title: Regional functional synchronizations in dementia with Lewy bodies and Alzheimer's disease.
abstract: Dementia with Lewy bodies (DLB) is a common cause of dementia in the elderly population after Alzheimer's disease (AD), and at early stages differential diagnosis between DLB and AD might be difficult due to their symptomatic overlap, e.g. cognitive and memory impairments. We aimed to investigate functional brain differences between both diseases in patients recently diagnosed.
  
  
  
  We investigated regional functional synchronizations using regional homogeneity (ReHo) in patients clinically diagnosed with DLB (n = 19) and AD (n = 18), and for comparisons we also included healthy controls (HC, n = 16). Patient groups were matched by age, education, and by the level of cognitive impairment (MMSE p-value = 0.36). Additionally, correlations between ReHo values and clinical scores were investigated.
  
  
  
  The DLB group showed lower ReHo in sensory-motor cortices and higher ReHo in left middle temporal gyrus when compared with HCs (p-value < 0.001 uncorrected). The AD group demonstrated lower ReHo in the cerebellum and higher ReHo in the left/right lingual gyri, precuneus cortex, and other occipital and parietal regions (p-value < 0.001 uncorrected).
  
  
  
  Our results agree with previous ReHo investigations in Parkinson's disease (PD), suggesting that functional alterations in motor-related regions might be a characteristic of the Lewy body disease spectrum. However, our results in AD contradict previously reported findings for this disease and ReHo, which we speculate are a reflection of compensatory brain responses at early disease stages. ReHo differences between patient groups were at regions related to the default mode and sensory-motor resting state networks which might reflect the aetiological divergences in the underlying disease processes between AD and DLB.
authors.affiliation: Institute of Neuroscience,Campus for Ageing and Vitality,Newcastle University,Newcastle upon Tyne,NE4 5PL,UK.
authors.forename: Luis R
authors.initials: LR
authors.lastname: Peraza
authors.affiliation: Institute of Neuroscience,Campus for Ageing and Vitality,Newcastle University,Newcastle upon Tyne,NE4 5PL,UK.
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Colloby
authors.affiliation: Institute of Neuroscience,Campus for Ageing and Vitality,Newcastle University,Newcastle upon Tyne,NE4 5PL,UK.
authors.forename: Liam
authors.initials: L
authors.lastname: Deboys
authors.affiliation: Department of Psychiatry,Cambridge Biomedical Campus,University of Cambridge School of Clinical Medicine,Cambridge,CB2 0SZ,UK.
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
authors.affiliation: Interdisciplinary Computing and Complex BioSystems (ICOS) research group,School of Computing Science,Newcastle University,Newcastle upon Tyne,NE1 7RU,UK.
authors.forename: Marcus
authors.initials: M
authors.lastname: Kaiser
authors.affiliation: Institute of Neuroscience,Campus for Ageing and Vitality,Newcastle University,Newcastle upon Tyne,NE4 5PL,UK.
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Taylor
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000523:psychology; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology; D003071:Cognition; D003937:Diagnosis, Differential; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis / Q000523:psychology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D000073216:Mental Status and Dementia Tests; D013223:Statistics as Topic; D006113:United Kingdom
keywords: Alzheimer's disease (AD); Dementia with Lewy bodies (DLB); hallucinations; magnetic resonance imaging (MRI); neuroimaging