Quantitative electroencephalography in unmedicated primary insomnia patients.

Aisha Cortoos, Edwin Verstraeten, Raymond Cluydts

Research output: Contribution to journalConference paper


Introduction : Recent studies examining EEG frequencies in primary insomnia during sleep support the concept of cortical hyperarousal in this population. Higher levels of beta power were found in comparison to healthy controls and comorbid insomnia patients. The question remains, however, if this cortical hyperarousal, is also apparent in the wake EEG.
Method : A quantitative EEG was obtained in 13 unmedicated primary insomnia patients, diagnosed according to the DSM-IV criteria. The EEG was measured during an eyes open and an eyes closed condition. 19 electrodes according to the International 10-20 system were used and referenced to both mastoid electrodes. EOG and EMG were measured to assure optimal artefact rejection and impedances were kept below 10 kOhm. A minimum of 90 seconds of artefact-free EEG per patient was used for further analysis using the Thatcher qEEG database. z-values were obtained for delta (1-3,5 Hz), theta (4-7,5 Hz), alpha (8-12 Hz), beta (12,5-25 Hz) and high beta (25,5-30 Hz) EEG power.
Results: The results indicate a trend of heightened high beta power (25,5-30 Hz) in the eyes open condition (Cz: z = 1.86; p.= 0.06) and a deficit in the delta range in the eyes closed condition (T3: z = 1.34; p.=0.18). Furthermore, in the eyes open condition, the excess in high beta power is significantly higher in the right hemisphere in comparison to the left, especially on Fp2 (df 12; p.= .014), F4 (df 12; p.= .011), F8 (df 12; p.= .000) and T4 (df 12; p.= .000) .
Conclusion: These preliminary results suggest that the observed cortical hyperarousal reflected by heightened beta power levels in the sleep EEG, continues to be apparent in the wake EEG. Furthermore, there might be a dominance of beta power in the right hemisphere in insomniacs. We stress again that all comparisons were made against the Thatcher database.
Original languageEnglish
Pages (from-to)265-265
Number of pages1
Issue numberabstract supplement
Publication statusPublished - 1 Jul 2007
EventFinds and Results from the Swedish Cyprus Expedition: A Gender Perspective at the Medelhavsmuseet - Stockholm, Sweden
Duration: 21 Sep 200925 Sep 2009


  • insomnia
  • Electroencephalography


Dive into the research topics of 'Quantitative electroencephalography in unmedicated primary insomnia patients.'. Together they form a unique fingerprint.

Cite this