Epilepsy: Classification, Etiology, Diagnosis & Treatment

By March 9, 2017 No Comments
Epilepsy: Classification, Etiology, Diagnosis & Treatment

Epilepsy is characterized by recurrent episodic, paroxysmal, involuntary clinical events associated with the abnormal electrical activity of the neurons. The patient may present with motor, sensory or psychomotor phenomenon, often with alteration in sensorium.

Classification of Epilepsy

Epilepsy is classified by appraisal of

  • Seizure type
  • Etiology
  • Electroencephalographic data

If the underlying etiology is identified it is symptomatic epilepsy otherwise it is called idiopathic. In cryptogenic, a cause is presumed.

A simple modified version of classification proposed by the International League Against Epilepsy (ILAE) is given.


  1. Idiopathic or primary epilepsy: the brain is anatomically normal though electric waves on EEG demonstrate abnormality. It may probably be an inherent tendency (genetic factor)

  2. Symptomatic or secondary epilepsy: the periodic burst of impulses is due to irritation of the brain by some other diseases and the fits are simple. It may be due to cerebral tumor inflammatory conditions like encephalitis head injury, CVA, uremic condition, and toxic substances.

Generalized seizures

  1. Major epilepsy: grand mal seizures, it refers to major convulsions in which patient may lose consciousness for several minutes. The convulsion proceeds as follows:

  • Aura: aura is a warning signal prior to the onset of seizure e.g. sensation of peculiar taste or smell spots before eyes, dizziness, and feeling of weakness; it serves a useful purpose in known epileptics as the patient seeks safety and privacy before the onset of a seizure.

  • Epileptic cry: the patient loses consciousness with an epileptic cry; it is caused by spasm of thoracic and abdominal muscles expelling air through the glottis.

  • Tonic stage: the patient fails to the ground with all his muscle in the increased tone with rigidity. The skin is pale and cyanotic because respiration ceases, hands are clenched, tongue bit, eyes widely open, pupil dilated and fixed; it lasts for 10-30sec.

  • Clonic stage: it is relaxation period when movement of all body muscles and quick irregular respiration begins. This stage lasts 1-5min. there is frothing at the mouth and incontinence of urine and faces.

  • Coma stage or postictal phase: after the clonic stage. The patient, if undisturbed, passes into ordinary deep sleep for hours and then awakens with a pulsatile headache

  1. Minor epilepsy:

  • Petit mal (Absence seizure): it occurs often in children end usually disappears often puberty. It consists of transient loss of consciousness lasting a few seconds. As a rule, such a patient doesn’t fall. The patient demonstrates a brief change such as rolling of the eyes, blinking and slight mouth movement. Patient often describe their attacks as “blackout”

  • Partial seizures (focal/Jacksonian seizures): begins as a localized motor seizure, with convulsions starting in one part of the body for e.g. from the thumb and gradually involving hand and arms, face and other parts of the body. A patient may or may not lose consciousness. The patient of seizure depends upon the area of the brain which is being irritated by the underlying cause.

  • Status epileptics: Status epileptic is when recurrent generalized seizure activity occurs at such frequencies that full consciousness is not regained between seizures. It is accompanied by respiratory distress. It is invariably always fatal. Status epileptic can lead to death from exhaustion.

Emergency management includes constant suction to clear the mouth, padded side rails, 02 inhalation, cardiac stimulants, injection diazepam etc.

Diagnosis and investigation

  • A complete neurological evaluation should follow, including the level of consciousness, reflexes, sensory and motor responses
  • Laboratory studies:
  • Serum electrolytes, magnesium, calcium and fasting blood sugar
  • Toxicology screen: drug overdose may cause seizures
  • Observation of an attack if possible
  • Patient history and description of seizure activity
  • Electroencephalogram (EEG)
  • EEG might be indicated to assess the brain’s electrical activity
  • Radiologic imaging such as CT or MRI may be performed to note any structural abnormality
  • Other investigation may include: serum glucose, calcium, skull X-ray, lumbar puncture


A chronic illness like epilepsy produces emotional and psychosocial disturbance. A physician must, therefore, give due consideration to them besides medical aspects such as drug therapy, side effects of drugs and identifying etiology.

Medical treatment

  • There is no known cure for idiopathic epilepsy, only prevention for attacks is striven for.
  • A general well-balanced diet is usually recommended variety of vegetables or fresh fruits
  • Drug therapy consists of administration of anticonvulsant drugs which must be continued for at least two years. It may vary except in severe neurodevelopment delay or structural malformation neurologic deficits where a risk of breakthrough and reoccurrence of seizures is higher.
  • The mainstay of treatment of epilepsy is anticonvulsant medications
  • Often, anticonvulsant medication treatment will be lifelong and can have major effects on quality of life
  • The choice among anticonvulsants and their effectiveness differs from epilepsy syndrome. Mechanism, effectiveness for particular epilepsy syndromes, and side effects among the individual anticonvulsant medications
  • Most patients can achieve this balance best with monotherapy, the use of a single anticonvulsant medication

Surgical management

  • Surgical removal is the appropriate treatment for an identified lesion, such as a hematoma or brain tumor
  • This treatment, such as hemispherectomy, nontemporal lobe resection, or corpus callosotomy or commissurotomy, may be performed in children with severe, medically intractable seizure disorders


  • Prognosis depends on type and severity of seizure disorder, co-existing mental retardation, organic disorders and the type of medical management
  • Medically treated seizures- spontaneous cessation of seizure may occur. Drug may be gradually discontinued when the patient has been free from attacks for an extended period and the EEG pattern has reverted to normal
  • Non-treated epilepsy- seizures tend to become more numerous


  • Apnea/hypoventilation
  • Injuries sustained during a seizure


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