Temporal lobe seizure

Temporal lobe seizure

Definition  :
Temporal lobe seizures are seizures that originate in the two temporal lobes of your brain.
The temporal lobes process emotions, fight-or-flight reactions, and are important for short-term memory. Some symptoms of a temporal lobe seizure may be related to these functions, including having odd feelings — such as euphoria, fear, panic and deja vu.

During a temporal lobe seizure, you may remain partially conscious. Or, if the temporal lobe seizure is more intense, you may be unresponsive, even though you look awake. You also may make repetitive movements of your lips and hands.

Temporal lobe seizures may stem from an anatomical defect or scar. But the cause often remains unknown.

Temporal lobe seizures may be resistant to anti-seizure medications. Surgery may be an option for some people who don't respond to medication.


Symptoms  :
An unusual sensation, known as an aura, may precede a temporal lobe seizure, acting as a warning. Not everyone who has temporal lobe seizures experiences auras, and those who have auras may not remember them. The aura is actually a small seizure itself — one that has not spread into an observable seizure that impairs consciousness and ability to respond. Examples of auras include:

• A sudden sense of unprovoked fear
• A deja vu experience — a feeling that what's happening has happened before
• The sudden occurrence of a strange odor or taste
• A rising sensation in the abdomen

People who have temporal lobe seizures can remain partially conscious during a seizure, but they also may lose awareness of their surroundings and often don't remember what happened.
A temporal lobe seizure usually lasts 30 seconds to two minutes. Characteristic signs and symptoms of temporal lobe seizures include:

• Loss of awareness of surroundings
• Staring
• Lip smacking
• Repeated swallowing or chewing
• Unusual finger movements, such as picking motions

After a temporal lobe seizure, you may have:

• A brief period of confusion and difficulty speaking
• Inability to recall the events that occurred during the seizure
• Unawareness of having had a seizure until someone else tells you

In extreme cases, what starts as a temporal lobe seizure evolves into a grand mal (tonic-clonic) seizure — featuring convulsions and a loss of consciousness.

When to see a doctor
Seek medical advice in these circumstances:

• If you think you're having seizures — early diagnosis is important
• When the number or severity of seizures increases significantly without explanation
• When new signs or symptoms of seizures appear

Seek emergency medical care if:

• A seizure lasts more than five minutes
• The person doesn't recover completely or as quickly as usual after the seizure is over
• Rhythmic muscle contractions or jerky movements occur, which may indicate a grand mal seizure is developing

If it appears a grand mal seizure may be developing:

• Call for medical help immediately.
• Gently roll the person onto one side and put something soft under his or her head.
• Loosen tight neckwear.
• Don't put anything in the mouth — the tongue can't be swallowed, and objects placed in the mouth can be bitten or inhaled.
• Don't try to restrain the person. Look for a medical alert bracelet, which may indicate an emergency contact person and other information.

Causes:
Often, the cause of temporal lobe seizures remains unknown. However, they can be a result of:

• Traumatic brain injury
• Infections, such as encephalitis or meningitis, or history of such infection
• A process that causes scarring (gliosis) in a part of the temporal lobe called the hippocampus
• Inflammatory disorders of the brain
• Injury due to a previous lack of oxygen
• Blood vessel malformations in the brain
• Stroke
• Brain tumors
• Genetic syndromes

During normal waking and sleeping, your brain cells produce varying electrical activity. If the electrical activity in many brain cells becomes abnormally synchronized, a convulsion or seizure may occur. If this happens in just one area of the brain, the result is a partial seizure. When this occurs in an area of the brain known as the temporal lobe, it's called a temporal lobe seizure.

Complications:
 Over time, repeated temporal lobe seizures can cause the part of the brain that's responsible for learning and memory to shrink. This area is called the hippocampus. Brain cell loss in this area may cause memory problems.

Treatments and drugs:

Medications
Numerous medications are available to treat temporal lobe seizures, including:

• Carbamazepine (Carbatrol, Tegretol, others)
• Phenytoin (Dilantin, Phenytek)
• Valproic acid (Depakene, Stavzor)
• Oxcarbazepine (Trileptal)
• Lamotrigine (Lamictal)
• Gabapentin (Gralise, Neurontin)
• Topiramate (Topamax)
• Phenobarbital
• Zonisamide (Zonegran)
• Levetiracetam (Keppra)
• Tiagabine (Gabitril)
• Pregabalin (Lyrica)
• Felbamate (Felbatol)
• Lacosamide (Vimpat)
• Vigabatrin (Sabril)

However, many people don't achieve seizure control with medications alone, and side effects, including fatigue, weight gain and dizziness, are common. In particular, the FDA has issued a warning that the drug Lamictal has been associated with a type of meningitis. Discuss possible side effects with your doctor when deciding about treatment options.
Surgery
Success rates for temporal lobe epilepsy surgery range from about 60 to 90 percent. Success, as defined in surgical outcome studies, means having no seizures or far fewer seizures. It doesn't mean discontinuing medication.
Surgery is generally not an option if:

• Your seizures come from a region of the brain that performs vital brain functions
• Your seizures come from more than one area
• Where your seizures originate can't be identified

Preparing for surgery likely involves talking to your surgeon about his or her experience, success rates and complication rates with the procedure you're considering. You may also want to request a second opinion before having surgery.
Before surgery, you'll need:

• A comprehensive evaluation
• MRI scans of your brain
• Observation of your seizures in a hospital-based monitoring unit using video recordings and EEG

In some cases, surgery to implant intracranial electrodes may be necessary before finally deciding about temporal lobe surgery.
After surgery, most people need to continue taking medication to help ensure that seizures don't recur. However, successful surgery often means being able to reduce the dose, and some people are able to stop taking medication. Infrequently, surgery can lead to neurological problems. Discuss the possible risks with your surgeon before making final decisions about surgery.
Radiosurgery
Researchers have been investigating the use of radiosurgery, which uses a Gamma Knife to deliver a precise dose of radiation to the damaged portion of the brain. This procedure is still considered experimental, and the anti-seizure effects as well as any side effects of the procedure may be delayed for one to two years.
Vagus nerve stimulation
A device called a vagus nerve stimulator may be an option if medications are ineffective or cause serious side effects. The stimulator is implanted into your chest under the collarbone. Wires from the stimulator are attached to the vagus nerve in your neck. The device turns on and off according to an adjustable program and can be activated with a magnet. The device doesn't detect seizures. It's usually well tolerated, but it's not a replacement for medication.
Pregnancy and seizures
The most important thing to remember is to plan pregnancy. Women who are on medications for seizures usually are able to have healthy pregnancies. However, the birth defect risk is about twice that of pregnant women who don't require seizure medications. Seizures pose a risk to a developing baby, so it is generally not recommended to stop medications during pregnancy. Discuss these risks with your doctor. Because pregnancy can alter medication levels, preconception planning is particularly important for women with seizures.
The risk of birth defects differs, depending on the seizure medication, and is considered to be higher in women taking more than one drug. The American Academy of Neurology recommends that women avoid using valproic acid during pregnancy because of risks to the baby. If your seizures can't be well controlled with any other medication, discuss the potential risks with your doctor.
Contraception and anti-seizure medications
Some anti-seizure medications can alter the effectiveness of oral contraceptive (birth control) medication. If contraception is a high priority, check with your doctor to evaluate whether your medication interacts with your oral contraceptive, and if other forms of contraception need to be considered.