565 research outputs found

    Comparison of techniques for identification of peripheral vestibular nystagmus.

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    To determine the best clinical method for identifying peripheral vestibular nystagmus, by comparing eye movement examination with optic fixation, and with fixation removed using Frenzel's glasses, infra-red video-Frenzel's goggles or an ophthalmoscope, with results of electronystagmography

    The effect of cerebellar tDCS on sequential motor response selection

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    Transcranial direct current stimulation (tDCS) transiently alters cortical excitability and synaptic plasticity. So far, few studies have investigated the behavioral effects of applying tDCS to the cerebellum. Given the cerebellum’s inhibitory effects on cortical motor areas as well as its role in fine motor control and motor coordination, we investigated whether cerebellar tDCS can modulate response selection processes and motor sequence learning. Seventy-two participants received either cerebellar anodal (excitatory), cathodal (inhibitory), or sham (placebo) tDCS while performing a serial reaction time task (SRTT). To compare acute and long-term effects of stimulation on behavioral performance, participants came back for follow-up testing at 24 h after stimulation. Results indicated no group differences in performance prior to tDCS. During stimulation, tDCS did not affect sequence-specific learning, but anodal as compared to cathodal and sham stimulations did modulate response selection processes. Specifically, anodal tDCS increased response latencies independent of whether a trained or transfer sequence was being performed, although this effect became smaller throughout training. At the 24-h follow-up, the group that previously received anodal tDCS again demonstrated increased response latencies, but only when the previously trained sequence and a transfer sequence had to be performed in the same experimental block. This increased behavioral interference tentatively points to a detrimental effect of anodal cerebellar tDCS on sequence consolidation/retention. These results are consistent with the notion that the cerebellum exerts an inhibitory effect on cortical motor areas, which can impair sequential response selection when this inhibition is strengthened by tDCS.Action Contro

    Treating spondyloarthritis, including ankylosing spondylitis and psoriatic arthritis, to target: recommendations of an international task force

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    Background: Therapeutic targets have been defined for diseases like diabetes, hypertension or rheumatoid arthritis and adhering to them has improved outcomes. Such targets are just emerging for spondyloarthritis (SpA). Objective: To define the treatment target for SpA including ankylosing spondylitis and psoriatic arthritis (PsA) and develop recommendations for achieving the target, including a treat-to-target management strategy. Methods: Based on results of a systematic literature review and expert opinion, a task force of expert physicians and patients developed recommendations which were broadly discussed and voted upon in a Delphi-like process. Level of evidence, grade and strength of the recommendations were derived by respective means. The commonalities between axial SpA, peripheral SpA and PsA were discussed in detail. Results: Although the literature review did not reveal trials comparing a treat-to-target approach with another or no strategy, it provided indirect evidence regarding an optimised approach to therapy that facilitated the development of recommendations. The group agreed on 5 overarching principles and 11 recommendations; 9 of these recommendations related commonly to the whole spectrum of SpA and PsA, and only 2 were designed separately for axial SpA, peripheral SpA and PsA. The main treatment target, which should be based on a shared decision with the patient, was defined as remission, with the alternative target of low disease activity. Follow-up examinations at regular intervals that depend on the patient's status should safeguard the evolution of disease activity towards the targeted goal. Additional recommendations relate to extra-articular and extramusculoskeletal aspects and other important factors, such as comorbidity. While the level of evidence was generally quite low, the mean strength of recommendation was 9-10 (10: maximum agreement) for all recommendations. A research agenda was formulated. Conclusions: The task force defined the treatment target as remission or, alternatively, low disease activity, being aware that the evidence base is not strong and needs to be expanded by future research. These recommendations can inform the various stakeholders about expert opinion that aims for reaching optimal outcomes of SpA

    Postural stability when walking: Effect of the frequency and magnitude of lateral oscillatory motion

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    While walking on an instrumented treadmill, 20 subjects were perturbed by lateral sinusoidal oscillations representative of those encountered in transport: frequencies in the range 0.5-2 Hz and accelerations in the range 0.1-2.0 ms-2 r.m.s., corresponding to velocities in the range 0.032-0.16 ms-1 r.m.s. Postural stability was assessed from the self-reported probability of losing balance (i.e., perceived risk of falling) and the movements of the centre of pressure beneath the feet. With the same acceleration at all frequencies, the velocities and displacements of the oscillatory perturbations were greater with the lower frequency oscillations, and these caused greater postural instability. With the same velocity at all frequencies, postural instability was almost independent of the frequency of oscillation. Movements of the centre of pressure show that subjects attempted to compensate for the perturbations by increasing their step width and increasing their step rate
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