Treatment of Hemispherotomy

Hemispherotomy is a highly specialized neurosurgical procedure performed to treat severe epilepsy that originates from one hemisphere of the brain. While it is considered a last resort treatment, it has proven to be life changing for many children and young adults suffering from drug-resistant epilepsy.

Hemispherotomy is not a common treatment, nor is it a decision made lightly. It is a complex brain surgery performed only in highly specialized neurosurgical centers, and it is usually reserved for children whose seizures originate from one hemisphere of the brain and cannot be controlled by medication alone.

What is Hemispherotomy?

Hemispherotomy is a type of brain surgery that involves disconnecting one hemisphere (half) of the brain to prevent the spread of epileptic seizures. Unlike hemispherectomy, which removes brain tissue, hemispherotomy aims to isolate the affected hemisphere while preserving as much healthy brain tissue as possible.

This procedure is primarily used in children with severe epilepsy caused by conditions such as Rasmussen’s encephalitis, Sturge-Weber syndrome, hemimegalencephaly, or traumatic brain injury. When seizures are localized to one hemisphere and do not respond to medication, hemispherotomy may be recommended as a surgical solution.

Why Hemispherotomy is Performed?

The main goal of hemispherotomy is seizure control. Epileptic seizures can severely impact a child’s development, cognition, and quality of life. When antiepileptic drugs (AEDs) fail to provide relief, surgery may be the only viable option.

Hemispherotomy is most effective in cases where :-

1. Seizures originate from one side of the brain only.

2. The affected hemisphere is significantly damaged or non-functional.

3. Early intervention is critical to prevent developmental regression.

Early surgical intervention can halt the progression of epilepsy related brain damage and allow the healthier hemisphere to take over essential functions like speech and motor skills.

Treatment of Hemispherotomy

Before hemispherotomy is considered, a thorough preoperative evaluation is essential. This includes :-

1. MRI scans to determine the structural abnormalities in the brain.

2. EEG monitoring to identify the origin and spread of seizures.

3. Neuropsychological testing to assess cognitive function and developmental status.

4. PET or SPECT scans to provide functional imaging of brain activity.

The surgical team will also evaluate the potential for the unaffected hemisphere to compensate for lost functions. In some cases, functional MRI or language mapping may be conducted to locate vital language or motor centers in the brain.

The Hemispherotomy Procedure

Hemispherotomy is performed under general anesthesia by a specialized neurosurgical team. There are different surgical approaches to hemispherotomy, including vertical parasagittal hemispherotomy, peri insular hemispherotomy, and trans sylvian approaches. The choice of technique depends on the patient’s condition and the surgeon’s expertise.

The surgery involves making an opening in the skull to access the brain. The surgeon then uses microsurgical techniques to disconnect the corpus callosum (the structure that connects the two hemispheres) and other fibers that allow seizures to spread. Importantly, no large portions of brain tissue are removed—only pathways are severed to isolate the seizure-generating hemisphere.

The entire procedure can take several hours and is usually followed by intensive monitoring in the pediatric intensive care unit (PICU).

Recovery After Hemispherotomy

Recovery from hemispherotomy varies from patient to patient, depending on age, pre-existing neurological conditions, and overall health. Immediately after surgery, the patient is closely monitored in the PICU for signs of complications like bleeding, infection, or increased intracranial pressure.

Initial recovery may include :-

1. Weakness or paralysis on one side of the body (hemiparesis), which is often already present before surgery and may temporarily worsen.

2. Speech and language delays, especially if the dominant hemisphere is disconnected.

3. Visual field deficits, such as loss of vision on one side.

Rehabilitation begins shortly after surgery and plays a critical role in recovery. Most children undergo :-

1. Physical therapy to improve strength and mobility.

2. Occupational therapy to develop everyday skills.

3. Speech therapy, particularly if the surgery affects language centers.

The brain’s plasticity, especially in young children, allows the unaffected hemisphere to adapt and compensate for lost functions over time.

Long Term Outcomes and Success Rates

One of the most significant benefits of hemispherotomy is the high rate of seizure freedom. Studies show that up to 70–80% of patients achieve complete seizure control, while others may experience a significant reduction in seizure frequency and severity.

In addition to seizure control, many patients show improvements in :-

1. Cognitive development

2. Behavioral issues

3. Overall quality of life

Parents and caregivers often report enhanced alertness, better school performance, and improved social interaction after the surgery.

However, outcomes depend on factors such as the underlying cause of epilepsy, the extent of brain damage, and the age at surgery. Children operated on at an earlier age often have better neurodevelopmental outcomes due to greater brain plasticity.

Risks and Considerations

Like any major brain surgery, hemispherotomy carries certain risks. These may include :-

1. Infection

2. Bleeding

3. Hydrocephalus (accumulation of cerebrospinal fluid)

4. Stroke

5. Permanent neurological deficits

That said, the surgery is generally safe in experienced hands, and the benefits of seizure control often outweigh the risks, especially in patients with intractable epilepsy.

The decision to proceed with hemispherotomy is made after careful consideration by a multidisciplinary team, including neurologists, neurosurgeons, neuropsychologists, and rehabilitation specialists.

Life After Hemispherotomy

Life after hemispherotomy often includes ongoing therapy and medical follow up. While the child may require assistance with certain activities, many are able to return to school, participate in daily routines, and enjoy a significantly improved quality of life.

Parents and caregivers play a vital role in supporting post-surgical recovery. Regular evaluations by neurologists and therapists help track developmental progress and address any new concerns.

Conclusion

Hemispherotomy is a powerful surgical intervention that can transform the lives of children suffering from severe, drug-resistant epilepsy. By disconnecting the affected hemisphere of the brain, it halts the spread of seizures and gives the healthy hemisphere a chance to take over essential functions. Though it is a complex procedure with certain risks, its benefits in terms of seizure control, development, and overall well being are often profound.