Alessandro Iavarone

Visuospatial Memory in Healthy Elderly, AD and MCI: A Review

In the literature it is commonly reported that several spatial abilities decline with normal aging, even though such a decline is not uniform. So far, it is not yet clear which spatial components present a normal age-related decline, which ones are preserved and at what point the deficit is so severe to represent an index of mild cognitive impairment (MCI) or a symptom of potential degenerative progression as in the early-stage Alzheimers disease (AD). In particular, AD (from early onset) is characterised by impairments in constructive abilities, visuospatial intelligence, spatial short-term memory deficits, and disorders of spatial orientation (topographical disorientation). MCI indicates a condition, generally affecting older individuals, characterized by cognitive deficits including memory and/or non memory impairments and at high risk of progression to dementia. Three MCI subgroups have been distinguished and a very high risk of developing AD is associated to the amnestic MCI subtypes. Further, recent studies have suggested that the allocentric component of spatial memory might be taken as predictor of AD from MCI. Given the frequency of visuospatial deficits in early-stage AD, evaluation of visuospatial processes is a promising approach to find predictive markers of AD. Here we report a review of the literature exploring specific visuospatial components in normal aging, MCI, and AD. In this way we could shed some light on the role of these components in the progression from MCI to AD and pave the way for future studies.

Episodic future thinking in amnesic mild cognitive impairment

Results from behavioral studies of amnesic patients and neuroimaging studies of individuals with intact memory suggest that a brain system involving direct contributions from the medial temporal lobes supports both remembering the past and imagining the future (Episodic Future Thinking). In the present study, we investigated whether amnesic Mild Cognitive Impairment (aMCI) affects EFT. Amnesic MCI is a high-risk factor for Alzheimers disease and is characterized by a selective impairment of episodic memory, likely reflecting hippocampal malfunctioning. The present study assessed, for the first time, whether the reduction of episodic specificity for past events, evident in aMCI patients, extends also to future events. We present data on 14 aMCI patients and 14 healthy controls, who mentally re-experienced and pre-experienced autobiographical episodes. Transcriptions were segmented into distinct details that were classified as either internal (episodic) or external (semantic). Results revealed that aMCI patients produced fewer episodic, event-specific details, and an increased number of semantic details for both past and future events, as compared to controls. These results are discussed with respect to the constructive episodic simulation hypothesis, which suggests that reminiscence and future thinking are the expression of the same neurocognitive system.

Anosognosia for memory deficit in amnestic mild cognitive impairment and Alzheimer's disease

to investigate patterns of anosognosia for memory deficit in subjects with amnestic mild cognitive impairment (MCI) and Alzheimers disease (AD).

Gait patterns in parkinsonian patients with or without mild cognitive impairment

Although in recent years the relationship between cognition and gait in Parkinsons disease (PD) has received increasing attention, the specific connections between gait patterns and cognitive features are not fully understood. The objective of this study was to describe the gait patterns in patients affected by PD with or without mild cognitive impairment (MCI+ and MCI−, respectively). We also sought to find an association between gait patterns and specific cognitive profiles. Using a gait analysis system, we compared the gait patterns among MCI+ patients (n = 19), MCI− patients (n − 24), and age‐ and sex‐matched healthy subjects (HS; n = 20) under the following conditions: (1) normal gait, (2) motor dual task, and (3) cognitive dual task. In PD patients, gait parameters were evaluated in both the off and on states. Memory, executive, and visuospatial domains were assessed using an extensive neuropsychological battery. Compared with MCI− PD and HS, MCI+ PD patients displayed reduced step length and swing time and impairment of measures of dynamic stability; these dysfunctions were only partially reversed by levodopa. We also found that dual‐task conditions affected several walking parameters in MCI+ PD in the off and on states relative to MCI− PD and HS. Factor analysis revealed 2 independent factors, namely, pace and stability. The latter was strongly and directly correlated to the visuospatial domain. In conclusion, dysfunctions on specific gait parameters, which were poorly responsive to levodopa and highly sensitive to dual‐task conditions, were associated with MCI in PD patients. Importantly, visuospatial impairment was strongly associated with the development of instability and more generally with the progression of PD.

Age-related differences in distractor interference on line bisection

Using a bisection paradigm, we investigated age-related differences in susceptibility to distractor interference. Older and younger participants were asked to bisect a horizontal line flanked by a pair of distractors, placed in either left or right hemispace. The results showed that (1) in both groups the distractors interfered with line bisection so that the localization of subjective midpoint was selectively shifted away from their position; (2) the shifting of subjective midpoint was greater in the older than in the younger group when the distractors were placed in the left hemispace. We suggest that the increase of the bisection bias in the older group depends on changes in attentional mechanisms involved in inhibiting irrelevant information.

Caregiver burden and coping strategies in caregivers of patients with Alzheimer’s disease

Background Alzheimer’s disease (AD) causes considerable distress in caregivers who are continuously required to deal with requests from patients. Coping strategies play a fundamental role in modulating the psychologic impact of the disease, although their role is still debated. The present study aims to evaluate the burden and anxiety experienced by caregivers, the effectiveness of adopted coping strategies, and their relationships with burden and anxiety. Methods Eighty-six caregivers received the Caregiver Burden Inventory (CBI) and the State-Trait Anxiety Inventory (STAI Y-1 and Y-2). The coping strategies were assessed by means of the Coping Inventory for Stressful Situations (CISS), according to the model proposed by Endler and Parker in 1990. Results The CBI scores (overall and single sections) were extremely high and correlated with dementia severity. Women, as well as older caregivers, showed higher scores. The trait anxiety (STAI-Y-2) correlated with the CBI overall score. The CISS showed that caregivers mainly adopted task-focused strategies. Women mainly adopted emotion-focused strategies and this style was related to a higher level of distress. Conclusion AD is associated with high distress among caregivers. The burden strongly correlates with dementia severity and is higher in women and in elderly subjects. Chronic anxiety affects caregivers who mainly rely on emotion-oriented coping strategies. The findings suggest providing support to families of patients with AD through tailored strategies aimed to reshape the dysfunctional coping styles.

Flanker interference effects in a line bisection task.

Previous studies have shown that flanking distractors influence line bisection. In the present study, we examined if reaching the flanker after bisecting the line resulted in a variation of flanker interference on line bisection. Right- and left-handed participants were asked to bisect a horizontal line flanked by a dot (bisection task, B-task) or to bisect the line and then to reach the dot (bisection plus reaching task, BR-task). The dot was placed laterally to, and above or below, the line edge. The results showed that in both tasks the subjective midpoint was shifted away from the position of the dot. However, this effect was greater in the BR-task than in the B-task. We suggest that the requirement to perform an action to the flanker in the BR-task induced participants to pay more attention to the dot, enhancing its salience and distorting effects on line bisection.

Frontal Behavioural Inventory in the differential diagnosis of dementia.

Objective –  To evaluate diagnostic properties of the Frontal Behavioural Inventory (FBI) in patients suffering from different forms of dementia.

Role of functional performance in diagnosis of dementia in elderly people with low educational level living in Southern Italy

Background and aims: Diagnosis of dementia is often difficult in subjects with low educational level. Our aim was to evaluate the role of functional performance and the possibility of preferring scores of activities of daily living (ADL) and instrumental activities of daily living (IADL) in screening elderly people for diagnosis of dementia in a rural population of Southern Italy with a very high percentage of non-educated subjects. Methods: a random sample of 300 residents, out of 1089 subjects over 60 years of age living in San Marcellino (Caserta, Campania), received door-to-door visit for information about their medical history, with clinical evaluation of general geriatric conditions, including the cumulative illness rating scale (CIRS). Dementia was diagnosed if subjects had a Clinical Dementia Rating score (CDR) ≥ 1 and according to the criteria of DSM-IV, but not according to scores on the Mini Mental State Examination (MMSE), ADL and IADL. Two hundred and nineteen normal subjects (NS) and 75 patients with dementia (DP) were evaluated. Results: in NS, their mean age- and education-corrected MMSE score was 22.15 (lower than the normal cut-off value of 23.8) and 12.60 in DP (p<0.0001). In NS, the mean ADL score was higher than in DP (5.53 vs 2.64, p<0.0001; only age was correlated with ADL scores (coeff=− 0.44, t=− 4.557, p<0.0001). Assuming age as covariate, ADL scores highly differentiated DP from NS (F(1, 289)=26.083, p<0.0001). In both sexes, mean IADL scores were higher in NS than in DP (4.46 vs 1.80 in men, p<0.0001); 6.85 vs 2.31 in women, p<0.0001. Age and education did not influence IADL scores in men, but age greatly affected performance in women. IADL scores clearly differentiated NS from DP. In NS, a positive correlation was evident between ADL and IADL scores (r=0.234, p<0.0005, but neither scores correlated with the MMSE scores, even when correlation was performed separately for men and women. In DP, a strong correlation was observed between ADL and IADL scores (r=0.709, p<0.0001 and significant correlations were also evident between the scores of MMSE and both ADL (r=0.492,p<0.0001) and IADL (r=0.398, p<0.0004). Conclusions: in a rural community with a high prevalence of non-educated subjects, cognitive impairment is related to education, whereas independent functioning is limited mainly to age and not to cognition, if the latter remains (relatively) unimpaired. These results point to the importance of an “ecological” approach to the evaluation of elderly people, particularly those living in small rural communities, where education and the social environment may give rise to difficulties in diagnosis of dementia. The assessment of functional autonomy by ADL and IADL scales may be a better screening tool in diagnosing dementia than the MMSE scores.

The Lost Ability to Find the Way: Topographical Disorientation After a Left Brain Lesion

OBJECTIVE We report the case of a patient (M.S.) who, after a left brain damage in posteromedial areas, showed a deficit in determining the direction of any destination with respect to his current position or to external frames (heading disorientation). Given that spatial cognition includes a wide range of cooperating abilities, we deemed that M.S.s spatial disorientation could be ascribed to specific alterations within this multicomponent system where landmarks and spatial frames of reference contribute to organize information for different purposes. METHOD M.S. and 12 healthy elderly people (NCs) were submitted to an extensive neuropsychological assessment and to 2 ad hoc spatial tasks: (a) Object-Location Memory Task (what, where, and their binding); and (b) spatial memory task combining categorical (nonmetric)/coordinate (metric) relations with egocentric/allocentric frames of reference (in verbal and visuomotor conditions). RESULTS M.S.s performance was compared with that of NCs by means of a modified t test to small control sample size. M.S. met difficulty in positional processing and binding but not in object recognition. M.S. showed a selective deficit in the coordinate component in verbal (combined with both egocentric and allocentric frames) and visuomotor (only with the egocentric frame) spatial judgment tasks. In contrast, the categorical component looked always preserved in both frames of reference. CONCLUSIONS The left posteromedial brain areas contribute in combining and translating metric relations according to frames of reference and in using these representations to guide actions according to an egocentric perspective.