View clinical trials related to Hemianopsia.
Filter by:Background: The most common visual field deficit after retro-chiasmatic lesions is homonymous hemianopia (HH), defined as the impossibility of seeing the contralesional visual hemisphere without ocular injury. HH affects between 90000 and 120 000 new cases per year in the United States and Europe HH was reported in 30% of patients after stroke (National Audit Office) (in France, with 130,000 strokes per year, 39,000 patients with HH). Despite the 30-year decline, the rehabilitation techniques have a low level of evidence of their effectiveness and few are used in routine clinical practice in France. Transcranial Alternate Current Stimulation (tACS) is a method of Alternative Current stimulation that can modulate neural activity by imposing local oscillatory activity. An observational study of occipital tACS in patients with optic nerve lesions showed an increase in visual field size, power, and occipital alpha synchrony. Two transorbital tACS studies showed visual improvements , and compensations for abnormally weak oscillatory activity by temporal resynchronization. Our team has demonstrated a role of noninvasive brain stimulation in right hemisphere frontal eye fields on cortical beta-high (~ 30 Hz) oscillatory activity, improving the visual perception of both hemi-fields and the fronto-parietal synchrony of the right hemisphere. Objective: This project aims to compare, on the same patient population, two tACS stimulation strategies, with the aim of increasing the attentional orientation towards the blind visual hemi-field and thus the visual detection of stimuli in this hemi-field. . For this, The investigator team will evaluate on the one hand an occipital stimulation (V1-IPS) contralateral to the lesion, at a alfa frequency (10 Hz), which induces the desynchronization of the contralateral hemisphere with the aim of improving the visual perception of targets in the blind visual hemi-field. the study will compare this intervention to a stimulation of the frontal region (FEF) of the right hemisphere at a high-beta frequency (30 Hz), which showed effects of facilitation of endogenous and exogenous attentional orientation. The two previous strategies will be compared to a placebo tACS stimulation session.
Information regarding the likely progress of post-stroke symptoms is vitally important to stroke survivors to allow them to plan for the future and to adjust to life after stroke. Moreover, the prevalence of morbidity secondary to stroke is of central importance to Health Professionals to understand the prognosis of the disease in the patients under their care. Additionally, it will also allow commissioners of care, planners and third sector organisations to adapt to and answer the needs of a post-stroke population. Currently, the data collected by national audit programmes are concentrated on what can be termed 'process or process of care' data. The utility of these data are in the ability to audit the care received by stroke survivors on stroke units against evidenced standards for care, thus ensuring evidence based practice. Nevertheless, process of care is only one form of measuring stroke unit care and the audit programmes collect some limited functional status data, data relating to risk-factor co-morbidities and treatment received data. Therefore, the scope of this study is to build on the minimum data set currently collected and to collect post-stroke data in domains not currently collected. The International Consortium for Health Outcomes Measurement (ICHOM) takes important steps to collect data outside of process of care data such as a Patient Reported outcome data in their minimum outcome data set for stroke [currently under review].. Nevertheless, the ICHOM doesn't currently advocate the specific collection of data relating to cognitive impairment or emotional problems secondary to stroke. It is in these important aspects that this study will augment the data set currently advocated by ICHOM to collect data in the areas of cognitive impairment and emotional problems secondary to stroke. Therefore, the aim of this study is to quantify the prevalence of morbidity at six months post-stroke.
This study investigates a new technology to assess the structure and function inside the eye. Retinal imaging of subjects with inner and outer retinal defects to detect areas of abnormal structure and function compared to other visual function tests.