Background and purpose
During the COVID-19 outbreak, the presence of extensive white matter microhemorrhages was detected by brain MRIs. The goal of this study was to investigate the origin of this ...atypical hemorrhagic complication.
Methods
Between March 17 and May 18, 2020, 80 patients with severe COVID-19 infections were admitted for acute respiratory distress syndrome to intensive care units at the University Hospitals of Strasbourg for whom a brain MRI for neurologic manifestations was performed. 19 patients (24%) with diffuse microhemorrhages were compared to 18 control patients with COVID-19 and normal brain MRI.
Results
The first hypothesis was hypoxemia. The latter seemed very likely since respiratory failure was longer and more pronounced in patients with microhemorrhages (prolonged endotracheal intubation (
p
= 0.0002), higher FiO
2
(
p
= 0.03), increased use of extracorporeal membrane oxygenation (
p
= 0.04)). A relevant hypothesis, the role of microangiopathy, was also considered, since patients with microhemorrhages presented a higher increase of the D-Dimers (
p
= 0.01) and a tendency to more frequent thrombotic events (
p
= 0.12). Another hypothesis tested was the role of kidney failure, which was more severe in the group with diffuse microhemorrhages (higher creatinine level median of 293 µmol/L versus 112 µmol/L,
p
= 0.04 and more dialysis were introduced in this group during ICU stay 12 versus 5 patients,
p
= 0.04).
Conclusions
Blood–brain barrier dysfunction secondary to hypoxemia and high concentration of uremic toxins seems to be the main mechanism leading to critical illness-associated cerebral microbleeds, and this complication remains to be frequently described in severe COVID-19 patients.
In this work, we introduce a method to classify Multiple Sclerosis (MS) patients into four clinical profiles using structural connectivity information. For the first time, we try to solve this ...question in a fully automated way using a computer-based method. The main goal is to show how the combination of graph-derived metrics with machine learning techniques constitutes a powerful tool for a better characterization and classification of MS clinical profiles.
Sixty-four MS patients 12 Clinical Isolated Syndrome (CIS), 24 Relapsing Remitting (RR), 24 Secondary Progressive (SP), and 17 Primary Progressive (PP) along with 26 healthy controls (HC) underwent MR examination. T1 and diffusion tensor imaging (DTI) were used to obtain structural connectivity matrices for each subject. Global graph metrics, such as density and modularity, were estimated and compared between subjects' groups. These metrics were further used to classify patients using tuned Support Vector Machine (SVM) combined with Radial Basic Function (RBF) kernel.
When comparing MS patients to HC subjects, a greater assortativity, transitivity, and characteristic path length as well as a lower global efficiency were found. Using all graph metrics, the best
-Measures (91.8, 91.8, 75.6, and 70.6%) were obtained for binary (HC-CIS, CIS-RR, RR-PP) and multi-class (CIS-RR-SP) classification tasks, respectively. When using only one graph metric, the best
-Measures (83.6, 88.9, and 70.7%) were achieved for modularity with previous binary classification tasks.
Based on a simple DTI acquisition associated with structural brain connectivity analysis, this automatic method allowed an accurate classification of different MS patients' clinical profiles.
Objective
To present clinical, radiological, and pathological features of a cohort of patients with motor neuron involvement in association with anti-Ma2 antibodies (Ma2-Ab).
Methods
Retrospective ...case-series of patients with definite paraneoplastic neurological syndrome (PNS) and Ma2-Ab, and cases identified from a review of the literature.
Results
Among 33 Ma2-Ab patients referred between 2002 and 2016, we retrospectively identified three patients (9.1%) with a motor neuron syndrome (MNS). Seven additional cases were retrieved among the 75 Ma2-patients reported in the literature (9.3%). A total of ten patients are, therefore, described herein. MNS was evident as combined upper and lower MNS in four patients, isolated upper MNS in two, and isolated lower MNS in one; three patients were diagnosed with myeloradiculopathy. The most common MNS signs/symptoms were: hyperreflexia (80%), proximal weakness (60%), proximal upper-limb fasciculations (50%), head drop (40%), and dysarthria/dysphagia (30%). Brain MRI abnormalities included bilateral pyramidal tract T2-weighted/FLAIR hyperintensities (three patients). Spine MRI found bilateral, symmetric, T2-weighted signal abnormalities in the anterior horn in two patients. CSF examination was abnormal in nine patients. Cancer was found in seven patients (four testicular, two lung, and one mesothelioma). Eight patients underwent first-line immunotherapy. Second-line immunotherapy was adopted in all our patients and in none of those identified in the literature. Motor improvement was observed in 33% of our patients, and 20% in the literature series.
Conclusions
Motor neuron involvement could complicate Ma2-Ab-associated PNS in almost 10% of patients and must be carefully studied to adapt treatment. This disorder differs from amyotrophic lateral sclerosis.
We report a very unique clinical presentation of a patient who complained, after a left parietal brain damage, about feeling tactile stimulations on his right upper limb without being able to ...localize them.
Using a single case study approach, we report three experiments relying on several custom-made tasks to explore the different levels of somatosensory information processing, ranging from somato-sensation to somato-representation.
Our results showed a preserved ability to localize tactile stimuli applied on the right upper limb when using pointing responses while the ability to localize was less efficient when having to name the stimulated part (akin Numbsense). When the stimuli were applied on more distal locations (i.e., on the hand and on fingers), the number of correct responses decreased significantly independently of the modality of response. Finally, when visually presented with a stimulus delivered on the hand of an examiner in synchrony with the stimulation on the hidden hand of the patient, responses were largely influenced by the visual information available. Altogether, the convergence of these different customized tasks revealed an absence of autotopagnosia for motor responses for the right upper limb, associated with altered abilities to discriminate stimulus applied on distal and restricted/closer zones in the hand.
The somato-representation of our patient seemed to significantly rely on visual information, leading to striking deficits to localize tactile stimuli when vision and somesthesic afferences are discordant. This case report offers a clinical illustration of pathological imbalance between vision and somesthesia. Implications of these troubles in somato-representation on higher cognitive level processes are discussed.
MRI plays a crucial role in multiple sclerosis diagnostic and patient follow-up. In particular, the delineation of T2-FLAIR hyperintense lesions is crucial although mostly performed manually - a ...tedious task. Many methods have thus been proposed to automate this task. However, sufficiently large datasets with a thorough expert manual segmentation are still lacking to evaluate these methods. We present a unique dataset for MS lesions segmentation evaluation. It consists of 53 patients acquired on 4 different scanners with a harmonized protocol. Hyperintense lesions on FLAIR were manually delineated on each patient by 7 experts with control on T2 sequence, and gathered in a consensus segmentation for evaluation. We provide raw and preprocessed data and a split of the dataset into training and testing data, the latter including data from a scanner not present in the training dataset. We strongly believe that this dataset will become a reference in MS lesions segmentation evaluation, allowing to evaluate many aspects: evaluation of performance on unseen scanner, comparison to individual experts performance, comparison to other challengers who already used this dataset, etc.
Management of severe traumatic brain injury (first 24hours) Geeraerts, Thomas; Velly, Lionel; Abdennour, Lamine ...
Anaesthesia critical care & pain medicine,
April 2018, 2018-Apr, 2018-04-00, 20180401, 2018-04, Volume:
37, Issue:
2
Journal Article
Peer reviewed
Open access
The latest French Guidelines for the management in the first 24hours of patients with severe traumatic brain injury (TBI) were published in 1998. Due to recent changes (intracerebral monitoring, ...cerebral perfusion pressure management, treatment of raised intracranial pressure), an update was required. Our objective has been to specify the significant developments since 1998. These guidelines were conducted by a group of experts for the French Society of Anesthesia and Intensive Care Medicine (Société francaise d’anesthésie et de réanimation SFAR) in partnership with the Association de neuro-anesthésie-réanimation de langue française (ANARLF), The French Society of Emergency Medicine (Société française de médecine d'urgence (SFMU), the Société française de neurochirurgie (SFN), the Groupe francophone de réanimation et d’urgences pédiatriques (GFRUP) and the Association des anesthésistes-réanimateurs pédiatriques d’expression française (ADARPEF). The method used to elaborate these guidelines was the Grade® method. After two Delphi rounds, 32 recommendations were formally developed by the experts focusing on the evaluation the initial severity of traumatic brain injury, the modalities of prehospital management, imaging strategies, indications for neurosurgical interventions, sedation and analgesia, indications and modalities of cerebral monitoring, medical management of raised intracranial pressure, management of multiple trauma with severe traumatic brain injury, detection and prevention of post-traumatic epilepsia, biological homeostasis (osmolarity, glycaemia, adrenal axis) and paediatric specificities.
Background:
Pseudocystic inflammatory demyelinating lesions (PIDLs) are poorly described in MS and might represent a diagnostic challenge.
Objectives:
We described the clinical, radiological, ...pathological, and follow-up characteristics of 13 PIDL in 9 MS patients.
Methods:
We constituted a single-center retrospective case series of PIDLs in MS, defined on MRI as expansive cyst-like lesions, with a fluid-signal content, and a diameter of 1 cm or more.
Results:
PIDL often occurred at first event (56%), were often asymptomatic (69%), and encircled by a hypo-T2 diffusion-restricted rim and a thin ring-like gadolinium enhancement (100%) on magnetic resonance imaging (MRI). Associated typical MS lesions were constant. Biopsies from two PIDLs displayed classical features of active MS, except for unusual edema.
Conclusion:
PIDLs are clinically unremarkable and associated with a good outcome. Their easily recognizable MRI features could help avoid biopsy.
The care of multiple sclerosis (MS) in France is based on two complementary interlinked networks: MS expert centers in university hospitals and regional networks of neurologists. The routine use of ...European database for multiple sclerosis (EDMUS) in all those centers has paved the way for the constitution of a national registry, designated as Observatoire Français de la Sclérose En Plaques (OFSEP). It promotes a prospective, standardized, high-quality, and multimodal collection of data. On June 2018, there were 68.097 files, with 71.1% females, representing 761,185 person-years. This huge database is open to the scientific community and might contribute exploring unresolved issues and unmet needs in MS.
Cerebral aspergillosis is associated with a significant morbidity and mortality rate. The imaging data present different patterns and no full consensus exists on typical imaging characteristics of ...the cerebral lesions. We reviewed MRI findings in 21 patients with cerebral aspergillosis and correlated them to the immune status of the patients and to neuropathological findings when tissue was available. The lesions were characterized by their number, topography, and MRI signal. Dissemination to the brain resulted from direct spread from paranasal sinuses in 8 patients, 6 of them being immunocompetent. Hematogenous dissemination was observed in 13 patients, all were immunosuppressed. In this later group we identified a total of 329 parenchymal abscesses involving the whole brain with a predilection for the corticomedullary junction. More than half the patients had a corpus callosum lesion. Hemorrhagic lesions accounted for 13% and contrast enhancement was observed in 61% of the lesions. Patients with hematogenous dissemination were younger (p = 0.003), had more intracranial lesions (p = 0.0004) and had a higher 12-week mortality rate (p = 0.046) than patients with direct spread from paranasal sinuses. Analysis of 12 aneurysms allowed us to highlight two distinct situations. In case of direct spread from the paranasal sinuses, aneurysms are saccular and located on the proximal artery portions, while the hematogenous dissemination in immunocompromised patients is more frequently associated with distal and fusiform aneurysms. MRI is the exam of choice for cerebral aspergillosis. Number and type of lesions are different according to the mode of dissemination of the infection.
Abstract
BACKGROUND
Predicting the displacement of cranial nerves by tumors could make surgery safer and the outcome better. Recent advances in imaging and processing have overcome some of the limits ...associated with cranial nerve tractography, such as spatial resolution and fiber crossing. Among others, probabilistic algorithms yield to a more accurate depiction of cranial nerve trajectories.
OBJECTIVE
To report how cranial nerve probabilistic tractography can help the surgical strategy in a series of various skull base tumors.
METHODS
After distortion correction and region of interest seeding, a probabilistic tractography algorithm used the constrained spherical deconvolution model and attempted the reconstruction of cranial nerve trajectories in both healthy and displaced conditions.
RESULTS
Sixty-two patients were included and presented: vestibular schwannomas (n = 33); cerebellopontine angle meningiomas (n = 15); arachnoid or epidermoid cysts (n = 6); cavernous sinus and lower nerves schwannomas (n = 4); and other tumors (n = 4). For each patient, at least one ‘displaced’ cranial nerve was not clearly identified on classical anatomical MRI images. All 372 cranial nerves were successfully tracked on each healthy side; among the 175 cranial nerves considered ‘displaced’ by tumors, 152 (87%) were successfully tracked. Among the 127 displaced nerves of operated patients (n = 51), their position was confirmed intraoperatively for 118 (93%) of them. Conditions that led to tractography failure were detailed. On the basis of tractography, the surgical strategy was adjusted for 44 patients (71%).
CONCLUSION
This study reports a cranial nerve probabilistic tractography pipeline that can: predict the position of most cranial nerves displaced by skull base tumors, help the surgical strategy, and thus be a pertinent tool for future routine clinical application.
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