Objective: Disorientation is a major clinical problem in Alzheimer's disease (AD), its mechanism is not well understood. In patients recovering from acute brain-injury, disorientation primarily reflects a confusion of memory traces (temporal context confusion, TCC), a failure mainly due to orbitofrontal damage or disconnection.
Design: The present study was carried out to test the potential contribution of TCC to disorientation in AD.
Materials and Methods: 23 AD outpatients with a Clinical Dementia Rating Scale between 1 and 2 were assessed at the Memory Clinic of Geneva. Orientation was evaluated by a 20-item questionnaire testing spatial, temporal, personal and circumstantial domains. Tests of general cognitive capacities, such as executive functioning, memory and verbal abilities were performed. Two runs of a continuous recognition task were used to measure information storage in memory (first run) and the tendency to confuse memory traces, TCC (second run).
Results: Disorientation, associated with behavioral disturbances and social consequences, was found in 12 of 23 patients. Half of the AD patients were disorientated in place and situation; very few were disoriented in time. Disorientation was moderately well correlated by general measures of dementia severity, verbal episodic memory, and executive functioning. By contrast, it was neither correlated by a failure to store information nor by TCC.
Conclusion: Disorientation in AD is distinct from disorientation after acute focal brain lesions. It concerns mainly orientation in place and situation and much less orientation in time. It is predicted by general cognitive dysfunction rather than by specific cognitive failure such as temporal context confusion in memory, which predicts disorientation after acute brain lesions.
Back to Poster Session 2
Back to Oral and Poster Sessions
Back to The IPA European Regional Meeting (1-4 April 2003) of IPA