title: Longitudinal EEG changes correlate with cognitive measure deterioration in Parkinson's disease.
abstract: BACKGROUND
  QEEG could provide physiological biomarkers for changes over time in Parkinson's disease (PD) cognitive decline if they track with longitudinal neuropsychological performance.
  
  
  OBJECTIVE
  Our aim was to correlate longitudinal changes in frequency domain quantitative electroencephalography (QEEG) measures with change in neuropsychological performance testing in PD.
  
  
  METHODS
  71 PD subjects, not demented at baseline, were studied from the Arizona Study of Aging and Neurodegenerative Disorders cohort. Baseline and follow-up digital EEG from PD subjects were analyzed for QEEG measures of background rhythm frequency and global relative power in delta (2.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-30 Hz) bands. Baseline and subsequent evaluation included Mini Mental Status Examination and five other neuropsychological tests that load on cognitive domains known to decline in PD. Pearson coefficient was used to assess correlations. Multiple linear regression modeling was used to assess the effect of variable combinations of QEEG and other measures, including age and PD duration.
  
  
  RESULTS
  Changes in delta bandpower showed the highest and most consistent pattern of correlations with longitudinal changes in neuropsychological testing. The highest correlation was between delta bandpower increase and decline in the Rey Auditory-Verbal Learning Test (-0.59:p < 0.001). Delta bandpower was also increased in the incident dementia group compared to non-dementia at followup.
  
  
  CONCLUSIONS
  1) Longitudinal change in the QEEG frequency domain measure of delta bandpower correlated best with longitudinal neuropsychological performance change in PD; 2) These results constitute preliminary evidence that delta bandpower may be a suitable biomarker for evaluating PD cognitive deterioration longitudinally.
authors.affiliation: Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: John N
authors.initials: JN
authors.lastname: Caviness
authors.affiliation: Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Hentz
authors.affiliation: Banner Sun Health Research Institute, Banner Health System, Sun City, AZ, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Belden
authors.affiliation: Banner Sun Health Research Institute, Banner Health System, Sun City, AZ, USA.
authors.forename: Holly A
authors.initials: HA
authors.lastname: Shill
authors.affiliation: Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Erika D
authors.initials: ED
authors.lastname: Driver-Dunckley
authors.affiliation: Banner Sun Health Research Institute, Banner Health System, Sun City, AZ, USA.
authors.forename: Marwan N
authors.initials: MN
authors.lastname: Sabbagh
authors.affiliation: Banner Sun Health Research Institute, Banner Health System, Sun City, AZ, USA.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Powell
authors.affiliation: Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Adler
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D058256:Brain Waves / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D015331:Cohort Studies; D004569:Electroencephalography; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D016014:Linear Models; D008297:Male; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D014706:Verbal Learning / Q000502:physiology
keywords: Parkinson's disease; biological markers; dementia; electroencephalography