KEY FACTS Terminology Corticobasal degeneration Progressive neurodegenerative disease Presents with cognitive dysfunction, “asymmetrical” parkinsonism Imaging Severe focal asymmetric cortical atrophy Perirolandic (posterior frontal, parietal cortex) Relative sparing of temporal, occipital regions ↑ signal intensity in frontal &/or parietal subcortical white…
KEY FACTS Terminology Posterior cortical atrophy (PCA) Rare neurodegenerative disorder of posterior cerebral cortex/connecting white matter (WM) Considered subtype of Alzheimer disease (AD) Results in impairment of ventral, dorsal visual perception pathways Typically precedes memory, executive impairment Imaging Sagittal T1WI,…
KEY FACTS Terminology Adult-onset fatal neurodegenerative disease Multiple system atrophy (MSA) has 3 clinical subtypes Cerebellar (MSA-C) Sporadic olivopontocerebellar (OPCA) atrophy Extrapyramidal (MSA-P) Parkinson subtype Striatonigral degeneration Autonomic (MSA-A) Shy-Drager syndrome Imaging General findings ↓ (“flat”) pons/medulla Cerebellar vermis/hemispheres atrophic…
KEY FACTS Terminology Parkinson disease (PD) Progressive neurodegenerative disease Primarily affects pars compacta of substantia nigra (SNpc) Imaging MR SNpc narrowed/inapparent (T2WI) SNpc progressively loses normal hyperintensity (from lateral to medial) Border between SNpc, red nucleus blurred in PD ↑…
KEY FACTS Terminology Important clinicopathologic Creutzfeldt-Jakob disease (CJD) variants Heidenhain variant CJD – Visual variant of CJD – Early isolated visual symptoms Brownell-Oppenheimer variant (rare) – Pure cerebellar syndrome Imaging FLAIR Subtle cortical hyperintensity in occipital lobes (“cortical ribbon”) Basal…
KEY FACTS Terminology Creutzfeldt-Jakob disease (CJD): Rapidly progressing, fatal, potentially transmissible dementia caused by prion Imaging Best imaging clue: Progressive T2 hyperintensity of basal ganglia, thalamus, and cerebral cortex Predominantly gray matter: Caudate and putamen > globus pallidus Thalamus: Common…
KEY FACTS Terminology Progressive neurodegenerative dementia caused by pathologic aggregation of α-synuclein protein in neurites (Lewy bodies) Imaging MR may differentiate Alzheimer disease (AD) from dementia with Lewy bodies (DLB) Voxel-based morphometry Relatively preserved hippocampal/medial temporal lobe volume in DLB…
KEY FACTS Terminology Clinical subtypes Behavioral-variant frontotemporal dementia (bvFTD) Primary progressive aphasia syndromes (PPA) – Semantic variant (sv-PPA) □ Previously known as semantic dementia – Nonfluent/agrammatic variant (nfv-PPA) □ Previously known as progressive nonfluent aphasia – Logopenic variant (lv-PPA) Frontotemporal…
KEY FACTS Terminology Vascular dementia (VaD), multiinfarct dementia (MID) Stepwise progressive ↓ in cognitive function Heterogeneous group of disorders with varying etiologies, pathologic subtypes VaD often mixed etiology Can occur alone or in association with Alzheimer disease (AD) MID secondary…
KEY FACTS Terminology Alzheimer disease (AD) Slowly progressive neurodegenerative disease Imaging Current role of imaging in AD Exclude other causes of dementia Identify region-specific patterns of brain volume loss Identify imaging markers of coexistent disease such as amyloid angiopathy Identify…