title: Evaluation of resting state gamma power as a response marker in schizophrenia.
abstract: OBJECTIVE
  An abnormal activity in the electroencephalography (EEG) gamma band (>30 Hz) has been demonstrated in schizophrenia and this has been suggested to be reflecting a deficit in the development and maturation of the basic cognitive functions of attention, working memory and sensory processing. Hypothesizing gamma oscillatory activity as a potential EEG biomarker to antipsychotic response in schizophrenia, the present study aimed at measuring baseline spontaneous gamma activity in schizophrenia patients, and evaluating its response to antipsychotic treatment over 8 weeks.
  
  
  METHODS
  Fifteen drug-free/naïve patients were recruited, compared at baseline with 15 age-, sex- and education-matched healthy controls, and were followed up for 8 weeks' treatment on antipsychotics. Resting state EEG waves were recorded using high (192-channel) resolution EEG at admission, 4 weeks and 8 weeks. Spectral power was calculated using fast Fourier transformation, Hanning window. The power was averaged region-wise over nine regions in three frequency ranges (30-50 Hz, 50-70 Hz, 70-100 Hz).
  
  
  RESULTS
  Patients and controls differed significantly at intake in terms of left temporal and parietal high (70-100 Hz) gamma power. Consequently, no significant differences were seen over the course of antipsychotic treatment on gamma spectral power in any of the regions.
  
  
  CONCLUSIONS
  Lack of significant effect of treatment on gamma power suggests that these gamma oscillations may be trait markers in schizophrenia.
authors: Department of Psychiatry and KS Mani Centre for Cognitive Neurosciences, Central Institute of Psychiatry, Ranchi, India.
authors: Sayantanava
authors: S
authors: Mitra
authors: Department of Psychiatry and KS Mani Centre for Cognitive Neurosciences, Central Institute of Psychiatry, Ranchi, India.
authors: S Haque
authors: SH
authors: Nizamie
authors: Department of Psychiatry and KS Mani Centre for Cognitive Neurosciences, Central Institute of Psychiatry, Ranchi, India.
authors: Nishant
authors: N
authors: Goyal
authors: Department of Psychiatry and KS Mani Centre for Cognitive Neurosciences, Central Institute of Psychiatry, Ranchi, India.
authors: Sai Krishna
authors: SK
authors: Tikka
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology*; D015415:Biomarkers; D004569:Electroencephalography / Q000379:methods*; D005069:Evaluation Studies as Topic; D005260:Female; D065818:Gamma Rhythm / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D012559:Schizophrenia / Q000188:drug therapy* / Q000503:physiopathology*; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D015415:Biomarkers
keywords: biomarker; resting state-gamma; schizophrenia; spectral power