What is a Hemispherectomy?

A hemispherectomy is brain surgery to physically remove or disconnect one half of the brain.

Why is a hemispherectomy needed?

To treat uncontrollable epilepsy in the developing brain due to congenital or acquired causes.

Listed below are known causes of severe epilepsy, including both conditions present at birth and those that develop later in life.

Rasmussen’s encephalitis​​

A rare, progressive brain disorder that causes severe, drug-resistant seizures, usually affecting one side of the brain.

Sturge-Weber syndrome

A rare condition present at birth, often causing a facial birthmark and abnormal blood vessels in the brain, which can trigger seizures.

Perinatal stroke or brain injury

Brain damage occurring around the time of birth, which can lead to seizures and other neurological challenges later in life.

Hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome

A condition starting with prolonged seizures on one side of the body in childhood, leading to lasting weakness and epilepsy.

Hemimegalencephaly

A rare disorder where one half of the brain is abnormally large, often causing severe, drug-resistant seizures and developmental delays.

Infantile spasms

A type of seizure seen in very young children, often in clusters, which can affect development if not treated promptly.

What does surgery involve?

The procedure can be done 1 of 3 ways

.cls-1{fill:#baa2dd;}.cls-2{fill:#7846bb;}

Anatomical Hemispherectomy

Surgical removal​ of nearly all of one half / hemisphere including all four lobes (frontal, parietal, temporal, and occipital) of the brain.
.cls-1{fill:#baa2dd;}.cls-2{fill:#7846bb;}

Functional Hemispherectomy

Surgical disconnection​ of the affected half / hemisphere of the brain whilst removing a small portion of its tissue.
.cls-1{fill:#baa2dd;}.cls-2{fill:#7846bb;}

Functional Hemispherotomy

Surgical disconnection​ of the affected half / hemisphere of the brain, leaving more of the damaged brain tissue intact.

What can life look like after a hemispherectomy?

While every child’s journey is unique, many experience fewer seizures, improved function, and the chance to thrive with the right support.

Children and young people who undergo a hemispherectomy often face a challenging journey, but the surgery can dramatically improve their quality of life. For most, the procedure significantly reduces or even eliminates seizures, which allows them to participate more fully in daily activities, learning, and social life.
While some physical changes are expected—such as weakness on one side of the body or visual field differences—most children adapt remarkably well over time with therapy and support.
 
Although outcomes vary between children, cognitive improvement usually occurs following hemispherectomy and many children go on to attend school, make friends, and pursue hobbies just like their peers.
Early intervention, ongoing rehabilitation, and a strong support network are key to maximizing outcomes. Families often report that, despite initial challenges, the improvement in seizure control and overall well-being brings a sense of relief and hope for the future.

Seizure Reduction or Elimination

Most children and young people experience far fewer seizures, and many become seizure-free.
.cls-1{fill:#7eba29;}

Improved Quality of Daily Life

With fewer seizures, children and young people can participate more fully in school and daily life.

Preservation of Cognitive Function

Despite some physical changes, overall learning and cognitive abilities are often improved.

Help us empower
our Hemi Heroes
and their families

Your support makes it possible to provide hope, connection, and life-changing resources to families on the hemispherectomy journey.

BECOME A SPONSOR