Aberrant brain stem function in schizophrenia

Abstract

Background and Aims:Earlier research has shown that schizophrenic individuals process complex sound in aberrant ways (Olsson.O., Dissertation, Lund, 2000). It has also been shown that they abnormally perceive forward and backward masking (Källstrand et al., Psychiatry Res. 2002 Dec 15; 11 (1-2); 115-25). Experiments described in those studies indicate that in schizophrenia, brain-stem activity is involved, where primitive sorting of sound elements takes place. Brain Stem Response Audiometry (BSRA) shows that e.g. dissimilar spectra significantly separates schizophrenics from healthy subjects (Nielzén.S., 15th AEP Congress, March 2007, p. S86). The present study aims at demonstrating effects of loudness change of complex sound stimulation.Method:Eighteen paranoid schizophrenic patients were compared with 25 healthy volunteers regarding BSRA recordings from 2048 sweeps of loud noise stimuli (76 dB) and 2048 quieter ones (73 dB). Analysis of latencies in ms and amplitudes in micro-volts of the peaks and troughs was performed.Results:The amplitude of the highest peak of the region 1-4 ms was significantly lower with quiet noise for the schizophrenic group (P=.0002).The schizophrenics showed significantly prolonged latencies of the highest peak during 4,5-9 ms with the quiet noise (P=.046); they had a significant longer latency from left than from right electrode (P=.049).Conclusion:The results corroborate earlier cumulative BSRA results. These have been collected in a model – S-Detect – which is used as an objective decision support for the diagnosis of schizophrenia.

Auditory Brainstem Response as a Diagnostic Tool for Patients Suffering From Schizophrenia, Attention Deficit Hyperactivity Disorder, and Bipolar Disorder: Protocol

“…Some studies have suggested that when these patient groups have been examined with brainstem audiometry, the resulting brainstem audiograms have displayed illness-specific aberrations [9,14,17,21]. These aberrations have also been noted in unpublished observations.…”

“…Prior studies have suggested that patients suffering from schizophrenia and ADHD may process certain sound stimuli in the brainstem in an unusual or aberrant manner [ 3 - 20 ]. Some studies have suggested that when these patient groups have been examined with brainstem audiometry, the resulting brainstem audiograms have displayed illness-specific aberrations [ 9 , 14 , 17 , 21 ]. These aberrations have also been noted in unpublished observations.…”

The influence of methylphenidate on auditory brainstem response patients with attention deficit hyperactivity disorder; an exploratory study

“…Based on research indicating that specific ABR peaks are correlated with certain psychiatric symptoms, it has been speculated that ABR could be used as a complementary clinical tool to aid in the diagnosis of schizophrenia, 10,14 bipolar disorders, 12 autism spectrum disorders, [15][16][17] and ADHD. 11,18,19 Methylphenidate (MPH) is a psychostimulant commonly prescribed as a first-line therapy for pediatric ADHD.…”

Abnormal auditory forward masking pattern in the brainstem response of individuals with Asperger syndrome

“…21 Previous studies by this group have shown that schizophrenic patients perceive sounds differently than nonschizophrenic comparison subjects, possibly partly reflecting abnormal functioning of the lower portion of the auditory pathway. 22,23 More specifically, auditory masking has been shown to be aberrant for schizophrenic patients. 22 Auditory forward masking refers to the reduced ability to detect a stimulus when preceded by a masking sound.…”