title: Latent profile analysis in frontotemporal lobar degeneration and related disorders: clinical presentation and SPECT functional correlates.
abstract: BACKGROUND
  Frontotemporal Lobar Degeneration (FTLD) thus recently renamed, refers to a spectrum of heterogeneous conditions. This same heterogeneity of presentation represents the major methodological limit for the correct evaluation of clinical designation and brain functional correlates. At present, no study has investigated clinical clusters due to specific cognitive and behavioural disturbances beyond current clinical criteria. The aim of this study was to identify clinical FTLD presentation, based on cognitive and behavioural profile, and to define their SPECT functional correlations.
  
  
  METHODS
  Ninety-seven FTLD patients entered the study. A clinical evaluation and standardised assessment were preformed, as well as a brain SPECT perfusion imaging study. Latent Profile Analysis on clinical, neuropsychological, and behavioural data was performed. Voxel-basis analysis of SPECT data was computed.
  
  
  RESULTS
  Three specific clusters were identified and named "pseudomanic behaviour" (LC1), "cognitive" (LC2), and "pseudodepressed behaviour" (LC3) endophenotypes. These endophenotypes showed a comparable hypoperfusion in left temporal lobe, but a specific pattern involving: medial and orbitobasal frontal cortex in LC1, subcortical brain region in LC2, and right dorsolateral frontal cortex and insula in LC3.
  
  
  CONCLUSIONS
  These findings provide evidence that specific functional-cluster symptom relationship can be delineated in FTLD patients by a standardised assessment. The understanding of the different functional correlates of clinical presentations will hopefully lead to the possibility of individuating diagnostic and treatment algorithms.
authors.affiliation: Center for Aging Brain and Dementia, Department of Neurology, University of Brescia, Brescia, Italy. bborroni@inwind.it
authors.forename: Barbara
authors.initials: B
authors.lastname: Borroni
authors.forename: Mario
authors.initials: M
authors.lastname: Grassi
authors.forename: Chiara
authors.initials: C
authors.lastname: Agosti
authors.forename: Barbara
authors.initials: B
authors.lastname: Paghera
authors.forename: Antonella
authors.initials: A
authors.lastname: Alberici
authors.forename: Monica
authors.initials: M
authors.lastname: Di Luca
authors.forename: Daniela
authors.initials: D
authors.lastname: Perani
authors.forename: Alessandro
authors.initials: A
authors.lastname: Padovani
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000145:classification* / Q000175:diagnosis*; D003704:Dementia / Q000145:classification* / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000145:classification* / Q000175:diagnosis*; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon