Published online by Cambridge University Press: 20 August 2020
When patients with epilepsy have seizures that are not completely controlled by medications, they are considered to have drug-resistant epilepsy. This condition is also known as medically intractable, medication-resistant, or medication-resistant epilepsy. The International League against Epilepsy defines this condition as the failure of adequate trials of two tolerated, appropriately chosen and administered antiepileptic drugs, whether as monotherapy or in combination, to achieve seizure freedom . An estimated 30% of patients with epilepsy may be medication-resistant.