Epilepsy
Seizure disorder, or epilepsy, is a condition of the brain characterized by a susceptibility to recurrent seizures (paroxysmal events associated with abnormal electrical discharges of neurons in the brain). Epilepsy is believed to affect 1% to 2% of the population. The prognosis is good if the patient with epilepsy adheres strictly to his prescribed treatment.
Causes
In about one-half of all epilepsy cases, the cause is unknown. Possible causes include:
birth trauma (inadequate oxygen supply to the brain, blood incompatibility, or hemorrhage)
perinatal infection
anoxia
infectious diseases (meningitis, encephalitis, or brain abscess)
ingestion of toxins (mercury, lead, or carbon monoxide)
brain tumors
inherited disorders or degenerative disease, such as phenylketonuria or tuberous sclerosis
head injury or trauma
metabolic disorders, such as hypoglycemia and hypoparathyroidism
stroke (hemorrhage, thrombosis, or embolism).
Signs and symptoms
The hallmark of epilepsy is recurring seizures, which can be classified as partial, generalized, status epilepticus, or unclassified (some patients may be affected by more than one type).
Partial seizures
Arising from a localized area of the brain, partial seizures cause focal symptoms. These seizures are classified by their effect on consciousness and whether they spread throughout the motor strip, causing a generalized seizure. When simple or complex seizures evolve to both sides of the brain, they’re termed secondary generalized seizures.
A simple partial seizure begins locally and generally doesn’t cause an alteration in consciousness. It isn’t uncommon for this type to present with sensory symptoms (lights flashing, smells, hearing hallucinations), autonomic symptoms (sweating, flushing, pupil dilation), and psychic symptoms (dream states, anger, fear). The seizure lasts for a few seconds and occurs without preceding or provoking events.
A complex partial seizure involves impairment in consciousness. Amnesia for the events that occur during and immediately after the seizure is a differentiating characteristic. During the seizure, the patient may follow simple commands. This type of partial seizure generally lasts for 1 to 3 minutes.
Generalized seizures
As the term suggests, generalized seizures cause a generalized electrical abnormality within the brain. They can be convulsive or nonconvulsive and include several types.
Absence seizures occur most commonly in children, although they may affect adults. They usually begin with a brief change in level of consciousness, indicated by blinking or rolling of the eyes, a blank stare, and slight mouth movements. The patient retains his posture and continues preseizure activity without difficulty. Typically, each seizure lasts from 1 to 10 seconds. If not properly treated, seizures can recur as often as 100 times per day. An
absence seizure is a nonconvulsive seizure, but it may progress to a generalized tonic-clonic seizure.
Myoclonic seizures (bilateral massive epileptic myoclonus) are characterized by brief, involuntary muscular jerks of the body or extremities, which may occur in a rhythmic manner. Consciousness isn’t usually affected.
Generalized tonic-clonic seizures typically begin with a loud cry, precipitated by air rushing from the lungs through the vocal cords. The patient then loses consciousness and falls to the ground. The body stiffens (tonic phase) and then alternates between episodes of muscle spasm and relaxation (clonic phase). Tongue biting, incontinence, labored breathing, apnea, and subsequent cyanosis may also occur.
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