Effects of sleep disturbances and circadian rhythms modifications on cognition in breast cancer women before and after adjuvant chemotherapy: the ICANSLEEP-1 protocol.

BACKGROUND: Many patients treated for breast cancer (BC) complain about cognitive difficulties affecting their daily lives. Recently, sleep disturbances and circadian rhythm disruptions have been brought to the fore as potential contributors to cognitive difficulties in patients with BC. Yet, studies on these factors as well as their neural correlates are scarce. The purpose of the ICANSLEEP-1 (Impact of SLEEP disturbances in CANcer) study is to characterize sleep using polysomnography and its relationship with the evolution of cognitive functioning at both the behavioral and the neuroanatomical levels across treatment in BC patients treated or not with adjuvant chemotherapy. METHODS: ICANSLEEP-1 is a longitudinal study including BC patients treated with adjuvant chemotherapy (n = 25) or not treated with adjuvant chemotherapy (n = 25) and healthy controls with no history of BC (n = 25) matched for age (45-65 years old) and education level. The evaluations will take place within 6 weeks after inclusion, before the initiation of chemotherapy (for BC patients who are candidates for chemotherapy) or before the first fraction of radiotherapy (for BC patients with no indication for chemotherapy) and 6 months later (corresponding to 2 weeks after the end of chemotherapy). Episodic memory, executive functions, psychological factors, and quality of life will be assessed with validated neuropsychological tests and self-questionnaires. Sleep quantity and quality will be assessed with polysomnography and circadian rhythms with both actigraphy and saliva cortisol. Grey and white matter volumes, as well as white matter microstructural integrity, will be compared across time between patients and controls and will serve to further investigate the relationship between sleep disturbances and cognitive decline. DISCUSSION: Our results will help patients and clinicians to better understand sleep disturbances in BC and their relationship with cognitive functioning across treatment. This will aid the identification of more appropriate sleep therapeutic approaches adapted to BC patients. Improving sleep in BC would eventually help limit cognitive deficits and thus improve quality of life during and after treatments. TRIAL REGISTRATION: NCT05414357, registered June 10, 2022. PROTOCOL VERSION: Version 1.2 dated March 23, 2022.

Effect of familial clustering in the genetic screening of 235 French ALS families.

OBJECTIVES: To determine whether the familial clustering of amyotrophic lateral sclerosis (ALS) cases and the phenotype of the disease may help identify the pathogenic genes involved. METHODS: We conducted a targeted next-generation sequencing analysis on 235 French familial ALS (FALS), unrelated probands to identify mutations in 30 genes linked to the disease. The genealogy, that is, number of cases and generations with ALS, gender, age, site of onset and the duration of the disease were analysed. RESULTS: Regarding the number of generations, 49 pedigrees had only one affected generation, 152 had two affected generations and 34 had at least three affected generations. Among the 149 pedigrees (63.4%) for which a deleterious variant was found, an abnormal G4C2 expansion in C9orf72 was found in 98 cases as well as SOD1, TARBP or FUS mutations in 30, 9 and 7 cases, respectively. Considering pedigrees from the number of generations, abnormal G4C2 expansion in C9orf72 was more frequent in pedigrees with pairs of affected ALS cases, which represented 65.2% of our cohort. SOD1 mutation involved all types of pedigrees. No TARDBP nor FUS mutation was present in monogenerational pedigrees. TARDBP mutation predominated in bigenerational pedigrees with at least three cases and FUS mutation in multigenerational pedigrees with more than seven cases, on average, and with an age of onset younger than 45 years. CONCLUSION: Our results suggest that familial clustering, phenotypes and genotypes are interconnected in FALS, and thus it might be possible to target the genetic screening from the familial architecture and the phenotype of ALS cases.

Self-awareness in Transient Global Amnesia: distinguishing the effects of transient memory disorder vs. pre-existing vulnerability factors.

Numerous evidences suggest the existence of relationships between the impairment of episodic memory, acute stress exposure and variations in self-awareness (SA). Here, we examined 27 patients presenting transient global amnesia (TGA), a clinical condition which combines episodic amnesia and high anxiety, thanks to state and trait questionnaires of SA. We observed variation of SA depending on the stage of TGA (acute, recovery and follow-up). We also found preexisting differences in patient's awareness of their own image when the precipitating event was physical, encouraging us to give more consideration to the social determinants of stress in physiological cascade of TGA.

Impact of breast cancer on prospective memory functioning assessed by virtual reality and influence of sleep quality and hormonal therapy: PROSOM-K study.

BACKGROUND: Breast cancer (BC) is the most frequent cancer in women with more than 70% of BC patients being treated with hormonal therapy (HT). Among these patients, some report difficulties in remembering what they are supposed to do at the right moment, referring to prospective memory (PM). PM is essential for autonomy and medical adherence of patients, and requires an ecological assessment. Virtual reality, that recreates naturalistic environment, seems to be a promising method to evaluate PM. Several BC patients also report sleep disturbances. Given the role of sleep on memory consolidation, it is imperative to explore the influence of sleep quality on PM in BC patients treated with HT. The purpose of PROSOM-K study is to assess PM functioning using virtual reality and sleep quality in BC treated or not with HT. METHODS: PROSOM-K is a prospective study including post-menopausal BC patients ≤70 years old treated with radiotherapy (n = 25) or with radiotherapy and HT (n = 25), and healthy post-menopausal women (n = 25) matched for age and education. PM will be assessed using a virtual reality based task. Other cognitive functions and psychosocial factors will be assessed with validated questionnaires and neuropsychological tests. The study is divided in 3 sessions: a session of familiarisation with the virtual environment and the PM task: a day-time session during which participants learn intentions during the morning and recall them in the evening; and a night-time session during which participants learn intentions in the evening and recall them the following morning. Women will be monitored by wrist actigraphy; during the night-time session, objective sleep quality and quantity will be measured by polysomnography. DISCUSSION: This is a novel study aiming to assess PM using virtual reality, coupled with the evaluation of other cognitive functions. Polysomnographic study of sleep will provide further information about architectural sleep disturbances in BC. Association between sleep architecture parameters and PM mechanism in BC women treated with HT will be described in detail. We expect our results will provide knowledge for patients and clinicians and further help to improve patient care and cognitive therapy. TRIAL REGISTRATION: NCT03420105 , registered: January 10, 2018.

The Still Enigmatic Syndrome of Transient Global Amnesia: Interactions Between Neurological and Psychopathological Factors.

Transient global amnesia (TGA) is a neurological syndrome that usually occurs in middle-aged or older people. It is characterized by the abrupt onset of profound anterograde amnesia, associated with more variable retrograde amnesia and repetitive questioning. The whole episode lasts no more than 24 h. Almost 60 years after its first descriptions, the etiology of TGA remains unknown. Until now, TGA has been described exclusively as a memory disorder, but there is a growing body of evidence to show that emotional and psychological factors (as anxious and depressive symptoms) are present at different times of TGA. Their role therefore needs to be clarified. First, these factors seem to play a part in triggering TGA, at least for a subgroup of patients, suggesting the existence of an emotional TGA subtype. Second, recent research shows that almost all the TGA patients displayed modifications of their emotional state during the episode, possibly linked to sudden memory loss. The level of depressive and anxious symptoms could even reach a pathological threshold in patients with the so-called "emotional TGA subtype". Third, the persistence of these depressive and anxious symptoms after the end of the episode could account for lasting memory disorders in some patients. Finally, the analysis of these emotional syndrome and emotional factors and the recent data in neuroimaging could allow us to gain a better understanding of the pathophysiological mechanisms behind TGA. The aim of this review was thus to discuss whether the anxious and depressive symptoms are causative, resultant or coincidental of TGA.

Long-term follow-up study of endarterectomy versus angioplasty in patients with symptomatic severe carotid stenosis trial.

BACKGROUND AND PURPOSE: We aimed at comparing the long-term benefit-risk balance of carotid stenting versus endarterectomy for symptomatic carotid stenosis. METHODS: Long-term follow-up study of patients included in Endarterectomy Versus Angioplasty in Patients With Symptomatic Severe Carotid Stenosis (EVA-3S), a randomized, controlled trial of carotid stenting versus endarterectomy in 527 patients with recently symptomatic severe carotid stenosis, conducted in 30 centers in France. The main end point was a composite of any ipsilateral stroke after randomization or any procedural stroke or death. RESULTS: During a median follow-up of 7.1 years (interquartile range, 5.1-8.8 years; maximum 12.4 years), the primary end point occurred in 30 patients in the stenting group compared with 18 patients in the endarterectomy group. Cumulative probabilities of this outcome were 11.0% (95% confidence interval, 7.9-15.2) versus 6.3% (4.0-9.8) in the endarterectomy group at the 5-year follow-up (hazard ratio, 1.85; 1.00-3.40; P=0.04) and 11.5% (8.2-15.9) versus 7.6% (4.9-11.8; hazard ratio, 1.70; 0.95-3.06; P=0.07) at the 10-year follow-up. No difference was observed between treatment groups in the rates of ipsilateral stroke beyond the procedural period, severe carotid restenosis (≥70%) or occlusion, death, myocardial infarction, and revascularization procedures. CONCLUSIONS: The long-term benefit-risk balance of carotid stenting versus endarterectomy for symptomatic carotid stenosis favored endarterectomy, a difference driven by a lower risk of procedural stroke after endarterectomy. Both techniques were associated with low and similar long-term risks of recurrent ipsilateral stroke beyond the procedural period. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00190398.

The effects of musical practice on structural plasticity: the dynamics of grey matter changes.

Intensive training and the acquisition of expertise are known to bring about structural changes in the brain. Musical training is a particularly interesting model. Previous studies have reported structural brain modifications in the auditory, motor and visuospatial areas of musicians compared with nonmusicians. The main goal of the present study was to go one step further, by exploring the dynamic of those structural brain changes related to musical experience. To this end, we conducted a regression study on 44 nonmusicians and amateur musicians with 0-26years of musical practice of a variety instruments. We sought first to highlight brain areas that increased with the duration of practice and secondly distinguish (thanks to an ANOVA analysis) brain areas that undergo grey matter changes after only limited years of musical practice from those that require longer practice before they exhibit changes. Results revealed that musical training results a greater grey matter volumes in different brain areas for musicians. Changes appear gradually in the left hippocampus and right middle and superior frontal regions, but later also include the right insula and supplementary motor area and left superior temporal, and posterior cingulate areas. Given that all participants had the same age and that we controlled for age and education level, these results cannot be ascribed to normal brain maturation. Instead, they support the notion that musical training could induce dynamic structural changes.

Ischemic stroke due to paradoxical embolism arising from a popliteal vein aneurysm.

Popliteal vein aneurysm (PVA) is a very uncommon cause of stroke. We present the case of a 63-year-old, right-handed man who presented to the emergency department with transitory ischemic accident (left superior extremity regressive monoplegia). Complete etiologic work-up led to the discovery of both a patent foramen ovale associated with an septum interauricular aneurysm, and of a PVA without mural thrombus. The diagnosis of brain paradoxical embolism was retained. The unique potentially embolic cause was the presence of the PVA. We decided to treat the PVA surgically to avoid a further cerebral vascular episode. Although uncommon, venous etiology must be considered for stroke.

Dynamics of the cognitive procedural learning in alcoholics with Korsakoff's syndrome.

BACKGROUND: While procedures acquired before the development of amnesia are likely to be preserved in alcoholic patients with Korsakoff's syndrome, the ability of Korsakoff patients (KS) to learn new cognitive procedures is called in question. According to the Adaptive Control of Thoughts model, learning a new cognitive procedure requires highly controlled processes in the initial cognitive phase, which may be difficult for KS with episodic and working memory deficits. The goals of the present study were to examine the learning dynamics of KS compared with uncomplicated alcoholic patients (AL) and control subjects (CS) and to determine the contribution of episodic and working memory abilities in cognitive procedural learning performance. METHODS: Fourteen KS, 15 AL, and 15 CS were submitted to 40 trials (4 daily learning sessions) of the Tower of Toronto task (disk-transfer task similar to the tower of Hanoi task) as well as episodic and working memory tasks. RESULTS: The 10 KS who were able to perform the cognitive procedural learning task obtained lower results than both CS and AL. The cognitive phase was longer in the Korsakoff's syndrome group than in the other 2 groups but did not differ between the 3 groups any more when episodic memory abilities were controlled. CONCLUSIONS: Our results indicate that KS have impaired cognitive procedural learning abilities compared with both AL and CS. Episodic memory deficits observed in KS result in a delayed transition from the cognitive learning phase to more advanced learning phases and, as a consequence, in an absence of automation of the procedure within 40 trials.

Focal cortical subarachnoid hemorrhage revealed by recurrent paresthesias: a clinico-radiological syndrome strongly associated with cerebral amyloid angiopathy.

BACKGROUND: Focal subarachnoid hemorrhage (SAH) is often revealed by transient and recurrent focal neurological episodes. This cause is important to identify because it carries a high risk of intracerebral hemorrhage (ICH). We report the clinical, imaging and prognostic data of 17 patients with focal SAH revealed by short episodes of paresthesias mimicking transient ischemic attacks. METHODS: The medical records and imaging data of patients with focal acute SAH at the cerebral convexity and at least one episode of focal paresthesia having attended the Neurology Department of Caen University Hospital in the last 10 years were retrospectively reviewed. Hemorrhagic lesions, ischemic lesions, cerebral microbleeds (CMBs), superficial siderosis, white matter changes (leukoaraiosis) and modified Boston criteria for cerebral amyloid angiopathy (CAA) were assessed. All patients or relatives were contacted after a median delay of 16 months in order to seek for new events (death, stroke, recurrent focal symptoms, ICH and dementia) that occurred since hospital discharge. RESULTS: Seventeen patients (12 men) aged 69-96 years were identified. All but 1 had multiple, repeated, stereotyped and brief attacks of paresthesias, associated in some of them with motor and/or speech difficulties, but only 1 had a headache. SAHs were seen on CT scans in 15/17 patients and on T2* gradient-echo magnetic resonance imaging (MRI) in all patients. They were multiple SAHs in 14/17 patients, including at least 1 SAH in the central or pre- or postcentral sulcus contralateral to the symptoms in all patients. Five patients had punctate cortical hyperintensities on diffusion-weighted MRI. Eleven patients had CMBs, and 4 of them had more than 5 CMBs. Seven patients met the modified Boston criteria for probable and 10 for possible CAA. At follow-up, 5 patients had a subsequent ICH, 4 of whom had received antithrombotic treatments. Five patients died (1 from ICH). Six patients developed dementia. CONCLUSION: The combination of transient, repeated and stereotyped attacks of unilateral paresthesias with a contralateral sulcal SAH seems to preferentially occur in elderly people and is often indicative of CAA.

[Genetics of amyotrophic lateral sclerosis]. / Génétique de la sclérose latérale amyotrophique.

GENETICS OF AMYOTROPHIC LATERAL SCLEROSIS. Approximately 10 to 15% of people with amyotrophic lateral sclerosis (ALS) have a family history of the disease. In 2/3 of them, but also in 10% of subjects without any family history of ALS, a pathogenic genetic variant can be identified. Many genes are involved, the four main ones being C9orf72 (which can also be responsible for dementia), SOD1, TARDBP and FUS. ALS of genetic origin is almost always inherited in an autosomal dominant pattern. The progress made in recent years in the knowledge of the genetic forms of ALS has led to a better understanding of the pathophysiology of the disease and has opened up new therapeutic avenues, some of which are already being explored. For all these reasons, it is now recommended that all patients with ALS, whether familial or not, undergo a genetic investigation, with analyses appropriate to their age and family history. When a pathogenic variant is found, it can then be sought in at-risk relatives who so desire. These tests must follow legally mandated procedures and can only be conducted in a specialized ALS center under the supervision of a geneticist after a thorough discussion of the personal and family implications of the result and written consent from the patient.

GÉNÉTIQUE DE LA SCLÉROSE LATÉRALE AMYOTROPHIQUE. Environ 10 à 15 % des sujets atteints de sclérose latérale amyotrophique (SLA) ont des antécédents familiaux. Chez les deux tiers d'entre eux, mais aussi chez 10 % des sujets sans aucun antécédent familial de SLA, un variant génétique pathogène peut être mis en évidence. De nombreux gènes sont concernés, les quatre principaux étant C9orf72 (qui peut également être responsable d'une démence), SOD1, TARDBP et FUS . La SLA d'origine génétique se transmet pratiquement toujours selon une hérédité autosomique dominante. Les progrès accomplis ces dernières années dans la connaissance des formes génétiques de SLA permettent de mieux connaître la physiopathologie de la maladie et ouvrent de nouvelles pistes thérapeutiques dont certaines sont déjà en cours d'exploration. Pour toutes ces raisons, il est aujourd'hui recommandé, chez tout sujet atteint de SLA, familiale ou non, d'entreprendre une enquête génétique, avec des analyses appropriées à l'âge et aux antécédents familiaux. Lorsqu'un variant pathogène est trouvé, il peut alors être recherché chez les apparentés à risque qui le souhaitent. Ces analyses doivent respecter des procédures encadrées par la loi, et ne peuvent être conduites que dans un centre spécialisé pour la prise en charge de la SLA, et sous la responsabilité d'un généticien, après une discussion approfondie sur les implications personnelles et familiales du résultat, et le consentement écrit du patient.

Disruption in normal correlational patterns of metabolic networks in the limbic circuit during transient global amnesia.

Transient global amnesia is characterized by the sudden apparition of severe episodic amnesia, mainly anterograde, associated with emotional changes. Even though the symptoms are stereotyped, cerebral mechanism underlying transient global amnesia remains unexplained and previous studies using positron emission tomography do not show any clear results or consensus on cerebral regions impacted during transient global amnesia. This study included a group of 10 transient global amnesic patients who underwent 18F-fluorodeoxyglucose positron emission tomography during the acute or recovery phase of the episode and 10 paired healthy controls. Episodic memory was evaluated with the encoding-storage-retrieval paradigm and a story recall test of the Wechsler's memory scale and anxiety was assessed with the Spielberger scale. We used statistical parametric mapping to identify modifications of whole-brain metabolism. Regarding hypometabolism, there was no brain region systematically affected in all transient global amnesic patients and the comparison between amnesic patients and controls did not show any significant differences. To better understand the specific implication of the limbic circuit in the pathophysiology of transient global amnesia, we then conducted a correlational analysis that included regions of this network. Our findings showed that in healthy controls, regions of the limbic circuit seem to operate in a synchronized way with all regions being highly correlated to each other. On the opposite, in transient global amnesic patients, we observed a clear disruption of this normal correlational patterns between regions with the medial temporal lobe (the hippocampus, parahippocampal gyrus and amygdala) included in one cluster and the orbitofrontal cortex, anterior and posterior cingulate gyrus and thalamus gathered in the other one. Given the individual variability in the time course of transient global amnesia, the direct comparison between a group of patients and controls does not seem to favour the identification of subtle and transient alterations in regional metabolism. The involvement of an extended network, such as the limbic circuit, seems more likely to explain the symptoms of patients. Indeed, the synchronization of regions within the limbic circuit seems to be altered during transient global amnesia, which could explain the amnesia and anxiety observed in transient global amnesic patients. The present study thus deepens our understanding of the mechanisms underlying not only amnesia but also the emotional component of transient global amnesia by considering it as a disruption in the normal correlational patterns within the limbic circuit.

C-reactive protein and D-dimer in cerebral vein thrombosis: Relation to clinical and imaging characteristics as well as outcomes in a French cohort study.

Introduction: Cerebral venous sinus thrombosis (CVST) is a rare disease with highly variable clinical presentation and outcomes. Clinical studies suggest a role of inflammation and coagulation in CVST outcomes. The aim of this study was to investigate the association of inflammation and hypercoagulability biomarkers with CVST clinical manifestations and prognosis. Methods: This prospective multicenter study was conducted from July 2011 to September 2016. Consecutive patients referred to 21 French stroke units and who had a diagnosis of symptomatic CVST were included. High-sensitivity C-reactive protein (hs-CRP), neutrophil-to-lymphocyte ratio (NLR), D-dimer, and thrombin generation using calibrated automated thrombogram system were measured at different time points until 1 month after anticoagulant therapy discontinuation. Results: Two hundred thirty-one patients were included. Eight patients died, of whom 5 during hospitalization. The day 0 hs-CRP levels, NLR, and D-dimer were higher in patients with initial consciousness disturbance than in those without (hs-CRP: 10.2 mg/L [3.6-25.5] vs 23.7 mg/L [4.8-60.0], respectively; NLR: 3.51 [2.15-5.88] vs 4.78 [3.10-9.59], respectively; D-dimer: 950 µg/L [520-2075] vs 1220 µg/L [950-2445], respectively). Patients with ischemic parenchymal lesions (n = 31) had a higher endogenous thrombin potential5pM than those with hemorrhagic parenchymal lesions (n = 31): 2025 nM min (1646-2441) vs 1629 nM min (1371-2090), respectively (P = .0082). Using unadjusted logistic regression with values >75th percentile, day 0 hs-CRP levels of >29.7 mg/L (odds ratio, 10.76 [1.55-140.4]; P = .037) and day 5 D-dimer levels of >1060 mg/L (odds ratio, 14.63 [2.28-179.9]; P = .010) were associated with death occurrence. Conclusion: Two widely available biomarkers measured upon admission, especially hs-CRP, could help predict bad prognosis in CVST in addition to patient characteristics. These results need to be validated in other cohorts.

Role of hippocampal CA1 atrophy in memory encoding deficits in amnestic Mild Cognitive Impairment.

Identifying the specific substrates of memory deficits in early Alzheimer's disease would help to develop clinically-relevant therapies. The present study assesses the relationships between encoding versus retrieval deficits in patients with amnestic Mild Cognitive Impairment (aMCI) and atrophy specifically within the hippocampus and throughout the white matter. Twenty-two aMCI patients underwent T1-weighted MRI scans and neuropsychological testing. Grey matter and white matter segments obtained from the MRI images were each entered in correlation analyses, assessed only in the hippocampus for grey matter segments, with encoding and retrieval memory performances. For the grey matter segments, the resulting spmT correlation maps were then superimposed onto a 3D surface view of the hippocampus to identify the relative involvement of the different subfields, a method already used and validated elsewhere. Memory encoding deficits specifically correlated with CA1 subfield atrophy, while no relationship was found with white matter atrophy. In contrast, retrieval deficits were weakly related to hippocampal atrophy and did not involve a particular subfield, while they strongly correlated with loss of white matter, specifically in medial parietal and frontal areas. In aMCI patients, encoding impairment appears specifically related to atrophy of the CA1 hippocampal subfield, consistent with the predominance of encoding deficits and CA1 atrophy in aMCI. In contrast, episodic retrieval deficits seem to be underlain by more distributed tissue losses, consistent with a disruption of a hippocampo-parieto-frontal network.

Silent cerebral infarcts after cardiac catheterization: a randomized comparison of radial and femoral approaches.

BACKGROUND: Single center studies using serial cerebral diffusion-weighted magnetic resonance imaging in patients having cardiac catheterization have suggested that cerebral microembolism might be responsible for silent cerebral infarct (SCI) as high as 15% to 22%. We evaluated in a multicenter trial the incidence of SCIs after cardiac catheterization and whether or not the choice of the arterial access site might impact this phenomenon. METHODS AND RESULTS: Patients were randomized to have cardiac catheterization either by Radial (n = 83) or Femoral (n = 77) arterial approaches by experimented operators. The main outcome measure was the occurrence of new cerebral infarct on serial diffusion-weighted magnetic resonance imaging. Patient and catheterization characteristics, including duration of catheterization, were similar in both groups. The risk of SCI did not differ significantly between the Femoral and Radial groups (incidence of 11.7% versus 17.5%; OR, 0.85; 95% CI, 0.62-1.16; P = .31). At multivariable analysis, the independent predictors of SCI were the patient's higher height and lower transvalvular gradient. CONCLUSIONS: The high rate of SCI after cardiac catheterization of patients with aortic stenosis was confirmed, but its occurrence was not affected by the selection of Radial and Femoral access.

[Lewy body disease, a frequent dementia]. / Une démence fréquente: la démence à corps de Lewy.

Dementia with Lewy bodies is probably the second most frequent neurodegenerative dementia. Its neuropathological features overlap those of both Parkinson's disease and Alzheimer's disease, and the neuropathological hallmarks are therefore uncertain. Dementia with Lewy bodies is rather a clinical syndrome than a "neuropathological diagnosis". A combination of six original but non specific features is useful for diagnosis, namely fluctuating attention and cognition; recurrent daytime well-formed and detailed visual hallucinations; features of parkinsonism; rapid eye movement sleep behavior disorders; severe neuroleptic sensitivity; and low dopamine uptake in the basal ganglia. Because of the therapeutic implications, diagnosis of dementia with Lewy bodies is an important challenge.

Attentional capture mediates the emergence and suppression of intrusive memories.

Intrusive memories hijack consciousness and their control may lead to forgetting. However, the contribution of reflexive attention to qualifying a memory signal as interfering is unknown. We used machine learning to decode the brain's electrical activity and pinpoint the otherwise hidden emergence of intrusive memories reported during a memory suppression task. Importantly, the algorithm was trained on an independent attentional model of visual activity, mimicking either the abrupt and interfering appearance of visual scenes into conscious awareness or their deliberate exploration. Intrusion of memories into conscious awareness were decoded above chance. The decoding accuracy increased when the algorithm was trained using a model of reflexive attention. Conscious detection of intrusive activity decoded from the brain signal was central to the future silencing of suppressed memories and later forgetting. Unwanted memories require the reflexive orienting of attention and access to consciousness to be suppressed effectively by inhibitory control.

Longitudinal grey matter and metabolic contributions to cognitive changes in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is characterized by rapidly evolving cognitive and brain impairments. While previous work revealed structural and functional alterations associated with cognitive decline in patients suffering from amyotrophic lateral sclerosis, the relationships between anatomo-functional changes and both disease's progression and the evolution of cognitive performance remain largely unexplored. Here, we took advantage of repeated multi-modal acquisitions in patients with amyotrophic lateral sclerosis over 1 year to assess the longitudinal sequence of grey matter atrophy, glucose metabolism and cognitive changes. Results revealed metabolic and structural changes over frontal, thalamic and temporal regions. Both cortical hypermetabolism and hypometabolism (right temporal gyrus and right angular gyrus, respectively) were associated with cognitive performance and thalamic hypometabolism during the follow-up testing session. Furthermore, the inferior frontal gyrus atrophy mediated the relation between early hypometabolism in this region and the subsequent decline of the theory of mind abilities. Marked volume loss was associated with larger hypometabolism and impaired cognitive performance. To our knowledge, this is the first study to longitudinally examine both grey matter volume and metabolic alteration patterns in patients with amyotrophic lateral sclerosis, over a mean follow-up time of 1 year. We identify how changes of the inferior frontal gyrus critically underly later cognitive performance, shedding new light on its high prognostic significance for amyotrophic lateral sclerosis-related changes. These results have important implications for our understanding of structural and functional changes associated with amyotrophic lateral sclerosis and how they underly cognitive impairments.

Altered predictive control during memory suppression in PTSD.

Aberrant predictions of future threat lead to maladaptive avoidance in individuals with post-traumatic stress disorder (PTSD). How this disruption in prediction influences the control of memory states orchestrated by the dorsolateral prefrontal cortex is unknown. We combined computational modeling and brain connectivity analyses to reveal how individuals exposed and nonexposed to the 2015 Paris terrorist attacks formed and controlled beliefs about future intrusive re-experiencing implemented in the laboratory during a memory suppression task. Exposed individuals with PTSD used beliefs excessively to control hippocampal activity during the task. When this predictive control failed, the prediction-error associated with unwanted intrusions was poorly downregulated by reactive mechanisms. This imbalance was linked to higher severity of avoidance symptoms, but not to general disturbances such as anxiety or negative affect. Conversely, trauma-exposed participants without PTSD and nonexposed individuals were able to optimally balance predictive and reactive control during the memory suppression task. These findings highlight a potential pathological mechanism occurring in individuals with PTSD rooted in the relationship between the brain's predictive and control mechanisms.