Focal cortical atrophy syndromes

Area of Science:

• Neuroscience
• Neuropathology
• Clinical Neurology

Background:

• Alzheimer's disease (AD) affects language, perception, and praxis, leading to focal cortical atrophy syndromes.
• Syndromes include primary progressive aphasia (PPA), posterior cortical atrophy (PCA), and corticobasal degeneration (CBD).
• Two main phenotypes: frontotemporal degeneration (FTD) affecting frontal/temporal lobes and AD with amyloid plaques/neurofibrillary tangles.

Purpose of the Study:

• To review and compare clinico-pathological features of PPA, PCA, and CBD.
• To differentiate these syndromes from AD and FTD using neuroimaging and pathology.
• To illustrate representative single photon emission computerized tomography (SPECT) scans for each syndrome.

Main Methods:

• Review of existing literature on AD, PPA, PCA, and CBD.
• Comparison of clinical presentations and neuropathological findings.
• Illustration of SPECT scan characteristics for each condition.

Main Results:

• PPA shows left perisylvian dysfunction; nonfluent PPA linked to FTD, fluent PPA to FTD or AD.
• PCA typically involves bilateral visual association cortex, indicative of AD.
• CBD presents as asymmetric akinetic-rigid syndrome with apraxia; molecular techniques suggest distinct pathology from FTD/Pick's disease.

Conclusions:

• Focal cortical atrophy syndromes have distinct clinico-pathological profiles.
• Neuroimaging and molecular techniques aid in differentiating these syndromes from AD and FTD.
• Understanding these distinctions is crucial for accurate diagnosis and management.