MRI-guided laser surgery yields less invasive epilepsy treatment

July 28, 2011
Able to destroy lesions in the brain that cause epilepsy and uncontrollable seizures, real-time, magnetic resonance imaging (MRI)-guided thermal imaging and laser surgery offers a safer and less invasive surgical treatment.

Able to destroy lesions in the brain that cause epilepsy and uncontrollable seizures, real-time, magnetic resonance imaging (MRI)-guided thermal imaging and laser surgery offers a safer and less invasive surgical treatment. Texas Children’s Hospital (Houston, TX) is the first hospital in the world to use the technique, which can be particularly life-changing for high-risk patients with deep brain lesions because the MRI-guided laser probe, inserted through a 3.2 mm hole in the skull, uses a much smaller pathway through the brain to reach a deep lesion, reducing the risk of complications related to contact with surrounding brain tissue.

The surgery is performed by first mapping the area of the brain where the lesion is located using MRI. Then, the catheter is inserted through the skull in the operating room and the patient is transferred to an MRI unit, where the ablation of the lesion is performed. The MRI confirms probe placement in the target, and the magnetic resonance thermal imaging allows the surgeon to see the ablation of the lesion by the laser heat as it happens with an automatic feedback system that shuts the laser off when the heat approaches nearby critical brain structures.

Angus Wilfong, director of Texas Children’s comprehensive epilepsy program and associate professor of pediatrics and neurology at Baylor College of Medicine, notes that MRI-guided laser surgery has been successfully used in treating brain tumors and that he and Daniel Curry, Texas Children’s director of pediatric surgical epilepsy and functional neurosurgery and assistant professor of neurological surgery at Baylor College, saw that its same attributes would apply to deep seated epilepsy-causing lesions. The neurologist and neurosurgeon introduced a first-of-its-kind trial of the treatment to pediatric epilepsy patients at the Blue Bird Circle Clinic for Pediatric Neurology at Texas Children’s Hospital.

A recent example of the effectiveness of this new surgery is Texas Children’s Hospital patient Keagan Dysart, 9, of Converse, TX, who suffered from two types of epileptic seizures when he was diagnosed with a hypothalamic hamartoma in his brain. The gelastic seizure caused him to giggle and laugh uncontrollably two or three times an hour. Keagan would also periodically experience a tonic seizure, with generalized body stiffening and loss of awareness that caused him to fall asleep for sometimes up to an hour afterward. Keagan’s case was particularly high-risk because his lesion was located in the hypothalamus, near the brain stem. In this highly sensitive region, there are a myriad of potential, serious complications from surgery, including loss of sight, damage to the pituitary gland, stroke from artery damage, or development of diabetes insipidus (DI), a potentially fatal condition where the kidneys are unable to conserve water because of disruption to the area of the brain that releases the body’s anti-diuretic hormone.

The location, size and complexity of Keagan’s brain lesion made him an ideal candidate for the new surgical procedure, which was successfully performed in March without any surgical complications. He is now seizure-free.

Five surgeries using this MRI-guided laser procedure have been successfully performed to date at Texas Children’s Hospital on pediatric epilepsy patients ranging in age from five to 15 years old, with widely varied types of brain lesions. In all cases, patients have been seizure-free since surgery and most were released within one to five days.


Posted by Lee Mather

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