BACKGROUND: Open surgery effectively treats mesial temporal lobe epilepsy, but carries the risk of neurocognitive deficits, which may be reduced with minimally invasive alternatives.
OBJECTIVE: To describe technical and clinical outcomes of stereotactic laser amygdalohippocampotomy with real-time magnetic resonance thermal imaging guidance.
METHODS: With patients under general anesthesia and using standard stereotactic methods, 13 adult patients with intractable mesial temporal lobe epilepsy (with and without mesial temporal sclerosis [MTS]) prospectively underwent insertion of a saline-cooled fiberoptic laser applicator in amygdalohippocampal structures from an occipital trajectory. Computer-controlled laser ablation was performed during continuous magnetic resonance thermal imaging followed by confirmatory contrast-enhanced anatomic imaging and volumetric reconstruction. Clinical outcomes were determined from seizure diaries.
RESULTS: A mean 60% volume of the amygdalohippocampal complex was ablated in 13 patients (9 with MTS) undergoing 15 procedures. Median hospitalization was 1 day. With follow-up ranging from 5 to 26 months (median, 14 months), 77% (10/13) of patients achieved meaningful seizure reduction, of whom 54% (7/13) were free of disabling seizures. Of patients with preoperative MTS, 67% (6/9) achieved seizure freedom. All recurrences were observed before 6 months. Variances in ablation volume and length did not account for individual clinical outcomes. Although no complications of laser therapy itself were observed, 1 significant complication, a visual field defect, resulted from deviated insertion of a stereotactic aligning rod, which was corrected before ablation.
CONCLUSION: Real-time magnetic resonance-guided stereotactic laser amygdalohippocampotomy is a technically novel, safe, and effective alternative to open surgery. Further evaluation with larger cohorts over time is warranted.
ABBREVIATIONS: AHC, amygdalohippocampal complex
ATLAH, anterior temporal lobectomy with amygdalohippocampectomy
DWI, diffusion-weighted imaging
FDA, Food and Drug Administration
FLAIR, fluid-attenuated inversion recovery
MRTI, magnetic resonance thermal imaging
MTLE, mesial temporal lobe epilepsy
MTS, mesial temporal sclerosis
SAH, selective amygdalohippocampectomy
SLAH, stereotactic laser amygdalohippocampotomy
SRS, stereotactic radiosurgery
Departments of *Neurosurgery,
¶Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia;
‖Interventional MRI Program, Emory University Hospital, Atlanta, Georgia;
#Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia;
**Department of Neurology, University of Washington School of Medicine, Seattle, Washington;
††Visualase, Inc., Houston, Texas
Correspondence: Robert E. Gross, MD, PhD, Department of Neurosurgery, Emory University School of Medicine, 1365 Clifton Road, NE, Suite 6200, Atlanta, GA 30322. E-mail: firstname.lastname@example.org
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Received August 31, 2013
Accepted February 18, 2014