Abstract
Gil R, Arroyo-Anllo EM, Ingrand P, Gil M, Neau JP, Ornon C,
Bonnaud V. Self-consciousness and Alzheimer’s disease.
Acta Neurol Scand 2001: 104: 296–300. # Munksgaard 2001.
Objectives – To propose a neuropsychological study of the various
aspects of self-consciousness (SC) in Alzheimer’s disease. Methods –
Forty-five patients with probable mild or moderate AD were included in
the study. Severity of their dementia was assessed by the Mini Mental
State (MMS). Fourteen questions were prepared to evaluate SC.
Results – No significant correlations were found between SC score and
educational level, age, and duration of disease. A significant correlation
was found between SC score and the severity of dementia, whereas
frontal disturbances were just short of the significance threshold. The
various aspects of SC were not impaired to the same degree. The most
disturbed ones were awareness of cognitive deficiencies, moral judgements
and prospective memory. The least disturbed aspects were
awareness of identity and of mental representation of the body. Items
relating to anosognosia and moral judgements were significantly
correlated with the MMS score, whereas affective state, body
representation disorders, prospective memory, and capacities for
introspection were not related to the severity of the dementia.
Consciousness of identity was sound, regardless of MMS score.
Conclusions – AD clearly induces an heterogeneous impairment of SC.
SC requires a convergence of many neural networks. In AD, neuronal
alterations involve many cortical areas and information sent to the
associative frontal cortex from memory, language and visuospatial areas
is lacking or disturbed. Thus, the sequential order of successive stimuli
cannot be maintained by the heteromodal associative cortex (dorsal
convexity of the prefrontal cortex), and the supramodal associative
cortex (located rostrally in the frontal lobes) is unable to provide reliable
monitoring and assessment of simultaneous neural cognitive networks
carrying insufficient and inadequate input. The core deficiency in AD
patients might be impaired SC equated with the disability to maintain
sequential and simultaneous ‘‘attention to life’’. The Self-Consciousness
Questionnaire, a clinical scale providing multidimensional measurement,
indicates that different aspects of consciousness are not correlated with
overall cognitive deficiency as determined by the MMSE.