BackgroundPsychiatric disorders, such as schizophrenia, attention deficit hyperactivity disorder (ADHD), and bipolar disorder, may sometimes be difficult to diagnose. There is a great need for a valid and reliable diagnostic tool to aid clinicians in arriving at the diagnoses in a timely and accurate manner. Prior studies have suggested that patients suffering from schizophrenia and ADHD may process certain sound stimuli in the brainstem in an unusual manner. When these patient groups have been examined with the electrophysiological method of brainstem audiometry, some studies have found illness-specific aberrations. Such aberrations may also exist for patients suffering from bipolar disorder.ObjectiveIn this study, we will examine whether the method of brainstem audiometry can be used as a diagnostic tool for patients suffering from schizophrenia, ADHD, and bipolar disorder.MethodsThe method includes three steps: (1) auditory stimulation with specific sound stimuli, (2) simultaneous measurement of brainstem activity, and (3) automated interpretation of the resulting brain stem audiograms with data-based signal analysis. We will compare three groups of 12 individuals with confirmed diagnoses of schizophrenia, ADHD, or bipolar disorder with 12 healthy subjects under blinded conditions for a total of 48 participants. The extent to which the method can be used to reach the correct diagnosis will be investigated.ResultsThe project is now in a recruiting phase. When all patients and controls have been recruited and the measurements have been performed, the data will be analyzed according to a previously arranged algorithm. We expect the recruiting phase and measurements to be completed in early 2015, the analyses to be performed in mid-2015, and the results of the study to be published in early 2016.ConclusionsIf the results support previous findings, this will lend strength to the idea that brainstem audiometry can offer objective diagnostic support for patients suffering from schizophrenia, ADHD, and bipolar disorder. A positive result from the study could imply that brainstem audiometry could become an important supportive tool for clinicians in their efforts to diagnose patients with these disorders in a timely and accurate manner.Trial RegistrationClinicalTrials.gov NCT01629355; https://clinicaltrials.gov/ct2/show/NCT01629355 (Archived by WebCite at http://www.webcitation.org/6VBfTwx5H).

RNAIC, associate professor. ABSTRACT Purpose: Various depth-of-anaesthesia monitors are available, but their trustworthiness is questioned. The aim of this study was to investigate brainstem auditory-evoked potentials during general anaesthesia using a specific audiometry method named SensoDetect Brainstem Evoked Response Audiometry (SD-BERA). Methods: Seven patients with American Society of Anaesthesiologists physical status I and II scheduled for elective orthopaedic surgery were assigned. Brainstem auditory evoked responses were recorded at different stages of anaesthesia. Bispectral index and end-tidal tension of Sevoflurane were measured at the same time. Results: The index (%) from pre-anaesthesia to anaesthesia were significantly reduced 100 [0-0] vs. 53 [49-72], respectively (p=0.0156). At extubation the index were set back to normal level with a significant increase from anaesthetized state, 102 [78-135] (p=0.0156). No significant difference could be observed between pre-anaesthesia and at extubation (p=0.6875). Conclusion: The findings imply that SD-BERA has a potential to measure depth of anaesthesia.