P12. Unawareness of deficits in Alzheimer’s disease patients

Abstract

Introduction Awareness of deficit in brain damaged patients is the capacity of a subject to recognize her/his cognitive and behavioral disturbances. Many terms have been used in the past to describe this deficit: lack of insight, anosognosia, reduced awareness of deficit. The term insight comes from the psychoanalytic literature and means a lack of introspective knowledge; instead the term is typically used to describe the inability to recognize possible consequences of a specific neurological deficit (e.g. anosognosia for hemiplegia, for unilateral neglect or for fluent aphasia). Our approach is to adopt the generic term of awareness of deficit: a descriptive term without neuropsychological preconceptions. The reason to use this approach is, that after many studies on this topic, it is still not clear if unawareness is correlated with specific cognitive functions, with behavioral disturbances or with the severity of the dementia (Vasterling et al., 1995; Migliorelli et al., 1995). Aim of the study The aim of this study is to analise unawareness with a global approach and to verify the following aspects: assess the prevalence of awareness, partial awareness and unawareness at the time of diagnosis and/or temporary admission in a specialized ward; evaluate the correlation between awareness and severity of cognitive impairment; evaluate the correlation between awareness of deficits and the neuropsychological functions (memory, language, executive functions). Subjects Sixty-two patients with a diagnosis of mild to moderate Alzheimer's disease and their caregivers were included in the study (41 women and 21 men). The patients met the criteria of NINCDS-ADRDA for probable Alzheimer's disease with a Mini Mental State Examination score >16/30; they had no history of brain injury, stroke or any other neurological or psychiatric illness; the subjects included in the study were either outpatient or patients admitted to our Centre. The patients and their caregivers signed a informed consent. Materials The study protocol included: – Socio-cultural questionnaire, – questionnaire of identification of deficits (QID) (memory, language, instrumental activities, executive functions, emotion) modified by Smyth et al. (2002). The overall score ranges from 0 (no deficit) to 52 (maximum impairment). For each patient a QIDp (obtained directly from the patient) and a QIDc (filled in by the caregiver) was calculated. – CIR Clinical Insight Rating, – ADL Activity Daily Living, – IADL Instrumental Activities of Daily Living scale, – Neuropsychological battery was composed by global tests (Mini Mental State Examination, Clinical Dementia Rating) and Specific tests for episodic memory (short story), for language (Token Test, Test of verbal and semantic fluency), for executive functions (Trail Making Test and Frontal Assessment Battery) – NPI (Neuropsychiatric Inventory), – CBI (Caregiver Burden Inventory), – GDS (Geriatric Depression Scale). Results The mean age of the patients was 79years (range 64–91, SD =6) and the mean MMSE score was 21 (range 15.4–27.9, SD =3.36). Thirty-four percentage of the patients were not aware, 35% of the patients were only partially aware and only in 18% of the subjects awareness seemed to be completely preserved. Global cognitive impairment was not related to awareness of deficits. There was a slight negative correlation between awareness of deficit and the results to the phonological fluency test ( n =59, r =−0.24 p =0.06). No significant correlations were found with the other neuropsychological tests and the QID. Discussion and conclusions Our study confirms the high prevalence of unawareness of deficits in a population with mild to moderate AD. No clear correlation was found between global cognitive level and awareness of deficit. No correlation was found between awareness of deficit and specific cognitive domains. Thus, in our sample, neither neuropsychological evaluation, nor the severity of dementia, seem to be related to unawareness of deficit. Our data are partially in contrast with previous studies showing a relationship of awareness with executive functions and memory (Vasterling et al., 1995; Migliorelli et al., 1995) and of awareness and the severity of dementia. Neuropsychological evaluation and the severity of dementia, in our sample, donot explain unawareness of deficit. Our study points to the need to investigate each patients with specific tools, like QID and CIR, and to acquire an expert opinion. This approach is useful to reduce the bias related to the tools utilized and, at the same time, to limit the influence of the caregiver burden on the results.