The brief executive language screen: sensitivity and specificity in acute to early sub-acute stroke.

INTRODUCTION: Propositional language and underlying executive functions can be impaired post-stroke and affect communication and quality of life. Current stroke screening tools are largely tailored to patients with aphasia, being either non-verbal or focussed on core language skills such as naming and repetition. The Brief Executive Language Screening Test (BELS) is a newly developed cognitive screening tool that assesses memory, oral apraxia, core language, as well as propositional language and associated executive functions that can be impacted and overlooked in stroke patients without aphasia. This study examines BELS sensitivity and specificity, and performance in acute to early sub-acute stroke relative to controls. METHOD: Cross-sectional BELS data from 88 acute left and right hemisphere stroke patients (within 7 weeks of stroke) and 116 age-matched healthy controls were compared using independent samples t-tests. ROC Curve Analysis was performed to determine a cutoff score for the BELS. RESULTS: Left and right stroke patients were reduced on all propositional language subtests, and executive function subtests of inhibition, strategy, and selection. Differences were also observed for Oral Apraxia, Naming, and Memory. By contrast, Word Comprehension and Repetition, and Sentence Completion Initiation (after corrections applied) did not differ between groups. A total BELS score of 79.25/100 was highly sensitive (.89) and specific (.89) when classifying stroke patients and healthy controls. CONCLUSION: The BELS is brief, sensitive, suitable for bedside administration, and can aid in detection and rehabilitation of subtle executive language impairments. This in turn will help improve relationships and quality of life post-stroke.

Hayling and stroop tests tap dissociable deficits and network-level neural correlates.

Although many executive function screens have been developed, it is not yet clear whether these assessments are equally effective in detecting post-stroke deficits of initiation and inhibition. This study presents a comparative analysis of the Stroop and Hayling tests aiming to evaluate whether these tests measure the same underlying cognitive functions and to identify the neural correlates of the deficits detected by both tasks. Sixty six stroke survivors and 70 healthy ageing controls completed the Hayling and Stroop tests. Stroke patients were found to exhibit qualitative performance differences across analogous Stroop and Hayling Test metrics intended to tap initiation and inhibition. The Stroop test was found to have high specificity to abnormal performance, but low sensitivity relative to the Hayling Test. Minimal overlap was present between the network-level correlates of analogous Stroop and Hayling Test metrics. Hayling Task strategy use metrics were significantly associated with distinct patterns of disconnection in stroke survivors, providing novel insight into the neural correlates of fine-grained behavioural patterns. Overall, these findings strongly suggest that the functions tapped by the Stroop and Hayling Test are both behaviourally and anatomically dissociable. The Hayling Test was found to offer improved sensitivity and detail relative to the Stroop test. This novel demonstration of the Hayling Test within the stroke population suggests that this task represents an effective measure for quantifying post-stroke initiation and inhibition deficits.

Post-stroke apathy: A case series investigation of neuropsychological and lesion characteristics.

Apathy is a multi-dimensional syndrome associated with reduced initiation, executive function and emotion toward goal-directed behaviour. Affecting ∼30% of stroke patients, apathy can negatively impact rehabilitation outcomes and increase caregiver burden. However, relatively little is known about the multi-dimensional nature of post-stroke apathy and whether these dimensions map onto neuropsychological and neuroanatomical correlates. The present study aimed to address this question in a case series of stroke patients with apathy. 65 patients with acute stroke were assessed on a comprehensive battery of neuropsychological tasks and 12 patients were identified as having clinically significant apathy on one or more domains on the Dimensional Apathy Scale. Individual scores were compared to a group of healthy controls and normative data where available. Lesion mapping was completed from clinical CT and MRI scans to characterise the extent and locations of each patient's lesion. All participants performed significantly poorer than controls on one or more tasks. Difficulties with inhibition were observed across all dimensions. Prospective memory deficits were also common, while speed and social cognition were only reduced in initiation and emotional apathy, respectively. Verbal fluency was not impaired in any of the patients, despite previously established relationships with apathy. Lesions were predominantly located in right subcortical regions, with some additional frontal, temporal and cerebellar/brainstem involvement. There was substantial overlap in lesion locations within and between dimensions, such that similar apathy symptoms occurred in patients with very different lesion sites. Overall, our results suggest that neuropsychological and lesion profiles of apathy in stroke patients may be more complex and heterogenous than in neurodegenerative disease, possibly due to functional changes occurring beyond the lesion site.

Investigating the role of future thinking in a case of highly superior autobiographical memory.

Highly superior autobiographical memory (HSAM) is characterised by a profound ability to recall personal experiences from long-term memory with extremely high detail and accuracy. Since the first documented case of HSAM in 2006, studies have demonstrated the apparent automatic and effortless retrieval of autobiographical memories, despite their Average performance on laboratory and neuropsychological tests of episodic memory. It remains unclear, however, if their ability to imagine future-oriented scenarios is also superior, a process that is known to rely heavily on our capacity to remember the past. Here we investigate autobiographical memory and future thinking in a case of HSAM. We report RS who endorses re-experiencing a constant influx of memories from almost every day of her life since early adolescence. RS's performance on tasks of autobiographical memory, episodic future thinking, and future-oriented scene construction was contrasted with six age- and sex-matched healthy control participants. Recollections of past autobiographical events were episodically richer in RS, but only when personal relevance of the event was highly constrained (i.e., cued by a single word and within a time limit). In addition, while imagination of plausible future events was significantly richer in episodic detail, construction of future-oriented narrative scenes was unremarkable. Our study is the first to investigate future thinking in HSAM. These individuals may engage in superior imagination of future scenarios, but only when these scenarios can be easily tied to their own personal narrative.

Initiation, Inhibition and Strategy Generation Across the Healthy Adult Lifespan.

OBJECTIVE: Executive functions are crucial for adaptive behavior in novel contexts. In healthy aging, these abilities are more sensitive to dysfunction than other cognitive abilities. The effect of aging on initiation, inhibition, and strategy use was investigated via performance on the Hayling Sentence Completion Test. METHOD: The standard Hayling Test and baseline cognitive tests were administered to healthy adults (N = 344), aged 18-89 years (cross-sectional study). Bivariate Pearson's correlations, partial correlations, and regression analyses were used to assess the impact of aging on the components of the Hayling Test. RESULTS: There were significant positive correlations between age and response time for both Initiation and Suppression, and the number of Suppression Errors. Further, older age was negatively associated with strategy use. These findings remained significant after controlling for demographic factors such as education and crystallized intelligence and other cognitive functions sensitive to aging such as fluid intelligence, attention, working memory and semantic and phonemic word fluency. CONCLUSIONS: This study provides clarification of the effect of age on the processes of initiation, inhibition, and strategy generation across the adult lifespan. The focus and analysis of strategy on the Hayling Test provides clinicians with an additional and valuable measure of executive functioning. That is, it provides insight into how older adults may be able to compensate for decline in these processes, and thus maximize quality of life and independence.

Verbal Initiation, Suppression, and Strategy Use and the Relationship with Clinical Symptoms in Schizophrenia.

OBJECTIVES: Individuals with schizophrenia have difficulties on measures of executive functioning such as initiation and suppression of responses and strategy development and implementation. The current study thoroughly examines performance on the Hayling Sentence Completion Test (HSCT) in individuals with schizophrenia, introducing novel analyses based on initiation errors and strategy use, and association with lifetime clinical symptoms. METHODS: The HSCT was administered to individuals with schizophrenia (N=77) and age- and sex-matched healthy controls (N=45), along with background cognitive tests. The standard HSCT clinical measures (initiation response time, suppression response time, suppression errors), composite initiation and suppression error scores, and strategy-based responses were calculated. Lifetime clinical symptoms [formal thought disorder (FTD), positive, negative] were calculated using the Lifetime Dimensions of Psychosis Scale. RESULTS: After controlling for baseline cognitive differences, individuals with schizophrenia were significantly impaired on the suppression response time and suppression error scales. For the novel analyses, individuals with schizophrenia produced a greater number of initiation errors and subtly wrong errors, and produced fewer responses indicative of developing an appropriate strategy. Strategy use was negatively correlated with FTD symptoms in individuals with schizophrenia. CONCLUSIONS: The current study provides further evidence for deficits in the initiation and suppression of verbal responses in individuals with schizophrenia. Moreover, an inability to attain a strategy at least partly contributes to increased semantically connected errors when attempting to suppress responses. The association between strategy use and FTD points to the involvement of executive deficits in disorganized speech in schizophrenia. (JINS, 2016, 22, 735-743).