Summary Objectives The aim of this study was to analyze the impact of deep brain stimulation (DBS) of the posteromedial hypothalamus (pHyp) on seizure frequency in patients with drug‐resistant epilepsy (DRE) associated with intractable aggressive behavior (IAB). Methods Data were collected retrospectively from nine patients, who received bilateral stereotactic pHyp‐DBS for the treatment of medically intractable aggressive behavior, focusing on five patients who also had DRE. All patients were treated at the Colombian Center and Foundation of Epilepsy and Neurological Diseases—FIRE (Chapter of the International Bureau for Epilepsy), in Cartagena de Indias, Colombia from 2010 to 2014. Each case was evaluated previously by the institutional ethical committee, assessing the impact of aggressive behavior on the patient's family and social life, the humanitarian aspects of preserving the safety and physical integrity of caregivers, and the need to prevent self‐harm. Epilepsy improvement was measured by a monthly seizure reduction percentage, comparing preoperative state and outcome. Additional response to epilepsy was defined by reduction of the antiepileptic drugs (AEDs). Aggressive behavior response was measured using the Overt Aggression Scale (OAS). Results All the patients with DRE associated with IAB presented a significant decrease of the rate of epileptic seizures after up to 4 years follow‐up, achieving a general 89.6% average seizure reduction from the state before the surgery. Aggressiveness was significantly controlled, with evident improvement in the OAS, enhancing the quality of life of patients and families. Significance In well‐selected patients, DBS of the pHyp seems to be a safe and effective procedure for treatment of DRE associated with refractory aggressive behavior. Larger and prospective series are needed to define the pHyp as a target for DRE in different contexts.

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Childhood meningiomas are uncommon lesions with a slight male predominance. Absence of large series with long follow-up precludes any definite conclusions on the clinical course and outcome of these tumors. Associated factors (such as RT and NF2), location, and extent of excision appear to be more important than histopathological grade in predicting outcome.

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Holmes tremor (HT) is a difficult-to-treat, very disabling symptomatic condition which characteristically appears weeks to years after a brain lesion. It features a unique combination of rest, action, and postural tremors. Pharmacotherapy is mostly not effective. Chronic deep brain stimulation (DBS) of ventralis intermedius nucleus (Vim) of thalamus has been described as being the best surgical approach in singular case series; various authors observe, however, cases with partial responses only; therefore, alternatives are still needed. We report ten patients with HT unresponsive to best medical therapy who underwent DBS in our center from March 2002 to June 2012. Based in our previous experience dealing with cases of unsatisfactory Vim intraoperative tremor control and in order to optimize surgical results, presurgical target planning included two Nuclei: Vim and posteroventral Globus pallidus internus (GPi) (Espinoza et al. 2010; Espinoza et al. Stereotact Funct Neurosurg 90(suppl 1):1-202, p 61, 2012). Definitive chosen target was decided after single-cell microelectrode recording, intraoperative test stimulation, thresholds for stimulation-induced adverse effects and best clinical response compared to baseline status. Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) was used to evaluate outcome. The electrode was implanted in the nucleus with the best tremor suppression achievement; on the other hand, GPi DBS was initially decided if one of the following conditions was present: (a) If Vim nucleus anatomy was grossly altered; (b) when intraoperative tremor control was unsatisfactory despite Vim high-intensity stimulation; or (c) if unaffordable side effects or even tremor worsening occurred during intraoperative macrostimulation. Seven patients received definitive Gpi DBS implantation, while three patients received Vim DBS. In all observed cases, we observed an improvement on the TRS. In two cases where Vim thalamic anatomy was altered by the pathological insult GPI was planned from the beginning, and same was true in two additional cases where the Gpi nucleus showed major alterations allowing only Vim planning. Over all cases, the average improvement in tremor was of 2.55 points on the TRS or a 64 % increase in measured results; with a minimum of 1 point (25 %) improvement in one case and a maximum of 4 points (100 % improvement) also in one case. All the results were sustained at 2 years follow-up. One case with predominant resting component, implanted in the GPi, achieved the maximum possible tremor reduction (from 4 to 0 points, meaning 100 % tremor reduction); in the nine resting cases, the average reduction was of 3 points (or 75 %). DBS demonstrated in this case series adequate tremor control in 10 patients unresponsive to medical therapy. Presurgical planning of two targets allowed choosing best optimal response. Gpi stimulation could be considered as an alternative target for cases in which thalamic anatomy is considerably altered or Vim intraoperative stimulation does not produce satisfactory results.

DBS of the medial forebrain bundle (MFB) has been investigated clinically in major depressive disorder patients with rapid and long-term reduction of symptoms. In the context of chronic bilateral high frequency deep brain stimulation (DBS) of the MFB, the current study looked at the impact of lesioning the ascending dopaminergic pathway at the level of the ventral tegmental area (VTA). Sprague-Dawley female rats were given bilateral injection of 6-OHDA into the VTA (VTA-lx group) or were left unlesioned (control group). Later, all animals received bilateral microelectrode implantation into the MFB followed by chronic continuous stimulation for 3 weeks. Behavioral tests were performed as baseline and following MFB-DBS, along with histological analysis. Pre-stimulation baseline testing of the VTA-lx animals indicated depressive-like phenotype in comparison with controls. Response to MFB-DBS varied according to (i) the degree of dopaminergic depletion: animals with severe mesocorticolimbic dopamine depletion did not, whilst those with mild dopamine loss responded well to stimulation; (ii) environmental conditions and the nature of the behavioral tests, e.g., stressful vs non-stressful situations. Neuromodulation-induced c-fos expression in the prelimbic frontal cortex and nucleus accumbens was also dependent upon integrity of the dopaminergic ascending projections. Our results confirm a potential role for dopamine in symptom relief observed in clinical MFB-DBS. Although mechanisms are not fully understood, the data suggests that the rescue of depressive phenotype in rodents can work via both dopamine-dependent and independent mechanisms. Further investigations concerning the network of depression using neuromodulation platforms in animal models might give insight into genesis and treatment of major depression disorder.

Objective: The treatment of hydrocephalus in children with endoscopic third ventriculostomy (ETV) has particular features and is associated with different success rates (SR). The aim of this study was to identify putative factors that could influence the outcome of ETV in children. Methods: Clinical data of 114 consecutive patients under 18 years of age who underwent 116 consecutive ETVs from January 2000 to January 2010 were reviewed. Data were analyzed with regards to clinical and radiological SR. The actual long-term SR was compared to that predicted by the ETV Success Score (ETVSS) model. Results: The study group included 49 males (43%) and 65 females (57%) with a mean age of 6.17 ± 1.02 years (ranging from 11 days to 18 years) at surgery. Concerning the etiology of hydrocephalus, tumors and aqueductal stenosis (AS) were the most frequently observed, with each occurring in 33 cases (29%), followed by malformations in 24 (21%), cystic lesions in 6 (5%) and other etiologies in 18 patients (16%). The overall SR at the first ETV attempt was 80% (91/114), compared to 74.8% (variance 14.35, 95% CI 69.37-78.22) predicted by the ETVSS. Regarding age, SR was 58% in patients under 6 months of age, 65% in children between 6 months and 1 year, and 86% in children older than 1 year. SR for AS and hydrocephalus associated with posterior fossa tumors were 88 and 90%, respectively. Unsatisfactory results were related to previous intraventricular hemorrhage and infection. The overall complication rate in this series was 13%. Conclusion: ETV is safe and effective in children. In this series, the age of the patient and etiology of hydrocephalus were related to SR. Also, the ETVSS was accurate to predict outcome. In a long-term follow-up, surgical experience was statistically significant in reducing complications.