[American Academy of Neurology, Washington, 18-25 April 2015]. / American Academy of Neurology, Washington, 18-25 avril 2015.

CEREBROVASCULAR DISEASES: The benefit of the thrombectomy using stents retrievers in the acute stroke phase is now demonstrated when there is a proximal occlusion of an intracranial artery, whatever its mechanism. The place of the anticoagulants in the management of cervical artery dissections remains uncertain, while the benefit of the blood pressure control in the secondary prevention of deep and lobar intracerebral hemorrhages is critical. The development of cardiac MRI, prolonged cardiac monitoring and transcranial doppler seems to improve the diagnosis of cardio-embolic sources of stroke. EPILEPSY: A specialized urgent-access single seizure clinic represents a model which reduces wait-times and improves patient access after a first fit. Co-locating a psychiatrist within outpatient epilepsy center leads to a reduction in psychiatric symptoms and people with psychogenic non-epileptic seizures. When neurologists around the world assess identical case scenarios for the diagnosis of epilepsy, concordance is between moderate and poor, showing that epilepsy diagnosis remains difficult. More than one third of elderly with new-onset epilepsy of unknown etiology exhibit temporal lobe atrophy on brain imaging. MOVEMENT DISORDERS: There is no major progress in the therapeutic approach of Parkinson's disease but the discovery of new genetic markers such as glucocerebrosidase mutations may greatly change our knowledge of the disease process and may induce new therapeutic strategies in the future. The natural history of the disease is also better understood from the prodromal phase to the post-mortem analysis of the brain and the classification of the processes based on abnormal protein deposits. DEMENTIA: The respective value of biomarkers (amyloid imaging versus CSF biomarkers) for in vivo diagnosis of Alzheimer's disease (AD) has been detailed. Therapeutic expectations mainly rely on anti-Aß immunization trials performed in preclinical (and no longer prodromal) stages of AD, with the aim of slowing the evolution of neuronal loss. Besides a lot of communications on dementia genetics or physiopathogeny, fascinating and promising results were presented on deep brain stimulation for depression resistant to medical treatment. PERIPHERAL NEUROPATHY: Ibudilast, administered with riluzole, is safe and tolerable in patients with amyotrophic lateral sclerosis (ALS), improves ALS function and delays progression. Patients with painful small fiber neuropathy have a high rate of mutations in the SCN9A gene, coding for Nav1.7 voltage-gated sodium-channels. Peripheral nerve lymphoma (NL) is a multifocal painful neuropathy that causes endoneurial inflammatory demyelination: primary NL is less severe than secondary NL, which occurs after remission, suggesting that nerve may be considered a "safe lymphoma haven". MULTIPLE SCLEROSIS (MS): Biotin in progressive forms of MS and daclizumab in relapsing-remitting forms appear to be promising treatments. In case of failure of current first-line and/or second-line therapeutics, alemtuzumab may be an interesting alternative treatment. Teriflunomide, dimethyl fumarate and fingolimod are oral treatments with confirmed efficacy and acceptable safety. Besides vitamin D insufficiency and smoking, which are confirmed risk factors for the disease, testosterone insufficiency (in males) and obesity are emerging risk factors, which could also be corrected.

[Dural-cavernous fistulas revealed by bilateral alternating third and sixth nerve palsies]. / Fistule durale carotido-caverneuse révélée par une paralysie bilatérale à bascule des troisièmes et sixièmes nerfs crâniens.

A 74-year-old male was referred for disequilibrium, associated with right third and sixth nerve palsies observed 2weeks after head trauma with no loss of consciousness. On clinical examination, 4months after the injury, contralateral (left) third and sixth nerve palsies were observed, while ocular motility was now normal on the right side. The remainder of the ophthalmological examination was normal. Upon further history, tinnitus was found to have been present since the trauma, and auscultation of the preauricular area demonstrated a systolic bruit. Cerebral angiogram confirmed the presence of bilateral dural-cavernous fistulas. Clinical features of indirect or dural-cavernous fistulas and therapeutic options proposed in the literature are reviewed.

Effect of gravity on vertical eye position.

There is growing evidence that gravity markedly influences vertical eye position and movements. A new model for the organization of brainstem upgaze pathways is presented in this review. The crossing ventral tegmental tract (CVTT) could be the efferent tract of an "antigravitational" pathway terminating at the elevator muscle motoneurons in the third nerve nuclei and comprising, upstream, the superior vestibular nucleus and y-group, the flocculus, and the otoliths. This pathway functions in parallel to the medial longitudinal fasciculus pathways, which control vertical eye movements made to compensate for all vertical head movements and may also comprise the "gravitational" vestibular pathways, involved in the central reflection of the gravity effect. The CVTT could provide the upgaze system with the supplement of tonic activity required to counteract the gravity effect expressed in the gravitational pathway, being permanently modulated according to the static positions of the head (i.e., the instantaneous gravity vector) between a maximal activity in the upright position and a minimal activity in horizontal positions. Different types of arguments support this new model. The permanent influence of gravity on vertical eye position is strongly suggested by the vertical slow phases and nystagmus observed after rapid changes in hypo- or hypergravity. The chin-beating nystagmus, existing in normal subjects with their head in the upside-down position, suggests that gravity is not compensated for in the downgaze system. Upbeat nystagmus due to brainstem lesions, most likely affecting the CVTT circuitry, is improved when the head is in the horizontal position, suggesting that this circuitry is involved in the counteraction of gravity between the upright and horizontal positions of the head. In downbeat nystagmus due to floccular damage, in which a permanent hyperexcitation of the CVTT could exist, a marked influence of static positions of the head is also observed. Finally, the strongest argument supporting a marked role of gravity in vertical eye position is that the eye movement alterations observed in the main, typical physiological and pathological conditions are precisely those that would be expected from a direct effect of gravity on the eyeballs, with, moreover, no single alternative interpretation existing so far that could account for all these different types of findings.

[The French version of the FOUR score: A new coma score]. / Le FOUR score en français, un nouveau score d'évaluation de la profondeur du coma.

BACKGROUND: Comatose state is a major cause for admission to the intensive care unit. The most commonly used assessment score is the Glasgow coma scale (GCS). Although widely accepted, this score has several limitations. Recently, the full outline of unresponsiveness score (FOUR) has been validated and tested as reliable as the GCS. METHODS: We translated this score in French and tested its reliability in a neurological critical care unit. This study included eight critical care patients and eight intensive care patients. The patients were successively evaluated by two neurologists, four experienced nurses and five inexperienced nurses; a total of 176 evaluations were performed. The weighted kappa (kappa(W)) was used to determine the reliability of the evaluation for both the FOUR score and the GCS. RESULTS: The mean age of the patients was 62 years. The interobserver reliability of the French version of the FOUR score was high (kappa(W)=0.86; IC 95%: 0.83-0.89) comparable to that of the GCS (kappa(W)=0.85; IC 95%: 0.82-0.88). CONCLUSION: The French version of the FOUR score has an excellent interobserver reliability. This score is easy to perform and well accepted, only requiring simple and short training.

Immunosuppressive therapy is more effective than interferon in neuromyelitis optica.

To determine long-term treatment (LTT) of neuromyelitis optica (NMO), we retrospectively reviewed therapies of 26 patients with NMO followed in five French neurological departments. To assess LTT efficacy, the probability of relapse free after LTT was analysed. Patients were divided into two groups according to the first treatment receiving interferon beta (IFN Group, seven patients) or immunosuppressants (IS Group, 19 patients). The probability of relapse was significantly lower in the IS Group (P =0.0007). From our results, interferon beta is not recommended, and one of the best current therapeutic options for NMO appears to be immunosuppressants.

Reproduction of self-rotation duration.

The vestibular system detects the velocity of the head even in complete darkness, and thus contributes to spatial orientation. However, during vestibular estimation of linear passive self-motion distance in darkness, healthy human subjects mainly rely on time, and they replicate also stimulus duration when required to reproduce previous self-rotation. We then made the hypothesis that the perception of vestibular-sensed motion duration is embedded within encoding of motion kinetics. The ability to estimate time during passive self-motion in darkness was examined with a self-rotation reproduction paradigm. Subjects were required to replicate through self-driven transport the plateau velocity (30, 60 and 90 degrees /s) and duration (2, 3 and 4s) of the previously imposed whole-body rotation (trapezoid velocity profile) in complete darkness; the rotating chair position was recorded (500 Hz) during the whole trials. The results showed that the peak velocity, but not duration, of the plateau phase of the imposed rotation was accurately reproduced. Suspecting that the velocity instruction had impaired the duration reproduction, we added a control experiment requiring subjects to reproduce two successive identical rotations separated by a momentary motion interruption (MMI). The MMI was of identical duration to the previous plateau phase. MMI duration was fidelitously reproduced whereas that of the plateau phase was hypometric (i.e. lesser reproduced duration than plateau) suggesting that subjective time is shorter during vestibular stimulation. Furthermore, the accurate reproduction of the whole motion duration, that was not required, indicates an automatic process and confirms that vestibular duration perception is embedded within motion kinetics.

Upbeat nystagmus due to a small pontine lesion: evidence for the existence of a crossing ventral tegmental tract.

We report a patient with an isolated large upbeat nystagmus (UBN) in the primary position of gaze. Eye movements were filmed and recorded using electro-oculography. The upward vestibulo-ocular reflex gain, evaluated by pitching the head forward, was markedly reduced compared to when pitching the head back. The lesion was a probable lacunar infarction located in the paramedian and posterior part of the basis pontis, at the upper pons level. This UBN case, with one of the smallest brainstem lesions reported so far, supports the existence in humans of the crossing ventral tegmental tract, described in the cat and transmitting excitatory upward vestibular signals to the third nerve nucleus. It is also suggested that the decussation of this tract lies at the same upper pons level as in the cat but in a slightly more ventral location, i.e. in the posterior basis pontis.

[From the abducens nucleus to spatial memory: an ocular motor journey]. / Du noyau abducens à la mémoire spatiale: un parcours oculomoteur.

Advances in our knowledge on eye movements over the last 25 years are reviewed, focusing on the author's experience. First, the advantages of binocular frontal vision, which is a common characteristic of all predator mammals, are compared to those of lateral vision, characterizing their preys. Binocular frontal vision implies a perfect parallelism of both eyes, which is ensured in the pons by means of the abducens nucleus, controlling abduction as well as adduction. The pathological example of the "one-and-a-half" syndrome, in which the abducens nucleus and the adjacent medial longitudinal fasciculus are simultaneously impaired, is described. The main brainstem syndromes involving vertical eye movements are also reviewed: in particular, the third nerve nucleus syndrome, in which both ipsilateral third nerve paralysis and contralateral superior rectus paralysis (with hypotropia) result from a unilateral third nerve nucleus lesion. A case of upbeat nystagmus (in the primary position of gaze) due to a small upper pontine lesion, probably affecting the ventral tegmental tract (VTT) is also reported. This is an opportunity to emphasize that, although a number of cases of upbeat nystagmus due to focal brainstem lesions affecting the upward vestibular pathway (UVP)--either at the upper pontine (VTT) or caudal medullary level--exist in the literature, no convincing cases with downbeat nystagmus (in the primary position of gaze) due to a focal brainstem lesion have been reported. Downbeat nystagmus could result from a UVP hyperactivity (secondary to a floccular lesion) and the notion that this pathway is physiologically predominant compared to the downward pathway, maybe due to gravity, is developed. A new hypothesis about the role of the caudal medulla in UVP is also proposed. Next, the cortical control of saccadic eye movements is reviewed, with a reminder that reflexive saccades are mainly triggered by the parietal eye field whereas intentional saccades depend upon the frontal eye field. The inhibition of reflexive saccades is mainly controlled by the dorsolateral frontal cortex (DLPFC), i.e. area 46 of Brodmann. A few examples of the use of saccades as a research tool and model in cognitive neurosciences are given. The use of memory-guided saccades allowed us to study spatial memory and led us to propose a relatively original conception of the cortical control of spatial memory in which the DLPFC, the parahippocampal cortex and the hippocampal formation could be involved successively according to specific periods of time. An experiment using functional magnetic resonance imaging in a paradigm studying decision is described, again with the involvement of the DLPFC in the decisional process. Lastly, the usefulness of eye movements in clinical neuro-ophthalmology at the bedside as well as in neurophysiological or even neuropsychological research in the laboratory is emphasized.

[Complete ophthalmoplegia complicating ophthalmic herpes zoster]. / Ophtalmoplégie complète compliquant un zona ophtalmique.

We report a case of a 73-year-old patient with complete ophthalmoplegia following an episode of ophthalmic herpes zoster. MRI showed an associated ipsilateral temporal meningioma with cavernous sinus extension. We discuss the possible responsibility of these two conditions in the ocular motor signs.

[Convergence nystagmus and vertical gaze palsy of vascular origin]. / Nystagmus de convergence et paralysie de la verticalité du regard d'origine vasculaire.

A case of convergence-retraction nystagmus with upward vertical gaze paralysis and skew deviation (right hypotropia), without any other neurological signs, is reported. The probably vascular lesion was located at the mesodiencephalic junction, lying between the right border of the posterior commissure, the right interstitial nucleus of Cajal and the periaqueductal grey matter, accounting for the three ocular motor signs. The particular interest of this case is due to the relative smallness of the lesion.