Impaired motor inhibition during perceptual inhibition in older, but not younger adults: a psychophysiological study.

The prefrontal cortex (PFC) governs the ability to rapidly cancel planned movements when no longer appropriate (motor inhibition) and ignore distracting stimuli (perceptual inhibition). It is unclear to what extent these processes interact, and how they are impacted by age. The interplay between perceptual and motor inhibition was investigated using a Flanker Task, a Stop Signal Task and a combined Stop Signal Flanker Task in healthy young (n = 33, Mean = 24 years) and older adults (n = 32, Mean = 71 years). PFC activity was measured with functional near-infrared spectroscopy (fNIRS), while electromyography (EMG) measured muscle activity in the fingers used to respond to the visual cues. Perceptual inhibition (the degree to which incongruent flankers slowed response time to a central cue) and motor inhibition (the speed of cancellation of EMG activation following stop cues) independently declined with age. When both processes were engaged together, PFC activity increased for both age groups, however only older adults exhibited slower motor inhibition. The results indicate that cortical upregulation was sufficient to compensate for the increased task demands in younger but not older adults, suggesting potential resource sharing and neural limitations particularly in older adults.

Cognitive inhibition tasks interfere with dual-task walking and increase prefrontal cortical activity more than working memory tasks in young and older adults

BACKGROUND: Prior work suggests there may be greater reliance on executive function for walking in older people. The pre-frontal cortex (PFC), which controls aspects of executive function, is known to be active during dual-task walking (DTW). However, there is debate on how PFC activity during DTW is impacted by ageing and the requirements of the cognitive task. RESEARCH QUESTION: Functional near infrared spectroscopy, was used to investigate how PFC activity during walking was affected by (i) healthy ageing; and (ii) dual-tasks that utilise inhibition or working memory aspects of executive function. METHODS: Young (n = 26, 16 females, mean 20.9 years) and older (n = 26, 16 females, mean 70.3 years) adults performed five conditions: normal walking; Reciting Alternate Letters of the alphabet (RAL, requiring cognitive inhibition and working memory) during standing and walking; and serial subtraction by threes (SS3, requiring working memory alone) during standing and walking. Walking speed, cognitive performance, the PFC haemodynamic response, and fear of falling ratings were analysed using linear mixed-effects modelling. RESULTS: Compared to quiet standing, PFC activity increased during normal walking for older adults but decreased for young adults (p < 0.01). Across both groups, fear of falling contributed to higher PFC activity levels when walking (p < 0.01). PFC activity increased during DTW, and this increase was greater when performing RAL compared to the SS3 task (p < 0.01). Although the rate of correct responses was higher for RAL, walking speed reduced more with RAL than SS3 in the young group (p = 0.01), and the rate of correct responses reduced more when walking with RAL than SS3 in the older group (p < 0.01). SIGNIFICANCE: Older adults have increased levels of PFC activation during walking compared to younger adults and fear of falling is a cofounding factor. The interference between gait and a concurrent cognitive task is higher when the cognitive task requires inhibition.

Finding meaning and purpose: a framework for the self-management of neurological conditions.

PURPOSE: Self-management has been proposed as the way forward in improving health outcomes for people with neurological conditions; yet the experience and meaning of self-management for people with neurological conditions has rarely been focused on specifically. The current study addressed the question, what is the experience of self-managing a neurological condition? A secondary aim was to examine the feasibility of exploring self-management across neurological conditions. MATERIALS AND METHODS: A qualitative, phenomenological approach was adopted, which recognised service users as the experts on their conditions. Data-prompted interviews, using scrapbooks, were conducted with eight people with various neurological conditions, residing in the north-east of England. RESULTS: Interpretative phenomenological analysis (IPA) identified two key themes. Theme one, "meaning and purpose," identified achieving meaning and purpose in life as central to the self-management experience. It comprised five sub-themes (what is important to me; me and my condition; embracing my body; connecting with others; taking charge) which represented areas that could influence finding meaning and purpose. Theme two, "finding the new normal," emphasised the centrality of reflection in an ongoing self-management process. CONCLUSIONS: The findings form the basis of a proposed framework for the self-management of neurological conditions which could inform practice and be developed into a self-management tool.IMPLICATIONS FOR REHABILITATIONSelf-management is an ongoing process requiring continuous reflection.A positive psychology approach to self-management can support people to find meaning and purpose in life.This framework could be adapted into a self-management tool for people with neurological conditions.This self-management framework can be applied across neurological conditions.

Do anti-smooth muscle antibodies predict development of autoimmune hepatitis in patients with normal liver function? - A retrospective cohort review.

BACKGROUND: The presence of anti-smooth muscle autoantibody (SMA) in Autoimmune Hepatitis (AIH) is well established. However, there are no data demonstrating the clinical significance in patients with normal liver function and few showing positive predictive value for AIH when alanine aminotransferase (ALT) is raised. METHODS: We retrospectively established outcomes in a cohort of 251 consecutive patients with positive tubular or glomerular SMA. Patient records were checked for 12years after the positive SMA result to identify development of AIH. RESULTS: Of 202 patients with SMA and ALT <55IU/L, one (0.5%) had a subsequent diagnosis of AIH and this patient probably had abnormal ALT at the time of SMA detection. 22% of 45 patients with raised ALT (>55IU/L) and 23% of 43 patients with persistently raised ALT (>3months duration), had a diagnosis of AIH on follow up. Of 10 patients with AIH, 80% were diagnosed within three months of the positive SMA. CONCLUSIONS: Progression to AIH in patients with normal liver function and positive SMA-T/G is rare but patients with positive SMA and raised ALT (>55IU/L) should be referred to secondary care for investigation. Positive predictive value of SMA with raised ALT for AIH was 22%.