Epilepsy

• Seizure


  Transient signs and symptoms of sudden changes in neurological function due to a transient disturbance of cerebral function caused by an abnormal neuronal discharge
• Types of seizures


  • Provoked seizures
  • Unprovoked seizures
• Provoked seizures


  Seizures that occur in acute medical and neurological illnesses
• Unprovoked seizures


  No clear underlying cause (Complete lab work is normal and no evidence of infection)
• Epilepsy


  • Recurrent two or more unprovoked seizures >24 h. apart
  • One unprovoked seizure with high risk of having another seizure (such as Epileptiform EEG, remote structural Brain lesion)
• Seizure is not a diagnosis; it's a symptom of other diseases like epilepsy
• Status epilepticus (SE)


  • Recurrent persistent convulsions that last for more than 20-30 minutes and are interrupted by only brief periods of partial relief
  • Recurrent seizure with no regain of consciousness in between
• Status epilepticus is a serious, potentially life-threatening condition
• Common causes of seizure

  • Primary neurological disorders
  • Systemic disorders
• Primary neurological disorders


  • Benign febrile convulsion of childhood
  • Idiopathic epilepsy
  • Head trauma
  • Stroke or vascular malformation
  • Mass lesion
  • Meningitis or encephalitis
  • Perinatal insult
• Systemic disorders


  • Hypoglycemia
  • Hypocalcemia
  • Uremia
  • Hepatic encephalopathy
  • Porphyria
  • Drug overdose
  • Drug withdrawal
  • Hyperosmolar state
  • Hyponatremia
  • Global cerebral ischemia
  • Hypertensive encephalitis
  • Eclampsia
  • Hyperthermia
• Triggers for seizure


  • Poor compliance
  • Sleep deprivation
  • Stress
  • Alcohol
  • Infection
  • Menstrual cycle
• Classification of seizures


  • Partial seizure
  • Generalized seizures
  • Unclassified seizures
• Partial seizure


  EEG activity commences in a small part 'focus' of the cerebrum and the conscious is not lost
• Generalized seizures


  The epileptic disturbance involves wide areas of both cerebral hemispheres simultaneously from the onset of the attack and the consciousness is almost invariably lost
• Benign febrile convulsion


  A seizure that occurs in children, 3 months to 6 years, usually during the 1st day of febrile illness, and in the absence of the CNS infection e.g, meningitis or encephalitis
• Generalized tonic-clonic seizure


  • Attacks in which conscious is lost, usually without aura
  • Tonic phase: Unconscious and tonic contraction of the limb muscles for 10 to 30 seconds
  • Clonic phase: Alternating muscle contraction and relaxation, producing symmetrical limb jerk which continues for an additional 30 to 60 seconds or longer
• Complex partial seizures


  • The most common types of partial seizures; about 50% arise in the temporal lobe, hence known as 'temporal lobe seizures', most others arise from frontal lobe
  • Aura: Psychic symptoms or somatic symptoms
  • Absence: Consciousness is lost, there is amnesia, motor activity stops and the patient stares blankly
  • Automatism: Motor activity comprises oro-facial movements, emotional expression, manual movements, ambulatory movements, and violent behavior
• Myoclonic seizures

  Comprises brief muscle jerks singly or in series, involving single or multiple muscles. Consciousness is usually not lost and it usually occurs as part of idiopathic generalized epilepsy
• Absence seizure (petit mal)

  Children stop what they are doing and stare blankly. The attack lasts few seconds only and the consciousness is lost and there is a rapid onset and a rapid recovery without confusion
• Evaluation of a new seizure disorder


  • History (including medications and recreational drugs)
  • General physical examination
  • Complete neurologic examination
  • Blood studies
  • EEG
  • MRI
• Epilepsy is a clinical diagnosis
• Mechanism of Action of Anti-Epileptic Drugs

  • Modulation of voltage gated ion channels
  • Enhancement of synaptic inhibition (increases GABA)
  • Inhibition of synaptic transmission (decrease Glutamate)
• Basic rules for drug treatment

  • Preferably using one anticonvulsant (monotherapy)
  • Add-on therapy (adding another drug) is necessary in some patients
  • If patient is seizure-free for three years, withdrawal of pharmacotherapy should be considered
• Other treatments


  • Surgical
  • Vagal nerve stimulation
  • Deep brain stimulation
  • Diet
• First line and second line drugs for different types of epilepsy

  • Idiopathic generalized seizure: Sodium valproate, Carbamazepine
  • Partial epilepsy: Carbamazepine, Sodium valproate
  • Myoclonic epilepsy: Sodium valproate, Clonazepam
  • Absence seizure: Sodium valproate, Ethosuximide