Video exposure through virtual reality can improve older people's ability to manage postural instability caused by distortive visual environments.

In older adults, age-related degenerative processes and disorders often degrade some sensory systems more than others, which can make postural control disproportionally dependent on one kind of sensory information. The study aims were to investigate 1) the postural stability when healthy older adults were repeatedly exposed to a video in an immersive virtual reality (VR) environment, and 2) the relationship between stability during VR video exposure and self-reported physical activity, balance confidence, and nausea during VR. Twenty-seven older adults (18 females, mean age 71.3 years (SD 4.4)) watched a 120-second VR video 5 times with 10 minutes between sessions, while standing on a force platform recording their stability. The first VR video session produced a marked stability challenge, reflected by significantly increased use of anteroposterior and lateral total (p<0.001) and high frequency (p<0.001) energy compared with the control test quiet stance eyes open. However, repeated VR video sessions produced a multidimensional decrease in used total (p<0.001), low (p = 0.002), and high frequency energy (p<0.001). Participants used more energy in anteroposterior compared with lateral direction across sessions within all spectral ranges (p<0.001). Participants with higher physical activity level used less low frequency energy in anteroposterior direction during VR video session 1 (p = 0.033). No association was seen between balance confidence or nausea during VR and energy used during VR video sessions 1 and 5. Healthy older adults adapt fast to distortive visual environments, and thus, CNS can utilize the information provided by a few repeated VR video sessions into suitable movement strategies that have a simultaneous multidimensionally positive effect. VR may introduce numerous opportunities to customize novel rehabilitation approaches to address when the visual system causes and/or suffers from issues. However, a common problem for the older adult was that about 33% of the participants became nauseated by the VR video stimuli.

Long-term linguistic outcome in adults with congenital cytomegalovirus infection.

BACKGROUND: Congenital cytomegalovirus (cCMV) is the most common prenatal infection and the main infectious cause of neurodevelopmental abnormalities in developed countries. Long-term neuropsychological outcome of cCMV infection is still not well understood. This is the first study that presents linguistic follow-up data performed on adults who were infected in utero. METHOD: All individuals from a universal newborn CMV screening study in Sweden sampled from 1977 to 1985 were invited to participate in a follow-up study. 34/71 persons (48%) with cCMV and 22/46 controls (48%) were enrolled. Participants were between 34 and 43 years. Linguistic ability was evaluated with two-word fluency tasks (FAS letter fluency and verb fluency), and a qualitative analysis of the participants' word retrieval strategies was conducted. RESULTS: No statistically significant group differences were found in the total number of retrieved words. When related to Swedish norm data, 43% of participants with cCMV infection, all asymptomatic at birth, had adequate results on both FAS and verb fluency tasks, compared to 86% of the controls. Education level was the most important factor for word fluency ability in both groups. Adults with cCMV infection and higher education levels used less effective retrieval strategies on FAS letter fluency than controls. CONCLUSION: This study suggests that adults with cCMV infection may have deficits in the word retrieval process, even in the absence of known neurodevelopmental disorders. Long-term effects of cCMV infection may exist even in those with asymptomatic infection at birth.

vHIT Testing of Vertical Semicircular Canals With Goggles Yield Different Results Depending on Which Canal Plane Being Tested.

Objective: The use of goggles to assess vertical semicircular canal function has become a standard method in vestibular testing, both in clinic and in research, but there are different methods and apparatus in use. The aim of this study was to determine what the cause of the systematic differences is between gain values in testing of the vertical semicircular canals with two different video head impulse test (vHIT) equipment in subjects with normal vestibular function. Study Design: Retrospective analysis of gain values on patients with clinically deemed normal vestibular function (absence of a corrective eye saccade), tested with either Interacoustics or Otometrics system. Prospective testing of subjects with normal vestibular function with the camera records the eye movements of both eyes. Finally, 3D sensors were placed on different positions on the goggles measuring the actual vertical movement in the different semicircular planes. Results: In the clinical cohorts, the gain depended on which side and semicircular canal was tested (p < 0.001). In the prospective design, the combination between the stimulated side, semicircular canal, and position of the recording device (right/left eye) highly influenced the derived gain (p < 0.001). The different parts of the goggles also moved differently in a vertical direction during vertical semicircular canal testing. Conclusion: The gain values when testing the function of the vertical semicircular canals seem to depend upon which eye is recorded and which semicircular plane is tested and suggests caution when interpreting and comparing results when different systems are used both clinically as well as in research. The results also imply that further research and development are needed to obtain accurate vertical semicircular canal testing, in regard to both methodology and equipment design.

Outward versus inward head thrusts with video-head impulse testing in normal subjects: does it matter?

OBJECTIVE: To investigate the effect of outward and inward head thrusts on the efficacy of compensatory eye movements generated during the video-Head Impulse Test (v-HIT) in healthy subjects. INTERVENTION: Diagnostic. Rapid movements of the head were performed either from the midline towards the side (outward thrusts) or from the side towards the midline (inward thrusts). MAIN OUTCOME MEASURE: Gain of the vestibulo-ocular reflex (VOR) as reported by two different v-HIT devices. RESULTS: A small but statistically significant increase of the VOR gain was found for outward impulses. This small difference is likely to be attributed to increased neck strain during outward impulses, and/or hypothetically, that an effect of Alexander's law during fast, high-frequency VOR could play a role. However, the differences are minute. CONCLUSION: We conclude that because the difference in the VOR gain between outward and inward thrusts was slight, both methods are acceptable for clinical use.

How to uncover the covert saccade during the head impulse test.

OBJECTIVE: The appearance of "covert" saccades in the head impulse test in patients with vestibular loss may lead to diagnostic misinterpretations. Here, we demonstrate a procedure that can convert covert eye saccades to overt when performing the head impulse test. PATIENTS: Patients with known vestibular deficits that have covert saccades during head impulse test. INTERVENTION: Diagnostic: random and sudden changes of the amplitude (degree of head turn) when performing the head impulse test. MAIN OUTCOME MEASURE: Evaluation of bedside test with video recording and registration from video head impulse test (v-HIT). RESULTS: A video recording and registration from v-HIT that demonstrate the covert saccades of a subject and how the overt saccade is uncovered by changing the amplitude of the head impulse. Five cases are briefly presented. CONCLUSION: By performing the head impulse test with random amplitudes, overt saccades may become detectable and advance accuracy in bedside diagnosis of vestibular deficits.