Crise de migraine spontanée (étude en tomographie par émission de positons)

Certains noyaux du tronc cérébral joueraient un rôle de " générateur " spécifique de la crise de migraine. L'objectif principal est d'étudier des crises de migraine spontanées en Tomographie par Emission de Positons pour confirmer l'implication du tronc cérébral. Sept patients, présentant une migraine sans aura, ont été étudiés dans les 6 premières heures d'une crise spontanée, avant et après sumatriptan, et en intercrise. Des activations significatives ont été retrouvées au niveau du tronc cérébral et de l'hypothalamus lors de la crise par rapport à l'intercrise. Ces activations persistaient après disparition de la douleur par l'injection de sumatriptan. Ces résultats confirment l'implication des noyaux du tronc cérébral, mais également de l'hypothalamus dans la physiopathologie de la migraine. L'hypothalamus pourrait être le " générateur " de la crise de migraine comme le suggère les prodromes de la crise tels que la modification de la faim ou de la soif.TOULOUSE3-BU Santé-Centrale (315552105) / SudocTOULOUSE3-BU Santé-Allées (315552109) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Interactions between antiseizure medications and contraception: A study about the knowledge of patients and their specialist physicians

International audiencePlanning pregnancy is very important for women with epilepsy (WWE), because of the potential teratogenic effects and neurodevelopmental disorders of different antiseizure medications (ASMs). Nevertheless, contraception in WWE can be challenging due to the existence of drug interactions between ASMs and hormonal contraception. The aim of this study was to assess women's knowledge of potential interactions between their ASMs and contraceptive options. The second objective was to assess neurologist's knowledge of the potential interactions between ASMs and contraceptive methods. An anonymous online survey was proposed to reproductive-age WWE during consultation with their neurologist. Another online survey was proposed to neurologists. These surveys were performed through a French regional medical network. A total of 79 patients agreed to respond to the survey. Forty-nine women used lamotrigine alone or in combination, 15 used an enzyme-inducing ASM alone or in combination, 13 used non-enzyme-inducing ASM and 2 used both lamotrigine and an enzyme-inducing ASM. Half of the WWE had mistaken beliefs about interactions between their ASM and contraception. Among them, 35% of the women treated with an enzyme-inducing ASM were unaware of a potential decreased efficacy of hormonal contraception. Moreover, 51% of the women who were taking lamotrigine did not know that combined hormonal contraception might decrease the efficacy of their ASM. On the other hand, 64.5% of WWE without an enzyme-inducing ASM wrongly thought that their ASM can decrease their hormonal contraceptive efficacy. A total of 20 neurologists answered the online survey. It revealed specific gaps concerning interactions between ASM and contraceptives; in fact, 35% of answers concerning the identification of specific enzyme-inducing ASMs were wrong. This study therefore highlights the need for educational efforts for both WWE and their physicians regarding drug interactions between ASMs and hormonal contraceptives

Interpretation of SEEG recordings

International audienceThe interpretation of SEEG recordings is a crucial step. It must be carried out by an epileptologist/neurophysiologist with sufficient training and qualification in this field. The objectives of the interpretation are to define the brain topography of interictal activities (irritative zone) and the epileptogenic zone, defined as the site of primary organization of ictal discharges. Several patterns of seizure onset are possible, the most typical including fast discharges. The interpretation of the SEEG is based on the recording of spontaneous activity but also on the results of intracerebral electrical stimulation. It must be done with accurate anatomical information on the location of the electrodes in terms of the patient's anatomy. Quantification of interictal activities (spikes, high frequency oscillations) and ictal activity (epileptogenicity index) is recommended. The interpretation of the SEEG must also take into account functional data and will be the basis for the final decision on the operability and type of intervention chosen

Photophobia in migraine: an interictal PET study of cortical hyperexcitability and its modulation by pain.

International audienceOBJECTIVE: Photophobia is an abnormal sensitivity to light experienced by migraineurs and is perhaps caused by cortical hyperexcitability. In clinical studies, an inter-relation between light perception and trigeminal nociception has been demonstrated in migraineurs but not in controls. The purpose of the study was to verify this interaction by functional imaging. METHODS: The authors used H(2)O(15) positron emitting tomography (PET) to study the cortical responses of seven migraineurs between attacks and the responses of seven matched control subjects to luminous stimulations at three luminance intensities: 0, 600 and 1800 Cd/m(2). All three intensities were both with and without concomitant trigeminal pain stimulation. In order to facilitate habituation, the stimulations were started 30 s before PET acquisitions. RESULTS: When no concomitant pain stimulation was applied, luminous stimulations activated the visual cortex bilaterally in migraineurs (specifically in the cuneus, lingual gyrus and posterior cingulate cortex) but not in controls. Concomitant pain stimulation allowed visual cortex activation in control subjects and potentiated its activation in migraineurs. These activations by luminous stimulations were luminance-intensity-dependent in both groups. Concomitant stimulation by pain was associated with activation of the posterior parietal cortex (BA7) in migraineurs and controls. INTERPRETATION: The study shows the lack of habituation and/or cortical hyperexcitability to light in migraineurs. Moreover, the activation by light of several visual cortex areas (including the primary visual cortex) was potentiated by trigeminal pain, demonstrating multisensory integration in these areas

A PET study of photophobia during spontaneous migraine attacks.

International audienceThese findings suggest that ictal photophobia is linked with a visual cortex hyperexcitability. The mechanism of this cortical hyperexcitability could not be explained only by trigeminal nociception because it persisted after headache relief. We hypothesize that modulation of cortical excitability during migraine attack could be under brainstem nuclei control

Hidden Objective Memory Deficits Behind Subjective Memory Complaints in Patients With Temporal Lobe Epilepsy

International audienceBackground and Objectives The aim of this work was to test the hypothesis that patients with temporal lobe epilepsy (TLE) with subjective initial memory complaints (not confirmed by an objective standard assessment) and various phenotypes also show objective very long-term memory deficit with accelerated long-term forgetting. We tested patients with TLE with 2 surprise memory tests after 3 weeks: the standard Free and Cued Selective Reminding Test (FCSRT) and Epireal, a new test specifically designed to capture more ecologic aspects of autobiographical memory. Methods Forty-seven patients with TLE (12 with hippocampal sclerosis, 12 with amygdala enlargement, 11 with extensive lesions, 12 with normal MRI) who complained about their memory, but for whom the standard neuropsychological assessment did not reveal any memory impairment after a standard delay of 20 minutes, underwent 2 surprise memory tests after 3 weeks. They were compared to 35 healthy controls. Results After 3 weeks, FCSRT and Epireal recall scores were significantly lower in patients than in controls ( p < 0.001). There was no significant correlation between FCSRT and Epireal scores ( p = 0.99). Seventy-six percent of patients with TLE had objective impairment on at least 1 of these very long-term memory tests, regardless of the existence and type of lesion or response to antiseizure medication. Easily applicable, Epireal had a higher effect size, detected deficits in 28% more patients, and is a useful addition to the standard workup. Discussion Assessing long-term memory should be broadened to a wide spectrum of patients with TLE with a memory complaint, regardless of the epileptic syndrome, regardless of whether it is associated with a lesion. This could lead to rethinking TLE nosology associated with memory

Specific profiles of new-onset vs. non-inaugural status epilepticus: From diagnosis to 1-year outcome

International audienceWhile new-onset status epilepticus (NOSE) is a harbinger of chronic epilepsy, prospective medical data are sparse in terms of specifying whether the evolution of status epilepticus (SE) and seizure expression in NOSE resembles what occurs in patients who have already been diagnosed with epilepsy [non-inaugural SE (NISE)] in all aspects apart from its inaugural nature. The aim of this study was to compare the clinical, MRI, and EEG features that could distinguish NOSE from NISE. We conducted a prospective monocentric study in which all patients ≥18 years admitted for SE over a 6-month period were included. A total of 109 patients (63 NISE and 46 NOSE cases) were included. Despite similar modified Rankin scores before SE, several aspects of the clinical history distinguished NOSE from NISE patients. NOSE patients were older and frequently had neurological comorbidity and preexisting cognitive decline, but they had a similar prevalence of alcohol consumption to NISE patients. NOSE and NISE evolve in the same proportions as refractory SE (62.5% NOSE, 61% NISE) and share common features such as the same incidence (33% NOSE, 42% NISE, and p = 0.53) and volumes of peri-ictal abnormalities on MRI. However, in NOSE patients, we observed greater non-convulsive semiology (21.7% NOSE, 6% NISE, and p = 0.02), more periodic lateral discharges on EEG ( p = 0.004), later diagnosis, and higher severity according to the STESS and EMSE scales ( p &lt; 0.0001). Mortality occurred in 32.6% of NOSE patients and 21% of NISE patients at 1 year ( p = 0.19), but with different causes of death occurring at different time points: more early deaths directly linked to SE at 1 month occurred in the NOSE group, while there were more remote deaths linked to causal brain lesions in the NISE group at final follow-up. In survivors, 43.6% of the NOSE cases developed into epilepsy. Despite acute causal brain lesions, the novelty related to its inaugural nature is still too often associated with a delay in diagnosing SE and a poorer outcome, which justifies the need to more clearly specify the various types of SE to constantly raise awareness among clinicians. These results highlight the relevance of including novelty-related criteria, clinical history, and temporality of occurrence in the nosology of SE

Local neuronal excitation and global inhibition during epileptic fast ripples in humans

International audienceAbstract Understanding the neuronal basis of epileptic activity is a major challenge in neurology. Cellular integration into larger scale networks is all the more challenging. In the local field potential, interictal epileptic discharges can be associated with fast ripples (FRs, 200-600 Hz), which are a promising marker of the epileptogenic zone. Yet, how neuronal populations in the epileptogenic zone and in healthy tissue are affected by FRs remain unclear. Here, we used a novel “hybrid” macro-micro depth electrode in nine drug-resistant epileptic patients, combining classic depth recording of local field potentials (macrocontacts) and two or three tetrodes (four microwires bundled together) enabling up to 15 neurons in local circuits to be simultaneously recorded. We characterized neuronal responses (190 single units) with the timing of FRs (2233 FRs) on the same hybrid and other electrodes that target other brain regions. Micro-wire recordings reveal signals that are not visible on macro-contacts. While FRs detected on the closest macro-contact to the tetrodes were always associated with FRs on the tetrodes, 82% of FRs detected on tetrodes were associated with detectable FR on the nearest macro-contact. Moreover, neuronal recordings were taken in and outside the epileptogenic zone of implanted epileptic subjects and they revealed an interlay of excitation and inhibition across anatomical scales. While FRs were associated with increased neuronal activity in very local circuits only, they were followed by inhibition in large-scale networks (beyond the epileptogenic zone, even in healthy cortex). Neuronal responses to FRs were homogeneous in local networks but differed across brain areas. Similarly, post-FR inhibition varied across recording locations and subjects and was shorter than typical inter-FR intervals, suggesting that this inhibition is a fundamental refractory process for the networks. These findings demonstrate that FRs engage local and global networks, including healthy tissue, and point to network features that pave the way for new diagnostic and therapeutic strategies. They also reveal how even localized pathological brain dynamics can affect a broad range of cognitive functions