The relevance of hippocampal subfield integrity and clock drawing test performance for the diagnosis of Alzheimer's disease and mild cognitive impairment.

Objectives: The clock drawing test (CDT) is one of the worldwide most used screening tests for Alzheimer's disease (AD). MRI studies have identified temporo-parietal regions being involved in CDT impairment. However, the contributions of specific hippocampal subfields and adjacent extrahippocampal structures to CDT performance in AD and mild cognitive impairment (MCI) have not been investigated so far.

Hippocampal formation alterations differently contribute to autobiographic memory deficits in mild cognitive impairment and Alzheimer's disease.

Autobiographical memory (AM) is part of declarative memory and includes both semantic and episodic aspects. AM deficits are among the major complaints of patients with Alzheimer's disease (AD) even in early or preclinical stages. Previous MRI studies in AD patients have showed that deficits in semantic and episodic AM are associated with hippocampal alterations.

Subcortical morphological correlates of impaired clock drawing performance.

The objective of this study was to investigate the associations between clock drawing test (CDT) performance and subcortical brain morphology. Fifty-four participants (21 patients with Alzheimer's disease, 23 with mild cognitive impairment and 10 healthy controls) underwent neuropsychological assessment and high-resolution magnetic resonance imaging at 3T. CDT performance was related to volume and shape measurements of amygdala, caudate nucleus, hippocampus, nucleus accumbens, pallidum, putamen, and thalamus, respectively.