Note: This information is intended to provide general information about the Hypothalamic Hamartoma disease process and the treatment available at Barrow Neurological Institute. This information is not intended to be used for treatment of an emergent condition requiring immediate attention.
1. What is a craniotomy and is it considered major brain surgery?
A craniotomy is an opening made into the skull to reach the brain for a variety of conditions, including resection and removal of a lesion.
It is a major operation associated with significant risks. A craniotomy should not be performed unless the patient's quality of life is significantly affected by seizures and behavioral concerns. All of the patients whom we have treated have been in critical situations. After treatment they improved with various degrees of success.
2. How long does the surgery take? What should I expect after surgery and the subsequent days in the hospital?
The patient treatment timetable can be found under Patient Resources/General Patient Information and can give an idea of what to expect on a day-to-day basis. Remember, however, that each patient is unique and is treated individually.
Various surgical approaches have been identified as treatment options for this disease. The specific approach depends on the size and exact location of the lesion. Open procedures are standard craniotomies and include the transcallosal, orbitozygomatic, and combined eyebrow approaches. These procedures usually take 4 to 6 hours. An incision is made near the top of the head behind the hairline. The length of the incision depends on the specific approach used. Bone is removed for surgery and replaced at the end of the procedure with titanium plates and screws. The plate and screws should not interfere with metal detectors or future MRI studies. The imaging facility, however, should be advised that these implants are in place before the patient undergoes a scan.
The closed procedure, otherwise known as the endoscopic approach, is appropriate if the lesion is small to moderate and located within the third ventricle. This approach reduces the risk of short-term memory loss and other complications associated with the open procedure. So little bone is removed that it is not replaced at the end of the procedure. Typically, the bone regrows within 6 weeks. This approach not only lessens the surgical time but also reduces the length of the patient's hospital stay to about 5 days.
The surgeons use a microscope or endoscope (depending on the approach) and a computerized guidance system to navigate between vital structures surrounding the HH lesion at the base of the brain. The hamartoma is a different color from the rest of the brain, and its tissue is slightly softer than brain tissue. The surgeons try to remove the entire lesion. Disconnection of the lesion from the hypothalamus, rather than total removal of the lesion, appears to be the key to reducing or eliminating seizures.
Patients seem to follow about the same course of recovery but at different rates. Younger children recover more quickly than older children. They remain sleepy for several days to a week after surgery. Some patients have been able to talk in the recovery room while others may not speak for a week or longer. A breathing tube may remain in place after surgery. The anesthesiologist removes this tube as soon as patients are breathing safely on their own. Once patients are fully awake, they will undergo a neurological assessment and any lingering symptoms will be addressed at that time.
3. What are the complications and side effects?
As with any craniotomy there can be significant complications. The most severe risks are death, hemorrhage, and coma. The most common complications are diabetes insipidus and short-term memory loss. Operating on the hypothalamus is risky because important structures that process short-term memory are nearby. Many patients already have some problems related to short-term memory. Other issues include abnormalities in hormone levels and blood chemistry. Hormone replacement therapy is available to treat such problems.
4. I have heard that weight gain is a complication of this surgery. What should I expect?
Most patients gain some weight the first few months after surgery, but this insatiable appetite usually subsides after a few weeks or at most a few months. Frequent, small, balanced meals throughout the day are recommended.
5. Can you guarantee that the patient will be seizure free after surgery?
There are absolutely no guarantees. Each patient's progress is different after surgery. However, most of our patients have been seizure free or significantly improved after treatment.
6. What are the ages of the patients who have had this surgery at Barrow? Does age affect outcomes after surgery?
Patients treated for this disease have ranged from infants through seniors.
In general, younger children have recovered quickly while recovery in older patients tends to take longer. The problems associated with HH appear to be progressive. Patients do not seem to respond to medication. They may have difficulties with behavior, including emotional outbursts, and in some cases, rage attacks associated with violent behavior. Usually the frequency of seizures decreases right away, but the behavioral problems may require additional therapy in the patient's local area.
7. How long has Barrow offered treatment for HH?
We have been performing this surgery since February 2003, when Dr. Rosenfeld came to teach us his specific modifications of an existing procedure.
8. Will the patient be asleep for the MRI before surgery?
If the patient requires more than light sedation to tolerate the MRI test performed before surgery, arrangements will be made to have the neuroanesthesiologist anesthetize him/her.
9. Should we obtain a new MRI before we contact your team for a current view of the lesion?
A hamartoma is considered a lesion, not a tumor, and it does not grow independently of the brain. The quality of the MRI is the most important concern. The type of MRI necessary to evaluate this lesion is a noncontrasted 1.5-Tesla scan although many patients have undergone a 3-Tesla scan. A skilled radiologist is of greater importance than obtaining a stronger MRI scan.
Learn more about magnetic resonance imaging at Barrow Neurological Institute.
10. What happens if the patient has a vagal nerve stimulator in place before surgery? Does it need to be addressed?
If the patient has a vagal nerve stimulator, it will be turned off before all radiographic studies (MRI) and surgeries. The stimulator can interfere with the test results of the MRI, and the facility providing treatment should be informed of its existence. After surgical treatment, the stimulator may be turned back on at the discretion of the team neurologist.