How and to what extent electrical brain activity reflects pharmacologically altered states and contents of consciousness, is not well understood. Therefore, we investigated whether measures of evoked and spontaneous electroencephalographic (EEG) signal diversity are altered by sub-anaesthetic levels of ketamine compared to normal wakefulness, and how these measures relate to subjective experience. High-density 62-channel EEG was used to record spontaneous brain activity and responses evoked by transcranial magnetic stimulation (TMS) in 10 healthy volunteers before...

Objectives: To compare days on sick leave and assess predictors of return to work following shoulder surgery. Design: A secondary analysis of a randomised controlled trial. Setting: Orthopaedic Department. Participants: 114 patients with type II superior labral tear from anterior to posterior (SLAP) lesions of the shoulder. Interventions: Labral repair, biceps tenodesis or sham surgery. Outcome measures: Sick leave was obtained from national registers for the last year before and two years following surgery. Total...

Objective: To define and validate criteria for accurate identification of EEG interictal epileptiform discharges (IEDs) using: (a) the six sensor space criteria proposed by the International Federation of Clinical Neurophysiology (IFCN), and, (b) a novel source space method. Criteria yielding high specificity are needed because EEG “over-reading” is a common cause of epilepsy misdiagnosis. Methods: Seven raters reviewed EEG segments containing sharp waveforms from 100 patients with and without epilepsy. Clinical diagnosis gold standard was...

Deep non-rapid eye movement sleep (NREM) and general anesthesia with propofol are prominent states of reduced arousal linked to the occurrence of synchronized oscillations in the electroencephalogram (EEG). Although rapid eye movement (REM) sleep is also associated with diminished arousal levels, it is characterized by a desynchronized, 'wake-like' EEG. This observation implies that reduced arousal states are not necessarily only defined by synchronous oscillatory activity. Using intracranial and surface EEG recordings in four independent data...