Hemispherectomy Surgery: Recovery, Success Rates and Advices

Contents

What is Hemispherectomy?

A hemispherectomy is a rare neurosurgical procedure where one half of the brain (a hemisphere) is removed or disconnected. It is generally done to treat severe epilepsy that doesn’t respond to other treatments. Despite losing a hemisphere many patients (especially children) can still function well thanks to the brain’s ability to adapt.

Statistcs Of Hemispherectomy

Medication Reduction: 81.3% of patients reduced their antiseizure medication usage and 56.3% were able to discontinue these medications entirely after surgery.

Long-Term Outcomes: Research from The Hospital for Sick Children reviewing 146 children over 35 years found that; 84% achieved complete seizure freedom (Engel Class I) in the short term and 61% maintaining this outcome in the long term.

Complications: The most common complication is hydrocephalus seen in about 14–23% of patients. Other potential complications include various types of hemorrhages, infections and in rare cases the need for additional epilepsy surgery. Mortality rates are low. Estimated between less than 1% to 2.2%.

Which Conditions Can A Hemispherectomy Treat?

1. Rasmussen’s Encephalitis (RE)

A rare and progressive neurological disorder causing chronic inflammation of one hemisphere.
Cause to frequent seizures, cognitive decline and weakness on one side of the body (hemiparesis).
Effects children between 1 and 14 years old.
Hemispherectomy is often the only effective treatment to stop seizures and prevent further neurological deterioration.

2. Hemimegalencephaly (HME)

Rare congenital brain malformation where one hemisphere is abnormally large.
Causes severe epilepsy, developmental delays and sometimes abnormal muscle tone.
Seizures usually start in infancy and are resistant to medication.
Surgery is often needed early in life to improve outcomes.

3. Sturge-Weber Syndrome (SWS)

A neurocutaneous disorder characterized by a facial birthmark (port-wine stain) and abnormal blood vessels in the brain.
Can lead to seizures, stroke-like episodes and progressive weakness or paralysis.
When epilepsy is severe and localized to one hemisphere and a hemispherectomy may be considered.

4. Perinatal Stroke

Stroke happen before or shortly after birth often because of blood clots, lack of oxygen or brain hemorrhage.
Can lead to severe brain damage, cause to epilepsy, motor impairments and developmental delays.
If seizures originate only from the damaged hemisphere and are unresponsive to medication. Hemispherectomy may be recommended.

5. Cortical Dysplasia (Focal or Hemispheric)

A condition where the brain’s cortex doesn’t form properly and cause to structural abnormalities.
One of the most common causes of drug-resistant epilepsy in children.
If only one hemisphere is effected; a hemispherectomy can help control seizures and improve quality of life.

6. Traumatic Brain Injury (TBI)

Severe brain injury effecting one hemisphere because of accidents, falls or other trauma.
Can cause to intractable epilepsy if brain damage is extensive and medication fails to control seizures.
A hemispherectomy is necessary when the damaged hemisphere lead to disabling seizures and other complications in rare cases.

7. Brain Tumors

Some large or aggressive brain tumors can lead to severe epilepsy if they effect an entire hemisphere.
If the tumor is not safely removable and the seizures are uncontrollable and a hemispherectomy might be an option.

What Are The Types Of Hemispherectomies?

1. Anatomical Hemispherectomy

Description: This is the most radical form of the surgery; where an entire cerebral hemisphere (either the left or right side of the brain) is physically removed.
When It’s Used: Performed in severe cases such as Rasmussen’s encephalitis, hemimegalencephaly or large strokes that effect an entire hemisphere.
Advantages: Completely removes the diseased tissue and eliminating seizure activity from that hemisphere.
Disadvantages: Higher risk of complications such as excessive bleeding and cerebrospinal fluid (CSF) leaks.

2. Functional Hemispherectomy

Description: Surgeons disconnect it from the healthy hemisphere instead of removing the effected hemisphere. This prevents seizure signals from spreading but preserves some brain tissue.
When It’s Used: Often performed in cases where the effected hemisphere is non-functional but removal might be too risky such as Sturge-Weber syndrome or perinatal strokes.
Advantages: Reduces surgical risks like blood loss and fluid buildup compared to anatomical hemispherectomy.
Disadvantages: There is a small chance seizures may return over time since the diseased hemisphere remains.

Variations of Functional Hemispherectomy

Hemidecortication; Only the outer layer (cortex) of the effected hemisphere is removed and leaving deeper brain structures intact.
Peri-Insular Hemispherotomy (PIH); A refined technique where key connections between hemispheres are cut while minimizing damage to surrounding tissue.
Trans-Sylvian Functional Hemispherectomy; A less invasive approach using natural brain folds (sulci) to access and disconnect the hemisphere.

Choosing the Right Type

Younger patients (especially infants and toddlers) often recover better from anatomical hemispherectomy because of brain plasticity.
Older children and adults may be better suited for functional hemispherectomy to reduce complications.
The choice according to the underlying condition, severity of seizures and surgical risks.

What Are The Complications Of Hemispherectomy?

1. Hydrocephalus (14–23% of cases)

Excess cerebrospinal fluid (CSF) buildup in the brain and cause to increased pressure.
May require a ventriculoperitoneal (VP) shunt to drain excess fluid.
More common in anatomical hemispherectomy than in functional hemispherectomy.

2. Hemiparesis or Hemiplegia (Permanent Weakness or Paralysis)

Patients may experience weakness (hemiparesis) or paralysis (hemiplegia) on the side opposite to the removed/disconnected hemisphere because of one hemisphere controls movement on the opposite side of the body,.
If the surgery is done early in life (brain can easily adapt) and mobility may improve with physical therapy.

3. Visual Field Loss (Hemianopia)

Loss of vision on the opposite side of the body (e.g., right hemispherectomy → left visual field loss).
Patients often adapt over time but driving and other activities requiring full vision may be effected.

4. Seizure Recurrence (10–20% of cases)

Seizures don’t completely stop or may return over time in some cases.
More common with functional hemispherectomy as some brain tissue remains.
Additional surgery may be needed in rare cases.

5. Cognitive and Developmental Challenges

Intellectual abilities vary according to the age at surgery and underlying condition.
Younger children tend to have better outcomes due to brain plasticity.
Speech and language may be effected. Especially if the left hemisphere (language center in most people) is removed.
Intensive rehabilitation, speech, and occupational therapy can help maximize recovery.

6. Behavioral and Psychological Effects

Some children may experience behavioral issues, learning difficulties or emotional challenges.
Supportive therapy and special education interventions can improve long-term outcomes.

7. Surgical Risks

Bleeding (hemorrhage)
Infections (meningitis, wound infections)
CSF leaks
Stroke or brain swelling (rare but serious complications)

What is The Life Expectancy Of Hemispherectomy?

1. High Survival Rate

The mortality rate from the surgery itself is low; less than 1% to 2.2%.
Most patients who undergo hemispherectomy (especially for epilepsy) can live a normal or near-normal lifespan if there are no severe complications.

2. Factors Affecting Life Expectancy

Underlying Condition:
- Patients with Rasmussen’s encephalitis, hemimegalencephaly or Sturge-Weber syndrome generally do well post-surgery.
- Those with severe birth injuries, genetic disorders or neurodegenerative diseases may have a shorter life expectancy because of other medical complications.
Seizure Control:
- About 78–85% of patients achieve seizure freedom after surgery.
- They may increase the risk of sudden unexpected death in epilepsy (SUDEP) if seizures persist.
Complications Like Hydrocephalus:
- If hydrocephalus develops (in 14–23% of cases) (VP shunt may be needed) which requires lifelong monitoring.
Overall Health and Rehabilitation:
- Many children and adults regain independence and quality of life with proper therapy.
- Early intervention with physical, occupational and speech therapy can significantly improve long-term outcomes.

3. Long-Term Outcomes and Quality of Life

Many children who have the procedure early in life grow up to be independent, attend school and even work.
Some limitations exist such as vision loss (hemianopia) and weakness on one side (hemiparesis/hemiplegia).
Cognitive function change but most patients can adapt well with supportive care.

How Should You Prepare For Hemispherectomy?

1. Medical Evaluations & Testing

MRI (Magnetic Resonance Imaging): Identifies the damaged brain area.
EEG (Electroencephalogram): Detects seizure activity.
PET or SPECT Scans: Measures brain function and metabolism.
Neuropsychological Testing: Assesses memory, speech and cognitive function.
Blood Tests & Physical Exam: Ensures the patient is healthy enough for surgery.

2. Consult with Specialists

Meet with a neurosurgeon, neurologist and rehabilitation team to discuss;

Risks and benefits of the surgery.
Expected motor, speech and cognitive changes post-surgery.
Rehabilitation plans and long-term care.

3. Emotional & Psychological Preparation

For Children: Explain the surgery in an age-appropriate way; using books, videos or play therapy.
For Parents/Caregivers: Counseling or support groups can help manage expectations and stress.
For Adults: Talking to other patients who have undergone hemispherectomy may help.

4. Hospital Stay Preparation

Pack essentials: Comfortable clothes, toiletries, favorite blanket/toy (for children), tablet/books and important medical documents.
Plan for at least 1–2 weeks in the hospital (may change).
Arrange for family members or caregivers to stay nearby.

5. Home & Lifestyle Adjustments

Set up a safe recovery space at home with easy access to essentials.
Arrange for physical therapy, occupational therapy and speech therapy after discharge.
Prepare for temporary or permanent mobility challenges (e.g., wheelchair, walker, handrails).

6. Post-Surgery Support System

Plan for rehabilitation programs (hospital-based or outpatient).
Work with schools, employers or disability services to accommodate new needs.
Connect with support groups for hemispherectomy patients and families.