The development of neuropsychological assessment and rehabilitation with dementia

Volume one presents two research papers on the development of neuropsychological assessment and rehabilitation in dementia. The first is a systematic review on the evidence base of direct everyday action rehabilitation in dementia. Aspects of person-centred approach in dementia rehabilitation are adopted in a number of studies but the effects are yet to be investigated more systematically. Whilst studies of errorful interventions reported more consistent evidence of benefits, the category represents diverse approaches and there is a lack of direct comparisons of techniques to evaluate the relative merits. The limitations in the studies quality and in the current review impacted on the generalizability of the results. The second reports an empirical study of the utility of the Birmingham Cognitive Screen (BCoS) assessment in differentiating the neuropsychological profile between early onset Alzheimer’s disease (AD) and subcortical ischaemic vascular cognitive impairment. BCoS profiles between a control group (N=47), a AD group (N=30) and a vascular group (N=28) were modelled with binary logistic regression. Receiver Operating Characteristic (ROC) analysis revealed good fit of the models. The identified profiles correspond with the existing understanding of the two disease pathologies

Preliminary findings on the reliability and validity of the Cantonese Birmingham Cognitive Screen in patients with acute ischemic stroke

BACKGROUND: There are no currently effective cognitive assessment tools for patients who have suffered stroke in the People’s Republic of China. The Birmingham Cognitive Screen (BCoS) has been shown to be a promising tool for revealing patients’ poststroke cognitive deficits in specific domains, which facilitates more individually designed rehabilitation in the long run. Hence we examined the reliability and validity of a Cantonese version BCoS in patients with acute ischemic stroke, in Guangzhou. METHOD: A total of 98 patients with acute ischemic stroke were assessed with the Cantonese version of the BCoS, and an additional 133 healthy individuals were recruited as controls. Apart from the BCoS, the patients also completed a number of external cognitive tests, including the Montreal Cognitive Assessment Test (MoCA), Mini Mental State Examination (MMSE), Albert’s cancellation test, the Rey–Osterrieth Complex Figure Test, and six gesture matching tasks. Cutoff scores for failing each subtest, ie, deficits, were computed based on the performance of the controls. The validity and reliability of the Cantonese BCoS were examined, as well as interrater and test–retest reliability. We also compared the proportions of cases being classified as deficits in controlled attention, memory, character writing, and praxis, between patients with and without spoken language impairment. RESULTS: Analyses showed high test–retest reliability and agreement across independent raters on the qualitative aspects of measurement. Significant correlations were observed between the subtests of the Cantonese BCoS and the other external cognitive tests, providing evidence for convergent validity of the Cantonese BCoS. The screen was also able to generate measures of cognitive functions that were relatively uncontaminated by the presence of aphasia. CONCLUSION: This study suggests good reliability and validity of the Cantonese version of the BCoS. The Cantonese BCoS is a very promising tool for the detection of cognitive problems in Cantonese speakers

The prognosis of allocentric and egocentric neglect : evidence from clinical scans

We contrasted the neuroanatomical substrates of sub-acute and chronic visuospatial deficits associated with different aspects of unilateral neglect using computed tomography scans acquired as part of routine clinical diagnosis. Voxel-wise statistical analyses were conducted on a group of 160 stroke patients scanned at a sub-acute stage. Lesion-deficit relationships were assessed across the whole brain, separately for grey and white matter. We assessed lesions that were associated with behavioural performance (i) at a sub-acute stage (within 3 months of the stroke) and (ii) at a chronic stage (after 9 months post stroke). Allocentric and egocentric neglect symptoms at the sub-acute stage were associated with lesions to dissociated regions within the frontal lobe, amongst other regions. However the frontal lesions were not associated with neglect at the chronic stage. On the other hand, lesions in the angular gyrus were associated with persistent allocentric neglect. In contrast, lesions within the superior temporal gyrus extending into the supramarginal gyrus, as well as lesions within the basal ganglia and insula, were associated with persistent egocentric neglect. Damage within the temporo-parietal junction was associated with both types of neglect at the sub-acute stage and 9 months later. Furthermore, white matter disconnections resulting from damage along the superior longitudinal fasciculus were associated with both types of neglect and critically related to both sub-acute and chronic deficits. Finally, there was a significant difference in the lesion volume between patients who recovered from neglect and patients with chronic deficits. The findings presented provide evidence that (i) the lesion location and lesion size can be used to successfully predict the outcome of neglect based on clinical CT scans, (ii) lesion location alone can serve as a critical predictor for persistent neglect symptoms, (iii) wide spread lesions are associated with neglect symptoms at the sub-acute stage but only some of these are critical for predicting whether neglect will become a chronic disorder and (iv) the severity of behavioural symptoms can be a useful predictor of recovery in the absence of neuroimaging findings on clinical scans. We discuss the implications for understanding the symptoms of the neglect syndrome, the recovery of function and the use of clinical scans to predict outcome

The case of the unfamiliar implement

We examined the role of schema knowledge in everyday action by assessing the use of unfamiliar implements by patients with subcortical and frontal lobe damage. Although the patients were relatively good at naming or showing how the unfamiliar implements could be used outside of the task context, the patients omitted using the objects in everyday life tasks more often than control participants--either omitting the action step involving the objects or performing the action using a familiar object that was not normally used for this purpose. The data suggest that knowledge about objects in the context of a task can play a determining role in how objects are used in everyday action. In patients with reduced attentional resources, the task schema can over-ride weak bottom-up cueing of action from the objects, with the result that unfamiliar implements are not used.

BCoS Cognitive Screen

Following different kinds of brain damage, including stroke, head injury, carbon monoxide poisoning, and degenerative change, people can experience a range of cognitive problems, in addition to any difficulties in motor function. These problems strongly influence a patient’s ability to recover, but often patients are not routinely screened to detect them. BCoS Cognitive Screen is a new test instrument. The test pack consists of a manual, a ringbound Test Book, the Auditory Attention Test stimuli on CD, a pack of 15 Examiner Booklets, a pack of 15 Examinee booklets, and a set of test objects, all contained in a durable messenger bag. Developed to screen patients for cognitive problems, it provides a novel 'cognitive profile' across a range of cognitive processes within a one-hour testing session, that will indicate whether a patient has a clinical impairment (related to norms) in five primary domains of cognition: Attention and executive function, Language, Memory, Number skills, Praxis and action

The frequency and severity of extinction after stroke affecting different vascular territories

We examined the frequency and severity of visual versus tactile extinction based on data from a large group of sub-acute patients (n=454) with strokes affecting different vascular territories. After right hemisphere damage visual and tactile extinction were equally common. However, after left hemisphere damage tactile extinction was more common than visual. The frequency of extinction was significantly higher in patients with right compared to left hemisphere damage in both visual and tactile modalities but this held only for strokes affecting the MCA and PCA territories and not for strokes affecting other vascular territories. Furthermore, the severity of extinction did not differ as a function of either the stimulus modality (visual versus tactile), the affected hemisphere (left versus right) or the stroke territory (MCA, PCA or other vascular territories). We conclude that the frequency but not severity of extinction in both modalities relates to the side of damage (i.e. left versus right hemisphere) and the vascular territories affected by the stroke, and that left hemisphere dominance for motor control may link to the greater incidence of tactile than visual extinction after left hemisphere stroke. We discuss the implications of our findings for understanding hemispheric lateralization within visuospatial attention networks