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The measurement of dielectric properties of foods is essential in the design and control of microwave drying systems as they describe the capability of a material to absorb, transmit and reflect electromagnetic energy. The relative complex permittivity, ɛr*, explains the interactions that may take place between a product and microwave. ɛr* is influenced by its composition (including the moisture content) and temperature. The real component of this complex permittivity is related to energy storage and is called dielectric constant, \({\text{ε}}_{\text{r}}^{{\prime }}\). The imaginary component, the loss factor or \({\text{ε}}_{\text{r}}^{\text{''}}\), is associated to energy dissipation. The dielectric properties of selected low-moisture products (corn starch, curry, paprika, dried chives, rice grain and wheat grain) were evaluated by open-ended coaxial probe (OECP) and cavity perturbation techniques. Semi-skimmed milk powder was heated at 50 and 60°C, and the change in dielectric properties with increasing temperature was measured. The increase in moisture content (from 7.19 to 13.08%, wet basis, w.b.) and its influence on the relative complex permittivity was verified for semi-skimmed milk powder. The results showed that the dielectric constant tends to increase with the increase in temperature and moisture content, and with the decrease in frequency from 2450 to 915 MHz. Values ranged from 1 for corn starch (OECP at 2450 MHz) to 4.36 for rice grain (cavity perturbation at 915 MHz). The loss factor ranged from 0.02 for curry to 0.48 for rice grain, both at 2450 MHz. Open-ended coaxial probe requires close contact between the sample and the probe; therefore, this system was not fit for measuring the dielectric properties of the tested powders (air gaps between the probe and the samples). The cavity perturbation technique has been proven to be reliable for many foods, especially at low moisture contents, but requires a specific microwave applicator to be designed for each evaluated frequency.

Cerebellar ataxia can be caused by neoplasia, toxics (drugs, heavy metals, alcohol), infection, vascular lesions or auto-immune and paraneoplastic pathologies. Neuroimaging must be performed urgently in case of sudden onset and serologies as well as a lumbar puncture should be performed. Several case reports of ataxia associated with COVID-19 have been published, however the underlying pathogenic mechanisms remain unclear. This is a diagnosis of exclusion when other causes are ruled out and when the ataxia appears simultaneously to COVID-19 infection. We lack data on best management, but the prognosis appears mostly favorable with good functional recovery without any specific treatment. This paper describes the case of a patient who developed a cerebellar ataxia as the only neurological manifestation of a SARS-CoV-2 infection.Une ataxie cérébelleuse peut être causée par un processus (para)néoplasique, auto-imun, une exposition toxique, une infection ou une lésion vasculaire. Une imagerie doit être réalisée en urgence devant toute atteinte aiguë et le bilan devrait être complété par des sérologies larges et une ponction lombaire. Plusieurs cas d’ataxie liée au Covid-19 ont été décrits, dont le mécanisme étiopathogénique reste incomplètement élucidé, le diagnostic se faisant plutôt par exclusion lorsque les symptômes apparaissent de manière concomitante à l’infection. Des données manquent sur la prise en charge mais le pronostic semble favorable, avec une bonne récupération fonctionnelle. Cet article décrit le cas d’une patiente ayant présenté une ataxie cérébelleuse comme symptôme neurologique isolé contemporain d’une infection à SARS-CoV-2.

Syphilis is a sexually transmitted disease which incidence increased over the last 10 years in Switzerland. The clinical and neurocognitive manifestations observed in case of symptomatic neurosyphilis can be very heterogeneous and can mimic neurocognitive disorders of other origins. This article discusses the diagnostic and management pitfalls in an older patient whose diagnosis of neurosyphilis was initially suspected during a home visit.La syphilis est une maladie à transmission sexuelle dont l’incidence est en constante augmentation ces 10 dernières années en Suisse. Les manifestations cliniques et neurocognitives observées en cas de neurosyphilis symptomatique sont très hétérogènes et peu spécifiques, pouvant mimer des troubles neurocognitifs d’autre origine. Cet article discute des écueils diagnostiques et de prise en charge d’un patient âgé chez lequel un diagnostic de neurosyphilis a été évoqué lors d’une visite à domicile.

Transient global amnesia (TGA) represents a benign neurological syndrome of unknown pathophysiology, often accompanied by vanishing hippocampal punctate lesions on diffusion-weighted imaging (hippocampal punctate diffusion lesion, HPDL). The recent literature suggests that TGA may be triggered by acute neurological conditions.To study patients with TGA triggered by an acute neurological disease.We retrospectively reviewed patients from two neurology centres with TGA (with or without HPDL) in whom an acute neurological condition could be identified as trigger. We also performed a systematic review of the literature of this situation using predefined search terms.We identified 38 patients (median age 62 years, 55.3% female): 6 from our centres and 32 from the literature. Acute neurovascular diseases that preceded or were associated with TGA included ischemic and haemorrhagic strokes, convexity subarachnoid haemorrhage, and reversible cerebral vasoconstriction syndrome. As non-vascular acute neurological diseases, we identified migraine and peripheral-origin vertigo. The clinical manifestation of the neurological trigger showed a variable temporal relation with TGA onset; in some cases preceding and in others co-occurring with TGA manifestation. In some cases, presumed neurological triggers were asymptomatic and diagnosed from the neuroimaging done for the TGA.Acute vascular and non-vascular neurological events may trigger TGAs or may occur simultaneously. In the first case, such an acute neurological disease may activate direct pathways within the nervous systems leading to TGA, or alternatively elicit a bodily sympathetic overactivity cascade. In the second case, both neurological events may be the result of a common external stressor.

Transient global amnesia (TGA) represents a benign neurological syndrome of unknown pathophysiology, often accompanied by vanishing hippocampal punctate diffusion-weighted imaging lesions (HPDL). The literature suggests that TGA may present with unusual features. This study analyses atypical clinical and radiological manifestations of patients with TGA and/or HPDL.We retrospectively reviewed patients with atypical clinical or radiological presentations of TGA and/or HPDL in three neurology centers. We also performed a systematic review of literature using predefined search terms. Results were classified as: A) Atypical clinical manifestations of TGA (such as amnesia with additional manifestations, or only non-amnesic manifestations); B) Atypical radiological manifestations of clinically typical TGA.We identified 83 patients: 18 in our centres (median age 63.5 years, 39% female) and 65 in the literature. In group A, 43 patients presented atypical clinical manifestations such as TGA with added transitory cognitive or sensory-motor deficits, seizures, headaches, but also non-amnesic presentations associated with HPDL and incidental HPDL without symptoms. In group B, 40 patients with typical clinical TGA showed extra-hippocampal punctate diffusion lesions (E-HPDL) which disappeared on follow-up imaging. Using clinical and radiological manifestations, we classified these patients into different categories describing a "TGA-PDL spectrum".TGA may have atypical clinical manifestations despite typical neuroimaging and patients with typical TGA may show vanishing extra-hippocampal punctate diffusion lesions. TGA, related clinical manifestations, and vanishing punctate diffusion lesions should be considered part of a larger "TGA-PDL spectrum", allowing for better diagnosis of typical and atypical cases and stimulating further studies.

In 2021, we assisted to the publication of new diagnostic criteria, classifications, and guidelines (CIDP, brain tumors, auto-immune encephalitis). Several studies helped to define the pharmacological management of focal and generalized epileptic seizures and epilepsy in pregnant women. The availability of biomarkers and the approval of immunotherapies are modifying the landscape of dementia management. Endovascular interventions without previous thrombolysis seems to be effective in anterior circulation acute ischemic stroke (AIS) and severe posterior circulation AIS. Neurologic complications of Sars-CoV-2 infection were further studied, as well as the efficacy of vaccines in immunosuppressed patients. New molecules and techniques show promising results for the treatment of migraine and cluster headache.L’année 2021 a été marquée par la publication des nouveaux critères diagnostiques, classifications et guidelines (polyradiculonévrite inflammatoire démyélinisante chronique, tumeurs cérébrales, encéphalites autoimmunes). L’attitude thérapeutique dans les épilepsies focales ou généralisées et l’épilepsie chez la femme enceinte a été mieux définie. Les marqueurs biologiques et les immunothérapies modifient le paysage de la prise en charge des démences. Le traitement endovasculaire des AVC de la circulation antérieure semble efficace indépendamment d’une thrombolyse préalable, ainsi qu’en cas d’AVC sévère de la circulation postérieure. Les complications neurologiques du SARS-CoV-2 ont été éclaircies et l’efficacité des vaccins étudiée chez les patients immunosupprimés. Plusieurs nouvelles molécules et techniques montrent des résultats prometteurs pour les migraines et céphalées en grappe.

Contains fulltext : 231797.pdf (Publisher’s version ) (Closed access) OBJECTIVES: Mild cognitive impairment (MCI) is associated with an increased risk of further cognitive decline, partly depending on demographics and biomarker status. The aim of the present study was to survey the clinical practices of physicians in terms of biomarker counseling, management, and follow-up in European expert centers diagnosing patients with MCI. METHODS: An online email survey was distributed to physicians affiliated with European Alzheimer's disease Consortium centers (Northern Europe: 10 centers; Eastern and Central Europe: 9 centers; and Southern Europe: 15 centers) with questions on attitudes toward biomarkers and biomarker counseling in MCI and dementia. This included postbiomarker counseling and the process of diagnostic disclosure of MCI, as well as treatment and follow-up in MCI. RESULTS: The response rate for the survey was 80.9% (34 of 42 centers) across 20 countries. A large majority of physicians had access to biomarkers and found them useful. Pre- and postbiomarker counseling varied across centers, as did practices for referral to support groups and advice on preventive strategies. Less than half reported discussing driving and advance care planning with patients with MCI. CONCLUSIONS: The variability in clinical practices across centers calls for better biomarker counseling and better training to improve communication skills. Future initiatives should address the importance of communicating preventive strategies and advance planning.

International audience; PURPOSE: Social cognition disorders after stroke are poorly described. Yet, rehabilitation difficulties are frequent after stroke. This study aimed to evaluate the frequency of social cognition disorders 3 years after a first-ever stroke and to assess the factors associated with this condition. The second aim was to describe all the cognitive domains altered in the same population. METHODS: Patients who suffered from a first-ever ischemic or hemorrhagic stroke underwent clinical and neuropsychological assessment, which included the mini-Social cognition and Emotional Assessment (SEA) for evaluating social cognition. RESULTS: The 43 included patients were 67+/-15 years old, with a median Neurological Institute of Health Stroke Scale (NIHSS) (+/- interquartile range) at 0+/-1, and a median modified Rankin Scale (+/- interquartile range) at 1+/-1. Twenty patients (46.5%) had poor results in the facial emotions subtest; this factor was associated with a low educational grade (P=0.001). Fourteen patients (34.2%) had poor results on the "faux-pas" recognition subtest; this factor was associated with nonverbal episodic memory disorders (P=0.01). Thirty four patients (79.1%) had cognitive impairment, with at least 1 cognitive domain affected. CONCLUSIONS: The study demonstrates the high frequency of social cognition impairment 3 years after the first-ever stroke in young patients. Doctors and nurses should be sensitized to cognitive handicap after stroke because of difficulties for rehabilitation and returning to work.

According to neuropsychological models of anosognosia, there is a failure to transfer on-line awareness of dysfunction into a more generalised long term belief about memory function in Alzheimer's disease. This failure results in specific metamemory deficits for global predictions: patients overestimate their performance before the task but are able to monitor their memory performance after having experienced the task. However, after a delay, they are still not able to make accurate predictions. As previous work has mainly focused on long-term memory, the present study investigates this issue in short-term and working memory. Using both global and item-by-item metacognitive judgements in a digit span task, we showed that Alzheimer's disease patients are as accurate as older adults in monitoring their performance despite impaired memory. When they have the opportunity to test themselves, or when they have already performed the task, patients are able to use feedback to adjust their metacognitive judgements. Overall, these results show that even for a relatively complex task, patients with Alzheimer's disease are aware of their difficulties in the here-and-now.

International audience; BACKGROUND: Difficulties with meal-related activities (preparing meals and food shopping) may influence food intake, and contribute to nutritional risk among elderly people. All known studies on this topic had a cross-sectional design, thereby no causal relationships could be derived. We aim to investigate if difficulties with meal-related activities can contribute to subsequent weight loss in community-dwelling older people. METHODS: We used data of older subjects from the MAPT Study (n = 1531, median age = 74 years, 64% women), who provided prospective data on weight every 6 months and cognitive, physical condition, and functional capacities every year during a 3-year period. Difficulties preparing meals and shopping were evaluated each year with the Alzheimer's Disease Cooperative Study-Activities of Daily Living Prevention Instrument (ADCS ADL-PI) Scale. The risk of losing weight (≥5% or ≥ 3 kg in the following year) was estimated using a time-dependent Cox regression model. RESULTS: During the 3-year follow-up, a total of 851 subjects experienced at least a 5% or 3 kg weight loss. Two hundred thirty-seven subjects declared having difficulties with meal preparation at least once, and 133 declared having difficulties shopping. Subjects reporting any meal-related difficulties were older (p \textless 0.001), had more depressive symptoms (p \textless 0.001), and a lower physical function (p \textless 0.001) compared to those without difficulties. They also had a lower cognitive score (preparing meals: p \textless 0.001; shopping: p = 0.005) and a lower body mass index (preparing meals: p = 0.005; shopping: p = 0.023) at the end of the study. Meal-related activities were not associated with weight loss in unadjusted analysis and after adjustment for sex, age, depression, physical and cognitive status. CONCLUSION: Difficulties preparing meals and shopping had no effect on weight loss in community-dwelling older people, despite their association with advanced age, functional decline, and depressive symptoms.

Significant developments were published in 2020 in the field of blood biomarkers in Alzheimer's disease. Several studies helped to define more accurately the management of status epilepticus and of epilepsy in women of childbearing age. The new Swiss guidelines for the pre-hospital management of acute stroke were issued, as are new targets for stroke prevention. Numerous advances concerning the management of NMO-SD (NeuroMyelitis Optica Spectrum Disorder) were published. Different neurological presentations linked to the COVID-19 pandemic were described (central and peripheral). Several studies confirmed the effectiveness of new migraine treatments (including anti-CGRP). New pharmacological therapies are available for Parkinson's disease.L’année 2020 a vu d’importantes avancées dans le domaine des biomarqueurs sanguins pour le diagnostic biologique de la maladie d’Alzheimer. Plusieurs études permettent de mieux définir la prise en charge de l’épilepsie chez la femme en âge de procréer et de l’état de mal épileptique. Les nouvelles recommandations suisses pour la prise en charge préhospitalière de l’AVC aigu sont en cours de publication, tout comme de nouvelles cibles pour leur prévention secondaire. De nombreuses avancées concernant la prise en charge des Neuromyelitis Optica Spectrum Disorder ont été publiées. Divers tableaux neurologiques (centraux et périphériques) liés à la pandémie de Covid-19 ont été décrits. Plusieurs études ont permis de confirmer l’efficacité des nouveaux traitements de la migraine (notamment les anti-Calcitonin Gene-Related Peptide). Enfin, de nouvelles thérapies pharmacologiques sont disponibles pour la maladie de Parkinson.

Cognitive impairment can interfere with the fitness to drive. An increase in requests to assess this aspect is observed at Leenaards Memory Centre. Changes in the law could be an explanatory factor. The views formulated in 2019 are mainly unfavorable because all the patients present cognitive disorders, generally attributed to Alzheimer's disease or a related disorder, but never linked with aging only. Moreover, unfavorable views are frequently expressed before the age of 75. Therefore, each patient is unique, and each decision is based neither on the patient's age or his diagnosis, but rather on his cognitive profile. In this article we discuss the reasons for an unfavorable view and discuss them in the context of the tasks of our centre.Les troubles cognitifs peuvent interférer avec l’aptitude à la conduite automobile. Une hausse des demandes d’évaluation ciblée sur cet aspect est observée au Centre Leenaards de la Mémoire. Les modifications de la loi pourraient être un facteur explicatif. Les avis formulés en 2019 sont majoritairement défavorables chez les patients présentant des troubles cognitifs dus à une maladie d’Alzheimer ou une pathologie apparentée, mais jamais en lien avec le vieillissement seul. Les avis défavorables sont fréquents avant l’âge de 75 ans. Chaque situation est donc unique et chaque décision prise se base non pas sur l’âge du patient, ni sur le diagnostic étiologique, mais sur le profil cognitif. Nous abordons dans cet article les raisons d’un avis défavorable et les discutons dans le contexte des missions de notre centre.

Background: The frontal variant of Alzheimer’s disease (fAD) is poorly understood and poorly defined. The diagnosis remains challenging. The main differential diagnosis is the behavioral variant of frontotemporal degeneration (bvFTD). For fAD, there is some dissociation between the clinical frontal presentation and imaging and neuropathological studies, which do not always find a specific involvement of the frontal lobes. DAPHNE is a behavioral scale, which demonstrated excellent performance to distinguish between bvFTD and AD. Objective: The aim of the present study was to assess the reliability of this new tool to improve the clinical diagnosis of fAD. Methods: Twenty fAD patients and their caregivers were prospectively included and were compared with 36 bvFTD and 22 AD patients. Results: The three main behavioral disorders in the fAD patients were apathy, loss of empathy, and disinhibition. Three disorders were discriminant because they were less frequent and less severe in the fAD patients than in the bvFTD patients, namely hyperorality, neglect, and perseverations. This specific pattern of behavioral disorders was corroborated by SPECT or 18FDG PET-CT scan that showed that patients with fAD could have a medial frontal hypoperfusion, whereas in bvFTD patients the orbitofrontal cortex was the main involved region, with more diffuse hypoperfusion. Conclusion: We demonstrated that DAPHNE had good sensitivity and good specificity to discriminate between the three groups and in particular between fAD and bvFTD patients. DAPHNE is a quick tool that could help clinicians in memory clinics not only to differentiate bvFTD from typical AD but also from fAD.

International audience; An original device dedicated to additive manufacturing was developed to pre-bake cake batter. Its originality lies in the fact that pre-baking is ensured by ohmic heating implemented in a rectangular channel equipped with two parallel electrodes. Experiments and numerical studies were carried out and benchmarked. The rheological properties of the cake batter (non-Newtonian power-law fluid) and the influence of voltage and temperature on electrical conductivity were accommodated in the numerical model. Due to the low velocities of the very viscous products near the solid-liquid interface, it was found that the heterogeneity of the temperature at the nozzle outlet under continuous ohmic heating could lead to nozzle clogging when high temperatures are reached. Hot spots were identified in different areas of the channel, such as corners where the electric field is high and velocity is close to zero. A parametric study was performed on the impact of the thermophysical properties of the batter, showing that specific heat has a much greater impact than thermal conductivity on the accuracy of the tem-peratures computed. Analysis of the process parameters showed that a stronger electric field leads to a higher temperature gradient in the nozzle section. The temperature gradient decreases with electrode distance (delect) and nozzle width (l). This model could be used to optimize the ohmic heating nozzle configuration, with the objective of obtaining a continuous flow of pre-baked cake batter, while preventing clogging. Such a system could be used as 3D printing head. Industrial relevance: Conventional 3D printing of bakery products is based on the deposition of a batter, followed by a baking. This study proposes an innovative approach based on a printing nozzle equipped with ohmic heating, with the objective of achieving a uniform temperature distribution and of obtaining high mass flow rate. Despite a significant temperature gradient in the baked batter at the exit of the nozzle, the obtained results showed that adjusting the nozzle geometry allows a reduction of the gradient. Further investigations are thus needed to reduce the temperature gradient and to accommodate expansion of the batter in the case of formu-lation using baking powder. The transfer of such concept for industry application may be doable in a close future.

Chemotherapy is associated with transient or permanent cognitive dysfunction ranging from subjective complaints to measurable deficits in working memory, attention and language. Given that old age may be related to cognitive decline, the interaction between chemotherapy-induced cognitive impairment and the effects of age is of growing concern in view of our aging population. Chemotherapy-associated cognitive dysfunction may have an additive impact on pre-existing age-related cognitive performance decline, which calls for awareness in its detection, to reduce impact on quality of life and improve management of older patients. We discuss here the « chemobrain », concept, review the existing evidence about pathophysiology, neuroimaging and cognitive phenotype and propose practical tools for routine detection in the outpatient setting.Les chimiothérapies peuvent induire une dysfonction cognitive transitoire ou permanente, pouvant aller d’une plainte cognitive subjective à une atteinte réelle de la mémoire de travail, de l’attention ou du langage. L’interaction entre l’atteinte cognitive attribuée à ces thérapies et celle liée à l’âge est une question grandissante compte tenu du vieillissement de la population. Elle justifie une attention particulière à la détection précoce de troubles cognitifs afin d’en réduire l’impact négatif sur la qualité de vie et optimiser la prise en charge médicale. Dans cet article, nous abordons le concept de « chemobrain », et en revoyons les connaissances actuelles de physiopathologie, de neuro-imagerie ainsi que les phénotypes neuropsychologiques, afin de proposer quelques outils de détection et de prise en charge au cabinet.

Physical activity (PA) demonstrated benefits on brain health, but its relationship with blood biomarkers of neurodegeneration remains poorly investigated. We explored the cross-sectional associations of PA with blood concentrations of neurofilament light chain (NFL) and beta amyloid (Aβ)42/40. We further examined whether the interaction between PA and these biomarkers was longitudinally related to cognition. Four-hundred and sixty-five nondemented older adults engaged in an interventional study and who had a concomitant assessment of PA levels and blood measurements of NFL (pg/mL) and Aβ 42/40 were analyzed. A composite Z-score combining 4 cognitive tests was used for cognitive assessment up to a 4-year follow-up. Multiple linear regressions demonstrated that people achieving 500–999 and 2000+ MET-min/week of PA had lower (ln)NFL concentrations than their inactive peers. Logistic regressions revealed that achieving at least 90 MET-min/week of PA was associated with a lower probability of having high NFL concentrations (ie, ≥91.961 pg/mL [third quartile]). PA was not associated with (Aβ)42/40. Mixed-model linear regressions demonstrated that the reverse relationship between PA and cognitive decline tended to be more pronounced as Aβ 42/40 increased, while it was dampened with increasing levels of (ln)NFL concentrations. This study demonstrates that PA is associated with blood NFL but not with Aβ 42/40. Furthermore, it suggests that PA may attenuate the negative association between amyloid load and cognition, while having high NFL levels mitigates the favorable relationship between PA and cognition. More investigations on non demented older adults are required for further validation of the present findings.

A 69-year-old man was admitted from the emergency department of our hospital for subacute onset of visual complaints. The evening before admission, around 10 pm, while watching TV, he experienced binocular and persistent discomposed colors in the lower left visual field (appearing both inside and outside the television screen) that did not change with the direction of gaze. He went to bed and woke up at 1 am for usual nocturia; then, trying to read his alarm clock, he was unable to understand what time it was despite correctly seeing the numbers. He did not report other visual difficulties at that moment. When he woke again at 3 am, he had the impression he could not correctly define his position in space and, returning to bed, bumped into a lamp and had the feeling that his head went inside the lamp. At 5 am, waking up again, he found he was completely blind.

International audience; Among innovative freezing processes, electromagnetic wave assistance during freezing has received great attention in recent years. The literature provides interesting studies indicating that smaller ice crystals may be obtained during freezing with the assistance of microwaves. In the companion paper, we designed a laboratory scale prototype to perform experiments of this type in well controlled conditions at 2.45 GHz. In the current study, we performed freezing experiments using this prototype and developed a protocol to measure ice crystal sizes using X-ray micro-tomography. The methodology was first validated by measuring ice crystal distribution in unidirectional conventional freezing. Then several microwave assisted freezing modalities were studied. Experiments were conducted with pulsed and continuously applied microwaves. The impact of microwave irradiation time was studied at a constant incident microwave power, and then at constant energy supplied to the system. We observed a significant reduction of up to 25% in ice crystal size when microwave assistance was used during freezing with both pulsed and continuously applied microwaves. These observations tend to disconfirm the hypothesis in the literature according to which ice crystal size reduction is due to temperature oscillations. The only remaining hypothesis in the literature is that ice crystal size reduction may be due to the perturbation of the H-bond network in water, which could be a precursor to crystalline structure. It appeared that at constant incident microwave power, the increase in irradiation time tended to decrease ice crystal size. No significant difference in ice crystal size reduction was observed for a constant energy supplied to the system. The amount of energy supplied by microwaves seems to be a factor influencing ice crystal size. Industrial relevance Microwave assisted freezing is an emerging process which permits reducing ice crystal size, and thus improving frozen product quality. The measurement of ice crystals in samples frozen in controlled conditions of both freezing and microwave irradiation allows studying the main parameters that induce the reduction of their size. Better understanding of the relevant factors influencing nucleation and/or crystal growth can help to optimize the process.