title: Altered body schema processing in frontotemporal dementia with C9ORF72 mutations.
abstract: BACKGROUND
  Mutations in C9ORF72 are an important cause of frontotemporal dementia (FTD) and motor neuron disease. Accumulating evidence suggests that FTD associated with C9ORF72 mutations (C9ORF72-FTD) is distinguished clinically by early prominent neuropsychiatric features that might collectively reflect deranged body schema processing. However, the pathophysiology of C9ORF72-FTD has not been elucidated.
  
  
  METHODS
  We undertook a detailed neurophysiological investigation of five patients with C9ORF72-FTD, in relation to patients with FTD occurring sporadically and on the basis of mutations in the microtubule-associated protein tau gene and healthy older individuals. We designed or adapted behavioural tasks systematically to assess aspects of somatosensory body schema processing (tactile discrimination, proprioceptive and body part illusions and self/non-self differentiation).
  
  
  RESULTS
  Patients with C9ORF72-FTD selectively exhibited deficits at these levels of body schema processing in relation to healthy individuals and other patients with FTD.
  
  
  CONCLUSIONS
  Altered body schema processing is a novel, generic pathophysiological mechanism that may link the distributed cortico-subcortical network previously implicated in C9ORF72-FTD with a wide range of neuropsychiatric and behavioural symptoms, and constitute a physiological marker of this neurodegenerative proteinopathy.
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Laura E
authors: LE
authors: Downey
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Phillip D
authors: PD
authors: Fletcher
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Hannah L
authors: HL
authors: Golden
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Colin J
authors: CJ
authors: Mahoney
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Jennifer L
authors: JL
authors: Agustus
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Jonathan M
authors: JM
authors: Schott
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Jonathan D
authors: JD
authors: Rohrer
authors: MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, University College London, London, UK.
authors: Jonathan
authors: J
authors: Beck
authors: MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, University College London, London, UK.
authors: Simon
authors: S
authors: Mead
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Martin N
authors: MN
authors: Rossor
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Sebastian J
authors: SJ
authors: Crutch
authors: Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, University College London, London, UK.
authors: Jason D
authors: JD
authors: Warren
mesh_terms: D000368:Aged; D001828:Body Image / Q000523:psychology*; D000073885:C9orf72 Protein; D016022:Case-Control Studies; D005260:Female; D057180:Frontotemporal Dementia / Q000235:genetics* / Q000523:psychology*; D006801:Humans; D007088:Illusions / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011506:Proteins / Q000235:genetics*; D012649:Self Concept; D024801:Tauopathies / Q000235:genetics / Q000523:psychology; D055698:Touch Perception; D016875:tau Proteins / Q000235:genetics
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins; D016875:tau Proteins
keywords: Dementia; Neuropsychiatry; Neuropsychology; Physiology