Epilepsy is defined as the repeated occurrence of sudden, excessive and/or synchronous discharges in cerebral cortical neurons resulting in disruption of consciousness, disturbance of sensation, movements, impairment of mental function, or some combination of these signs. Because of their sudden nature, seizures are called ictal events, from the Latin ictus meaning ‘to strike’. The terms epilepsy, seizure and convulsion are not synonymous.
Brain of epileptic and Normal brain
Types of epileptic seizures
There are three diagnoses a doctor might make when treating a patient with epileptic seizures:
- Idiopathic – this means there is no apparent cause.
- Cryptogenic – this means the doctor thinks there is most probably a cause, but cannot pinpoint it.
- Symptomatic – this means that the doctor knows what the cause is.
There are three descriptions of seizures, dependant on what part of the brain the epileptic activity started:
A partial seizure means the epileptic activity took place in just part of the patient’s brain. There are two types of partial seizure:
- Simple partial seizure – the patient is conscious during the seizure. In most cases, the patient is also aware of their surroundings, even though the seizure is in progress.
- Complex partial seizure – the patient’s consciousness is impaired. The patient will generally not remember the seizure, and if they do, their memory will be vague.
A generalized seizure occurs when both halves of the brain have epileptic activity. The patient’s consciousness is lost while the seizure is in progress.
- Tonic-clonic seizures (previously known as grand mal seizures) – these are perhaps the best known type of generalized seizure. They cause a loss of consciousness, body stiffness, and shaking.
- Absence seizures (previously called petit mal seizures) – these involve short lapses in consciousness where the individual appears to be staring off into space. Absence seizures often respond well to treatment.
- Tonic seizures – muscles become stiff. They may cause a fall.
- Atonic seizures – loss of muscle control, causing the individual to drop suddenly.
- Clonic seizures – associated with rhythmic, jerking movements.
Secondary generalized seizure
A secondary generalized seizure occurs when the epileptic activity starts as a partial seizure, but then spreads to both halves of the brain. As this development happens, the patient loses consciousness.
Ancient descriptions and concepts
The earliest detailed account of epilepsy is in the British Museum, London. It is part of a Babylonian text on medicine, Sakikku [All diseases], which was written over 3000 years ago, i.e. before 1000 BC. I have had the privilege of working with a Babylonian scholar, James Kinnier Wilson, on the translation of this text.
The Babylonians were keen observers of clinical phenomena and provide remarkable descriptions of many of the seizure types (miqtu) that we recognize today, including what we would call tonic clonic seizures, absences, drop attacks, simple and complex partial seizures and even focal motor (Jacksonian) or gelastic attacks. They also understood some aspects of prognosis, including death in status as well as post-ictal phenomena. The Babylonians had no concept of pathology, however, and each seizure type was associated with invasion of the body by a particular named evil spirit. Thus treatment was not medical but spiritual.
Interestingly, Hippocrates also had some notion that epilepsy could become chronic and intractable if not treated early and effectively, although it is not clear exactly what treatments he had in mind: “Moreover it can be cured no less than other diseases so long as it has not become inveterate and too powerful for the drugs which are given. When the malady becomes chronic, it becomes incurable.” Unfortunately the Hippocratic concept of a treatable brain disorder had little influence on the prevailing supernatural view, as is well described in the scholarly history of epilepsy from the Greeks to the late 19th century by Temkin.
Incidence and prevalence
The incidence (the number of new cases per year) of epilepsy is 24–53 per 100 000 population in developed countries. There are few incidence studies in developing countries, none of which is prospective: they show rates from 49.3 to 190 per 100 000 population. Higher incidence rates in developing countries, thought to be attributable to parasitosis particularly neurocysticercosis, HIV, trauma, perinatal morbidity and consanguinity, are difficult to interpret because of methodological issues, particularly the lack of age adjustment, which is important because epilepsy has a bimodal peak with age. Incidence rates worldwide are greater in men than women. In developed countries, incidence among the elderly is rising and among children it is falling. This is relevant to developing countries as longevity rises and risk of cerebrovascular disease increases. Conversely, better obstetric care and infection control can diminish incidence in children.
The prevalence (the total number of cases at a particular point in time) of active epilepsy in a large number of studies has been shown to be fairly uniform at 4–10 per 1000 population. Higher prevalences in sub-Saharan Africa and Central and South America have been reported, possibly due to methodological differences, consanguinity or environmental factors and particularly so in rural areas. It is difficult to tease out racial and socioeconomic factors. Prevalence data are primarily used by health planners and for generating aetiological hypotheses.
Some causes of epilepsy
In the majority of cases, no cause for epilepsy can be found and it is described as idiopathic. There are, however, a number of recognized factors that increase a person’s risk of developing epilepsy. These include:
- Brain scarring or brain damage, e.g. due to birth injuries, accidents, physical assaults, excessive use of alcohol/drugs
- Infections and fevers, e.g. meningitis, rubella, encephalitis, AIDS.
- Benign and malignant tumours
- Genetic factors, e.g. tuberous sclerosis
- Dementia and neurodegenerative disorders, e.g. Alzheimer’s disease
- Stroke, which can occur at any age
- Parasitic infections, e.g. malaria
- Developmental disorders – for instance, autism or neurofibromatosis
Sometimes a risk factor can cause scarring of the brain or lead to areas of the brain not developing or working right. Risk factors include:
- Babies who are born small for their age
- Babies who have seizures in the first month of life
- Babies who are born with abnormal areas in the brain
- 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
- Conditions with intellectual and developmental disabilities
- Seizures occurring within days after head injury (“early posttraumatic seizures”)
- Family history of epilepsy or fever-related seizures
- Alzheimer’s disease (late in the illness)
- Autism spectrum disorder
- Fever-related (febrile) seizures that are unusually long
- Long episodes of seizures or repeated seizures called status epilepticus
- Use of illegal drugs such as cocaine
- Mild head injuries, such as a concussion with just a very brief loss of consciousness, do not cause epilepsy. Yet the effects of repeated mild head injuries and epilepsy is unknown.
The main symptom of epilepsy is repeated seizures. If one or more of the following symptoms are present, the individual should see a doctor, especially if they recur:
- A convulsion with no temperature (no fever)
- Short spells of blackout, or confused memory
- Intermittent fainting spells, during which bowel or bladder control is lost, which is frequently followed by extreme tiredness
- For a short period, the person is unresponsive to instructions or questions
- The person becomes stiff, suddenly, for no apparent reason
- The person suddenly falls for no clear reason
- Sudden bouts of blinking without apparent stimuli
- Sudden bouts of chewing, without any apparent reason
- For a short time the person seems dazed and unable to communicate
- Repetitive movements that seem inappropriate
- The person becomes fearful for no apparent reason; they may even panic or become angry
- Peculiar changes in senses, such as smell, touch, and sound
- The arms, legs, or body jerk, in babies these will appear as a cluster of rapid jerking movements
Complications of Epilepsy
- If you fall during a seizure, you can injure your head or break a bone.
- If you have epilepsy, you’re 15 to 19 times more likely to drown while swimming or bathing than the rest of the population because of the possibility of having a seizure while in the water.
- Car accidents. A seizure that causes either loss of awareness or control can be dangerous if you’re driving a car or operating other equipment.
- Pregnancy complications. Seizures during pregnancy pose dangers to both mother and baby, and certain anti-epileptic medications increase the risk of birth defects. If you have epilepsy and you’re considering becoming pregnant, talk to your doctor as you plan your pregnancy.
- Emotional health issues. People with epilepsy are more likely to have psychological problems, especially depression, anxiety and, in extreme cases, suicide. Problems may be a result of difficulties dealing with the condition itself as well as medication side effects.
- Sudden unexplained death in epilepsy (SUDEP).People with epilepsy also have a small risk of sudden unexplained death. The cause is unknown, but some research shows it may occur due to heart or respiratory conditions.
Diagnosis and Testing of Epilepsy
The evaluation of patients with epilepsy is aimed at determining the type of seizures and their cause, since different types respond best to specific treatments. The diagnosis is based on:
- The patient’s medical history, including any family history of seizures, associated medical conditions and current medications.
- A complete physical and neurological examination —your muscle strength, reflexes, eye sight, hearing and ability to detect various sensations are tested so your doctors can better understand the cause of your seizures.
- An electroencephalogram (EEG), which measures electrical impulses in the brain. This is the only test that directly detects electrical activity in the brain, and seizures are defined by abnormal electrical activity in the brain. During an EEG, electrodes (small metal disks) are attached to specific locations on your head. The electrodes are attached to a monitor to record the brain’s electrical activity. The EEG is useful not only to confirm a diagnosis of epilepsy, but also to determine the type of epilepsy.
A routine EEG only records about 20 minutes of brain waves (however, the routine EEG procedure takes about 90 minutes). Because 20 minutes is such a short amount of time, the results of routine EEG studies are often normal, even in people known to have epilepsy. Therefore, prolonged EEG monitoring may be necessary.
- EEG-video monitoring is an even better diagnostic method. During this type of monitoring, an EEG monitors the brain’s activity and cameras videotape body movements and behavior during a seizure. Prolonged monitoring often requires the patient to spend time in a special facility for several days. Prolonged EEG-video monitoring is the only definitive way to diagnose epilepsy.
- Imaging studies of the brain, such as those provided by magnetic resonance imaging (MRI). This can identify the cause of the seizures, but the vast majority of patients with epilepsy have normal MRIs.
Medication and Treatment
Many drugs are available to treat epilepsy, several of which have only recently been released. Older, classic medications used to treat epilepsy include:
- Phenytoin (Dilantin)
- Carbamazepine (Tegretol, Carbatrol)
- Primidone (Mysoline)
- Ethosuximide (Zarontin)
- Valproic acid (Depakote)
- Diazepam (Valium) and its derivatives
Newer drugs to treat epilepsy include:
- Felbamate (Felbatol)
- Gabapentin (Neurontin)
- Lamotrigine (Lamictal)
- Oxcarbazepine (Trileptal)
- Topiramate (Topamax)
- Tiagabine (Gabitril)
- Levetiracetam (Keppra)
- Zonisamide (Zonegran)
Other Treatment Options
- Epilepsy surgery is safe and effective, and is the treatment of choice when drugs do not work. (see pamphlet on epilepsy surgery).
- The ketogenic diet is effective for treating certain types of epilepsy. Specifically, it is effective in children with severe symptomatic generalized epilepsies with more than one type of seizure and brain damage. However, the diet requires careful planning and may be difficult to follow, so is usually not feasible in older children or adults. The diet is started in the hospital, and when successful, it is usually maintained for 2 to 3 years. It requires a very motivated family, and a qualified dietician.
- Vagus nerve stimulation (VNS). This treatment requires minor surgery to implant a stimulator, which is about the size of a pacemaker. It is placed under the skin in the left upper chest, like a pacemaker. This treatment appears to be effective for seizures that do not respond well to medications alone.
First aid steps for an Epilepsy person
- Stay calm.
- Look around – is the person in a dangerous place? If not, don’t move them. Move objects like furniture away from them.
- Note the time the seizure starts.
- Stay with them. If they don’t collapse but seem blank or confused, gently guide them away from any danger. Speak quietly and calmly.
- Cushion their head with something soft if they have collapsed to the ground.
- Don’t hold them down.
- Don’t put anything in their mouth.
- Check the time again. If a convulsive (shaking) seizure doesn’t stop after 5 minutes, call for an ambulance.
- After the seizure has stopped, put them into the recovery position and check that their breathing is returning to normal.
- Stay with them until they are fully recovered.
Prevention and control of epilepsy
Here are some tips that may help reduce your risk of having an epilepsy seizure:
- Get plenty of sleep each night — set a regular sleep schedule, and stick to it.
- Learn stress management and relaxation techniques.
- Avoid drugs and alcohol.
- Take all of your medications as prescribed by your doctor.
- Avoid bright, flashing lights and other visual stimuli.
- Skip TV and computer time whenever possible.
- Avoid playing video games.
- Eat a healthy diet.