Technical NoteStereotactic Radiofrequency Thermocoagulation of Hypothalamic Hamartoma Using Robotic Guidance (ROSA) Coregistered with O-arm Guidance—Preliminary Technical Note
Introduction
Gelastic seizures (GSs) are the typical semiology of hypothalamic hamartomas (HH). The available treatment options for HH include microscopic surgery (MS),1, 2 endoscopic disconnection (ED),3 stereotactic radiofrequency thermocoagulation (SRT),4, 5 laser interstitial thermal therapy (LITT),6, 7 and Gamma Knife surgery (GKS).8, 9 MS and ED are invasive and involve dissection around critical structures. Higher rates of complications have been reported for MS, and this procedure is rarely performed currently.5 GKS is not a suitable option for big hamartomas. Minimally invasive SRT and LITT have been shown to be effective alternatives to MS.5, 10 LITT requires intraoperative magnetic resonance imaging (MRI) thermographic imaging, which is not readily available at many centers across the world. In addition, it involves disposable laser electrodes, which are expensive, especially for countries with financial constraints. SRT for HHs has also been shown to be an effective treatment option.5, 11, 12, 13 We used robotic guidance (ROSA, Medtech, Montpellier, France, approved by the U.S. Food and Drug Administration) for stereotactic placement of the SRT electrode. Intraoperative computed tomography was acquired using O-arm (Medtronic Inc., Minneapolis, Minnesota) and merged with preoperative MRI, showing superimposed electrode and preoperative trajectory. Accurate placement of an electrode using a robot and its intraoperative validation improves the safety profile of this procedure. Use of these technologic adjuncts (ROSA and O-arm) are being reported for the first time in this case series.
Section snippets
Material and Methods
Five patients with HHs, aged 6 months to 13 years, presented with GS ± behavioral disorder (BD), precocious puberty (PP), and delayed milestones. Seizures were refractory to antiepileptic drugs. We performed MRI T1, T2, 2-FLAIR and contrast-enhanced MRI in 1-mm slices, 0-gap, 1-mm increment, and square matrix in all patients. SRT was performed under robotic (ROSA) and O-arm guidance. A proper, informed consent was taken for each patient, as per our institutional policy. Ethics committee
Technical Note
Preoperative volumetric sequences of contrast-enhanced MRI and CT were done. T1 weighted and flair-based MRI sequences were merged with contrast CT scan using ROSA planning software to generate a composite image. Trajectory planning was performed on ROSA console. Multiple trajectories were drawn in such a way that once ablation is complete, hamartoma's interface with hypothalamus is sufficiently disconnected. The first lesion was done at the interface and subsequent lesions at 5-mm intervals
Results
We operated on 5 male patients, with age ranging from 6 months to 13 years. Patients' demographic data, clinical data, surgical data, outcome, and follow-up data are shown in Table 1. The duration of epilepsy ranged from 5.5 months to 7 years. Video electroencephalography (EEG) in all cases were nonlocalizing and widespread. Video EEG was performed to confirm that these were true seizures. MRI revealed hypothalamic hamartoma of mean size 3.56 ± 2.88 cm3 (all type III as per Regis
Discussion
HH is an intrinsically epileptogenic lesion causing intractable epilepsy, characterized by GS. Though most commonly occurring in the hypothalamic area, it may also occur in other areas like the cerebellum to cause epilepsy.15 Cognitive impairment and behavioral disorders can also occur due to epileptic encephalopathy.16, 17, 18 These can improve with timely surgical intervention.19, 20 These include MS (pterional, transcallosal, or orbitofrontal approaches),21, 22 ED,23 GKS,24, 25 SRT, and LITT,
Conclusions
SRT electrodes can be placed accurately using robotic assistance and seem to be safe. Intraoperative validation of an electrode's location by doing intraoperative CT can help in reconfirming the site of the electrode in comparison with a planned trajectory.
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2021, Journal of the Neurological SciencesCitation Excerpt :Notably, Wang et al. [18] did not report whether the partial seizures experienced by their single patient were simple or complex. Only five articles described seizure frequency [11,18–20,22]. The most common associated symptoms were intellectual disabilities (79/176, 44.9%), behavioral disorders (83/176, 47.2%), and precocious puberty (72/176, 40.9%).
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2021, Epilepsy and BehaviorCitation Excerpt :Encouraging results have been achieved in RFTC, including gray-matter nodular heterotopy [19], focal cortical dysplasia [20], and mesial temporal lobe epilepsy [21]. So far, only sixteen studies [5,6,22–35] reported successful application of this technique for HH. Most of the cases were from the same center.
Surgical techniques: Stereoelectroencephalography-guided radiofrequency-thermocoagulation (SEEG-guided RF-TC)
2020, SeizureCitation Excerpt :Moreover, the good results obtained by surgery and radiosurgery [48], the better volume control of LiTT, and the difficulty to perform a meaningful functional mapping in this area makes it harder to justify SEEG-guided RF-TC in this condition. When economic constraints limit the access to the reference techniques, standard monopolar RF-TC remain an option [49]. The last very empirical and restricted indication is the use of SEEG-guided RF-TC as a diagnostic tool when multiple hypotheses are difficult to differentiate during a SEEG.
Improvement of Hypothalamic Hamartoma-Related Psychiatric Disorder After Stereotactic Laser Ablation: Case Report and Review of Literature
2019, World NeurosurgeryCitation Excerpt :With this in mind, less invasive modalities such as SRS, SRT, and SLA therapy are increasingly being used in the treatment of HHs. SRS has the benefit of being noninvasive; however, it is not a viable option for larger or giant lesions, it carries an initial increase in the risk of seizures, the desired effects may be delayed up to 1−2 years post treatment, and potential radiation-induced injury limits the treatment doses.17,18 SRT and SLA therapy have been shown to be safe and effective methods for ablation and/or disconnection of deep-seated lesions such as HHs.
Radiofrequency Thermocoagulation in Refractory Focal Epilepsy: The Montreal Neurological Institute Experience
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