Improvement of Hearing in Schizophrenia

Schizophrenia disorder is depicted as a long-term, destructive brain disorder that begins during neural development. Individuals with this disorder tend to have delusions, are socially awkward, and have progressive deterioration of their cognitive abilities. Dr. John G. Csernansky, from Northwestern University Feinberg School of Medicine, presented his research regarding neural adaptation and the long-term course of schizophrenia. Csernansky referred to people with schizophrenia as having a broken mind and created his own model for the brain disorder. His model explained the origin of the schizophrenic biological process occurring in neural development along with the tendency of children to be shy, troublesome making friends, and problem with fine motor skills. After this premorbid state, until around fourteen or fifteen years of age, the teenager enters a prodromal state characterized by the onset of psychosis. The affected person typically starts to lose friends, develop more distractions, hear their thoughts spoken aloud, and find special meaning in ordinary objects. In addition, Csernansky distinguished positive symptoms of schizophrenia as experiences that normal people do not have for example, thought disorganization. Negative symptoms were described as social withdrawal, social awkwardness. After the onset of psychosis, the neurodegenerative disorder enters a progressive state involving delusions and paranoid themes. I found it particularly interesting that Csernansky mentioned the content within the delusions and paranoia often reflects the cultural upbringing of the individual. In the progressive state, usually schizophrenics start to receive treatment, but the treatment only seems to better the negative symptoms of the disorder while psychosis is still evident throughout their lifetime. The human brain physically grows until around fourteen years of age. Csernansky said that white matter continues to grow, further developing the brain and basically fills in the spots where the grey matter eventually thins out. Previous work indicated that grey matter decline is more exacerbated in schizophrenia. Csernansky provided neuroimaging evidence of anatomical progression involving changes in the anterior regions of the caudate and thalamus. Thus, he focused on the frontal and temporal cortical structures where he found cortical thinning and associated the increase in grey matter decline with a more disturbed thalamus. Csernansky concludes with saying that schizophrenic patients require more cognitive activation in dorsolateral prefrontal cortex to fulfill tasks as opposed to normal people. Furthermore, there is a possible adaptive mechanism that can compensate for the neuroanatomical changes in cognitive function in people with schizophrenia.

The long-term course of schizophrenia is extremely difficult to deal with. Whether it’s the deterioration in cognitive deficits, or detrimental effects of psychosis, finding ways to communicate with people in regards to this neurodegenerative disorder is an obstacle that many people face. Columbia University Medical Center offers evidence in improving hearing with their journal, Hearing deficits in schizophrenia tied to specific brain receptor, with the utilization of D-serine and auditory training exercises. Dr. Joshua T. Kantrowitz, assistant professor of clinical psychiatry at CUMC, explaining the essence of voice tone, “ This inability to detect subtle changes in pitch can also make it difficult to "sound out" words while reading, with over 70 percent of patients meeting criteria for dyslexia and further exacerbating communication problems in social and work situations.” Kantrowitz and his research team chose 40 schizophrenic patients and 42 healthy patients who had to listen to multiple tones and indicate which tone was higher. The pitch difference of the tones decreased as the test went on, and once the subjects were not able to pick the higher pitch, researchers would increase the pitch difference again. Kantrowitz says, “People with normal auditory plasticity usually get better at discriminating between the two tones as the test progresses, reflecting the ability to learn”. The results showed he was correct because non-schizophrenic subjects distinguished tones with a different in pitch of 3%, while schizophrenic patients averaged 16%. Thus, the auditory plasticity of schizophrenic subjects is impaired and the CUMC research team proposed that an NMDA receptor abnormality could play a part in this deficit. The NMDA receptor is crucial for long-term potentiation in both memory and learning and its activation involves binding of both glutamate and glycine. Researchers gave some schizophrenic subjects the amino acid glycine, or D-serine, one time a week up to three weeks, while other schizophrenic subjects were given a placebo. Results showed that schizophrenic individuals who took D-serine for two consecutive weeks improved tone detection, but schizophrenic patients who took D-serine for only one week did not see improvement. Understanding that D-serine with different auditory training exercises improves pitch detection in schizophrenia, researchers can test the use of different glycine and glutamate agonists to see if they make NMDA activity more efficient. Both glycine and glutamate binding are needed in order for the NMDA channel to open and allow an influx of calcium to rush into the cell. The controlled activation and deactivation of NMDA receptors ultimately determines the effectiveness of synaptic plasticity, memory, and learning. Learning from Csernansky’s presentation that psychosis, cognitive deficits, and the miscommunication that schizophrenics experience on a daily basis, finding the most effective learning-enhancing drug can possibly improve the long-term auditory deficits in schizophrenic patients. Moreover, making the NMDA receptor more functional would help alleviate the negative symptoms of schizophrenia including social awkwardness, inability to act, and thought disorganization that causes confusion/delusions in schizophrenics. Csernansky’s research should also be followed up on because identifying a possible adaptive, compensatory mechanism would spark methods to counteract the deterioration of cognition seen in schizophrenia.

Works Cited

            Columbia University Medical Center. "Hearing deficits in schizophrenia tied to specific brain receptor." ScienceDaily. ScienceDaily, 2 December 2016. <www.sciencedaily.com/releases/2016/12/161202150855.htm>.

Northwestern University. "Map Of Your Brain May Reveal Early Mental Illness." ScienceDaily. ScienceDaily, 10 July 2009. <www.sciencedaily.com/releases/2009/07/090709095431.htm>.