Table 1. Frontal lobe changes associated with Alzheimer's disease and mild cognitive impairment: results of voxel-based morphometry studies.

Findings	Frontal lobe portions implicated
Alzheimer's disease
Reduced grey matter volume in comparison to elderly controls (cross-sectional design)	Overall frontal cortex [37, 38, 42] Overall prefrontal cortex [40, 41] Dorsolateral prefrontal cortex [21, 32] Orbitofrontal cortex [11, 18, 21, 26, 30] Frontal pole [13, 27, 35] Inferior frontal gyrus [10-23] Middle frontal gyrus [11, 12, 20, 22, 23-26, 33] Superior frontal gyrus [10-12, 16-18, 27, 28] Medial frontal gyrus [10, 20, 21, 29, 30] Anterior cingulate gyrus [14, 20, 21, 25, 29-32] Cortical pre-motor regions [28, 36] Precentral gyrus [18, 28, 30, 34]
Reduced grey matter volume over time (longitudinal design)	Superior frontal cortex [43, 45] Medial frontal gyrus [20, 29] Inferior frontal gyrus [20] Middle frontal gyrus [45]
Correlation between cortical atrophy and Clinical Dementia Rating scores	Overall frontal lobe [20, 33] Superior frontal gyrus [16]
Correlation between cortical atrophy and Disability Assessment for Dementia scores	Orbitofrontal cortex [37] Precentral gyrus [37] Superior frontal gyrus [37] Inferior frontal gyrus [37] Middle frontal gyrus [37]
Correlation between cortical atrophy and Mini-Mental State Examination Scores	Precentral gyrus [25] Medial frontal gyrus [25]
Correlation between cortical atrophy and episodic memory deficits	Overall frontal lobe [13, 27, 35]
Correlation between cortical atrophy and self-appraisal	Medial prefrontal cortex [41]
Correlation between cortical atrophy and semantic memory deficits	Anterior cingulate cortex [31, 32]
Correlation between frontal cortical atrophy and naming ability	Pre-motor cortex [41] Precentral gyrus [41] Middle superior frontal gyrus [41]
Correlation between cortical atrophy and agitation	Middle frontal cortex [11] Inferior frontal cortex [11] Anterior cingulate gyrus [21]
Correlation between cortical atrophy and depression	Overall frontal cortex [11]
Correlation between cortical atrophy and apathy	Anterior cingulate cortex [12] Orbitofrontal cortex [21] Dorsolateral prefrontal cortex [21]
Correlation between cortical atrophy and aberrant motor behaviour	Olfactory gyrus [11] Medial orbitofrontal gyrus [11] Inferior frontal gyrus[11] Middle frontal gyrus [11]
Amnestic mild cognitive impairment
Reduced grey matter volume in comparison to elderly controls (cross-sectional design)	Overall frontal cortex [29, 42] Anterior regions of frontal lobe [43] Anterior cingulate gyrus [20, 25, 44] Middle frontal gyrus [44] Precentral gyrus [44]