3,007 research outputs found
The “broken escalator” phenomenon: Vestibular dizziness interferes with locomotor adaptation
BACKGROUND: Although vestibular lesions degrade postural control we do not know the relative contributions of the magnitude of the vestibular loss and subjective vestibular symptoms to locomotor adaptation. OBJECTIVE: To study how dizzy symptoms interfere with adaptive locomotor learning. METHODS: We examined patients with contrasting peripheral vestibular deficits, vestibular neuritis in the chronic stable phase (n = 20) and strongly symptomatic unilateral Meniere’s disease (n = 15), compared to age-matched healthy controls (n = 15). We measured locomotor adaptive learning using the “broken escalator” aftereffect, simulated on a motorised moving sled. RESULTS: Patients with Meniere’s disease had an enhanced “broken escalator” postural aftereffect. More generally, the size of the locomotor aftereffect was related to how symptomatic patients were across both groups. Contrastingly, the degree of peripheral vestibular loss was not correlated with symptom load or locomotor aftereffect size. During the MOVING trials, both patient groups had larger levels of instability (trunk sway) and reduced adaptation than normal controls. CONCLUSION: Dizziness symptoms influence locomotor adaptation and its subsequent expression through motor aftereffects. Given that the unsteadiness experienced during the “broken escalator” paradigm is internally driven, the enhanced aftereffect found represents a new type of self-generated postural challenge for vestibular/unsteady patients
A pilot randomized controlled trial of self-help relaxation to reduce post-stroke depression
© 2017, © The Author(s) 2017. Objective: To consider the potential of self-help relaxation training to treat depression after stroke. Design: Randomized controlled trial with cross-over at three months. Setting: Community. Participants: In total, 21 people with stroke, aged 49–82 years. Intervention: Autogenic relaxation CD. Main measure: Hospital Anxiety and Depression Scale–Depression (HADS-D) subscale. Results: No difference in depression change scores was identified between the treatment and control groups; however, on two follow-ups, significant positive differences relative to screening were found for the treatment group (at 2 months Z = −2.55, P =.011 and 12 months Z = −2.44, P =.015). A partial η2 =.07 was identified. Conclusion: Self-help relaxation holds promise as a self-help treatment for depression after stroke. Findings from this trial, considered with others of relaxation for depression, suggest that a study including a total of 80 participants would likely be sufficient to establish efficacy of the treatment, relative to controls, in those with stroke
Twelve month follow-up on a randomised controlled trial of relaxation training for post-stroke anxiety
© The Author(s) 2016. Objective: To follow up participants in a randomised controlled trial of relaxation training for anxiety after stroke at 12 months. Design: Twelve month follow-up to a randomised controlled trial, in which the control group also received treatment. Setting: Community. Participants: Fifteen of twenty one original participants with post-stroke anxiety participated in a one year follow-up study. Interventions: A self-help autogenic relaxation CD listened to five times a week for one month, immediately in the intervention group and after three months in the control group. Main measures: Hospital Anxiety and Depression Scale-Anxiety subscale and the Telephone Interview of Cognitive Status for inclusion. Hospital Anxiety and Depression Scale-Anxiety subscale for outcome. All measures were administered by phone. Results: Anxiety ratings reduced significantly between pre and post-intervention, and between pre-intervention and one year follow-up (‡2(2) = 22.29, p < 0.001). Conclusions: Reductions in anxiety in stroke survivors who received a self-help autogenic relaxation CD appear to be maintained after one year
Impairment of spatial cognitive function with preservation of verbal performance during spatial disorientation
Spatial disorientation, which is responsible for up to 30% of aircraft accidents causes impairment of cognitive function which may further compromise a pilot's ability to think his way out of the situation and regain control [1,]. The functional-anatomical separation of spatial and verbal processing [10,11] raises the possibility of selective interference between the task of resolving spatial disorientation and the ability to perform concurrent spatial, as opposed to verbal, secondary tasks. We report for the first time a degradation of spatial task performance with preservation of verbal performance when subjects in a simulator are disoriented by conflict between self- motion and visual flow in the view of the external environment
VEGF guides angiogenic sprouting utilizing endothelial tip cell filopodia
Vascular endothelial growth factor (VEGF-A) is a major regulator of blood vessel formation and function. it controls several processes in endothelial cells, such as proliferation, survival, and migration, but it is not known how these are coordinately regulated to result in more complex morphogenetic events, such as tubular sprouting, fusion, and network formation. We show here that VEGF-A controls angiogenic sprouting in the early postnatal retina by guiding filopodial extension from specialized endothelial cells situated at the tips of the vascular sprouts. The tip cells respond to VEGF-A only by guided migration; the proliferative response to VEGF-A occurs in the sprout stalks. These two cellular responses are both mediated by agonistic activity of VEGF-A on VEGF receptor 2. Whereas tip cell migration depends on a gradient of VEGF-A, proliferation is regulated by its concentration. Thus, vessel patterning during retinal angiogenesis depends on the balance between two different qualities of the extracellular VEGF-A distribution, which regulate distinct cellular responses in defined populations of endothelial cells
Long-term follow-up of intratympanic methylprednisolone versus gentamicin in patients with unilateral Menière’s disease
Objectives: To determine whether long term (>48 months)
symptomatic vertigo control is sustained in patients with
Menie`re’s disease from a previous comparative trial of
intratympanic methylprednisolone versus gentamicin, and if the two treatments remain nonsignificantly different at longterm follow-up.
Study Design: Mail survey recording vertigo frequency in
the previous one and six months, further intratympanic
treatment received, and validated symptom questionnaires.
Setting: Outpatient hospital clinic setting.
Patients: Adult patients with definite unilateral refractory Menie`re’s disease, who previously received in tratympanic treatment in a comparative trial.
Intervention: A survey of trial participants who received
intratympanic gentamicin (40 mg/mL) or methylprednisolone
(62.5 mg/mL).
Outcome measures: Primary: number of vertigo attacks in
the 6 months prior to receiving this survey compared with
the 6 months before the first trial injection.
Secondary: : Number of vertigo attacks over the previous 1 month; validated symptom questionnaire scores of tinnitus, dizziness, vertigo, aural fullness, and functional disability.
Results: Average follow-up was 70.8 months (standard
deviation 17.0) from the first treatment injection. Vertigo attacks in the 6 months prior to receiving the current survey reduced by 95% compared to baseline in both drug groups (intention-to-treat analysis, both p<0.001). No significant difference between drugs was found for the primary and secondary outcomes. Eight participants (methylprednisolone ¼ 5 and gentamicin ¼ 3) required further injections for relapse after completing the original trial.
Conclusion: Intratympanic methylprednisolone treatment provides effective long-lasting relief of vertigo, without the known inner-ear toxicity associated with gentamicin. There are no significant differences between the two treatments at long term follow-up
Cohort profile: the avon longitudinal study of parents and children: ALSPAC mothers cohort
The Avon Longitudinal Study of Children and Parents (ALSPAC) was established to understand how genetic and environmental characteristics influence health and development in parents and children. All pregnant women resident in a defined area in the South West of England, with an expected date of delivery between 1st April 1991 and 31st December 1992, were eligible and 13 761 women (contributing 13 867 pregnancies) were recruited. These women have been followed over the last 19–22 years and have completed up to 20 questionnaires, have had detailed data abstracted from their medical records and have information on any cancer diagnoses and deaths through record linkage. A follow-up assessment was completed 17–18 years postnatal at which anthropometry, blood pressure, fat, lean and bone mass and carotid intima media thickness were assessed, and a fasting blood sample taken. The second follow-up clinic, which additionally measures cognitive function, physical capability, physical activity (with accelerometer) and wrist bone architecture, is underway and two further assessments with similar measurements will take place over the next 5 years. There is a detailed biobank that includes DNA, with genome-wide data available on >10 000, stored serum and plasma taken repeatedly since pregnancy and other samples; a wide range of data on completed biospecimen assays are available. Details of how to access these data are provided in this cohort profile
Fifty years of spellchecking
A short history of spellchecking from the late 1950s to the present day, describing its development through dictionary lookup, affix stripping, correction, confusion sets, and edit distance to the use of gigantic databases
Dynamics of Tunneling Centers in Metallic Systems
Dynamics of tunneling centers (TC) in metallic systems is studied, using the
technique of bosonization. The interaction of the TC with the conduction
electrons of the metal involves two processes, namely, the screening of the TC
by electrons, and the so-called electron assisted tunneling. The presence of
the latter process leads to a different form of the renormalized tunneling
frequency of the TC, and the tunneling motion is damped with a temperature
dependent relaxation rate. As the temperature is lowered, the relaxation rate
per temperature shows a steep rise as opposed to that in the absence of
electron assisted process. It is expected that this behavior should be observed
at very low temperatures in a careful experiment. The present work thus tries
to go beyond the existing work on the {\it dynamics} of a two-level system in
metals, by treating the electron assisted process.Comment: REVTeX twocolumn format, 5 pages, two PostScript figures available on
request. Preprint # : imsc 94/3
- …