Grand mal seizures occur when the electrical activity over the whole surface of the brain becomes abnormally synchronized. The brain's nerve cells normally communicate with each other by sending electrical and chemical signals across the synapses that connect the cells.

In people who have seizures, the brain's usual electrical activity is altered. Exactly what causes the changes to occur remains unknown in about half the cases.

However, grand mal seizures are sometimes caused by underlying health problems, such as:

Injury or infection

  • Traumatic head injuries
  • Infections, such as encephalitis or meningitis, or history of such infections
  • Injury due to a previous lack of oxygen
  • Stroke

Congenital or developmental abnormalities

  • Blood vessel malformations in the brain
  • Genetic syndromes
  • Brain tumors

Metabolic disturbances

  • Very low blood levels of glucose, sodium, calcium or magnesium

Withdrawal syndromes

  • Using or withdrawing from drugs, including alcohol
Jun. 10, 2014

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