title: Neurophysiological biomarkers for Lewy body dementias.
abstract: OBJECTIVE
  Lewy body dementias (LBD) include both dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD), and the differentiation of LBD from other neurodegenerative dementias can be difficult. Currently, there are few biomarkers which might assist early diagnosis, map onto LBD symptom severity, and provide metrics of treatment response. Traditionally, biomarkers in LBD have focussed on neuroimaging modalities; however, as biomarkers need to be simple, inexpensive and non-invasive, neurophysiological approaches might also be useful as LBD biomarkers.
  
  
  METHODS
  In this review, we searched PubMED and PsycINFO databases in a semi-systematic manner in order to identify potential neurophysiological biomarkers in the LBDs.
  
  
  RESULTS
  We identified 1491 studies; of these, 37 studies specifically examined neurophysiological biomarkers in LBD patients. We found that there was substantial heterogeneity with respect to methodologies and patient cohorts.
  
  
  CONCLUSIONS
  Generally, many of the findings have yet to be replicated, although preliminary findings reinforce the potential utility of approaches such as quantitative electroencephalography and motor cortical stimulation paradigms.
  
  
  CONCLUSIONS
  Various neurophysiological techniques have the potential to be useful biomarkers in the LBDs. We recommend that future studies focus on maximising the diagnostic specificity and sensitivity of the most promising neurophysiological biomarkers.
authors.affiliation: Institute of Neuroscience, Campus for Aging and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, UK. Electronic address: r.a.cromarty@ncl.ac.uk.
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Cromarty
authors.affiliation: Institute of Neuroscience, Campus for Aging and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: Greg J
authors.initials: GJ
authors.lastname: Elder
authors.affiliation: Institute of Neuroscience, Framlington Place, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Sara
authors.initials: S
authors.lastname: Graziadio
authors.affiliation: Institute of Neuroscience, Framlington Place, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Baker
authors.affiliation: Clinica Neurologica, Dipartimento di Neuroscienze e Imaging, Università "G.D'Annunzio" Chieti-Pescara, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Bonanni
authors.affiliation: Clinica Neurologica, Dipartimento di Neuroscienze e Imaging, Università "G.D'Annunzio" Chieti-Pescara, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Onofrj
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0SP, UK.
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
authors.affiliation: Institute of Neuroscience, Campus for Aging and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Taylor
mesh_terms: D004569:Electroencephalography / Q000379:methods*; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D015225:Magnetoencephalography / Q000379:methods*; D009483:Neuropsychological Tests; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Biomarkers; Cognitive fluctuations; Dementia with Lewy bodies; Neurophysiology; Parkinson’s disease with dementia