Facts About Hemispherectomy
What is a hemispherectomy?
A hemispherectomy is a surgical procedure in which half of the brain is removed or disconnected. The deep structures of the brain (the thalamus, brain stem and basal ganglia) are left intact.
When is a hemispherectomy indicated?
A hemispherectomy is a radical operation. Most often, this surgery is considered in patients with severe seizure disorders coming from one side of the brain. Even then, the procedure is considered only when drugs cannot control the seizures and the patient is increasingly handicapped. Candidates may also show bi-hemispheric EEG abnormalities but be surgical candidates if a lesion is found in one hemisphere. While most have surgery for seizures, there are some unusual cases where patients may not have seizures. Cases such as mostly uni-hemispheric damage from viral or bacterial infections, trauma or tumors. Children with tuberous sclerosis may also be candidates for surgery.
The most common variety of uni-hemispheric neurologic disorders include:
- A rare degenerative brain disease that initially affects only one side of the brain. It first manifests in childhood with the onset of epileptic seizures. Later, it can progress to paralysis of one side of the body, field of vision cut in both eyes and loss of mental function. The seizures in Rasmussen's Encephalitis usually resist therapy with anticonvulsant drugs, but respond well to hemispherectomy.
- Often characterized by a facial birthmark, this rare and progressive disorder includes symptoms such as glaucoma, seizures and developmental delays. Neurologic involvement is typically limited to one side of the brain. Antiepileptic drugs are often effective in controlling seizures in those with Sturge-Weber. In the rare instance that medication therapy is not effective, hemispherectomy surgery may be necessary.
- Hemimegalencephaly is a rare dysplastic malformation of the brain resulting from overgrowth of part, or all, of a cerebral hemisphere. Clinical findings include psychomotor retardation, hemiparesis, and intractable seizures. Early control of seizures is needed to allow maximal psychomotor development. Seizures associated with hemimegalencephaly are difficult or impossible to control medically. Hemispherectomy has been used in several series to effectively control seizures.
- Cortical dysplasia is a congenital abnormality where the neurons in an area of the brain failed to migrate in the proper formation in utero. Occasionally neurons will develop that are larger than normal in certain areas. This causes the signals sent through the neurons in these areas to misfire, which sends an incorrect signal. It is commonly found near the cerebral cortex and is associated with seizures and may be associated with some level of developmental delay(s). Instead of using medication to suppress the seizures, surgery is increasingly becoming a popular solution for the problem.
- A stroke occurs when the blood supply to any part of the brain is interrupted, resulting in tissue injury and loss of brain function. The severity of impairment resulting from the stroke depends on the location and extent of injury to the brain tissue. Seizures are often associated with the stroke and may or may not respond to anticonvulsant therapy. Hemispherectomy is becoming more and more common in helping control seizures that do not respond to medication as a successful way to reduce or eliminate seizures.
Infantile spasms often occur in the uni-hemispheric neurologic disorders listed above. Visit the infantile spasms page to learn more.
Also known as "West Syndrome," "salaam attacks," "jacknife spasm," "generalized flexion epilepsy syndrome," among others, Infantile spasms are a
rare catastrophic epileptic disorder typically found in infants between 4-8 months of age. Although uncommon, an onset of spasms can occur much
earlier in life during the neonatal period or in utero, or later in childhood after 1 year of age.
Who is affected by hemispherectomy surgery?
The patient, as well as the entire family, is affected in many ways. Aside from the emotional strain of dealing with the diagnosis, the family must make the difficult decision to put their loved one through this extreme operation. There is also the financial burden of the surgery and the multiple rehabilitative therapies required to regain strength and relearn motor functions. These doctor appoint-ments and therapy schedules can compromise a parent’s time at work and income.
At what age can a hemispherectomy be performed?
A hemispherectomy can be performed at any age. However, it appears that younger children do better because the remaining side of the brain takes over functions from the lost side. Although it's not clear as to what age transference for speech to the remaining hemisphere occurs, it may take place up to age 14, and sometimes later. For many children, the damage in the speech area causes language to be transferred to the opposite side even before the operation.
What are the risks of surgery?
Surgery may take as long as 12 hours. There are always risks of infections and bleeding into the empty space, and there is even a small risk of death. On two occasions there were apparent shifts of the brain, causing coma which lasted for weeks before the children completely recovered. There are also risks of hydrocephalus which may require a shunt.
Do hemispherectomy patients suffer any long-term disability?
Patients with hemispherectomies always have some paralysis on the side of the body opposite the removed hemisphere. They are usually able to walk with only a limp, and perhaps an ankle brace. They are able to move the elbow and shoulder on the paralyzed side, but do not have normal function in the hand and fingers, or normal sensation. Therefore, the paralyzed hand becomes a "helper" hand and never completely recovers. However, all the children have some paralysis before the operation. Surgery does not appear to decrease a child's intellect. Intelligence sometimes, in fact, improves due, partly, to a lack of seizures and elimination of anti-seizure medications. Where there are no complications, many of these children leave the hospital for rehabilitation within two weeks of surgery.
Questions to ask neurologists / neurosurgeons.
- What happens if the EMU EEG shows that my child is having seizure activity in the Good Hemisphere? Does that disqualify my child from surgery?
- What if the seizure activity is beginning in the bad side, but quickly moves to the other side? Would that disqualify my child from surgery?
- What are the qualifications for surgery? Paresis? Failed Medications?
- How long can we wait for surgery? What is the hospital schedule and how long will it take until surgery?
- Surgeon: How many Hemispherectomies have you done? Neurologist: How many Hemispherectomies have you been involved in?
- How many Hemispherectomies has this hospital done?
- What special training/experience do you have with Hemispherectomy surgery?
- May I have a tour of the PICU and In-Patient Rehab Facility?
- Will my child be able to speak after surgery? If left-side, should you do a WADA test to ensure that her language center has moved to the right hemisphere? Is my child to young for a WADA Test? If it hasn’t moved yet, can we wait a few months on surgery in hopes more language will transfer? Would it do any good to wait?
- What type of Hemispherectomy approach do you propose? Hemisphereotomy? Anatomic, Functional, or somewhere in between? What are the pros and cons of each? Returning Seizures? Hydrocephelus? Shunt?
- Explain Hemianopsia to me? Will my child have that after surgery? What does that mean to her vision?
- In PICU, Do you ensure that the head is hemispherectomy-side up until enough time has passed that the cavity has filled with cerebrospinal fluid? Only then moving the head to midline. (face up) Is it important?
- Can you tell me the difference in how you would approach a hemispherectomy for a child with this disease versus a child with Hemimegalencephaly (HME), Sturge-Weber Syndrome, Rasmussen’s Syndrome, Stroke, Other? If any.
- There are no guarantees, but how long would you guess that my child would stay in PICU if all goes well? Regular Room? In-patient Rehab?
- Will my child be dazed, non-emotional the first several days after surgery? How long can this last?
- Memory Loss? Cognitive Loss? Personality Loss?
- Explain Hemiplegia? Will my child be hemiplegic right after surgery? Will those muscles wake up, but be permanently weak? Does that include torso muscles, swallowing muscles, lips, tongue, etc?
- Explain Hemiparesis? Is this permanent?
- What are other possible complications of surgery?
How to Choose a Hemi Center
Read Testimonials from Parents About Hospitals and the Physicians Who Performed Hemispherectomies. Testimonials have been provided by our members who have volunteered to share their firsthand experience with hemispherectomy surgery.