From Phineas Gage and Monsieur Leborgne to H.M.: Revisiting Disconnection Syndromes.

On the 50th anniversary of Norman Geschwind's seminal paper entitled 'Disconnexion syndrome in animal and man', we pay tribute to his ideas by applying contemporary tractography methods to understand white matter disconnection in 3 classic cases that made history in behavioral neurology. We first documented the locus and extent of the brain lesion from the computerized tomography of Phineas Gage's skull and the magnetic resonance images of Louis Victor Leborgne's brain, Broca's first patient, and Henry Gustave Molaison. We then applied the reconstructed lesions to an atlas of white matter connections obtained from diffusion tractography of 129 healthy adults.

[Informatics and health, from digitization to information and communication technologies (TIC)].

Integrating the progress that has been made on a daily basis since it was jointly commissioned in 2013 by the French National Academy of Medicine (Biotechnology Committee XX, Prof Emmanuel-Alain Cabanis) and the Technologies Academy (Pr Jean de Kervasdoué), this report, covering such a vast subject, can only represent one step in a long process. Summarized here in a volume compatible with the Bulletin, it makes reference to the full report (52 pages ; 22 pages of text, 4 pages of references, a 20-page glossary for physicians, plus 522 figures spanning 6 pages), which is available on the Academy's website. The six chapters first define "health" (WHO) and "informatics" and provide a brief history.

Shape and volume of craniofacial cavities in intentional skull deformations.

Intentional cranial deformations (ICD) have been observed worldwide but are especially prevalent in preColombian cultures. The purpose of this study was to assess the consequences of ICD on three cranial cavities (intracranial cavity, orbits, and maxillary sinuses) and on cranial vault thickness, in order to screen for morphological changes due to the external constraints exerted by the deformation device. We acquired CT-scans for 39 deformed and 19 control skulls.

[Virtual endoscopic navigation and body transparency based on computed tomography. A step towards in vivo imaging].

Progress in HR-CTdata processing has led to lower X-ray exposure and to better diagnostic performance. We describe 19 adult patients (among 5000) examined by HR CT with 64 detectors, acquisition and exposure protocols in mSv, spiral, 0.6-mm slices, 5To PACS.

[Boxing: traumatology and prevention].

In 1986, a surgeon who, as an amateur boxer himself was concerned with boxers' health, approached a pioneering Parisian neuroimaging unit. Thus began a study in close cooperation with the French Boxing Federation, spanning 25 years. In a first series of 52 volunteer boxers (13 amateurs and 39 professionals), during which MRI gradually replaced computed tomography, ten risk factors were identified, which notably included boxing style: only one of 40 "stylists" with a good boxing technique had cortical atrophy (4.

[Health risks of long-distance air travel. Role of the general practitioner].

Air transport is seeing an increase in long-distance flights (12-16 hours average flight time), greater seating capacity, and a higher proportion of elderly, and hence more fragile, passengers. The French Academy of Medicine recommends that medical care be reinforced, particularly on long-distance flights, through the following measures: (i) passengers should be informed in advance of potential risks, through a Passenger's Guide, (ii) all future passengers should be encouraged to seek health advice and information from their general practitioner, (iii) flight crew members should receive training as "in-flight medical correspondents", and (iv) airlines and plane designers should reserve a "medical space" on the plane, equipped with appropriate medical materials.

[Value of the functional neural tractography in the reconstruction of the visual pathways in DTMRI].

Objective: This article shows that functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are very useful in the in vivo description of the visual pathways using today's most advanced techniques and allowing fusion between fMRI and tractography. Two complementary techniques were combined: (1) DTI coupled with the tractography and (2) fMRI.

Materials And Methods: A group of 205 cases, normal and pathological, children and adults, were studied for tractographic reconstitution of visual pathways.

[Imaging the brain, from the cell to the organ].

Brain imaging has progressed over the centuries, from prehistory (surgical and sculptural empiricism), through the Middle Ages (dissection and drawings), the Renaissance (printing) and the 18th century (Spallanzani and ultrasounds), to the 19th century and the discovery of piezoelectricity by the Curie brothers and X-rays by Röntgen in 1895. The head had finally become transparent! The microscope was used by Ramon Y Cajal for histological and neuropathological brain studies. Marie Curie's discovery of radioisotopes paved the way for advances in in vivo neurophysiology.

Functional connectivity of the human red nucleus in the brain resting state at 3T.

Background And Purpose: Previous structural data obtained with diffusion tensor imaging axonal tracking have demonstrated possible in vivo connections between the human red nucleus (RN) and the sensorimotor and associative cortical areas. However, tractographic reconstructions can include false trajectories because of, for instance, the low spatial resolution of diffusion images or the inability to precisely detect fiber crossings. The rubral network was therefore reassessed by functional connectivity during the brain resting state.

[The results of MRI exploration of glaucoma patients: what are the benefits?].

After 13 years of glaucoma exploration using MRI at 1.5 and 3 Tesla, we have deduced that there is no specific characteristic between the different forms of this disease, which is manifested by a slowly progressing degenerative optical neuropathy, predominant from front to back (with volume of the optic nerve head always greater than the distal portions of the 2nd neurone, chiasma, and optic tract), interspersed with clinical flare-ups that are recognized by an intense localized hypersignal (frequently from the apex progressing along the canal). Visual tract involvement is always bilateral, even in cases where symptoms are exclusively unilateral (asymmetry can be observed in these cases).

[Personal identification with biometric and genetic methods].

The need for personal identification is growing in many avenues of society. To "identify" a person is to establish a link between his or her observed characteristics and those previously stored in a database. To "authenticate" is to decide whether or not someone is the person he or she claims to be.

Dissociation of the neural networks recruited during a haptic object-recognition task: complementary results with a tensorial independent component analysis.

Background And Purpose: The cerebral and cerebellar networks involved in bimanual object recognition were assessed by blood oxygen level-dependent functional MR imaging by using multivariate model-free analysis, because conventional univariate model-based analysis, such as the general linear model (GLM), does not allow investigation of resting, background, and transiently task-related brain activities.

Materials And Methods: Data from 14 healthy right-handed volunteers, scanned while successively performing bilateral finger movements and a bimanual tactile-tactile matching discrimination task were analyzed by using tensor-independent component analysis (TICA), which computes statistically independent spatiotemporal processes (P > .7) thought to reflect specific and distinct anatomofunctional neural networks.

[Computed tomography and cranial paleoanthropology].

Since its invention in 1972, computed tomography (C.T.) has significantly evolved.

Neural correlates of simple unimanual discrete and continuous movements: a functional imaging study at 3 T.

Introduction: The cerebral and cerebellar network involved in unimanual continuous and discrete movements was studied in blood oxygenation level-dependent functional magnetic resonance imaging (fMRI) at 3 T.

Methods: Seven healthy right-handed volunteers were scanned (1) while drawing a circle with the tip of the right index finger (continuous motor task), and (2) while drawing a triangle with the tip of the right index finger (discrete motor task).

Results: In both motor tasks, extensive activations were observed in the sensorimotor (M1/S1), parietal, prefrontal, insular, lateral occipital (LOC) and anterior cerebellar cortices.

Anatomical parcellation of the brainstem and cerebellar white matter: a preliminary probabilistic tractography study at 3 T.

Introduction: The aims of this study were: (1) to test whether higher spatial resolution diffusion tensor images and a higher field strength (3 T) enable a more accurate delineation of the anatomical tract within the brainstem, and, in particular, (2) to try to distinguish the different components of the corticopontocerebellar paths in terms of their cortical origins.

Methods: The main tracts of the brainstem of four volunteers were studied at 3 T using a probabilistic diffusion tensor imaging (DTI) axonal tracking. The resulting tractograms enabled anatomical well-delineated structures to be identified on the diffusion tensor coloured images.

Cortical projection to the human red nucleus: complementary results with probabilistic tractography at 3 T.

Introduction: In a previous study using streamlined diffusion tensor imaging (DTI) axonal tracking at 1.5 T, we found that the main afferents to the human red nucleus arise from the sensorimotor and prefrontal cortices. However, the spatial resolution of our data was low and our streamlining DTI algorithm was less powerful than the probabilistic tractography algorithm usually used to define connections between low anisotropic cortical or nuclear areas.

The neural network involved in a bimanual tactile-tactile matching discrimination task: a functional imaging study at 3 T.

Introduction: The cerebral and cerebellar network involved in a bimanual object recognition was studied in blood oxygenation dependent level functional magnetic resonance imaging (fMRI).

Methods: Nine healthy right-handed volunteers were scanned (1) while performing bilateral finger movements (nondiscrimination motor task), and (2) while performing a bimanual tactile-tactile matching discrimination task using small chess pieces (tactile discrimination task).

Results: Extensive activations were specifically observed in the parietal (SII, superior lateral lobule), insular, prefrontal, cingulate and neocerebellar cortices (HVIII), with a left predominance in motor areas, during the tactile discrimination task in contrast to the findings during the nondiscrimination motor task.

Three-dimensional Procrustes analysis of modern human craniofacial form.

The objective of this study was to analyze modern human craniofacial form using 3D Procrustes superimposition in order to establish a reference model and validate it on computed tomography (CT). The sample consists of 136 specimens from five modern human regional groups. Thirty-three craniofacial landmark coordinates have been recorded using a Microscribe and calculated on CT scans for five crania from the sample.

Paul Broca's historic cases: high resolution MR imaging of the brains of Leborgne and Lelong.

In 1861, the French surgeon, Pierre Paul Broca, described two patients who had lost the ability to speak after injury to the posterior inferior frontal gyrus of the brain. Since that time, an infinite number of clinical and functional imaging studies have relied on this brain-behaviour relationship as their anchor for the localization of speech functions. Clinical studies of Broca's aphasia often assume that the deficits in these patients are due entirely to dysfunction in Broca's area, thereby attributing all aspects of the disorder to this one brain region.

[Functional amblyopia: a functional MRI evaluation of the visual cortex response after treatment].

Purpose: Functional MRI evaluation of the cortical response in treated amblyopic patients.

Material And Methods: Clinical and functional MRI exploration of ten patients, seven men and three women aged from 21 to 59 years, with strabismus management during childhood. Functional evaluations were performed on a 1.

Cortical projections to the human red nucleus: a diffusion tensor tractography study with a 1.5-T MRI machine.

Introduction: Previous studies in apes and monkeys have shown that the red nucleus receives projections from the sensorimotor and premotor cortices, whereas other experiments carried out with injured human brains have found corticorubral projections issuing from associative areas. Therefore, we reassessed in vivo the human anatomical projections from the cerebral cortex to the red nucleus using diffusion tensor imaging (DTI) axonal tracking.

Methods: The connectivity between the cerebral cortex and the red nuclei of seven volunteers was studied at 1.

Resolution of homonymous visual field loss documented with functional magnetic resonance and diffusion tensor imaging.

A 68-year-old man developed right homonymous hemianopic paracentral scotomas from acute infarction of the left extrastriate area. He was studied over the ensuing 12 months with visual fields, conventional MRI, functional MRI (fMRI), and diffusion tensor imaging (DTI). As the visual field defect became smaller, fMRI demonstrated progressively larger areas of cortical activation.