title: EEG findings in early-stage corticobasal degeneration and progressive supranuclear palsy: a retrospective study and literature review.
abstract: OBJECTIVE
  Although neuroimaging and electrophysiological tests are potentially useful to distinguish corticobasal degeneration (CBD) from progressive supranuclear palsy (PSP), little is known about the diagnostic value of electroencephalography (EEG) for their distinction. We assessed the value of EEG for differentiating CBD from PSP.
  
  
  METHODS
  We reviewed conventional EEGs recorded at an early stage of disease in 10 CBD patients and 14 PSP patients. We focused on slowing of background activity (SBA), frontal intermittent rhythmic delta activity (FIRDA) and focal slow waves (FSWs). Statistical analysis was performed by Fisher's exact test.
  
  
  RESULTS
  SBA was observed in 1 CBD patient and 2 PSP patients. FSWs were found in 8 CBD patients (80.0%), but only 2 PSP patients (14.3%) (p=0.002); they appeared contralateral to the dominantly-affected side in 6 of 8 CBD patients, and ipsilateral to the side with most atrophy on MRI in 7 of 8 CBD patients. FIRDA was observed in 2 CBD patients (20.0%) and 5 PSP patients (35.7%) (p=0.357).
  
  
  CONCLUSIONS
  FSWs are characteristic of CBD, but FIRDA was not disease-specific.
  
  
  CONCLUSIONS
  FSWs on EEG, in addition to clinical criteria, yield useful supplementary information to distinguish between these diseases at early stages.
authors.affiliation: Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan. ketashi@neurophy.med.kyushu-u.jp
authors.forename: Kenshi
authors.initials: K
authors.lastname: Tashiro
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ogata
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Goto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Taniwaki
authors.forename: Akira
authors.initials: A
authors.lastname: Okayama
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kira
authors.forename: Shozo
authors.initials: S
authors.lastname: Tobimatsu
mesh_terms: D000328:Adult; D000368:Aged; D001480:Basal Ganglia Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D003937:Diagnosis, Differential; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013494:Supranuclear Palsy, Progressive / Q000175:diagnosis* / Q000503:physiopathology*