Epilepsy
The term
Epilepsy is derived from a Greek word meaning 'to take hold of or ‘to seize’ and this reflected the belief, that the bizarre symptoms often exhibited were an indication that the
patient was held / possessed by devils. During the Roman Era the condition was thought due to a lack of sexual drive and, therefore, a main therapy was the drinking of a potion of hippopotamus testicles. By the 1700s this idea was replaced by an equally unfounded idea that it was due to excessive masturbation and by the 1800s castration was recommended as a treatment for male epileptics. Thus, the pre-occupation with genitalia remained during the 1900s and even today, a few states in the U.S.A. still have laws prohibiting the marriage of epileptics.
Epilepsy is a chronic disorder characterized by recur rent self-limited
seizures in which the
brain is subject to
abnormal, excessive discharges synchronized throughout a localized or generalized population of neu rons. Approximately 0.5% of the population currently suffer from epilepsy, Seventy-five percent of which had their first seizure before 18 years of age.
There are many causes of epilepsy including genetic factors. There have been some 20+ genes implicated in the condition. It is most certainly polygenomic. Neonatal asphyxia, birth trauma and congenital abnormalities can lead to brain damage which can give rise to epilepsy. Infection of the nervous system (e.g. meningitis, brain abscess, virus encephalitis) may be accompanied by epilepsy, or epilepsy may be a later consequence of brain damage caused by the infection. The damage may be localized as is usually the case with a brain abscess, or it may be diffuse as can arise from virus encephalitis. Epileptic attacks often occur as an aftermath of lead, iron, or mercury poisoning. Abrupt cessation of use of various drugs that depress the central nervous system (e.g. ethanol. barbi turates, meprobamate) may precipitate convulsive episodes, particularly if the drug has been used in high doses for a prolonged period.
Cerebral injury, metabolic and nutritional disorders, circulatory disturbances, neoplasm and degenerating / ageing diseases may also produce cerebral damage that leads to epilepsy of late onset in older age groups.
The extensive neuronal interconnections within a local area of cortex and between distant areas such as the thalamus produce the ex tensive serial and parallel connections for processing of information. However, these same connections can conduct an abnormal synchrony of dis charge which then affects large ensembles of neurones. An abnormal syn chronous activity of this kind is called a
Seizure. A seizure can have serious behavioural consequences. The synchronous neuronal discharge usually produces stereotyped and involuntary jerking movements, transient loss of awareness. A massive seizure, called a convulsion will produce loss of consciousness. These behavioural changes profoundly al ter the life of epileptic patients. The current classification of seizure recognizes two broad categories: Focal or Partial seizures arise in small part of one cerebral hemi sphere. They are simple if no alter ation of consciousness occurs and complex if consciousness is impaired. The English Physician Hughlings Jackson (who was an epileptic) first described his own seizures which are now sometimes called Jacksonian fits. A patient experiencing a Jacksonian fit remains conscious since the abnormal activity is restricted. Some partial seizures from the limbic regions in the temporal lobe and orbital frontal cortex often give rise to complicated illusory phenomena, deja-vue, auras, hallucinations, out-of-body and religious, profound experiences.
Generalised seizures in volve all or large parts of both cerebral hemi spheres. They can be sub-classified by the presence or absence of certain motor convulsions. Absence seizures, characterized by brief losses of conscious ness have few motor effects, perhaps lip and eye movements that last about 6 sec. Tonic-clonic seizures in are widespread with convulsive motor activity that can last 30 mins. Status epilepticus occurs when seizures happen with increasing frequency such that base-line consciousness is not regained in-between. The patient is con sidered to be in status epilepticus when seizures last at least 30 minutes. Status epilepticus is a medical emer gency with a mortality of 15%. Status epilepti cus leads to systemic hypoxia, acidemia, hyperpyrexia, cardiovascular collapse, and renal shutdown.
More abstracts about the Epilepsy Overview