This Article  • Full text  • PDF  • Reply to article  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on HighWire  • Citing articles on ISI (11)  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Topic Collections  • Radiologic Imaging  • Alzheimer Disease  • Dementias  • Diagnosis  • Neurology, Other  • Magnetic Resonance Imaging  • Alert me on articles by topic

Josephine Barnes, MA; Jennifer L. Whitwell, PhD; Chris Frost, MA, DipStat; Keith A. Josephs, MST, MD; Martin Rossor, MD, FRCP; Nick C. Fox, MD, FRCP

Arch Neurol. 2006;63:1434-1439.

Background  Differentiating between Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD) can be difficult, particularly in the earliest stages of the diseases. Patterns of atrophy on magnetic resonance imaging may help distinguish these diseases and aid diagnosis.

Objective  To assess the diagnostic utility of magnetic resonance imaging–derived amygdala and hippocampal volumes from patients with pathologically proved AD and FTLD.

Design  Cross-sectional volumetric magnetic resonance imaging study of the hippocampus and amygdala.

Setting  Specialist cognitive disorders clinic.

Subjects  Thirty-seven subjects, including 10 patients with pathologically proved AD, 17 patients with pathologically proved FTLD, and 10 age-matched control subjects.

Main Outcome Measures  Hippocampal and amygdala volumes.

Results  Geometric mean amygdala and hippocampal volumes were, respectively, 15.0% (95% confidence interval [CI], 4.2%-24.5%) and 16.4% (95% CI, 5.9%-25.6%) lower in the AD than in the control group. In FTLD, the equivalent differences were 43.1% (95% CI, 31.9%-52.6%) in the amygdala and 36.1% (95% CI, 27.5%-43.7%) in the hippocampus. Volumes were significantly lower in the FTLD than in the AD group (P<.01 in both regions). Within the FTLD clinical subgroups, there was evidence of a difference in pattern of atrophy with greater asymmetry (left smaller than right) in semantic dementia compared with frontal variant FTLD (P<.001). On average, the left hippocampus was 14% smaller in semantic dementia than in frontal variant FTLD, whereas the right hippocampus was 37% larger. On average, the left amygdala was 39% smaller in semantic dementia than in frontal variant FTLD, whereas the right amygdala was only 1% smaller.

Conclusions  Hippocampal atrophy is not specific to AD or FTLD. However, severe or asymmetrical amygdala atrophy should suggest FTLD. Atrophy patterns follow clinical syndromes rather than pathology.

Author Affiliations: Dementia Research Centre, University College London, Institute of Neurology (Ms Barnes; Drs Whitwell, Rossor, and Fox; and Mr Frost), Medical Statistics Unit, London School of Hygiene and Tropical Medicine (Mr Frost), Department of Clinical Neurology, National Hospital for Neurology and Neurosurgery (Drs Rossor and Fox), and Division of Neuroscience and Psychological Medicine, Faculty of Medicine, Imperial College London (Dr Rossor), London, England; and Departments of Diagnostic Radiology (Dr Whitwell) and Neurology (Dr Josephs), Mayo Clinic, Rochester, Minn.

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Fear conditioning in frontotemporal lobar degeneration and Alzheimer's disease
Hoefer et al.
Brain 2008;131:1646-1657.
ABSTRACT | FULL TEXT  

Abnormal TDP-43 immunoreactivity in AD modifies clinicopathologic and radiologic phenotype
Josephs et al.
Neurology 2008;70:1850-1857.
ABSTRACT | FULL TEXT  

Distinct MRI Atrophy Patterns in Autopsy-Proven Alzheimer's Disease and Frontotemporal Lobar Degeneration
Rabinovici et al.
AM J ALZHEIMERS DIS OTHER DEMEN 2008;22:474-488.
ABSTRACT  

Imaging of mild cognitive impairment and early dementia
SCHUFF and ZHU
Br. J. Radiol. 2007;80:S109-S114.
ABSTRACT | FULL TEXT