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Post-stroke dementia is common but has heterogenous mechanisms that are not fully understood, particularly in patients with atrial fibrillation (AF)-related ischaemic stroke or TIA. We investigated the relationship between MRI small-vessel disease markers (including a composite cerebral amyloid angiopathy, CAA, score) and cognitive trajectory over 12 months. We included patients from the CROMIS-2 AF study without pre-existing cognitive impairment and with Montreal Cognitive Assessment (MoCA) data. Cognitive impairment was defined as MoCA

Neuropsychological assessments, raw scores I & II. Data displayed as raw scores for each patient on each assessment, at baseline and follow-up. Greyed scores represent impairment based on normalised scores thresholds. CW = colour-word; RMW/RMF = Recognition Memory Test, Words/Faces. ~ means data missing. (PDF 63 kb)

Initiation and suppression deficits are documented in patients with frontal lesions although this has typically been with different tasks that are hard to compare. The Hayling Sentence Completion Test (Burgess & Shallice, 1997) was designed to tap initiation, suppression and strategy use within the same sentence completion task. There are few studies specifically investigating the neural correlates of initiation and suppression using the same task in frontal patients. We investigated initiation, suppression and strategy use on the Hayling Test in 40 frontal patients, 30 posterior patients and 40 matched healthy controls. Lesions were analysed with a finer-grained frontal localisation method (Right/Left Lateral, Medial) and traditional methods (i.e., anterior/posterior). We analysed the standard clinical measures (Initiation RT, Suppression RT, Suppression Errors and Overall Score), composite error scores and strategic responses. The results showed that all four Hayling Test clinical measures were sensitive to frontal lesions; however, only Suppression Errors and the Overall measure were specific to frontal lobe damage. All frontal patients produced blatant suppression failures but there was a specific Right Lateral frontal effect for producing subtly incorrect responses. In addition, Right Lateral patients produced fewer correct strategic responses and incurred longer response times in doing so. These findings suggest that the right lateral frontal cortex plays a role in suppression and strategic processes.

Introduzione. In compiti di ricerca visiva i processi top-down coinvolti nel riconoscimento della forma dell’oggetto possono interferire nella elaborazione bottom-up degli attributi elementari che compongono l’oggetto. La performance in tali compiti può essere facilitata dopo inibizione selettiva della corteccia parietale destra tramite r-TMS. In questo studio abbiamo indagato il ruolo di lesioni cerebrali nei compiti di ricerca visiva per singole caratteristiche caratterizzati da interferenza tra il livello dell’oggetto e degli attributi elementari. Pazienti con lesione focale del lobo parietale potrebbero paradossalmente non risentire dell’effetto interferente esercitato dal riconoscimento della forma dell’oggetto. Metodo. Hanno partecipato allo studio quattro pazienti (1 femmina e 3 maschi) destrimani con lesione parietale destra (età media: 48 ± 7 anni; scolarità media: 10 ± 2 anni) suddivisi in 2 gruppi in base ai risultati della valutazione neuropsicologica: un gruppo con segni di neglect (N+ = 2) e un gruppo senza segni di neglect (N- = 2). Sono stati somministrati due compiti di ricerca visiva: un compito (A) caratterizzato dalla presenza di interferenza tra il livello dell’oggetto e degli attributi elementari e l’altro (B) privo di tale interferenza. Sono stati analizzati i tempi di reazione e l’accuratezza delle risposte mediante due ANOVA con i fattori Gruppo (N+ vs. N-) e Compito (A vs. B). Risultati. I pazienti N- presentavano tempi di reazione significativamente diversi tra compito A e B (p < 0.0001) con un vantaggio a favore di quest’ultimo. I pazienti N- non hanno tempi di reazione significativamente diversi tra i due compiti (p = 0.23) suggerendo pertanto che non risentono dell'effetto di interferenza che contraddistingue il compito A. Conclusioni. Questi dati suggeriscono che network distinti giocano un ruolo nei compiti di ricerca visiva e che la presenza di neglect può tradursi in una facilitazione paradossale della prestazione in tali compiti.

Objective:Cognitive reserve (CR) suggests that premorbid efficacy, aptitude, and flexibility of cognitive processing can aid the brain’s ability to cope with change or damage. Our previous work has shown that age and literacy attainment predict the cognitive performance of frontal patients on frontal-executive tests. However, it remains unknown whether CR also predicts the cognitive performance of non-frontal patients.Method:We investigated the independent effect of a CR proxy, National Adult Reading Test (NART) IQ, as well as age and lesion group (frontal vs. non-frontal) on measures of executive function, intelligence, processing speed, and naming in 166 patients with focal, unilateral frontal lesions; 91 patients with focal, unilateral non-frontal lesions; and 136 healthy controls.Results:Fitting multiple linear regression models for each cognitive measure revealed that NART IQ predicted executive, intelligence, and naming performance. Age also significantly predicted performance on the executive and processing speed tests. Finally, belonging to the frontal group predicted executive and naming performance, while membership of the non-frontal group predicted intelligence.Conclusions:These findings suggest that age, lesion group, and literacy attainment play independent roles in predicting cognitive performance following stroke or brain tumour. However, the relationship between CR and focal brain damage does not differ in the context of frontal and non-frontal lesions.

To investigate the hemispheric lateralization of attentional processes during visual search tasks depending on the stimulus material embedding the target, twelve patients with unilateral left (n = 7) or right (n = 5) parietal lesions and 20 age and education matched healthy controls (HC) were recruited. We used a visual search task for a uniquely tilted oblique bar embedded in an object shape 'N' or in its mirror reversal 'И'. The accuracy and the averaged reaction times (RTs) in each stimulus type ('N' or 'И') were analysed.\ud \ud HC presented significantly longer RTs when the target bar was embedded in 'N' among its mirror reversed 'И' (p