Removing “What Ifs” Around Pediatric Epilepsy and Tumors like Hypothalamic Hamartoma (HH)

What if there was a possible surgical cure for pediatric epilepsy in kids whose seizures are not controlled through medication? And what if that surgery was significantly less invasive, reduced the risk of infection and shortened the recovery time from weeks to mere days, or even allowing a child to go home the day after the procedure?

Well, there’s no more “what ifs” here at Barrow Neurological Institute at Phoenix Children’s.

It is laser ablation surgery and it’s the latest advancement in the treatment of pediatric epilepsy. In fact, Phoenix Children's is the only pediatric hospital in Arizona and the Southwest, and one of only a handful of centers in the country, offering laser ablation for pediatric epilepsy and brain tumors.

Laser ablation removes tumors and other lesions through the use of light to heat and destroy unwanted cells. Historically, doctors have used laser ablation to treat conditions in other parts of the body, but thanks to recent advances, neurosurgeons are now using this treatment in the brain. With new technology from Visualase/Medtronic, doctors use MRI (magnetic resonance imaging) to first place a thin laser probe in the brain and then watch as they perform the laser ablation surgery. On high resolution monitors, they see precisely what area is being heated and how much, making this treatment pinpoint within millimeters accurate.

The Procedure

For laser ablation surgery, your child is placed under general anesthesia and will not feel any pain and will not move, which is important for the treatment to be precise.

A frame is then placed around your child's head to help increase the accuracy that the surgeon needs to insert a probe in the best place to treat the lesion. An MRI is obtained to get the most recent and accurate coordinates of the lesion and define the optimal approach to the lesion. The surgeon makes a small incision (~3 millimeters) in the scalp. The small entry point means most patients have little or no hair removed. The surgeon then makes a small hole the same size in the skull and inserts the probe.

The probe is a thin, flexible tube about as wide as a pencil lead. It holds clear fibers that emit the laser light in a precise manner. The probe’s pathway made through your child’s brain is very narrow and is much less likely to cause damage that could affect how your child's brain works.

After probe insertion, the surgical team moves your child into the MRI scanner. Using the MRI display, the surgeon confirms the precise placement of the tip of the probe in the brain. MRI guidance allows surgeons to position the probe in the exact spot within a millimeter tolerance applying heat only to the lesion and protecting healthy surrounding tissue.

The surgeon then turns on the laser. Light comes out of the tip of the probe and the monitors show precisely where and how warm the tissue is getting. From this, the surgeon can judge how much laser treatment is needed to treat the lesion and prevent spread to surrounding healthy tissue.

When the laser treatment is complete, the surgeon removes the probe and closes the incision typically with a one-stitch suture. Amazingly, the treatment itself, when the laser is on, takes only a few minutes. The careful set-up and mapping the pathway to the affected area before treatment though takes longer. The total time under anesthesia is about four hours.

There are three key advantages to the precision of laser ablation surgery at Barrow Neurological Institute at Phoenix Children’s:

  1. As one of the few center’s in the world with the capacity to provide resting-state MRI to target an epileptic focus, we have unmatched precision in identifying the affected area to treat and broaden the indications for its use
  2. Precision in mapping the best possible pathway to the lesion to minimize contact with healthy parts of the brain
  3. Precision in treating the actual lesion as the laser heats only the targeted area, significantly reducing negative impacts on brain functions (vision, movement, memory, language, learning, etc.)

Precision Perfect

It’s that precision that makes this type of surgery perfect for treating hypothalamic hamartomas - rare, benign tumors of the hypothalamus, a region of the brain that regulates many critical functions.

Hypothalamic hamartomas affect children from infancy onward and commonly cause seizures, precocious puberty, abnormalities in endocrine function and cognitive and behavioral problems. These tumors are most often found during the diagnostic evaluation of patients for epilepsy (particularly gelastic seizures) or precocious puberty.

As a rare and challenging disease, we believe that hypothalamic hamartoma patients are best evaluated and treated in centers like ours that specialize in this condition.

Multidisciplinary Team Provides Treatment for Hypothalamic Hamartoma

Our Hypothalamic Hamartoma Program is made up of a multidisciplinary team designed to provide comprehensive evaluation, diagnostic testing and definitive treatment for patients with hypothalamic hamartoma tumors, including laser ablation surgery.

Our mission is to serve as a resource to the hypothalamic hamartoma community of patients and families throughout the world. We accomplish this goal by offering definitive treatment and education, and conducting research to benefit the hypothalamic hamartoma patients of the future. Most recently, our own John “Jack” Kerrigan, MD, co-director of our HH Program co-authored an article in Epilepsia, The Journal of the International League Against Epilepsy on the quest to cure hypothalamic hamartoma.

In summary, like all surgery, laser ablation is not without some risks, such as the risk of infection. Also, there may be some chance of affecting a healthy part of the brain. This depends, in part, on where the tumor or lesion is located. Our team will talk with you about the risks for your child.

Also because it is less invasive, the results can also vary. About half of patients with epilepsy become seizure-free, sometimes within a week. This is almost the same success rate as with open surgery, but with less risk. Some patients still have seizures, but they are less severe or happen less often. It could take up to a year to know the full results because the brain requires time to heal after surgery.

Additionally, children who have undergone laser ablation surgery may still have open surgery at a later date if laser ablation surgery failed to cure their lesion.

To learn more about laser ablation surgery, Hypothalamic Hamartoma and our Services contact:

Maggie Bobrowitz, RN
Phone: (602) 406-7585

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