How technology is driving the landscape of epilepsy surgery

Abstract

This article emphasizes the role of the technological progress in changing the landscape of epilepsy surgery and provides a critical appraisal of robotic applications, laser interstitial thermal therapy, intraoperative imaging, wireless recording, new neuromodulation techniques, and high-intensity focused ultrasound. Specifically, (a) it relativizes the current hype in using robots for stereo-electroencephalography (SEEG) to increase the accuracy of depth electrode placement and save operating time; (b) discusses the drawback of laser interstitial thermal therapy (LITT) when it comes to the need for adequate histopathologic specimen and the fact that the concept of stereotactic disconnection is not new; (c) addresses the ratio between the benefits and expenditure of using intraoperative magnetic resonance imaging (MRI), that is, the high technical and personnel expertise needed that might restrict its use to centers with a high case load, including those unrelated to epilepsy; (d) soberly reviews the advantages, disadvantages, and future potentials of neuromodulation techniques with special emphasis on the differences between closed and open-loop systems; and (e) provides a critical outlook on the clinical implications of focused ultrasound, wireless recording, and multipurpose electrodes that are already on the horizon. This outlook shows that although current ultrasonic systems do have some limitations in delivering the acoustic energy, further advance of this technique may lead to novel treatment paradigms. Furthermore, it highlights that new data streams from multipurpose electrodes and wireless transmission of intracranial recordings will become available soon once some critical developments will be achieved such as electrode fidelity, data processing and storage, heat conduction as well as rechargeable technology. A better understanding of modern epilepsy surgery will help to demystify epilepsy surgery for the patients and the treating physicians and thereby reduce the surgical treatment gap.

Keywords: epilepsy surgery; high-intensity focused ultrasound; intraoperative MRI; laser ablation; neuromodulation; robots.

Figure 1

Illustration of a miniature robotic device used for implantation of depth electrodes with the help of neuronavigation. The head is fixed in a standard head clamp with the reference for the navigation and the robot attached to it via an adapter (for details please refer to reference 10)

Figure 2

Laser interstitial thermal therapy (LITT) procedure. The laser probe is inserted into the targeted area via a fixation bolt using different stereotactic or navigational platforms. The approach for the treatment of a hypothalamic hamartoma is shown

Figure 3

Laser interstitial thermal therapy (LITT) procedure. (A) Axial T2‐weighted and sagittal fluid‐attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) slices depicting left‐sided hippocampal sclerosis. (B) Laser probe inserted via an occipital approach along the long axis of the hippocampus. (C) Early T1 contrast‐enhanced MRI obtained after laser ablation showing the size of the lesion

Figure 4

Intraoperative magnetic resonance imaging (IMRI) in a 17‐month‐old child with multiple tubers. Surface electroencephalography (EEG) suggested a right frontal seizure onset, and seizure semiology was congruent with a frontal focus. Because there were multiple tubers, including bilateral frontal tubers, α‐[11C]‐Methyl‐l‐tryptophan–PET (AMT‐PET) was used to identify the most active tuber. At surgery, the typical rubbery nature of the tuber was found and IMRI documented the complete resection. By the time of this writing, the child was seizure‐free for 8 months and showed marked improvement in neuropsychological development. A, Preoperative MRI showing a large frontobasal tuber. B, AMT‐PET suggesting this tuber was highly epileptogenic. C‐E, IMRI showing complete resection of the lesion

Figure 5

High‐intensity focused ultrasound (HIFU) schematics. This illustration shows the delivery of acoustic energy generated by the HIFU unit to a centrally located area of the brain