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58 result(s) for "Racine, Caroline"
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Cognitive Processing Speed in Older Adults: Relationship with White Matter Integrity
Cognitive processing slows with age. We sought to determine the importance of white matter integrity, assessed by diffusion tensor imaging (DTI), at influencing cognitive processing speed among normal older adults, assessed using a novel battery of computerized, non-verbal, choice reaction time tasks. We studied 131 cognitively normal adults aged 55-87 using a cross-sectional design. Each participant underwent our test battery, as well as MRI with DTI. We carried out cross-subject comparisons using tract-based spatial statistics. As expected, reaction time slowed significantly with age. In diffuse areas of frontal and parietal white matter, especially the anterior corpus callosum, fractional anisotropy values correlated negatively with reaction time. The genu and body of the corpus callosum, superior longitudinal fasciculus, and inferior fronto-occipital fasciculus were among the areas most involved. This relationship was not explained by gray or white matter atrophy or by white matter lesion volume. In a statistical mediation analysis, loss of white matter integrity mediated the relationship between age and cognitive processing speed.
Long-term wireless streaming of neural recordings for circuit discovery and adaptive stimulation in individuals with Parkinson’s disease
Neural recordings using invasive devices in humans can elucidate the circuits underlying brain disorders, but have so far been limited to short recordings from externalized brain leads in a hospital setting or from implanted sensing devices that provide only intermittent, brief streaming of time series data. Here, we report the use of an implantable two-way neural interface for wireless, multichannel streaming of field potentials in five individuals with Parkinson’s disease (PD) for up to 15 months after implantation. Bilateral four-channel motor cortex and basal ganglia field potentials streamed at home for over 2,600 h were paired with behavioral data from wearable monitors for the neural decoding of states of inadequate or excessive movement. We validated individual-specific neurophysiological biomarkers during normal daily activities and used those patterns for adaptive deep brain stimulation (DBS). This technological approach may be widely applicable to brain disorders treatable by invasive neuromodulation. An implanted device in the brain enables wireless neural monitoring and stimulation for up to 15 months following implantation.
Neurocognitive Function in Newly Diagnosed Low-grade Glioma Patients Undergoing Surgical Resection With Awake Mapping Techniques
Abstract BACKGROUND: Low-grade glioma (LGG) patients have increased life expectancy, so interest is high in the treatments that maximize cognition and quality of life. OBJECTIVE: To examine presurgical baseline cognitive deficits in a case series of LGG patients and determine cognitive effects of surgical resection with awake mapping. METHODS: We retrospectively assessed neurological deficits, subjective concerns from patient or caregiver, and cognitive deficits at baseline and postsurgery for 22 patients with newly diagnosed LGG who underwent baseline neuropsychological evaluation and magnetic resonance imaging before awake surgical resection with mapping. Twelve of the 22 patients returned for postoperative evaluation approximately 7 months after surgery. RESULTS: At baseline, 92% of patients/caregivers reported changes in cognition or mood. Neurological examinations and Montreal Cognitive Assessment Scale scores were largely normal; however, on many tests of memory and language, nearly half of individuals showed deficits. After surgery, 45% had no deficits on neurological examination, whereas 55% had only transient or mild difficulties. Follow-up neuropsychological testing found most performances stable to improved, particularly in language, although some patients showed declines on memory tasks. CONCLUSION: Most LGG patients in this series presented with normal neurological examinations and cognitive screening, but showed subjective cognitive and mood concerns and cognitive decline on neuropsychological testing, suggesting the importance of comprehensive evaluation. After awake mapping, language tended to be preserved, but memory demonstrated decline in some patients. These results highlight the importance of establishing a cognitive baseline before surgical resection and further suggest that awake mapping techniques provide reasonable language outcomes in individuals with LGG in eloquent regions.
Prefrontal Physiomarkers of Anxiety and Depression in Parkinson’s Disease
Objective: Anxiety and depression are prominent non-motor symptoms of Parkinson’s disease (PD), but their pathophysiology remains unclear. We sought to understand their neurophysiological correlates from chronic invasive recordings of the prefrontal cortex (PFC). Methods: We studied four patients undergoing deep brain stimulation (DBS) for their motor signs, who had comorbid mild to moderate anxiety and/or depressive symptoms. In addition to their basal ganglia leads, we placed a permanent prefrontal subdural 4-contact lead. These electrodes were attached to an investigational pulse generator with the capability to sense and store field potential signals, as well as deliver therapeutic neurostimulation. At regular intervals over 3–5 months, participants paired brief invasive neural recordings with self-ratings of symptoms related to depression and anxiety. Results: Mean age was 61 ± 7 years, mean disease duration was 11 ± 8 years and a mean Unified Parkinson’s Disease Rating Scale, with part III (UPDRS-III) off medication score of 37 ± 13. Mean Beck Depression Inventory (BDI) score was 14 ± 5 and Beck Anxiety Index was 16.5 ± 5. Prefrontal cortex spectral power in the beta band correlated with patient self-ratings of symptoms of depression and anxiety, with r -values between 0.31 and 0.48. Mood scores showed negative correlation with beta spectral power in lateral locations, and positive correlation with beta spectral power in a mesial recording location, consistent with the dichotomous organization of reward networks in PFC. Interpretation: These findings suggest a physiological basis for anxiety and depression in PD, which may be useful in the development of neurostimulation paradigms for these non-motor disease features.
Invasive brain mapping identifies personalized therapeutic neuromodulation targets that suppress OCD network activity
Deep brain stimulation has been used to treat severe, refractory obsessive-compulsive disorder (OCD) with variable outcomes across multiple anatomical targets. To overcome these limitations, we developed an invasive brain mapping paradigm in which electrodes were implanted across the OCD cortico-striato-thalamo-cortical circuit. We then performed extensive stimulation mapping during a multi-day inpatient stay to identify personalized therapeutic targets and characterize their downstream circuit effects. We found two targets within the right ventral capsule (VC) that acutely reduced OCD symptoms. Prolonged VC stimulation suppressed high frequency activity within the structurally and functionally connected orbitofrontal and cingulate cortex, which were identified to be cortical nodes encoding the severity of OCD symptoms. These VC sites were implanted for DBS and combined stimulation of these targets led to a rapid therapeutic response. This case provides the first proof-of-concept that invasive brain mapping can be used to guide a novel personalized, multi-site neuromodulation approach to treat refractory OCD.
UNC45A deficiency causes microvillus inclusion disease–like phenotype by impairing myosin VB–dependent apical trafficking
Variants in the UNC45A cochaperone have been recently associated with a syndrome combining diarrhea, cholestasis, deafness, and bone fragility. Yet the mechanism underlying intestinal failure in UNC45A deficiency remains unclear. Here, biallelic variants in UNC45A were identified by next-generation sequencing in 6 patients with congenital diarrhea. Corroborating in silico prediction, variants either abolished UNC45A expression or altered protein conformation. Myosin VB was identified by mass spectrometry as client of the UNC45A chaperone and was found misfolded in UNC45AKO Caco-2 cells. In keeping with impaired myosin VB function, UNC45AKO Caco-2 cells showed abnormal epithelial morphogenesis that was restored by full-length UNC45A, but not by mutant alleles. Patients and UNC45AKO 3D organoids displayed altered luminal development and microvillus inclusions, while 2D cultures revealed Rab11 and apical transporter mislocalization as well as sparse and disorganized microvilli. All those features resembled the subcellular abnormalities observed in duodenal biopsies from patients with microvillus inclusion disease. Finally, microvillus inclusions and shortened microvilli were evidenced in enterocytes from unc45a-deficient zebrafish. Taken together, our results provide evidence that UNC45A plays an essential role in epithelial morphogenesis through its cochaperone function of myosin VB and that UNC45A loss causes a variant of microvillus inclusion disease.
A phase II double-blind multicentre, placebo-controlled trial to assess the efficacy and safety of alpelisib (BYL719) in paediatric and adult patients with Megalencephaly-CApillary malformation Polymicrogyria syndrome (MCAP): the SESAM study protocol
IntroductionThe megalencephaly capillary malformation polymicrogyria (MCAP syndrome) results from mosaic gain-of-function PIK3CA variants. The main clinical features are macrocephaly, somatic overgrowth, neurodevelopmental delay and brain anomalies. Alpelisib (Vijoice) is a recently FDA-approved PI3Kα-specific inhibitor for patients with PIK3CA-related overgrowth spectrum (PROS). During its development, in patients with the MCAP subgroup of PROS, there was no specific, standardised evaluation of the effect on neuro-cognitive functioning. Moreover, it remains unknown if the molecule crosses the blood-brain barrier. Our objective is to evaluate the efficacy of a 24 month treatment with alpelisib on adaptive behaviour in patients with MCAP syndrome.Methods and analysisSESAM is an industry-sponsored two-period multicentre French academic phase II trial, with a 6-month double-blind, placebo-controlled period followed by an open-label period. The primary endpoint is a ≥4-point improvement in the Vineland II Adaptive Behaviour Scale (VABS), 24 months after treatment initiation. Secondary objectives are safety, VABS improvement at 6 months, impact on the quality of life, epilepsy and hypotonia. 20 patients aged 2 to 40 years with an MCAP diagnosis and neurodevelopmental disorders of various degrees, will be followed monthly in local centres, centrally assessed (clinical, biological, neuropsychological and functional evaluation) at baseline and every 6 months. Patients will be evaluated by volumetric MRI at baseline and at 24 months. An optional lumbar puncture will be performed to investigate blood-brain barrier crossing. Inclusions were completed by April 2024, with the end of follow-up in November 2026.Given the efficacy of alpelisib in patients with PROS, if the drug crosses the blood-brain barrier, we can expect a clinical benefit for patients with neurocognitive disorders.Ethics and disseminationEthical approval was given by CPP Sud-Ouest et Outre-Mer I (reference: 2022-500197-34-01). Findings from this study will be disseminated via publication, reports and conference presentations.Trial registration number NCT05577754
Second-tier trio exome sequencing after negative solo clinical exome sequencing: an efficient strategy to increase diagnostic yield and decipher molecular bases in undiagnosed developmental disorders
Developmental disorders (DD), characterized by malformations/dysmorphism and/or intellectual disability, affecting around 3% of worldwide population, are mostly linked to genetic anomalies. Despite clinical exome sequencing (cES) centered on genes involved in human genetic disorders, the majority of patients affected by DD remain undiagnosed after solo-cES. Trio-based strategy is expected to facilitate variant selection thanks to rapid parental segregation. We performed a second step trio-ES (not only focusing on genes involved in human disorders) analysis in 70 patients with negative results after solo-cES. All candidate variants were shared with a MatchMaking exchange system to identify additional patients carrying variants in the same genes and with similar phenotype. In 18/70 patients (26%), we confirmed causal implication of nine OMIM-morbid genes and identified nine new strong candidate genes (eight de novo and one compound heterozygous variants). These nine new candidate genes were validated through the identification of patients with similar phenotype and genotype thanks to data sharing. Moreover, 11 genes harbored variants of unknown significance in 10/70 patients (14%). In DD, a second step trio-based ES analysis appears an efficient strategy in diagnostic and translational research to identify highly candidate genes and improve diagnostic yield.
A new mutational hotspot in the SKI gene in the context of MFS/TAA molecular diagnosis
SKI pathogenic variations are associated with Shprintzen–Goldberg Syndrome (SGS), a rare systemic connective tissue disorder characterized by craniofacial, skeletal and cardiovascular features. So far, the clinical description, including intellectual disability, has been relatively homogeneous, and the known pathogenic variations were located in two different hotspots of the SKI gene. In the course of diagnosing Marfan syndrome and related disorders, we identified nine sporadic probands (aged 2–47 years) carrying three different likely pathogenic or pathogenic variants in the SKI gene affecting the same amino acid (Thr180). Seven of these molecular events were confirmed de novo. All probands displayed a milder morphological phenotype with a marfanoid habitus that did not initially lead to a clinical diagnosis of SGS. Only three of them had learning disorders, and none had intellectual disability. Six out of nine presented thoracic aortic aneurysm, which led to preventive surgery in the oldest case. This report extends the phenotypic spectrum of variants identified in the SKI gene. We describe a new mutational hotspot associated with a marfanoid syndrome with no intellectual disability. Cardiovascular involvement was confirmed in a significant number of cases, highlighting the importance of accurately diagnosing SGS and ensuring appropriate medical treatment and follow-up.
Exome sequencing in severe non-syndromic specific learning and language disorders in a French cohort
Background Specific learning disorders (SLDs) affect approximately 5% of school-age children. In France, genetic investigations of complex non-syndromic SLD cases include chromosomal microarray analysis and fragile X syndrome testing. However, the examples of genes being described in intellectual disability or autism spectrum disorder and also reported in patients with complex and severe SLDs are multiplying. International efforts using exome sequencing have identified monogenic diseases that explain severe SLDs in some instances. The aim of our study was to investigate the value of exome sequencing in children with SLDs without intellectual disability and autism spectrum disorder. Methods We initiated a prospective study using exome sequencing in patients with well-documented, severe SLD. Results Analysis of 82 patients revealed pathogenic/likely pathogenic variants in 11 (13.4%) patients ( ADNP , BRAF , CREBBP , KCNN2 , KIF1A , RERE , SCN8A , SET , SMARCC2 (x2), TRIO ). In addition, 38 variants of uncertain significance in candidate genes for severe neurodevelopmental disorders (NDDs) or in genes of unknown significance that could contribute to the phenotype were identified in 30 patients. Limitations The study of 82 patients does not provide sufficient statistical power to conclude that exome testing adds value over chromosomal microarray analysis, or to determine which patient profiles are more likely to benefit from genetic testing. Studies with larger patient numbers are needed to increase statistical power. Conclusions This study confirms the involvement of NDD genes in milder phenotypes and suggests the potential of exome sequencing for diagnosing severe SLDs. Further research on larger samples is required to determine which SLDs are most likely to benefit from pangenomic explorations and to clarify the implication of candidate variants.