Decisions you need to take before head for a brain surgery

In trying to decide whether an adult or child will benefit from brain surgery, doctors want to know:

Is the problem really epilepsy?
Is it the kind of seizure that can be helped by an operation?
Have we tried hard enough to control the seizures with medicine, diet, or other treatment?
Might the condition get better without surgery?
Might it get worse without surgery?
Do the benefits outweigh the risks?
Can surgery be done safely in the affected area of the brain?

These are very individual questions with different answers for each person based on the medical history of the patient or his family; physical examinations; medical records; and a whole battery of pre-surgical tests.

All epilepsy surgery involves the brain. However, different types of operations may be done. In general they fall into two main groups:

Removal of the area of the brain that is producing the seizures.

Interruption of nerve pathways along which seizure impulses spread.


Lobectomy -- Seizures that begin in one or more areas of the brain are known as simple or complex partial seizures. The seizures can take on different forms, depending on where they originate in the brain. The brain is divided into areas called lobes. There are temporal lobes, frontal lobes, parietal lobes and occipital lobes. There are two of each lobe on either side of the head. An operation to remove all or part of these areas is called a lobectomy. This type of surgery may be performed when a person has seizures that start in the same lobe every time. It is sometimes possible to stop the seizures by removing the seizure-producing area if it can be safely done without damaging vital functions.
While there are risks in all surgical procedures, including the placement of depth electrodes and grids, most brain surgery for epilepsy appears to be relatively safe. The success rate for epilepsy surgeries depends on the type of operation performed and can usually be predicted after all the test results are available.

* For temporal lobectomies, 65 to 85% of patients will be seizure-free.

Complications occur in about 4 out of every 100 of these operations. Depending on the kind of surgery that's performed, possible complications include: partial losses of vision, motor ability, memory or speech. Infection or temporary swelling of the brain may also sometimes happen.

Hemispherectomy -- A lobectomy removes a fairly small area of the brain. However, when a child has Rasmussen’s encephalitis, a rare, progressive disease affecting one whole hemisphere of the brain, a hemispherectomy to remove all or almost all of one side of the brain may be performed. While it seems impossible that someone could function with only half a brain (the other side fills up with fluid), children manage to do so because the half that remains takes over many of the functions of the half that was removed. Weakness on the side opposite the operation will continue, however. Hemisperectomies may also be performed when children are born with conditions that cause excessive damage to one side of the brain, such as bleeding in the brain prior to birth.

Excellent results for this operation, which involve removal of one half or almost one half of the brain, are being reported by the small number of very specialized centers doing these operations. However, there are more risks with hemispherectomies than with other types of epilepsy surgery.

Children who have hemispherectomy operations will continue to have loss of function on the side of the body opposite the side where the brain was removed.

Corpus Callosotomy -- Another kind of surgery for epilepsy is called a corpus callosotomy (split brain surgery).

The corpus callosotomy operation does not take out brain tissue. Instead, it interrupts the spread of seizures by cutting the nerve fibers connecting one side of the brain to the other. This nerve bridge is called the corpus callosum.

The seizures which may respond to this type of surgery include uncontrolled generalized tonic clonic (grand mal) seizures, drop attacks, or massive jerking movements.

These seizures affect both sides of the brain at once and there is usually no one area which can be removed to stop them from happening.

Seizures are usually not stopped entirely by the operation. Some type of seizure activity on one side of the brain or the other is likely to continue, but the effects are generally less severe than the repeated drop attacks or convulsions.

The corpus callosotomy operation is often done in two steps. The first operation partially separates the two halves of the brain but leaves some connections in place.

If the generalized seizures stop, no further surgery is done. If they continue, the doctors may recommend a second step that completes the separation.

Among patients having a corpus callosotomy (split brain operation), risks of major and minor complications after surgery are around 20 per 100 operations. Generalized seizures may stop or happen less often than before the operation. Partial seizures (that is, changes in movement, feeling or emotion without loss of consciousness) will probably continue and may even get worse. Still, the uncontrolled drop attacks and generalized tonic clonic seizures that the operation is designed to treat have risks of their own. Decisions to operate take all these possibilities into account.

Multiple Subpial Transection -- Some seizures originate in or spread to parts of the brain that are responsible for functions such as movement or language. Removing these areas would lead to paralysis or loss of language function.

A surgical technique called multiple subpial transection (MST) may be performed in these situations. It involves making small incisions in the brain which interfere with the spread of seizure impulses.

This technique may be used alone or in addition to a lobectomy.

Vagus nerve stimulation (VNS) -- is a type of treatment in which short bursts of electrical energy are directed into the brain via the vagus nerve, a large nerve in the neck. The energy comes from a battery, about the size of a silver dollar, which is surgically implanted under the skin, usually on the chest. Leads are threaded under the skin and attached to the vagus nerve in the same procedure. The physician programs the device to deliver small electrical stimulation bursts every few minutes. This is a relatively new type of treatment. It may be tried when other treatment is not effective. Just how it works to prevent seizures is being studied.