Neurological surgery offers an opportunity to study brain functions, through either resection or implanted neuromodulation devices. Pathological aggressive behavior in patients with intellectual disability is a frequent condition that is difficult to treat using either supportive care or pharmacological therapy. The bulk of the laboratory studies performed throughout the 19th century enabled the formulation of hypotheses on brain circuits involved in the generation of emotions. Aggressive behavior was also studied extensively. Lesional radiofrequency surgery of the posterior hypothalamus, which peaked in the 1970s, was shown to be an effective therapy in many reported series. As with other surgical procedures for the treatment of psychiatric disorders, however, this therapy was abandoned for many reasons, including the risk of its misuse. Deep brain stimulation (DBS) offers the possibility of treating neurological and psychoaffective disorders through relatively reversible and adaptable therapy. Deep brain stimulation of the posterior hypothalamus was proposed and performed successfully in 2005 as a treatment for aggressive behavior. Other groups reported positive outcomes using target and parameter settings similar to those of the original study. Both the lesional and DBS approaches enabled researchers to explore the role of the posterior hypothalamus (or posterior hypothalamic area) in the autonomic and emotional systems.
Michele Rizzi, Andrea Trezza, Giuseppe Messina, Alessandro De Benedictis, Angelo Franzini and Carlo Efisio Marras
Carlo Efisio Marras, Michele Rizzi, Flavio Villani, Giuseppe Messina, Francesco Deleo, Roberto Cordella and Angelo Franzini
Hypothalamic hamartomas (HHs) are developmental malformations associated with a range of neurological problems, including intractable seizures. There is increasing evidence of the epileptogenicity of the hamartoma and of the inhomogeneous distribution of the epileptic abnormalities within the malformation. The management strategy for treatment and results differ according to the insertion plane and the extension of the malformation into the hypothalamus. Cases characterized by extensive involvement of the hypothalamus are particularly challenging.
The authors describe the case of a patient with drug-resistant epilepsy and a large hypothalamic hamartoma with an extensive area of attachment. The patient underwent implantation of 2 deep brain electrodes. The intraoperative recording showed a synchronous interictal epileptic discharge in the left temporal lobe and on the left side of the lesion. The patient was treated with chronic high-frequency stimulation. No side effects due to the stimulation were reported. At 18 months' follow-up, a reduction in complex partial seizure frequency was reported, but no significant reduction in overall seizure frequency was noticed (p = 0.14, t-test).
The authors report on neurophysiological studies of the relationship between HH and epilepsy, and also discuss the literature on chronic high-frequency stimulation, including its rationale and the results of chronic stimulation of various targets for the treatment of drug-resistant epilepsy due to HH.
Francesco Cardinale, Michele Rizzi, Piergiorgio d’Orio, Giuseppe Casaceli, Gabriele Arnulfo, Massimo Narizzano, Davide Scorza, Elena De Momi, Michele Nichelatti, Daniela Redaelli, Maurizio Sberna, Alessio Moscato and Laura Castana
The purpose of this study was to compare the accuracy of Neurolocate frameless registration system and frame-based registration for robotic stereoelectroencephalography (SEEG).
The authors performed a 40-trajectory phantom laboratory study and a 127-trajectory retrospective analysis of a surgical series. The laboratory study was aimed at testing the noninferiority of the Neurolocate system. The analysis of the surgical series compared Neurolocate-based SEEG implantations with a frame-based historical control group.
The mean localization errors (LE) ± standard deviations (SD) for Neurolocate-based and frame-based trajectories were 0.67 ± 0.29 mm and 0.76 ± 0.34 mm, respectively, in the phantom study (p = 0.35). The median entry point LE was 0.59 mm (interquartile range [IQR] 0.25–0.88 mm) for Neurolocate-registration–based trajectories and 0.78 mm (IQR 0.49–1.08 mm) for frame-registration–based trajectories (p = 0.00002) in the clinical study. The median target point LE was 1.49 mm (IQR 1.06–2.4 mm) for Neurolocate-registration–based trajectories and 1.77 mm (IQR 1.25–2.5 mm) for frame-registration–based trajectories in the clinical study. All the surgical procedures were successful and uneventful.
The results of the phantom study demonstrate the noninferiority of Neurolocate frameless registration. The results of the retrospective surgical series analysis suggest that Neurolocate-based procedures can be more accurate than the frame-based ones. The safety profile of Neurolocate-based registration should be similar to that of frame-based registration. The Neurolocate system is comfortable, noninvasive, easy to use, and potentially faster than other registration devices.
Alessandro De Benedictis, Andrea Trezza, Andrea Carai, Elisabetta Genovese, Emidio Procaccini, Raffaella Messina, Franco Randi, Silvia Cossu, Giacomo Esposito, Paolo Palma, Paolina Amante, Michele Rizzi and Carlo Efisio Marras
During the last 3 decades, robotic technology has rapidly spread across several surgical fields due to the continuous evolution of its versatility, stability, dexterity, and haptic properties. Neurosurgery pioneered the development of robotics, with the aim of improving the quality of several procedures requiring a high degree of accuracy and safety. Moreover, robot-guided approaches are of special interest in pediatric patients, who often have altered anatomy and challenging relationships between the diseased and eloquent structures. Nevertheless, the use of robots has been rarely reported in children. In this work, the authors describe their experience using the ROSA device (Robotized Stereotactic Assistant) in the neurosurgical management of a pediatric population.
Between 2011 and 2016, 116 children underwent ROSA-assisted procedures for a variety of diseases (epilepsy, brain tumors, intra- or extraventricular and tumor cysts, obstructive hydrocephalus, and movement and behavioral disorders). Each patient received accurate preoperative planning of optimal trajectories, intraoperative frameless registration, surgical treatment using specific instruments held by the robotic arm, and postoperative CT or MR imaging.
The authors performed 128 consecutive surgeries, including implantation of 386 electrodes for stereo-electroencephalography (36 procedures), neuroendoscopy (42 procedures), stereotactic biopsy (26 procedures), pallidotomy (12 procedures), shunt placement (6 procedures), deep brain stimulation procedures (3 procedures), and stereotactic cyst aspiration (3 procedures). For each procedure, the authors analyzed and discussed accuracy, timing, and complications.
To the best their knowledge, the authors present the largest reported series of pediatric neurosurgical cases assisted by robotic support. The ROSA system provided improved safety and feasibility of minimally invasive approaches, thus optimizing the surgical result, while minimizing postoperative morbidity.
Michele Rizzi, Martina Revay, Piergiorgio d’Orio, Pina Scarpa, Valeria Mariani, Veronica Pelliccia, Martina Della Costanza, Matteo Zaniboni, Laura Castana, Francesco Cardinale, Giorgio Lo Russo and Massimo Cossu
Surgical treatment of drug-resistant epilepsy originating from the posterior quadrant (PQ) of the brain often requires large multilobar resections, and disconnective techniques have been advocated to limit the risks associated with extensive tissue removal. Few previous studies have described a tailored temporoparietooccipital (TPO) disconnective approach; only small series with short postoperative follow-ups have been reported. The aim of the present study was to present a tailored approach to multilobar PQ disconnections (MPQDs) for epilepsy and to provide details about selection of patients, presurgical investigations, surgical technique, treatment safety profile, and seizure and cognitive outcome in a large, single-center series of patients with a long-term follow-up.
In this retrospective longitudinal study, the authors searched their prospectively collected database for patients who underwent MPQD for drug-resistant epilepsy in the period of 2005–2017. Tailored MPQDs were a posteriori grouped as follows: type I (classic full TPO disconnection), type II (partial TPO disconnection), type III (full temporooccipital [TO] disconnection), and type IV (partial TO disconnection), according to the disconnection plane in the occipitoparietal area. A bivariate statistical analysis was carried out to identify possible predictors of seizure outcome (Engel class I vs classes II–IV) among several presurgical, surgical, and postsurgical variables. Preoperative and postoperative cognitive profiles were also collected and evaluated.
Forty-two consecutive patients (29 males, 24 children) met the inclusion criteria. According to the presurgical evaluation (including stereo-electroencephalography in 13 cases), 12 (28.6%), 24 (57.1%), 2 (4.8%), and 4 (9.5%) patients received a type I, II, III, or IV MPQD, respectively. After a mean follow-up of 80.6 months, 76.2% patients were in Engel class I at last contact; at 6 months and 2 and 5 years postoperatively, Engel class I was recorded in 80.9%, 74.5%, and 73.5% of cases, respectively. Factors significantly associated with seizure freedom were the occipital pattern of seizure semiology and the absence of bilateral interictal epileptiform abnormalities at the EEG (p = 0.02). Severe complications occurred in 4.8% of the patients. The available neuropsychological data revealed postsurgical improvement in verbal domains, whereas nonunivocal outcomes were recorded in the other functions.
The presented data indicate that the use of careful anatomo-electro-clinical criteria in the presurgical evaluation allows for customizing the extent of surgical disconnections in PQ epilepsies, with excellent results on seizures and an acceptable safety profile.
Roman Rodionov, Aidan O’Keeffe, Mark Nowell, Michele Rizzi, Vejay N. Vakharia, Victoria Wykes, Sofia H. Eriksson, Anna Miserocchi, Andrew W. McEvoy, Sebastien Ourselin and John S. Duncan
The accuracy of stereoelectroencephalography (SEEG) electrode implantation is an important factor in maximizing its safety. The authors established a quality assurance (QA) process to aid advances in implantation accuracy.
The accuracy of three consecutive modifications of a frameless implantation technique was quantified in three cohorts comprising 22, 8, and 23 consecutive patients. The modifications of the technique aimed to increase accuracy of the bolt placement.
The lateral shift of the axis of the implanted bolt at the level of the planned entry point was reduced from a mean of 3.0 ± 1.6 mm to 1.4 ± 0.8 mm. The lateral shift of the axis of the implanted bolt at the level of the planned target point was reduced from a mean of 3.8 ± 2.5 mm to 1.6 ± 0.9 mm.
This QA framework helped to isolate and quantify the factors introducing inaccuracy in SEEG implantation, and to monitor ongoing accuracy and the effect of technique modifications.