IntroductionEpilepsy is a brain disorder in which clusters of nervecells, or neurons, in the brain sometimes signalabnormally. the normal pattern of neuronal activitybecomes disturbed, causing strange sensations,emotions, and behavior or sometimes convulsions,muscle spasms, and loss of consciousness.In epilepsy, the normal pattern of neuronal activitybecomes disturbed, causing strange sensations,emotions, and behavior, or sometimes convulsions,muscle spasms, and loss of consciousness.
EpilepsyEpilepsy is a disorder of the brains electricalsystem. Abnormal electrical impulses cause briefchanges in movement, behavior, sensation, orawareness. These interruptions, known asseizures, may last from a few seconds to a fewminutes. People who have had two or moreseizures are considered to have epilepsy.
Risk factors Babies who are born with abnormal brain structures Bleeding into the brain Abnormal blood vessels in the brain Serious brain injury or lack of oxygen to the brain Brain tumors Infections of the brain: abscess, meningitis, or encephalitis Stroke resulting from blockage of arteries Cerebral palsy
Causes an imbalance of nerve signaling chemicals called neurotransmitters. Genetic Factors- Abnormalities in the genes that control neuronal migration -- a critical step in brain development -- can lead to areas of misplaced or abnormally formed neurons, or dysplasia, in the brain that can cause epilepsy. ,brain tumors, alcoholism, Alzheimers disease frequently lead to epilepsy because they alter the normal workings of the brain.
Meningitis, AIDS, viral encephalitis, and other infectious diseases can lead to epilepsy, hydrocephalus -- a condition in which excess fluid builds up in the brain. Epilepsy also can result from intolerance to wheat gluten (also known as celiac disease), or from a parasitic infection of the brain called neurocysticercosis. Head Injury Poisoning- exposure to lead, carbon monoxide
Classification1.Primary generalized seizures begin with awidespread electrical discharge that involves bothsides of the brain at once.2. Partial seizures-Partial seizures begin with anelectrical discharge in one limited area of thebrain. Some are related to head injury, braininfection, stroke, or tumor, but in most cases thecause is unknown.
The patient loses consciousness and usuallycollapses. The loss of consciousness is followed bygeneralized body stiffening (called the "tonic"phase of the seizure) for 30 to 60 seconds, then byviolent jerking (the "clonic" phase) for 30 to 60seconds, after which the patient goes into a deepsleep (the "postictal" or after-seizure phase.During grand-mal seizures, injuries and accidentsmay occur, such as tongue biting and urinaryincontinence.
Primary Generalized Seizures or grandmal seizures Absence seizures-involve an interruption to consciousness where the person experiencing the seizure seems to become vacant and unresponsive for a short period of time (usually up to 30 seconds). Slight muscle twitching may occur. Atypical absence seizure-involve the loss of muscle tone, causing the person to fall to the ground. These are sometimes called drop attacks but should be distinguished from similar looking attacks that may occur in cataplexy. Myoclonic seizures-involve an extremely brief (< 0.1 second) muscle contraction and can result in jerky movements of muscles or muscle groups, usually on both sides of the body.
Atonic seizures-cause a loss of normal muscle tone Tonic seizures-cause stiffening of muscles of the body, generally those in the back, legs, and arms. Clonic seizures-are myoclonus that are regularly repeating at a rate typically of 2-3 per second. in some cases, the length varies. Tonic-clonic seizures- involve an initial contraction of the muscles (tonic phase) which may involve tongue biting, urinary incontinence and the absence of breathing. This is followed by rhythmic muscle contractions (clonic phase). This type of seizure is usually what is referred to when the term epileptic fit is used colloquially
Partial seizuresFocal seizures, also called partial seizures, occur injust one part of the brain.In a simple focal seizure, the person will remainconscious but experience unusual feelings orsensations that can take many forms. The personmay experience sudden and unexplainablefeelings of joy, anger, sadness, or nausea. He orshe also may hear, smell, taste, see, or feel thingsthat are not real.
subdivided into four categoriesaccording to the nature of their symptoms: Motor -Motor symptoms include movements such as jerking and stiffening. autonomic -Autonomic symptoms affect the autonomic nervous system, which is the group of nerves that control the functions of our organs, like the heart, stomach, bladder, intestines. sensory-Sensory symptoms caused by seizures involve unusual sensations affecting any of the five senses (vision, hearing, smell, taste or touch, are called "auras psychological-Simple partial seizures with psychological symptoms are characterized by various experiences involving memory (the sensation of deja-vu), emotions (such as fear or pleasure), or other complex psychological phenomena.
complex partial seizureA complex partial seizure may involve theunconscious repetition of simple actions, gesturesor verbal utterances, or simply a blank stare andapparent unawareness of the occurrence of theseizure, followed by no memory of the seizure.examples arerepetitious behaviors such asblinks, twitches, mouth movements, or evenwalking in a circle. These repetitious movementsare called automatisms
Partial Seizures Symptoms(Produced by a small area of the brain)Simple (awareness is retained) a) Jerking, muscle rigidity, spasms, head-a. Simple Motor turningb. Simple Sensory b) b. Unusual sensations affecting eitherc. Simple Psychological the vision, hearing, smell taste or touch c) c. Memory or emotional disturbancesComplex Automatisms such as lip smacking, chewing,(Impairment of awareness) fidgeting, walking and other repetitive, involuntary but coordinated movementsPartial seizure with secondary generalization Symptoms that are initially associated with a preservation of consciousness that then evolves into a loss of consciousness and convulsions.
1) An EEG (electroencephalogram) can confirm thediagnosis and offer more information about theseizures. This painless procedure records thebrains electrical activity as wavy lines. Thepattern changes during a seizure and may revealwhich part of the brain is prone to seizures.
Brain scanDetailed images of the brain from CT or MRI scanscan help doctors rule out tumors or blood clots asa possible cause of seizures. This information isessential in planning surgery to treat epilepsy
CT and MRI scans reveal the structure of the brain, which can be useful for identifying brain tumors, cysts, and other structural abnormalities. SPRCT- (single photon emission computed tomography) is a relatively new kind of brain scan that is sometimes used to locate seizure foci in the brain. Magnetoencephalogram/MEG- detects the magnetic signals generated by neurons to allow doctors to monitor brain activity at different points in the brain over time, revealing different brain functions
Magnetic resonance spectroscopy (MRS) that can detect abnormalities in the brains biochemical processes, and with near-infrared spectroscopy, a technique that can detect oxygen levels in brain tissue. Blood Tests- infections, lead poisoning, anemia, and diabetes that may be causing or triggering the seizures.
Anti-seizure drugs are the most common treatment for epilepsy.eg. carbamazepine, valproate, lamotrigine, oxcarbazepine, or phenytoin . For absence seizures, ethosuximide is often the primary treatment. A ketogenic diet can eliminate or nearly eliminate seizures in a third of children with epilepsy who try it. The diet is very high in fat and low in carbs, a combination that makes the body burn fat instead of sugar. This creates changes in the brain that reduce or eliminate seizures.
A ketogenic diet -causes the body to break downfats instead of carbohydrates to survive. Thiscondition is called ketosis.side effects include retarded growth due tonutritional deficiency and a buildup of uric acid inthe blood, which can lead to kidney stones. One study showed that a byproduct of ketosiscalled beta-hydroxybutyrate (BHB) inhibitsseizures .
VNSVagus nerve stimulation, a treatment that issometimes called a "pacemaker for the brain." Ituses a small surgically implanted device to sendelectrical pulses to the brain. The pulses travel viathe vagus nerve, a large nerve in the neck. VNS isan option for people who dont do well withmedication
Side effects of the vagus nerve stimulator aregenerally mild but may include hoarseness, earpain, a sore throat, or nausea.
lobectomy -is a temporal lobe resection, which isperformed for people with temporal lobe epilepsy.Temporal lobe resection leads to a significantreduction or complete cessation of seizures about70 - 90 percent of the time.Corpus callosotomy, or severing the network ofneural connections between the right and lefthalves, or hemispheres, of the brain.
Hemispherectomy and hemispherotomy-removehalf of the brains cortex, or outer layer.
Transcranial magnetic stimulation (TMS), aprocedure which uses a strong magnet heldoutside the head to influence brain activity, mayreduce seizures. They also hope to developimplantable devices that can deliver drugs tospecific parts of the brain.