have a cerebral aneurysm.

Much remains to be known. Many patients with AVMs have seizures or persistent headaches. If a rupture occurs, the patient almost always experiences an extreme headache.

No comments: