What is Epilepsy? – Causes – Treatment – Prognosis
Basic Information on Epilepsy – Epileptic vs. Nonepileptic Seizures – Diagnosis and Management – Value of Diagnostic Testing in Epilepsy
What is Epilepsy?
Epilepsy is one of the most diverse disorders in neurology field. This page introduces the reader into epilepsy phenomenology.
Epilepsy is a brain disorder characterized by periodic attacks caused by abnormal nerve cells discharges. While this abnormal activity remains contained within a small brain region, the symptoms are minimal or absent. Involvement of a larger area produces the range of symptoms – from shaking of a body part to altered or complete loss of conciseness with or without convulsions.
Epilepsy symptoms are diverse and sometimes bizarre, but they are usually very stereotypical in each particular patient. The attacks are produced by multiple nerve cells firing in sync. This, in turn, shuts down normal function in some portion of the brain.
First symptoms of epilepsy can present at any age, but this disorder typically starts either during childhood childhood or in the elderly.
The underlying cause remains unknown in half of epilepsy cases. The reminder is a result of either physical brain damage or genetic predisposition.
Causes of Epilepsy
There is no single cause of epilepsy. One general rule does apply – nerve cells are abnormally excitable. Excessive excitability of neurons (nerve cells) is often genetically predetermined. Some epileptic syndromes have known gene mutations.
Presence of an abnormal gene doesn’t guarantee either a particular set of symptoms, or a specific prognosis. Some mutations can produce a variable picture – from mild symptoms to a total devastation. This is probably because of the fact that most of genetic epileptic syndromes depend on multiple genes expression.
The majority of genetic epilepsies are caused by mutations of genes that encode for proteins responsible for electrolyte transport across the cell membranes.
The effects of genetic abnormalities may be limited to seizures as the only type of symptoms. Others lead to severe encephalopathy with developmental delay and regression.
Considering nerve cell membrane abnormalities, most of genetic epilepsies are associated with at least some minor behavioral abnormalities and mood disorders.
Epilepsy attacks often have known precipitating factors: alcohol, sleep deprivation, fatigue, excitement, hyperventilation, and flickering lights. In epilepsy, triggers are seizure type and seizure syndrome specific, rather than universal. In some patients, besides maybe alcohol and sleep deprivation, no triggers are evident.
A wide variety of brain disorders caused by metabolic abnormalities have seizures as one of the symptoms – from metabolic disorders of childhood to MS and Alzheimer’s disease.
Physical damage to the brain tissue due to trauma or stroke may lead to epilepsy as well.
Seizures may be brought up by some medications, electrolyte imbalance, or withdrawal from alcohol or benzodiazepines.
Diagnosis of Epilepsy
The hallmark of diagnosis in epilepsy is a neurological evaluation – detailed family history, seizure description, frequency and precipitating factors. The diagnostic work up is supplementary. Specific findings on EEG are often helpful. Brain imaging has use only in suspected brain disorder (developmental anomalies, tumors, strokes, and trauma).
Presence of symptoms other than seizures might require an extensive diagnostic work up for a wide variety of brain disorders and other medical conditions.
The seizure phenomenon itself remains mostly a clinical (based on neurology evaluation alone) diagnosis.
Treatment of an epileptic syndrome almost exclusively depends on the type of seizures.
Not all medications work on all types of seizures. Some antiepileptic drugs are very seizure type specific and may even aggravate other types of seizures.
Especially important is the drug choice in women of a childbearing age. Besides interaction of medications with fluctuating sex hormone levels and seizure dependence on the phase of the menstrual cycle, birth defects control is an area of great importance.
Increased rate of birth defects and developmental problems in children brought to women with epilepsy are due to medications, rather than the result of epilepsy itself.
Management of epilepsy during pregnancy is a challenging task for neurologist.
The prognosis on epilepsy depends exclusively on the cause of seizures. The Prognosis of seizures caused by some other disease will depend on the treatment success of the underlying disorder.
Known genetic epilepsy syndromes often have a pretty much predictable prognosis. Some of them are a lifetime struggle, others predictably resolve by a particular age or transform into a different type of seizures.
Not all types of seizures are genetic and none of genetic epileptic syndromes is guaranteed in the next generation. Having genetic form of epilepsy in the family only increases the chance of epilepsy, often just a few times above the population averages.
Pseudoseizures, Psychogenic, or Nonepileptic Seizures
There is a great deal of confusion regarding the nature of nonepileptic seizures even among medical professionals.First of all, pseudoseizure, or an nonepileptic seizure, has nothing in common with epilepsy. They just look alike.
There are multiple reasons for this phenomenon. The vast majority of pseudoseizures is caused by conversion disorder. Psychiatric disorders are beyond the scope of my expertise. In brief, conversion disorder is a semi-volitional imitation of symptoms characteristic for neurological disorders, including epilepsy. Please, do not confuse it with malingering, in which the imitation of symptoms is produced intentionally in order to get some benefit. In conversion disorder, patients are unable to understand the cause of neurological symptoms. For them, the symptoms are real.
It is sometimes hard to differentiate conversion disorder from a real epilepsy even with the advanced diagnostic work up. Moreover, pseudoseizures are not uncommon in people with epilepsy, which complicates the matter even more.
Nonepileptic seizure does not require antiepileptic drugs. Once epilepsy is ruled out, a neurologist does not and should not treat pseudoseizures, since conversion disorder treatment is a privilege of psychiatry services.
Many doctors tend to shy away from the discussion of “psychogenic” seizures with their patients. The major concern is that patients are “faking” the symptoms and will feel offended by the doctor. This is totally untrue. Conversion disorder has nothing to do with faking symptoms. In reality, all that patients need is to understand the actual cause of the trouble. Unfortunately, it is not that simple. Patients with conversion disorder have very poor insight. “Breaking” this internal wall of defense requires lots of time and effort by a highly motivated professional, which is not practical most of the time.
Conversion disorder is associated attention seeking. It puts a substantial burden on the caregivers and relatives, who have to be educated about this disorder as well.
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Disclosure: This Web Site is intended for education purpose only. The information provided on this site must not be perceived as a guide for self-diagnosis or self-treatment. Every effort is made to keep the information current, but there are absolutely no guarantees of timely updates. By Andre Strizhak