Longitudinal trajectory of plasma p-tau217 in cognitively unimpaired subjects.

Background: The advent of Alzheimer's disease-modifying drugs requires accurate biological diagnosis to identify candidates for these therapies. So far, the most promising single plasma biomarker is phosphorylated tau at threonine 217 (p-tau217). To understand its biological features, it is essential to know its longitudinal trajectory and factors influencing it in cognitively unimpaired subjects with no brain pathology.

Neuroradiological findings in GAA- ataxia (SCA27B): more than cerebellar atrophy.

Background: GAA- ataxia (SCA27B) is a recently reported late-onset ataxia caused by a GAA repeat expansion in intron 1 of the gene. Initial studies revealed cerebellar atrophy in 74-97% of patients. A more detailed brain imaging characterization of GAA- ataxia is now needed to provide supportive diagnostic features and earlier disease recognition.

Dynamic sampling rate: harnessing frame coherence in graphics applications for energy-efficient GPUs.

In real-time rendering, a 3D scene is modelled with meshes of triangles that the GPU projects to the screen. They are discretized by sampling each triangle at regular space intervals to generate fragments which are then added texture and lighting effects by a shader program. Realistic scenes require detailed geometric models, complex shaders, high-resolution displays and high screen refreshing rates, which all come at a great compute time and energy cost.

Omega-Test: A Predictive Early-Z Culling to Improve the Graphics Pipeline Energy-Efficiency.

The most common task of GPUs is to render images in real time. When rendering a 3D scene, a key step is to determine which parts of every object are visible in the final image. There are different approaches to solve the visibility problem, the Z-Test being the most common.

Heschl's gyrus fiber intersection area: a new insight on the connectivity of the auditory-language hub.

Objective: The functional importance of the superior temporal lobe at the level of Heschl's gyrus is well known. However, the organization and function of these cortical areas and the underlying fiber tracts connecting them remain unclear. The goal of this study was to analyze the area formed by the organization of the intersection of Heschl's gyrus-related fiber tracts, which the authors have termed the "Heschl's gyrus fiber intersection area" (HGFIA).

POLR3A-related spastic ataxia: new mutations and a look into the phenotype.

Adolescent-onset spastic ataxia is a proposed novel phenotype in compound heterozygous carriers of an intronic mutation (c.1909 + 22G > A) in the POLR3A gene. Here, we present ten new cases of POLR3A-related spastic ataxia and discuss the genetic, clinical and imaging findings.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) with chronic cough and preserved muscle stretch reflexes: evidence for selective sparing of afferent Ia fibres.

The aim of this study was to describe five patients with cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) with chronic cough and preserved limb muscle stretch reflexes. All five patients were in the seventh decade of age, their gait imbalance having been initiated in the fifth decade. In four patients cough antedated gait imbalance between 15 and 29 years; cough was spasmodic and triggered by variable factors.

Intraoperative Identification and Preservation of Verbal Memory in Diffuse Gliomas: A Matched-Pair Cohort Study.

Background: Recent glioma surgery series with intraoperative electrical stimulation (IES) language mapping have demonstrated high rates of postoperative memory impairment, raising a question regarding the efficacy of this approach to preserve memory.

Objective: To evaluate if intraoperative identification and preservation of verbal memory sites with IES mapping in diffuse gliomas in eloquent areas consistently protect patients from long-term postoperative decline in short-term memory.

Methods: A cohort of 16 subjects with diffuse low-grade or anaplastic gliomas that were operated with IES and intraoperative evaluation of language and verbal memory (cohort A) was matched by tumor side, pathology, and radiotherapy with a cohort of 16 subjects that were operated with IES and evaluation of language (cohort B).

Cross-Modal Recruitment of Auditory and Orofacial Areas During Sign Language in a Deaf Subject.

Background: Modern sign languages used by deaf people are fully expressive, natural human languages that are perceived visually and produced manually. The literature contains little data concerning human brain organization in conditions of deficient sensory information such as deafness.

Case Description: A deaf-mute patient underwent surgery of a left temporoinsular low-grade glioma.

Recovery of long-term paresis following resection of WHO grade II gliomas infiltrating the pyramidal pathway.

Recent publications had reported high rates of preoperative neurological impairments in WHO grade II gliomas (GIIG) that significantly affect the quality of life. Consequently, one step further in the analysis of surgical outcome in GIIG is to evaluate if surgery is capable to improve preoperative deficits. Here are reported two cases of GIIG infiltrating the primary motor cortex and pyramidal pathway that had a long-term paresis before surgery.

Super-refractory nonconvulsive status epilepticus secondary to fat embolism: A clinical, electrophysiological, and pathological study.

Background: Fat embolism syndrome (FES) is a rare complication of long-bone fractures and joint reconstruction surgery. To the best of our knowledge, we describe the clinical, electrophysiological, neuroimaging, and neuropathological features of the first case of super-refractory nonconvulsive status epilepticus (sr-NCSE) secondary to fat embolism.

Clinical Case: An 82-year-old woman was transferred to our intensive care unit because of a sudden decrease of consciousness level, right hemiparesis, and acute respiratory failure in the early postoperative period of knee prosthesis surgery.

Subcortical anatomy as an anatomical and functional landmark in insulo-opercular gliomas: implications for surgical approach to the insular region.

Object: Little attention has been given to the functional challenges of the insular approach to the resection of gliomas, despite the potential damage of essential neural networks that underlie the insula. The object of this study is to analyze the subcortical anatomy of the insular region when infiltrated by gliomas, and compare it with the normal anatomy in nontumoral hemispheres.

Methods: Ten postmortem human hemispheres were dissected, with isolation of the inferior fronto-occipital fasciculus (IFOF) and the uncinate fasciculus.

Subcortical anatomy of the lateral association fascicles of the brain: A review.

Precise knowledge of the connectivities of the different white matter bundles is of great value for neuroscience research. Our knowledge of subcortical anatomy has improved exponentially during recent decades owing to the development of magnetic resonance diffusion tensor imaging tractography (DTI). Although DTI tractography has led to important progress in understanding white matter anatomy, the precise trajectory and cortical connections of the subcortical bundles remain poorly determined.

Progressive multifocal leukoencephalopathy and idiopathic CD4 lymphocytopenia.

Idiopathic CD4 lymphocytopenia (ICL) is a syndrome described in patients with low counts of CD4 cells and no other causes for immunosuppression. A few cases of progressive multifocal leukoencephalopathy (PML) have been described in association with this entity. There is no effective treatment for any of them, and the clinical course and outcome are unpredictable.

Foix-Chavany-Marie syndrome caused by a disconnection between the right pars opercularis of the inferior frontal gyrus and the supplementary motor area.

Foix-Chavany-Marie syndrome (FCMS) is a rare type of suprabulbar palsy characterized by an automatic-voluntary dissociation of the orofacial musculature. Here, the authors report an original case of FCMS that occurred intraoperatively while resecting the pars opercularis of the inferior frontal gyrus. This 25-year-old right-handed man with an incidentally diagnosed right frontotemporoinsular tumor underwent surgery using an asleep-awake-asleep technique with direct cortical and subcortical electrical stimulation and a transopercular approach to the insula.

Analysis of the subcomponents and cortical terminations of the perisylvian superior longitudinal fasciculus: a fiber dissection and DTI tractography study.

The anatomy of the perisylvian component of the superior longitudinal fasciculus (SLF) has recently been reviewed by numerous diffusion tensor imaging tractography (DTI) studies. However, little is known about the exact cortical terminations of this tract. The aim of the present work is to isolate the different subcomponents of this tract with fiber dissection and DTI tractography, and to identify the exact cortical connections.

Cortex-sparing fiber dissection: an improved method for the study of white matter anatomy in the human brain.

Classical fiber dissection of post mortem human brains enables us to isolate a fiber tract by removing the cortex and overlying white matter. In the current work, a modification of the dissection methodology is presented that preserves the cortex and the relationships within the brain during all stages of dissection, i.e.

Imaging findings of lower limb apophysitis.

Objective: The objective of this article is to present a comprehensive review of apophysitis of the lower limb regarding anatomy, physiopathology, clinical findings, differential diagnosis, and imaging features with special emphasis on MRI.

Conclusion: Apophysitis, which is inflammation of the traction epiphysis resulting from chronic trauma, is a common abnormality that affects the growing child. Understanding the physiopathology of apophysitis is essential for a precise diagnosis on MRI.

White matter integrity and cognitive impairment in first-episode psychosis.

Objective: Impaired cognitive function has been identified as a core feature of schizophrenia. However, a significant proportion of patients do not show any cognitive deficits. The aim of this study was to assess if there were differences in white matter integrity between patients with and without cognitive impairment.

Specific brain structural abnormalities in first-episode schizophrenia. A comparative study with patients with schizophreniform disorder, non-schizophrenic non-affective psychoses and healthy volunteers.

Evidence so far indicates the consistent association between brain structural abnormalities and schizophrenia already present at the early phases of the illness. This study investigates the specificity of brain structural abnormalities in schizophrenia by using region-of-interest method of volumetric analysis in a heterogeneous sample of schizophrenia spectrum patients at their first break of the illness. 225 subjects, comprising 82 schizophrenia patients, 36 schizophreniform disorder patients and 24 patients with non-schizophrenic non-affective psychoses, and 83 healthy individuals underwent a magnetic resonance imaging brain scan.

White matter defects in first episode psychosis patients: a voxelwise analysis of diffusion tensor imaging.

Objective: Disruptions in white matter structure have consistently been shown in schizophrenia--but mainly in patients in whom the illness is well-established. In order to determine whether white matter abnormalities are present at illness onset, and to minimise the potentially confounding effects of chronic illness and treatment, we used diffusion tensor imaging to study a large cohort of first episode psychotic patients who were medication-naive.

Methods: Sixty two first episode patients and 54 controls matched on age, sex, years of education and laterality index underwent diffusion tensor imaging.

CT-guided fine-needle aspiration in vertebral osteomyelitis: true usefulness of a common practice.

Computed tomography (CT)-guided biopsy of the spine is considered a safe, accurate, and relatively inexpensive examination technique. Our purpose was to determine the diagnostic accuracy of CT-guided biopsies exclusively for vertebral osteomyelitis. A retrospective study was performed from a consecutive series of 72 patients with confirmed vertebral osteomyelitis with 46 CT-guided biopsies performed in 40 patients.