44 research outputs found

    A method for the assessment of time-varying brain shift during navigated epilepsy surgery

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    Image guidance is widely used in neurosurgery. Tracking systems (neuronavigators) allow registering the preoperative image space to the surgical space. The localization accuracy is influenced by technical and clinical factors, such as brain shift. This paper aims at providing quantitative measure of the time-varying brain shift during open epilepsy surgery, and at measuring the pattern of brain deformation with respect to three potentially meaningful parameters: craniotomy area, craniotomy orientation and gravity vector direction in the images reference frame

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    Longitudinal clinical and biomarker characteristics of non-manifesting LRRK2 G2019S carriers in the PPMI cohort

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    We examined 2-year longitudinal change in clinical features and biomarkers in LRRK2 non-manifesting carriers (NMCs) versus healthy controls (HCs) enrolled in the Parkinson’s Progression Markers Initiative (PPMI). We analyzed 2-year longitudinal data from 176 LRRK2 G2019S NMCs and 185 HCs. All participants were assessed annually with comprehensive motor and non-motor scales, dopamine transporter (DAT) imaging, and biofluid biomarkers. The latter included cerebrospinal fluid (CSF) Abeta, total tau and phospho-tau; serum urate and neurofilament light chain (NfL); and urine bis(monoacylglycerol) phosphate (BMP). At baseline, LRRK2 G2019S NMCs had a mean (SD) age of 62 (7.7) years and were 56% female. 13% had DAT deficit (defined as <65% of age/sex-expected lowest putamen SBR) and 11% had hyposmia (defined as ≤15th percentile for age and sex). Only 5 of 176 LRRK2 NMCs developed PD during follow-up. Although NMCs scored significantly worse on numerous clinical scales at baseline than HCs, there was no longitudinal change in any clinical measures over 2 years or in DAT binding. There were no longitudinal differences in CSF and serum biomarkers between NMCs and HCs. Urinary BMP was significantly elevated in NMCs at all time points but did not change longitudinally. Neither baseline biofluid biomarkers nor the presence of DAT deficit correlated with 2-year change in clinical outcomes. We observed no significant 2-year longitudinal change in clinical or biomarker measures in LRRK2 G2019S NMCs in this large, well-characterized cohort even in the participants with baseline DAT deficit. These findings highlight the essential need for further enrichment biomarker discovery in addition to DAT deficit and longer follow-up to enable the selection of NMCs at the highest risk for conversion to enable future prevention clinical trials

    Technological advances in glioma surgery

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    In the recent past, the impact of surgery has increased because of important technical advances which have significantly improved tumour resection for both high- and low-grade gliomas and at the same time patient quality of life. Today, surgery is asked not only to obtain tissue to reach a precise histological and molecular diagnosis but to influence many functional and oncological endpoints. To reach all these complex issues, surgery has significantly changed in the way it is performed. Surgeons have had the opportunity to incorporate many technical advances, particularly in imaging and intraoperative neurophysiology, which has significantly modified the way resection is conceived and technically performed. The surgeon should be able to critically integrate all these technologies, both at the time of surgical planning and also during surgery. Thanks to these improvements, surgery is today able to impact both survival and quality of life in patients with low- and high-grade gliomas

    Sleep Related Hypermotor Seizures with a Right Parietal Onset

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    Nocturnal frontal lobe epilepsy (NFLE) is a syndrome characterized by the occurrence of sleep related seizures of variable complexity and duration. Hypermotor seizures (HMS) represent a classic manifestation of this syndrome, associated with a perturbation of the ventromesial frontal cortex and anterior cingulate gyrus regions. Nevertheless, in recent years, reports have showed that the seizure onset zone (SOZ) need not be of frontal origin to generate HMS. Here we report an unusual case of a patient presenting with a seven-year history of drug-resistant sleep related HMS arising from the mesial parietal region. The presence of an infrequent feeling of levitation before the HMS was key to suspecting a subtle focal cortical dysplasia in the right precuneus region. A stereo-EEG investigation confi rmed the extra-frontal seizure onset of the HMS and highlighted the interrelationship between unstable sleep and seizure precipitation
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