Epilepsy in Patients With Primary CNS Lymphoma: Prevalence, Risk Factors, and Prognostic Significance.

BACKGROUND AND OBJECTIVES: Epilepsy is a common comorbidity of brain tumors; however, little is known about the prevalence, onset time, semiology, and risk factors of seizures in primary CNS lymphoma (PCNSL). Our objectives were to determine the prevalence of epilepsy in PCNSL, to identify factors associated with epilepsy, and to investigate the prognostic significance of seizures in PCNSL. METHODS: We performed an observational, retrospective single-center study at a tertiary neuro-oncology center (2011-2023) including immunocompetent patients with PCNSL and no history of seizures. We collected clinical, imaging, and treatment data; seizure status over the course of PCNSL; and oncological and seizure outcome. The primary outcome was to determine the prevalence of epilepsy. Furthermore, we aimed to identify clinical, radiologic, and treatment-related factors associated with epilepsy. Univariate analyses were conducted using the χ2 test for categorical variables and unpaired t test for continuous variables. Predictors identified in the unadjusted analysis were included in backward stepwise logistic regression models. RESULTS: We included 330 patients, 157 (47.6%) were male, median age at diagnosis was 68 years, and the median Karnofsky Performance Status score was 60. Eighty-three (25.2%) patients had at least 1 seizure from initial diagnosis to the last follow-up, 40 (12.1%) as the onset symptom, 16 (4.8%) during first line of treatment, 27 (8.2%) at tumor progression and 6 (1.8%) while in remission. Focal aware seizures were the most frequent seizure type, occurring in 43 (51.8%) patients. Seizure freedom under antiseizure medication was observed in 97.6% patients. Cortical contact (odds ratio [OR] 8.6, 95% CI 4.2-15.5, p < 0.001) and a higher proliferation index (OR 5.7, 95% CI 1.3-26.2, p = 0.02) were identified as independent risk factors of epilepsy. Patients with PCNSL and epilepsy had a significantly shorter progression-free survival (median progression-free survival 9.6 vs 14.1 months, adjusted hazard ratio 1.4, 95% CI 1.0-1.9, p = 0.03), but not a significantly shorter overall survival (17 vs 44.1 months, log-rank test, p = 0.09). DISCUSSION: Epilepsy affects a quarter of patients with PCNSL, with half experiencing it at the time of initial presentation and potentially serving as a marker of disease progression. Further research is necessary to assess the broader applicability of these findings because they are subject to the constraints of a retrospective design and tertiary center setting.

Hippocampal activations obtained during language fMRI tasks: A complementary tool for predicting postoperative memory prognosis.

In medial temporal lobe epilepsy (MTLE), the benefits of surgery must be balanced against the risk of post-operative memory decline. Prediction of postoperative outcomes based on functional magnetic resonance imaging (fMRI) tasks is increasingly common but remains uncertain. The aim of this retrospective study was to determine whether hippocampal activations elicited by fMRI language tasks could enhance or refine memory fMRI in MTLE patients candidates to surgery. Forty-six patients were included: 30 right and 16 left MTLE, mostly with hippocampal sclerosis. Preoperative assessment included neuropsychological tests and fMRI with language (syntactic verbal fluency) and memory tasks (encoding, delayed, and immediate recognition of images of objects). Thirty patients underwent surgery and had neuropsychological evaluations one year after surgery. Worsening was defined as a degradation of more than 10 % in postoperative forgetting scores compared to preoperative scores in verbal, non-verbal and global memory. Memory fMRI had the best sensitivity with hippocampal activations obtained in 95 % of patients, versus 65 % with language fMRI. Considering the patients who elicited an hippocampal activation, language fMRI led to 80 %, 65 % and 85 % of correct predictions for respectively global, verbal and non verbal memory (versus 71 %, 64 % and 68 % with memory fMRI). Memory and language fMRI predictions outperformed those made by neuropsychological tests. In summary, language fMRI was less sensitive than memory fMRI to elicit hippocampal activations but when it did, the proportion of correct memory predictions was better. Moreover, it proved to be an independent predictive factor regardless of the side of the epileptic focus. Given the ease of setting up a language task in fMRI, we recommend the systematic combination of memory and language tasks to predict the post-operative memory outcome of MTLE patients undergoing epilepsy surgery.

Resective surgery for mesial temporal lobe epilepsy associated with hippocampal sclerosis in patients over 50 years: a case-control study.

BACKGROUND: Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE/HS) is the most common cause of drug-resistant focal seizures and surgical resection is the primary treatment option, with seizure-free rates ranging from 60 to 80%. However, data on postsurgical seizure outcomes in patients ≥ 50 years of age are limited. This study aimed to assess the efficacy and safety of surgery in this age group compared to younger patients. METHODS: We performed a retrospective analysis of data from resective surgeries conducted in patients with MTLE/HS between 1990 and 2022. We focused on patients aged ≥ 50 years and compared the surgical safety and efficacy variables between this group and a control group of patients aged < 50 years through a case-control study. RESULTS: Among the 450 MTLE/HS patients who underwent surgery during the inclusion period, 61 (13.6%) were aged ≥ 50 years and matched with 183 younger patients, totaling 244 study participants. The two groups had similar characteristics. At the last follow-up (median 5.7 years), Engel I outcomes were achieved in 80.3% of the older patients and 81.4% of the younger patients, with no significant difference (p = 0.85). Postoperative cognitive and psychiatric outcomes did not differ between the groups. Major complication rates were also comparable, at 3.3% in the older group and 2.7% in the younger group (p = 0.83). The extratemporal ictal abnormalities observed on video-EEG were the only variable that demonstrated a significant association with an unfavorable seizure outcome in the older group (OR 9.3, 95% CI [1.8-47.6], p = 0.005). CONCLUSIONS: This study provides grade 3 evidence that resective surgery for MTLE/HS patients aged ≥ 50 years is as effective and safe as it is for younger patients, and thus should be considered as the primary treatment option for drug-resistant cases.

Anatomy of the medial wall of the cavernous sinus: A systematic review of the literature.

The existence, composition, and continuity of the medial wall of the cavernous sinus (MWCS) have been extensively studied and debated. However, the precise nature of this membrane remains unknown. Understanding the anatomical characteristics of the MWCS is crucial, notably in relation to pituitary adenomas, which often invade the cavernous sinus. Indeed, surgical treatment of those tumors is frequently incomplete because of such invasion. The anatomical and molecular basis of the peculiar and often lateralized tropism of adenomatous cells to the cavernous sinus is not yet understood and it has been suggested repeatedly that the MWCS is physiologically frail. During the past three decades, there have been several conflicting accounts of the existence, composition, and continuity of this medial wall, but methodological differences and varying definitions could have contributed to the current lack of consensus regarding it. The aim of this systematic review was to summarize previously published data concerning the existence, anatomy, composition, and continuity of the MWCS.

A standardized protocol for assessing the performance of automatic detection systems used in onshore wind power plants to reduce avian mortality.

While wind power plants are an important contribution to the production of renewable energy to limit climate change, collision mortality from turbines is a danger for birds, including many protected species. To try to mitigate collision risks, automatic detection systems (ADSs) can be deployed on wind power plants; these work by detecting incoming birds using a detection/classification process and triggering a specific reaction (scaring off the bird or shutting down the turbine). Nonetheless, bird fatalities still occur at ADS-equipped wind power plants, which raises the question of the performance of these tools. To date, the lack of a transparent, peer-reviewed experimental process to compare the performance of types of ADS has meant there is no robust protocol to assess these systems. With the aim of filling this gap, we developed two standardized protocols that provide objective and unbiased assessments of the performance of different types of ADS, based on their probability of detecting/classifying birds at risk of collision. Both protocols rely on precise 3D tracking of wild birds by human observers using a laser rangefinder, and the comparison of these tracks with those detected and recorded by an ADS. The first protocol evaluates a system's general performance, generating comparable data for all types of ADS. In this protocol, detection/classification probability is estimated conditional on several abiotic and biotic environmental factors such as bird size, distance from the target, the flight angle and azimuth of the bird, as well as weather conditions. The second protocol aims to verify that the performance of an ADS installed on a given wind power plant complies with its regulatory requirements. In this protocol, detection/classification probability is specifically estimated for a given target species at a given regulatory detection distance. This protocol also estimates the proportion of time an ADS is functional on site over a year, and the proportion of reaction orders successfully operated by wind turbines. These protocols have been field-tested and made publicly available for use by government agencies and wind power plant operators.

Measuring neuronal avalanches to inform brain-computer interfaces.

Large-scale interactions among multiple brain regions manifest as bursts of activations called neuronal avalanches, which reconfigure according to the task at hand and, hence, might constitute natural candidates to design brain-computer interfaces (BCIs). To test this hypothesis, we used source-reconstructed magneto/electroencephalography during resting state and a motor imagery task performed within a BCI protocol. To track the probability that an avalanche would spread across any two regions, we built an avalanche transition matrix (ATM) and demonstrated that the edges whose transition probabilities significantly differed between conditions hinged selectively on premotor regions in all subjects. Furthermore, we showed that the topology of the ATMs allows task-decoding above the current gold standard. Hence, our results suggest that neuronal avalanches might capture interpretable differences between tasks that can be used to inform brain-computer interfaces.