Epilepsy is a very common disorder, characterized by seizures, which take various forms and result from episodic neuronal discharges, the form of the seizure depending on the part of the brain affected.‘Epilepsy’ is used to define a group of neurological disorders all of which exhibit periodic seizures.The characteristic event is the seizure, which may be associated with convulsions but may take other forms.The seizure is caused by an asynchronous high-frequency discharge of a group of neurons, starting locally and spreading to a varying extent to affect other parts of the brain. In absence seizures, the discharge is regular and oscillatory.No recognizable cause, although it may develop after brain damage, such as trauma, stroke, infection or tumor growth, or other kinds of neurological disease, including various inherited neurological syndromes. Treated mainly with drugs, although brain surgery may be used for suitable severe cases. PATHOPHYSIOLOGY
Seizures are associated with episodic high-frequency discharge of impulses by a group of neurons (sometimes referred to as the focus) in the brain. What starts as a local abnormal discharge may then spread to other areas of the brain. The site of the primary discharge and the extent of its spread determines the symptoms that are produced, which range from a brief lapse of attention to a full convulsive fit lasting for several minutes, as well as odd sensations or behaviors. The particular symptoms produced depend on the function of the region of the brain that is affected. Thus, involvement of the motor cortex causes convulsions, involvement of the hypothalamus causes peripheral autonomic discharge, and involvement of the reticular formation in the upper brain stem leads to loss of consciousness. It is important to note that not all seizures involve convulsions.
SIGNS AND SYMPTOMS
-Loss of consciousness
-Foaming from the mouth
-Inconsistency urination or passing of stools
-Post seizure sleeping etc.
TYPES OF EPILEPSY
Classification of epilepsy is done on the basis of the characteristics of the seizure rather than on the cause or underlying pathology.Two major categories, namely partial and generalized seizures, although there is some overlap and many varieties of each. Either form is classified as simple (if consciousness is not lost) or complex (if consciousness is lost)
In partial seizures, electric discharge begins locally and often remains localized. Symptoms depend on the brain region or regions involved, and include involuntary muscle contractions, abnormal sensory experiences or autonomic discharge, or effects on mood and behaviour, often termed psychomotor epilepsy (bizarre behavior). Partial seizures incidence increases with age.
Generalized seizures involves the whole brain, including the reticular system, thus producing abnormal electrical activity throughout both hemispheres. Immediate loss of consciousness is characteristic of generalized seizures. There are two main types of Generalized seizures and they are;
-Tonic–clonic seizures /grand mal.
-Absence seizures or petit mal.Others include myoclonic, tonic, atonic and clonic seizures, infantile spasms.
TONIC CLONIC SEIZURES
Tonic clonic seizures consists of an initial strong contraction of the whole musculature, causing a rigid extensor spasm and an involuntary cry. SIGNS
-Respiration stops (loss of consciousness)
This tonic phase lasts for about 1 min, during which the face is suffused, and is followed by a series of violent, synchronous jerks that gradually die out in 2–4 min. The patient stays unconscious for a few more minutes and then gradually recovers, feeling ill and confused. Injury may occur during the convulsive episode. Figure 1
Absence seizures mostly occurs in children; they are much less dramatic but may occur more frequently (many seizures each day) than tonic–clonic seizures. The patient abruptly ceases whatever he or she was doing with little or no motor disturbance. Affected children are unaware of their surroundings and recover abruptly with no after effects.
CAUTIOUS TO BE TAKEN DURING AN EPILEPTIC EPISODE.
-Move all sharp objects, inflammatory objects away from the person.
– Ensure that clothing around the neck is loose.
– Ensure that the airways are clear especially the nose.
-Do not force a spoon or any object into the mouth.
-Remove false teeth if present.
General anesthesia and ventilation may be required in severe cases, together with anticonvulsants and antiepileptic medications.