A partial loss of effectiveness of deep brain stimulation of the ventral intermediate nucleus of the thalamus (VIM) has been reported in some patients with essential tremor (ET), possibly due to ...habituation to permanent stimulation. This study focused on the evolution of VIM local-field potentials (LFPs) data over time to assess the long-term feasibility of closed-loop therapy based on thalamic activity. We performed recordings of thalamic LFPs in 10 patients with severe ET using the ACTIVA™ PC + S (Medtronic plc.) allowing both recordings and stimulation in the same region. Particular attention was paid to describing the evolution of LFPs over time from 3 to 24 months after surgery when the stimulation was Off. We demonstrated a significant decrease in high-beta LFPs amplitude during movements inducing tremor in comparison to the rest condition 3 months after surgery (1.91 ± 0.89 at rest vs. 1.27 ± 1.37 µV
/Hz during posture/action for N = 8/10 patients; p = 0.010), 12 months after surgery (2.92 ± 1.75 at rest vs. 2.12 ± 1.78 µV
/Hz during posture/action for N = 7/10 patients; p = 0.014) and 24 months after surgery (2.32 ± 0.35 at rest vs 0.75 ± 0.78 µV
/Hz during posture/action for 4/6 patients; p = 0.017). Among the patients who exhibited a significant decrease of high-beta LFP amplitude when stimulation was Off, this phenomenon was observed at least twice during the follow-up. Although the extent of this decrease in high-beta LFPs amplitude during movements inducing tremor may vary over time, this thalamic biomarker of movement could potentially be usable for closed-loop therapy in the long term.
One of the most challenging aspects of the surgical treatment of tuberculum sellae meningioma is to control the involvement of the inferomedial side of the optic nerve, which is not directly ...visualized by an ipsilateral approach and thus requires optic nerve mobilization.
Between 2003 and 2017, 21 consecutive patients were operated on using this approach. The surgical technique is described and the visual outcomes, resection and recurrence rates, and complications are analyzed.
Twenty patients were included, with a median follow-up of 5.6 years. Regarding visual outcomes, among the 19 patients who had a visual impairment before surgery, 14 (74%) improved, 2 were stabilized (10%), and 2 (10%) showed a worsening of the most-compromised optic nerve and 1 (5%) of the less-compromised optic nerve. Gross total resection was achieved in 18 patients (90%) and 1 patient experienced recurrence 10 years after the initial surgery.
This approach allowed lower mobilization of the compromised optic nerve, better preservation of the vascularization of the visual pathways, and direct access to the inferomedial side of the optic nerve.
•The control of the intracanalar infiltration is one of the most challenging aspect of tuberculum sellae meningioma surgery.•The contralateral to the most compromised optic nerve approach provides a better visualization of this part of the tumor.•This approach led to high rates of visual improvement with an acceptable risk regarding the noncompromised optic nerve.
Background
Aneurysms at the posterior face of the internal carotid artery can lead to oculomotor nerve palsy (ONP) with an uncertain prognosis of recovery post-treatment. The aim of this study was to ...define the prognostic factors for ONP recovery, with particular interest in treatment modality (surgery or endovascular techniques).
Method
A literature review was performed to select the most pertinent prognostic factors. A retrospective study was then performed to determine whether these factors had significantly modified the prognosis of ONP recovery in our series of patients.
Results
In the literature, factors linked to poorer outcome were age, vascular risk factors, initial ONP severity and delay before treatment; better recovery was associated with surgical treatment. Between 2000 and 2013, 23 consecutive patients were treated in our department for ONP-inducing aneurysms: 14 by endovascular embolization and 9 by surgical clipping and aneurysm puncture. Mean follow-up was 48.8 months. After treatment, overall recovery occurred in 87 % of cases, always within 6 months. Apart from treatment modality, no selected prognostic factor significantly modified the quality or timing of ONP recovery. In the endovascular group, four patients recovered completely, seven partially and three did not recover. In the surgical group, seven patients recovered completely and two partially. Surgery was significantly associated with a more complete and earlier ONP recovery (
p
< 0.05).
Conclusions
Surgery was associated with a more complete and earlier ONP recovery as compared to endovascular treatment, confirming the results of previous studies. However, conclusions must be confirmed by a prospective randomized study.
Les gliomes du tronc cérébral sont un groupe de tumeurs cliniquement, histologiquement et chirurgicalement hétérogènes. Ils sont en général diagnostiqués sur les bases cliniques et radiologiques. ...Dans une perspective chirurgicale, cinq groupes sont définis : tectal, diffus, focal, dorsal exophytique, et cervico-médullaire. Les trois derniers peuvent parfois être candidats à une exérèse, souvent partielle. Les gliomes tectaux, peu évolutifs, ne nécessitent pas de biopsie ou d’exérèse. Les gliomes diffus intrinsèques du pont (DIPG, diffuse intrinsic pontine gliomas), sont les tumeurs du tronc cérébral les plus fréquentes de l’enfant, avec un pronostic effroyable de l’ordre de 2 ans. Historiquement, ces lésions étaient peu biopsiées, car le geste était considéré comme risqué et le diagnostic était fait à l’imagerie. Cependant, l’absence d’informations de biologie moléculaire est un frein à l’utilisation de thérapies ciblées qui constituent une des avancées les plus prometteuses en cancérologie. On évalue la faisabilité d’une biopsie selon deux paramètres : la localisation anatomique et la fonction de la zone infiltrée par la lésion. Du premier dépend l’accès : stéréotaxique, notamment via le pédoncule cérébelleux moyen pour le pont, ou par craniotomie. Du deuxième dépend le risque encouru par la biopsie proprement dite, certaines parties d’une lésion étant soigneusement évitées. Les séries récentes font état d’une morbidité de l’ordre de 3 % et d’une mortalité nulle. Ainsi, bien que l’imagerie soit souvent suffisante au diagnostic, la biopsie de ces lésions est techniquement réalisable dans un nombre significatif de cas, associée à des risques acceptables, permettant de fournir des données biologiques indispensables à la meilleure compréhension de ces tumeurs, et donc à leur prise en charge. L’obtention d’un échantillon tumoral doit être discutée de manière systématique. En France, il existe une RCP nationale consacrée aux gliomes du Tronc Cérébral dans le cadre du réseau RENOCLIP-LOC, labellisé par l’Institut National du Cancer.
Background
The effects of surgical site infections (SSI) after glioblastoma surgery on patient outcomes are understudied. The aim of this retrospective multicenter study was to evaluate the impact of ...SSI on the survival of glioblastoma patients.
Methods
Data from SSI cases after glioblastoma surgeries between 2009 and 2016 were collected from 14 French neurosurgical centers. Collected data included patient demographics, previous medical history, risk factors, details of the surgical procedure, radiotherapy/chemotherapy, infection characteristics, and infection management. Similar data were collected from gender- and age-paired control individuals.
Results
We used the medical records of 77 SSI patients and 58 control individuals. 13 were excluded. Our analyses included data from 64 SSI cases and 58 non-infected glioblastoma patients. Infections occurred after surgery for primary tumors in 38 cases (group I) and after surgery for a recurrent tumor in 26 cases (group II). Median survival was 381, 633, and 547 days in patients of group I, group II, and the control group, respectively. Patients in group I had significantly shorter survival compared to the other two groups (
p
< 0.05). The one-year survival rate of patients who developed infections after surgery for primary tumors was 50%. Additionally, we found that SSIs led to postoperative treatment discontinuation in 30% of the patients.
Discussion
Our findings highlighted the severity of SSIs after glioblastoma surgery, as they significantly affect patient survival. The establishment of preventive measures, as well as guidelines for the management of SSIs, is of high clinical importance.
Background:
Deep brain stimulation is an efficacious treatment for refractory essential tremor, though targeting the intra-thalamic nuclei remains challenging.
Objectives:
We sought to develop an ...inverse approach to retrieve the position of the leads in a cohort of patients operated on with optimal clinical outcomes from anatomical landmarks identifiable by 1.5 Tesla magnetic resonance imaging.
Methods:
The learning database included clinical outcomes and post-operative imaging from which the coordinates of the active contacts and those of anatomical landmarks were extracted. We used machine learning regression methods to build three different prediction models. External validation was performed according to a leave-one-out cross-validation.
Results:
Fifteen patients (29 leads) were included, with a median tremor improvement of 72% on the Fahn–Tolosa–Marin scale. Kernel ridge regression, deep neural networks, and support vector regression (SVR) were used. SVR gave the best results with a mean error of 1.33 ± 1.64 mm between the predicted target and the active contact position.
Conclusion:
We report an original method for the targeting in deep brain stimulation for essential tremor based on patients' radio-anatomical features. This approach will be tested in a prospective clinical trial.
Background: The incidence of newly diagnosed meningiomas, particularly those diagnosed incidentally, is continually increasing. The indication for treatment is empirical because, despite numerous ...studies, the natural history of these tumours remains difficult to describe and predict. Methods: This retrospective single-centre study included 294 consecutive patients with 333 meningiomas who underwent three or more brain imaging scans. Linear, exponential, power, and Gompertz models were constructed to derive volume–time curves, by using a mixed-effect approach. The most accurate model was used to analyse tumour growth and predictors of rapid growth. Findings: The Gompertz model provided the best results. Hierarchical clustering at the time of diagnosis and at the end of follow-up revealed at least three distinct groups, which can be described as pseudoexponential, linear, and slowing growth with respect to their parameters. Younger patients and smaller tumours were more frequent in the pseudo-exponential clusters. We found that the more “aggressive” the cluster, the higher the proportion of patients with grade II meningiomas and who have had a cranial radiotherapy. Over a mean observation period of 56.5 months, 21% of the tumours moved to a cluster with a lower growth rate, consistent with the Gompertz’s law. Interpretation: Meningiomas exhibit multiple growth phases, as described by the Gompertz model. The management of meningiomas should be discussed according to the growth phase, comorbidities, tumour location, size, and growth rate. Further research is needed to evaluate the associations between radiomics features and the growth phases of meningiomas. Funding: No funding.
The incidence of newly diagnosed meningiomas, particularly those diagnosed incidentally, is continually increasing. The indication for treatment is empirical because, despite numerous studies, the ...natural history of these tumours remains difficult to describe and predict.
This retrospective single-centre study included 294 consecutive patients with 333 meningiomas who underwent three or more brain imaging scans. Linear, exponential, power, and Gompertz models were constructed to derive volume–time curves, by using a mixed-effect approach. The most accurate model was used to analyse tumour growth and predictors of rapid growth.
The Gompertz model provided the best results. Hierarchical clustering at the time of diagnosis and at the end of follow-up revealed at least three distinct groups, which can be described as pseudoexponential, linear, and slowing growth with respect to their parameters. Younger patients and smaller tumours were more frequent in the pseudo-exponential clusters. We found that the more “aggressive” the cluster, the higher the proportion of patients with grade II meningiomas and who have had a cranial radiotherapy. Over a mean observation period of 56.5 months, 21% of the tumours moved to a cluster with a lower growth rate, consistent with the Gompertz’s law.
Meningiomas exhibit multiple growth phases, as described by the Gompertz model. The management of meningiomas should be discussed according to the growth phase, comorbidities, tumour location, size, and growth rate. Further research is needed to evaluate the associations between radiomics features and the growth phases of meningiomas.
No funding.
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