What is Hemispherotomy

Hemispherotomy is a highly specialized brain surgery designed to treat severe epilepsy that originates from one hemisphere of the brain. Although it’s not a commonly performed procedure, it plays a critical role in helping children particularly those with drug-resistant epilepsy achieve seizure control and a better quality of life. By disconnecting the affected hemisphere from the healthy side, hemispherotomy prevents the spread of abnormal electrical signals that cause debilitating seizures.

For parents and caregivers watching a child suffer from uncontrollable seizures, the journey can be exhausting and emotionally overwhelming. Medications, lifestyle changes, and even dietary therapies may offer limited relief, but when these fail, surgical options like hemispherotomy emerge as potential lifesavers. This procedure doesn’t remove any part of the brain; instead, it interrupts faulty communication pathways that allow seizures to spread.

What is Hemispherotomy?

Hemispherotomy is a type of brain surgery performed to treat severe epilepsy that originates from one cerebral hemisphere (half of the brain). It involves disconnecting the affected hemisphere from the rest of the brain to prevent the spread of seizures. Unlike hemispherectomy, which removes part or all of the hemisphere, hemispherotomy preserves brain tissue but cuts off communication pathways.

This disconnection surgery is typically reserved for patients who have intractable epilepsy, meaning seizures that do not respond to medications or other non-invasive treatments. Hemispherotomy is primarily performed in children, whose brains are more adaptable and capable of recovering functions over time.

Why Is Hemispherotomy Done?

The main goal of hemispherotomy is to stop or significantly reduce seizures caused by damage or malformation in one hemisphere of the brain. Some common conditions that may make a patient eligible for this surgery include :-

1. Rasmussen’s encephalitis

2. Hemimegalencephaly

3. Sturge-Weber syndrome

4. Cortical dysplasia

5. Perinatal stroke

In these disorders, abnormal brain activity is typically limited to one side. When anti-epileptic drugs fail to control seizures, hemispherotomy offers a way to isolate the damaged hemisphere and prevent seizure activity from affecting the entire brain.

How Does Hemispherotomy Work?

Hemispherotomy works by surgically severing the neural connections between the affected hemisphere and the rest of the brain. The procedure ensures that abnormal electrical activity cannot cross over to the healthy hemisphere, thus stopping the seizures or limiting their impact.

There are different surgical approaches to hemispherotomy, such as :-

1. Vertical parasagittal hemispherotomy

2. Peri insular hemispherotomy

3. Trans sylvian hemispherotomy

The choice of technique depends on the surgeon’s preference, the patient’s age, the condition being treated, and the anatomical structure of the brain.

The surgery is usually performed under general anesthesia and can last several hours. Advanced imaging techniques such as MRI and EEG are used before the procedure to locate the precise areas responsible for seizure generation.

Who Is a Good Candidate for Hemispherotomy?

Not all patients with epilepsy are suitable for hemispherotomy. It is typically recommended for :-

1. Children with drug-resistant epilepsy limited to one hemisphere

2. Patients with significant neurological deficits on one side of the body (e.g., weakness or paralysis)

3. Cases where brain imaging and EEG confirm that seizures are confined to a single hemisphere

Adults are rarely considered unless their brain shows similar characteristics, and seizures severely impair quality of life.

A comprehensive evaluation by a multidisciplinary epilepsy team including neurologists, neurosurgeons, and neuropsychologists is essential to determine eligibility.

Benefits of Hemispherotomy

For suitable candidates, hemispherotomy can offer significant benefits :-

1. Seizure freedom or major reduction :- Up to 70–90% of patients experience complete seizure control after the surgery.

2. Improved quality of life :- Children may regain developmental progress once seizures are under control.

3. Reduced medication dependence :- Many patients can reduce or stop anti-seizure medications post-surgery.

4. Brain adaptability :- Especially in children, the healthy hemisphere can take over many lost functions, particularly if the surgery is done early.

Risks and Possible Complications

Like any major brain surgery, hemispherotomy carries risks. However, complications are relatively rare in experienced hands. Some possible risks include :-

1. Infection

2. Bleeding or stroke

3. Hydrocephalus (fluid buildup in the brain)

4. Worsening of existing motor weakness

5. Cognitive or behavioral changes

In most cases, children already have some neurological impairment due to their underlying condition. Hemispherotomy doesn’t usually cause new deficits but can make existing weaknesses more noticeable, especially in motor skills.

Post Surgery Recovery and Rehabilitation

Recovery from hemispherotomy is a gradual process that involves hospitalization, rehabilitation, and regular follow-up. Here’s what to expect :-

1. Hospital Stay :- Patients usually stay in the hospital for 1–2 weeks after surgery. During this time, doctors monitor for signs of infection, hydrocephalus, or bleeding. Anti-seizure medications may be continued temporarily.
2. Rehabilitation :- Rehabilitation plays a vital role in recovery, especially for children. Physical therapy, occupational therapy, and speech therapy help improve motor skills, coordination, and communication. Young brains are incredibly adaptable, and with the right support, children can regain many lost abilities.
3. Long Term Outlook :- Many patients enjoy a significant improvement in quality of life. Some children go on to attend regular schools, participate in social activities, and lead relatively normal lives. However, regular follow-up with the neurology team remains important for ongoing care and support.

Hemispherotomy vs Hemispherectomy: What’s the Difference?

People often confuse hemispherotomy with hemispherectomy, but there are important differences.

1. Hemispherectomy involves removal of brain tissue from one hemisphere.

2. Hemispherotomy involves disconnecting the affected hemisphere while preserving the tissue.

The shift toward hemispherotomy in recent years is due to its reduced risk of complications, shorter surgery time, and comparable success rates. It’s now considered the preferred approach in many pediatric epilepsy centers.

Success Rates and Prognosis

Success rates of hemispherotomy vary depending on the condition, patient age, and how early the surgery is performed. On average :-

1. 70% to 90% of children become seizure free

2. Many children show developmental improvement in learning, behavior, and motor skills

3. Early intervention often leads to better outcomes, as the young brain can compensate more efficiently

However, continued therapy and support remain crucial in helping the child adapt and thrive after surgery.

Conclusion

Hemispherotomy is a highly specialized but transformative surgical option for children with severe, drug resistant epilepsy affecting one hemisphere of the brain. By disconnecting the damaged side, this procedure can halt seizures, improve developmental outcomes, and offer a new lease on life.