Post-epileptic seizure posttraumatic stress Disorder: A mediation analysis.

OBJECTIVE: Previous studies investigated the varying prevalence of post-epileptic seizure posttraumatic stress disorder (PS-PTSD). The current study aimed first to compare the profiles of patients with and without PS-PTSD and, second, to study the interaction between other past traumatic experiences, subjective ictal anxiety, psychiatric comorbidities, and PS-PTSD in people with epilepsy (PWE). METHODS: We conducted an observational study, investigating past traumatic experiences and PS-PTSD through standardized scales (CTQ-28, LEC-5 and PCL-5). We used semi-structured interviews and validated psychometric scales (NDDIE for depression and GAD-7 for anxiety) to collect data on general psychiatric comorbidities. We also assessed epilepsy specific psychiatric symptoms (interictal and peri-ictal). We performed a mediation analysis through PROCESS for SPSS to evaluate the effect of history of past trauma and subjective ictal anxiety on PS-PTSD through interictal depression and anxiety symptoms. RESULTS: We enrolled 135 PWE, including 35 patients with PS-PTSD (29.5 %). Patients with PS-PTSD had significantly higher depression (12.87 vs 10; p = 0.005) and anxiety (7.74 vs 5.01; p = 0.027) scores and higher prevalence of peri-ictal psychiatric symptoms, compared to patients without PS-PTSD. The relationship between other past traumatic experiences and PS-PTSD was totally mediated by interictal depression and anxiety. We found a significant indirect effect of interictal anxiety symptoms on the path between subjective ictal anxiety and PS-PTSD. SIGNIFICANCE: Our results showed that patients with PS-PTSD have a more severe psychopathological profile (more peri ictal and inter ictal depressive and anxiety symptoms). Both inter ictal and subjective ictal anxiety appear to have a significant role in PS-PTSD.

Neurophysiological evidence for crossmodal (face-name) person-identity representation in the human left ventral temporal cortex.

Putting a name to a face is a highly common activity in our daily life that greatly enriches social interactions. Although this specific person-identity association becomes automatic with learning, it remains difficult and can easily be disrupted in normal circumstances or neurological conditions. To shed light on the neural basis of this important and yet poorly understood association between different input modalities in the human brain, we designed a crossmodal frequency-tagging paradigm coupled to brain activity recording via scalp and intracerebral electroencephalography. In Experiment 1, 12 participants were presented with variable pictures of faces and written names of a single famous identity at a 4-Hz frequency rate while performing an orthogonal task. Every 7 items, another famous identity appeared, either as a face or a name. Robust electrophysiological responses were found exactly at the frequency of identity change (i.e., 4 Hz / 7 = 0.571 Hz), suggesting a crossmodal neural response to person identity. In Experiment 2 with twenty participants, two control conditions with periodic changes of identity for faces or names only were added to estimate the contribution of unimodal neural activity to the putative crossmodal face-name responses. About 30% of the response occurring at the frequency of crossmodal identity change over the left occipito-temporal cortex could not be accounted for by the linear sum of unimodal responses. Finally, intracerebral recordings in the left ventral anterior temporal lobe (ATL) in 7 epileptic patients tested with this paradigm revealed a small number of "pure" crossmodal responses, i.e., with no response to changes of identity for faces or names only. Altogether, these observations provide evidence for integration of verbal and nonverbal person identity-specific information in the human brain, highlighting the contribution of the left ventral ATL in the automatic retrieval of face-name identity associations.

Association between retinal and cortical visual electrophysiological impairments in schizophrenia.

BACKGROUND: Electrophysiological impairments in the magnocellular visual system have been reported among patients with schizophrenia, but previous theories proposed that these deficits may begin in the retina. We therefore sought to evaluate the potential contribution of the retina by comparing retinal and cortical visual electrophysiological impairments between patients with schizophrenia and healthy controls. METHODS: We recruited patients with schizophrenia and age- and sex-matched healthy controls. We recorded the P100 amplitude and latency using electroencephalography (EEG) while projecting low (0.5 cycles/degree) or high (15 cycles/degree) spatial frequency gratings at a temporal frequency of 0 Hz or 8 Hz. We compared the P100 results with previous results for retinal ganglion cell activity (N95) in these participants. We analyzed data using repeated-measures analysis of variance and correlation analyses. RESULTS: We recruited 21 patients with schizophrenia and 29 age- and sex-matched healthy controls. Results showed decreased P100 amplitude and increased P100 latency among patients with schizophrenia compared with healthy controls (p < 0.05). Analyses reported the main effects of spatial and temporal frequency but no interaction effects of spatial or temporal frequency by group. Moreover, correlation analysis indicated a positive association between P100 latency and previous retinal results for N95 latency in the schizophrenia group (p < 0.05). DISCUSSION: Alterations in the P100 wave among patients with schizophrenia are consistent with the deficits in early visual cortical processing shown in the literature. These deficits do not seem to correspond to an isolated magnocellular deficit but appear to be associated with previous retinal measurements. Such an association emphasizes the role of the retina in the occurrence of visual cortical abnormalities in schizophrenia. Studies with coupled electroretinography-EEG measurements are now required to further explore these findings. CLINICAL TRIALS REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02864680.

Stratifying sudden death risk in adults with drug-resistant focal epilepsy: The SUDEP-CARE score.

BACKGROUND AND PURPOSE: A clinical risk score for sudden unexpected death in epilepsy (SUDEP) in patients with drug-resistant focal epilepsy could help improve prevention. METHODS: A case-control study was conducted including (i) definite or probable SUDEP cases collected by the French National Sentinel Mortality Epilepsy Network and (ii) control patients from the French national research database of epilepsy monitoring units. Patients with drug-resistant focal epilepsy were eligible. Multiple logistic regressions were performed. After sensitivity analysis and internal validation, a simplified risk score was developed from the selected variables. RESULTS: Sixty-two SUDEP cases and 620 controls were included. Of 21 potential predictors explored, seven were ultimately selected, including generalized seizure frequency (>1/month vs. <1/year: adjusted odds ratio [AOR] 2.6, 95% confidence interval [CI] 1.25-5.41), nocturnal or sleep-related seizures (AOR 4.49, 95% CI 2.68-7.53), current or past depression (AOR 2.0, 95% CI 1.19-3.34) or the ability to alert someone of an oncoming seizure (AOR 0.57, 95% CI 0.33-0.98). After internal validation, a clinically usable score ranging from -1 to 8 was developed, with high discrimination capabilities (area under the receiver operating curve 0.85, 95% CI 0.80-0.90). The threshold of 3 has good sensitivity (82.3%, 95% CI 72.7-91.8), whilst keeping a good specificity (82.7%, 95% CI 79.8-85.7). CONCLUSIONS: These results outline the importance of generalized and nocturnal seizures on the occurrence of SUDEP, and show a protective role in the ability to alert someone of an oncoming seizure. The SUDEP-CARE score is promising and will need external validation. Further work, including paraclinical explorations, could improve this risk score.

A brain atlas of axonal and synaptic delays based on modelling of cortico-cortical evoked potentials.

Epilepsy presurgical investigation may include focal intracortical single-pulse electrical stimulations with depth electrodes, which induce cortico-cortical evoked potentials at distant sites because of white matter connectivity. Cortico-cortical evoked potentials provide a unique window on functional brain networks because they contain sufficient information to infer dynamical properties of large-scale brain connectivity, such as preferred directionality and propagation latencies. Here, we developed a biologically informed modelling approach to estimate the neural physiological parameters of brain functional networks from the cortico-cortical evoked potentials recorded in a large multicentric database. Specifically, we considered each cortico-cortical evoked potential as the output of a transient stimulus entering the stimulated region, which directly propagated to the recording region. Both regions were modelled as coupled neural mass models, the parameters of which were estimated from the first cortico-cortical evoked potential component, occurring before 80 ms, using dynamic causal modelling and Bayesian model inversion. This methodology was applied to the data of 780 patients with epilepsy from the F-TRACT database, providing a total of 34 354 bipolar stimulations and 774 445 cortico-cortical evoked potentials. The cortical mapping of the local excitatory and inhibitory synaptic time constants and of the axonal conduction delays between cortical regions was obtained at the population level using anatomy-based averaging procedures, based on the Lausanne2008 and the HCP-MMP1 parcellation schemes, containing 130 and 360 parcels, respectively. To rule out brain maturation effects, a separate analysis was performed for older (>15 years) and younger patients (<15 years). In the group of older subjects, we found that the cortico-cortical axonal conduction delays between parcels were globally short (median = 10.2 ms) and only 16% were larger than 20 ms. This was associated to a median velocity of 3.9 m/s. Although a general lengthening of these delays with the distance between the stimulating and recording contacts was observed across the cortex, some regions were less affected by this rule, such as the insula for which almost all efferent and afferent connections were faster than 10 ms. Synaptic time constants were found to be shorter in the sensorimotor, medial occipital and latero-temporal regions, than in other cortical areas. Finally, we found that axonal conduction delays were significantly larger in the group of subjects younger than 15 years, which corroborates that brain maturation increases the speed of brain dynamics. To our knowledge, this study is the first to provide a local estimation of axonal conduction delays and synaptic time constants across the whole human cortex in vivo, based on intracerebral electrophysiological recordings.

Extracting the Invisible: Mesial Temporal Source Detection in Simultaneous EEG and SEEG Recordings.

Epileptic source detection relies mainly on visual expertise of scalp EEG signals, but it is recognised that epileptic discharges can escape to this expertise due to a deep localization of the brain sources that induce a very low, even negative, signal to noise ratio. In this methodological study, we aimed to investigate the feasibility of extracting deep mesial temporal sources that were invisible in scalp EEG signals using blind source separation (BSS) methods (infomax ICA, extended infomax ICA, and JADE) combined with a statistical measure (kurtosis). We estimated the effect of different methodological and physiological parameters that could alter or improve the extraction. Using nine well-defined mesial epileptic networks (1949 spikes) obtained from seven patients and simultaneous EEG-SEEG recordings, the first independent component extracted from the scalp EEG signals was validated in mean from 46 to 80% according to the different parameters. The three BSS methods equally performed (no significant difference) and no influence of the number of scalp electrodes used was found. At the opposite, the number and amplitude of spikes included in the averaging before the extraction modified the performance. Anyway, despite their invisibility in scalp EEG signals, this study demonstrates that deep source extraction is feasible under certain conditions and with the use of common signal analysis toolboxes. This finding confirms the crucial need to continue the signal analysis of scalp EEG recordings which contains subcortical signals that escape to expert visual analysis but could be found by signal processing.

Intracerebral electrical stimulation of the right anterior fusiform gyrus impairs human face identity recognition.

Brain regions located between the right fusiform face area (FFA) in the middle fusiform gyrus and the temporal pole may play a critical role in human face identity recognition but their investigation is limited by a large signal drop-out in functional magnetic resonance imaging (fMRI). Here we report an original case who is suddenly unable to recognize the identity of faces when electrically stimulated on a focal location inside this intermediate region of the right anterior fusiform gyrus. The reliable transient identity recognition deficit occurs without any change of percept, even during nonverbal face tasks (i.e., pointing out the famous face picture among three options; matching pictures of unfamiliar or familiar faces for their identities), and without difficulty at recognizing visual objects or famous written names. The effective contact is associated with the largest frequency-tagged electrophysiological signals of face-selectivity and of familiar and unfamiliar face identity recognition. This extensive multimodal investigation points to the right anterior fusiform gyrus as a critical hub of the human cortical face network, between posterior ventral occipito-temporal face-selective regions directly connected to low-level visual cortex, the medial temporal lobe involved in generic memory encoding, and ventral anterior temporal lobe regions holding semantic associations to people's identity.

Functional (psychogenic non-epileptic/dissociative) seizures: why and how?

Functional seizures (FS) known also as psychogenic non-epileptic seizures or dissociative seizures, present with ictal semiological manifestations, along with various comorbid neurological and psychological disorders. Terminology inconsistencies and discrepancies in nomenclatures of FS may reflect limitations in understanding the neuropsychiatric intricacies of this disorder. Psychological and neurobiological processes of FS are incompletely understood. Nevertheless, important advances have been made on underlying neuropsychopathophysiological mechanisms of FS. These advances provide valuable information about the underlying mechanisms of mind-body interactions. From this perspective, this narrative review summarises recent studies about aetiopathogenesis of FS at two levels: possible risk factors (why) and different aetiopathogenic models of FS (how). We divided possible risk factors for FS into three categories, namely neurobiological, psychological and cognitive risk factors. We also presented different models of FS based on psychological and neuroanatomical understanding, multilevel models and integrative understanding of FS. This work should help professionals to better understand current views on the multifactorial mechanisms involved in the development of FS. Shedding light on the different FS profiles in terms of aetiopathogenesis will help guide how best to direct therapy, based on these different underlying mechanisms.

Anticipatory anxiety of seizures is associated with ictal emotional distress and amygdala onset seizures.

OBJECTIVE: Anxiety disorders are a frequent psychiatric condition in patients with epilepsy. Anticipatory anxiety of seizures (AAS) is described as a daily persistent fear or excessive worry of having a seizure. AAS seems to be related to "subjective ictal anxiety" reported by patients. The current study aimed to assess the association between objective ictal features and the presence of AAS. METHODS: Ninety-one patients with drug-resistant focal epilepsy underwent a standardized psychiatric assessment, specific for epilepsy, and presurgical long-term video-electroencephalography (EEG) or stereo-EEG (SEEG). We compared seizure semiology and epilepsy features of patients with AAS (n = 41) to those of patients without AAS (n = 50). We analyzed emotional and motor behavior ictal signs as well as ictal consciousness. We further assessed amygdala ictal involvement in seizures recorded with SEEG (n = 28). RESULTS: AAS was significantly associated with the presence of ictal emotional distress; negative emotional behavior (p < .01) and negative emotion were explicitly reported to the examiner during recording (p = .015), regardless of the ictal level of consciousness. Among the patients recorded with SEEG, we found a significant involvement of amygdala within the seizure onset zone (p < .01) for patients with AAS. SIGNIFICANCE: Higher risk of developing AAS is associated with seizures expressing negative emotional symptoms, independently of ictal consciousness level. Persistent interictal fear of seizures might be viewed as the consequence of a reinforcement of the emotional networks secondary to amygdala involvement in seizures of temporal origin. Physicians should screen for AAS not only to assess the impact of epilepsy on daily life, but also as an interictal biomarker of ictal semiology and emotional network involvement at seizure onset.

Minimum standards for inpatient long-term video-electroencephalographic monitoring: A clinical practice guideline of the International League Against Epilepsy and International Federation of Clinical Neurophysiology.

The objective of this clinical practice guideline is to provide recommendations on the indications and minimum standards for inpatient long-term video-electroencephalographic monitoring (LTVEM). The Working Group of the International League Against Epilepsy and the International Federation of Clinical Neurophysiology develop guidelines aligned with the Epilepsy Guidelines Task Force. We reviewed published evidence using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) statement. We found limited high-level evidence aimed at specific aspects of diagnosis for LTVEM performed to evaluate patients with seizures and nonepileptic events. For classification of evidence, we used the Clinical Practice Guideline Process Manual of the American Academy of Neurology. We formulated recommendations for the indications, technical requirements, and essential practice elements of LTVEM to derive minimum standards used in the evaluation of patients with suspected epilepsy using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). Further research is needed to obtain evidence about long-term outcome effects of LTVEM and to establish its clinical utility.

Epileptic spasms are associated with increased stereo-electroencephalography derived functional connectivity in tuberous sclerosis complex.

OBJECTIVE: Epileptic spasms (ES) are common in tuberous sclerosis complex (TSC). However, the underlying network alterations and relationship with epileptogenic tubers are poorly understood. We examined interictal functional connectivity (FC) using stereo-electroencephalography (SEEG) in patients with TSC to investigate the relationship between tubers, epileptogenicity, and ES. METHODS: We analyzed 18 patients with TSC who underwent SEEG (mean age = 11.5 years). The dominant tuber (DT) was defined as the most epileptogenic tuber using the epileptogenicity index. Epileptogenic zone (EZ) organization was quantitatively separated into focal (isolated DT) and complex (all other patterns). Using a 20-min interictal recording, FC was estimated with nonlinear regression, h2 . We calculated (1) intrazone FC within all sampled tubers and normal-appearing cortical zones, respectively; and (2) interzone FC involving connections between DT, other tubers, and normal cortex. The relationship between FC and (1) presence of ES as a current seizure type at the time of SEEG, (2) EZ organization, and (3) epileptogenicity was analyzed using a mixed generalized linear model. Spike rate and distance between zones were considered in the model as covariates. RESULTS: Six patients had ES as a current seizure type at time of SEEG. ES patients had a greater number of tubers with a fluid-attenuated inversion recovery hypointense center (p < .001), and none had TSC1 mutations. The presence of ES was independently associated with increased FC within both intrazone (p = .033) and interzone (p = .011) networks. Post hoc analyses identified that increased FC was associated with ES across tuber and nontuber networks. EZ organization and epileptogenicity biomarkers were not associated with FC. SIGNIFICANCE: Increased cortical synchrony among both tuber and nontuber networks is characteristic of patients with ES and independent of both EZ organization and tuber epileptogenicity. This further supports the prospect of FC biomarkers aiding treatment paradigms in TSC.

Heterogeneity of patients with functional/dissociative seizures: Three multidimensional profiles.

OBJECTIVE: Current concepts highlight the neurological and psychological heterogeneity of functional/dissociative seizures (FDS). However, it remains uncertain whether it is possible to distinguish between a limited number of subtypes of FDS disorders. We aimed to identify profiles of distinct FDS subtypes by cluster analysis of a multidimensional dataset without any a priori hypothesis. METHODS: We conducted an exploratory, prospective multicenter study of 169 patients with FDS. We collected biographical, trauma (childhood and adulthood traumatic experiences), semiological (seizure characteristics), and psychopathological data (psychiatric comorbidities, dissociation, and alexithymia) through psychiatric interviews and standardized scales. Clusters were identified by the Partitioning Around Medoids method. The similarity of patients was computed using Gower distance. The clusters were compared using analysis of variance, chi-squared, or Fisher exact tests. RESULTS: Three patient clusters were identified in this exploratory, hypothesis-generating study and named on the basis of their most prominent characteristics: A "No/Single Trauma" group (31.4%), with more male patients, intellectual disabilities, and nonhyperkinetic seizures, and a low level of psychopathology; A "Cumulative Lifetime Traumas" group (42.6%), with clear female predominance, hyperkinetic seizures, relatively common comorbid epilepsy, and a high level of psychopathology; and A "Childhood Traumas" group (26%), commonly with comorbid epilepsy, history of childhood sexual abuse (75%), and posttraumatic stress disorder, but also with a high level of anxiety and dissociation. SIGNIFICANCE: Although our cluster analysis was undertaken without any a priori hypothesis, the nature of the trauma history emerged as the most important differentiator between three common FDS disorder subtypes. This subdifferentiation of FDS disorders may facilitate the development of more specific therapeutic programs for each patient profile.

Postictal psychosis, a cause of secondary affective psychosis: A clinical description study of 77 patients.

OBJECTIVE: Postictal psychosis (PIP) is a severe complication occurring at least in 2% of patients with epilepsy. Since the 19th century, psychiatrists have reported the specificity of PIP presentation, but descriptions did not clearly distinguish PIP from after-seizure delirium. This study aimed to provide a precise description of psychiatric signs occurring during PIP, and improve recognition of PIP. METHODS: We performed a review of clinical descriptions available in literature (48 patients), that we gathered with a retrospective multicentric case series of patients from three French epilepsy units (29 patients). For each patient, we collected retrospectively the psychiatric signs, and epilepsy features. RESULTS: We found a high prevalence of persecutory (67.5%) and religious (55.8%) delusions, with almost systematic hallucinations (83.1%) and frequent mood disturbances (76.6%), especially euphoria. Severe consequences were not negligible (other-directed assault in 20.8%, self-directed in 13.0%). The type of delusion was associated with mood symptoms (p = 0.017). Episode onset was mainly sudden/rapid (90.9%), its duration was mostly between one and 14 days (64.9%) and the response to antipsychotic medication was good. Disorder was recurrent in more than a half of the sample (57.1% of patients with at least 2 episodes). CONCLUSION: Considering our findings, PIP resembles more an affective psychosis, than a purely psychotic disorder. The presence of affective signs differentiates PIP from other psychotic comorbidities in epilepsy. Additionally, resemblance between PIP and psychotic manic episode might help to discuss links between epilepsy and bipolar disorder.

Coffee consumption and seizure frequency in patients with drug-resistant focal epilepsy.

OBJECTIVE: To assess the relation between coffee consumption and seizure frequency in patients with drug-resistant focal epilepsy. METHODS: Cross-sectional analysis of data collected in the SAVE study, which included patients with drug-resistant focal epilepsy during long-term EEG monitoring. Patients in whom both coffee consumption and data about seizure frequency, including focal to bilateral tonic-clonic seizures (FBTCS), were available were selected. Coffee consumption was collected using a standardized self-report questionnaire and classified into four groups: none, rare (from less than 1 cup/week to up 3 cups/week), moderate (from 4 cups/week to 3 cups/day), and high (more than 4 cups/day). RESULTS: Six hundred and nineteen patients were included. There was no relation between coffee consumption and total seizure frequency (p = 0.902). In contrast, the number of FBTCS reported over the past year was significantly associated with usual coffee consumption (p = 0.029). Specifically, number of FBCTS in patients who reported moderate coffee consumption was lower than in others. In comparison with patients with moderate coffee consumption, the odds ratio (95%CI) for reporting at least 1 FBTCS per year was 1.6 (1.03-2.49) in patients who never take coffee, 1.62 (1.02-2.57) in those with rare consumption and 2.05 (1.24-3.4) in those with high consumption. Multiple ordinal logistic regression showed a trend toward an association between coffee consumption and number of FBTCS (p = 0.08). CONCLUSIONS AND RELEVANCE: Our data suggest that effect of coffee consumption on seizures might depend on dose with potential benefits on FBTCS frequency at moderate doses. These results will have to be confirmed by prospective studies.

Preserved time but altered numerosity processing in epileptic patients with postoperative lesion in the inferior frontal gyrus.

Previous researches have shown that the inferior frontal gyrus (IFG) is involved in time and numerosity processing. This study aimed at examining (i) interval timing and (ii) interaction between duration and numerosity processing in four drug-resistant epileptic patients with postoperative lesions in the IFG in comparison with thirteen healthy controls. The duration reproduction and discrimination tasks performed in the sub- and supra-second ranges did not reveal any significant differences between patients and controls. The duration discrimination task of stimuli varying in numerosity (DurN) and the numerosity discrimination task of stimuli varying in duration (NumD) revealed that only numerosity judgment was altered in IFG patients. A time-order effect was notably observed in the NumD task but in opposite directions for the two groups: The second patch was perceived as more numerous than the first patch in controls and conversely as less numerous in patients. Finally in the DurN task, we observed a congruency effect which was dependent on numerical distance in patients but not in controls. These converging results suggest that the IFG would be more specifically involved in numerosity than in duration processing, possibly playing a role in numerical decision.

Report on Electroencephalographic Findings in Critically Ill Patients with COVID-19.

In March 2020, we treated a cohort of 26 critically ill hospitalized SARS-CoV-2-infected patients who underwent electroencephalography to assess unexplained altered mental status, loss of consciousness, or poor arousal and responsiveness. Of the 26 patients studied, 5 patients had electroencephalograms that showed periodic discharges consisting of high-amplitude frontal monomorphic delta waves with absence of epileptic activity. These findings may suggest central nervous system injury potentially related to COVID-19 in these patients. ANN NEUROL 2020;88:626-630.

Working toward the ideal situation: A pragmatic Epi-Psy approach for the diagnosis and treatment of psychogenic nonepileptic seizures.

Medical international guidelines recommend regular psychiatric consultations for patients with epilepsy, in order to detect comorbidities. However, there is a lack of guidance about PNES that constitute both a differential diagnosis and a comorbidity of epilepsy. While waiting for the ideal collaboration between neurologists and psychiatrists, we develop a pragmatic approach. Wrong diagnosis between epilepsy and Psychogenic nonepileptic seizures (PNES) is frequent and may lead to iatrogenic consequences for patients. To limit the risk of misdiagnosis, psychiatrists and neurologists should collaborate and be more trained about epilepsy, PNES, and their comorbidities. We illustrate the aim of this collaboration through the case of a patient, initially diagnosed with epilepsy, then with PNES only and finally with comorbid epilepsy and PNES. The correct final diagnosis would not have been performed without the collaboration of psychiatrists and neurologists, trained in "Epi-Psy" approach.

Post-traumatic factors are involved in the evolution of the number of seizures in patients with PNES.

OBJECTIVE: The purpose of this prospective study was to identify predictive factors of the evolution of the number of seizures. METHODS: We included 85 individuals with a diagnosis of Psychogenic Nonepileptic Seizure (PNES) who completed at least two clinical interviews spaced by 6 months during a 24-month follow-up. Participants underwent a structured interview with an experimented clinician in PNES to complete standardized evaluation and validated scales. We collected sociodemographic and clinical data on PNES (number of seizures, duration of the disease), anxiety, depression, history of traumas, alexithymia, dissociation, and post-traumatic stress disorder (PTSD). We used a multivariate linear regression analysis to predict the characteristics independently associated with the evolution of the number of seizures in percentage. RESULTS: Dissociation score was significantly associated with a negative evolution of the number of seizures (p < 0.002). Conversely, the diagnosis of PTSD at inclusion was correlated to a positive evolution of the number of seizures (p < 0.029). CONCLUSION: Dissociation was related to a more pejorative evolution of the number of seizures while PTSD diagnosis was associated with a decreased number of seizures. It is therefore essential to improve detection and treatment of post-traumatic dissociation. Further studies are required to understand the impact of PTSD on the evolution of the number of seizures.

Spatially Dissociated Intracerebral Maps for Face- and House-Selective Activity in the Human Ventral Occipito-Temporal Cortex.

We report a comprehensive mapping of the human ventral occipito-temporal cortex (VOTC) for selective responses to frequency-tagged faces or landmarks (houses) presented in rapid periodic trains of objects, with intracerebral recordings in a large sample (N = 75). Face-selective contacts are three times more numerous than house-selective contacts and show a larger amplitude, with a right hemisphere advantage for faces. Most importantly, these category-selective contacts are spatially dissociated along the lateral-to-medial VOTC axis, respectively, consistent with neuroimaging evidence. At the minority of "overlap" contacts responding selectively to both faces and houses, response amplitude to the two categories is not correlated, suggesting a contribution of distinct populations of neurons responding selectively to each category. The medio-lateral dissociation also extends into the underexplored anterior temporal lobe (ATL). In this region, a relatively high number of intracerebral recording contacts show category-exclusive responses (i.e., without any response to baseline visual objects) to faces but rarely to houses, in line with the proposed role of this region in processing people-related semantic information. Altogether, these observations shed novel insight on the neural basis of human visual recognition and strengthen the validity of the frequency-tagging approach coupled with intracerebral recordings in epileptic patients to understand human brain function.

Selective visual representation of letters and words in the left ventral occipito-temporal cortex with intracerebral recordings.

We report a comprehensive cartography of selective responses to visual letters and words in the human ventral occipito-temporal cortex (VOTC) with direct neural recordings, clarifying key aspects of the neural basis of reading. Intracerebral recordings were performed in a large group of patients (n = 37) presented with visual words inserted periodically in rapid sequences of pseudofonts, nonwords, or pseudowords, enabling classification of responses at three levels of word processing: letter, prelexical, and lexical. While letter-selective responses are found in much of the VOTC, with a higher proportion in left posterior regions, prelexical/lexical responses are confined to the middle and anterior sections of the left fusiform gyrus. This region overlaps with and extends more anteriorly than the visual word form area typically identified with functional magnetic resonance imaging. In this region, prelexical responses provide evidence for populations of neurons sensitive to the statistical regularity of letter combinations independently of lexical responses to familiar words. Despite extensive sampling in anterior ventral temporal regions, there is no hierarchical organization between prelexical and lexical responses in the left fusiform gyrus. Overall, distinct word processing levels depend on neural populations that are spatially intermingled rather than organized according to a strict postero-anterior hierarchy in the left VOTC.