Shape analysis of the neostriatum in subtypes of frontotemporal lobar degeneration: neuroanatomically significant regional morphologic change.
Frontostriatal circuit mediated cognitive dysfunction has been implicated in frontotemporal lobar degeneration (FTLD) and may differ across subtypes of FTLD. We manually segmented the neostriatum (caudate nucleus and putamen) in FTLD subtypes: behavioral variant frontotemporal dementia, FTD, n=12; semantic dementia, SD, n=13; and progressive non-fluent aphasia, PNFA, n=9); in comparison with controls (n=27). Diagnoses were based on international consensus criteria. Manual bilateral segmentation of the caudate nucleus and putamen was conducted blind to diagnosis by a single analyst, on MRI scans using a standardized protocol. Intracranial volume was calculated via a stereological point counting technique and was used for normalizing the shape analysis. Segmented binaries were analyzed using the Spherical Harmonic (SPHARM) Shape Analysis tools (University of North Carolina) to perform comparisons between FTLD subtypes and controls for global shape difference, local significance maps and mean magnitude maps of shape displacement. Shape analysis revealed that there was significant shape difference between FTLD subtypes and controls, consistent with the predicted frontostriatal dysfunction and of significant magnitude, as measured by displacement maps. These differences were not significant for SD compared to controls; lesser for PNFA compared to controls; whilst FTD showed a more specific pattern in regions relaying fronto- and corticostriatal circuits. Shape analysis shows regional specificity of atrophy, manifest as shape deflation, with a differential between FTLD subtypes, compared to controls.
Research Centre for the Neurosciences of Ageing, Australian National University Medical School, Canberra Hospital, Canberra, Australia. Jeffrey.looi@anu.edu.au
Jeffrey Chee Leong
JC
Looi
Mark
M
Walterfang
Martin
M
Styner
Marc
M
Niethammer
Leif Anders
LA
Svensson
Olof
O
Lindberg
Per
P
Ostberg
Lisa
L
Botes
Eva
E
Orndahl
Phyllis
P
Chua
Dennis
D
Velakoulis
Lars-Olof
LO
Wahlund
D000328:Adult; D000368:Aged; D001931:Brain Mapping; D005260:Female; D057180:Frontotemporal Dementia / Q000473:pathology; D057174:Frontotemporal Lobar Degeneration / Q000145:classification* / Q000473:pathology*; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D017072:Neostriatum / Q000473:pathology*; D057178:Primary Progressive Nonfluent Aphasia / Q000473:pathology; D011569:Psychiatric Status Rating Scales; D016037:Single-Blind Method