Hemispherectomy is a very rare neurosurgical procedure in which a cerebral hemisphere (half of the brain) is removed, disconnected, or disabled. This procedure is used to treat a variety of seizure disorders where the source of the epilepsy is localized to a broad area of a single hemisphere of the brain, notably Rasmussen's encephalitis. About one in three patients with epilepsy will continue to have persistent seizures despite epileptic drug therapy. Hemispherectomy is reserved for the most extreme cases of this one-third in which the individual's seizures are irresponsive to medications or other less invasive surgeries and significantly impair functioning or put the patient at risk of further complications. The procedure successfully cures seizures in about 85%-90% of patients. Additionally, it is also known to often markedly improve the cognitive functioning and development of the individual. Subtotal hemispherectomy sparing sensorimotor cortex can be performed with successful seizure control expected in 70-80% of patients. Even with the presence of widespread unilateral epileptogenicity or anatomic/functional imaging abnormalities, complete hemispherectomy can often be avoided, particularly when there is little hemiparesis.

Can we conclude that can you remove half your brain and live?
yes