title: Quantitative EEG parameters correlate with the progression of human prion diseases.
abstract: BACKGROUND
  Prion diseases are universally fatal and often rapidly progressive neurodegenerative diseases. EEG has long been used in the diagnosis of sporadic Creutzfeldt-Jakob disease; however, the characteristic waveforms do not occur in all types of prion diseases. Here, we re-evaluate the utility of EEG by focusing on the development of biomarkers. We test whether abnormal quantitative EEG parameters can be used to measure disease progression in prion diseases or predict disease onset in healthy individuals at risk of disease.
  
  
  METHODS
  In the National Prion Monitoring Cohort study, we did quantitative encephalography on 301 occasions in 29 healthy controls and 67 patients with prion disease. The patients had either inherited prion disease or sporadic Creutzfeldt-Jakob disease. We computed the main background frequency, the α and θ power and the α/θ power ratio, then averaged these within 5 electrode groups. These measurements were then compared among participant groups and correlated with functional and cognitive scores cross-sectionally and longitudinally.
  
  
  RESULTS
  We found lower main background frequency, α power and α/θ power ratio and higher θ power in patients compared to control participants. The main background frequency, the power in the α band and the α/θ power ratio also differed in a consistent way among the patient groups. Moreover, the main background frequency and the α/θ power ratio correlated significantly with functional and cognitive scores. Longitudinally, change in these parameters also showed significant correlation with the change in clinical and cognitive scores.
  
  
  CONCLUSIONS
  Our findings support the use of quantitative EEG to follow the progression of prion disease, with potential to help evaluate the treatment effects in future clinical-trials.
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.
authors.forename: Edit
authors.identifier: http://orcid.org/0000-0002-8088-842X
authors.initials: E
authors.lastname: Franko
authors.affiliation: Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Wehner
authors.affiliation: MRC Cognition and Brain Sciences Unit, Cambridge, UK.
authors.forename: Olivier
authors.identifier: http://orcid.org/0000-0002-5818-6552
authors.initials: O
authors.lastname: Joly
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Jessica
authors.initials: J
authors.lastname: Lowe
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Porter
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kenny
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Thompson
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Rudge
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.
authors.forename: John
authors.initials: J
authors.lastname: Collinge
authors.affiliation: NHS National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Mead
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D007562:Creutzfeldt-Jakob Syndrome / Q000175:diagnosis / Q000235:genetics; D018450:Disease Progression; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017096:Prion Diseases / Q000175:diagnosis* / Q000235:genetics; D011446:Prospective Studies; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D013223:Statistics as Topic