The influences of gender, medication status, and smoking on effect sizes were not significant across studies. No differential deficits were observed across domains of odor identification, detection threshold sensitivity, discrimination, and memory. Results indicated that substantial olfactory deficits, across all domains, are observed in patients with schizophrenia. Moderator variables such as gender, medication status, and smoking history were also examined. To help elucidate some of this controversy, we conducted a qualitative and quantitative (meta-analytic) review of the English language literature on olfaction in schizophrenia. Despite increasing knowledge, controversy has existed about possible differential deficits among olfactory tests as well as the influences of gender, smoking, and medication status on olfactory measures. Olfactory dysfunction in patients with schizophrenia has been a topic of increasing interest, with deficits in odor identification, detection threshold sensitivity, discrimination, and memory being reported. This could help to clarify underlying brain mechanisms and facilitate identification of clinically relevant biomarkers. With the opportunity to obtain olfactory neural tissue from live patients through nasal epithelial biopsy, the peripheral olfactory system offers a uniquely accessible window through which the pathophysiological antecedents and sequelae of schizophrenia may be observed. A unifying mechanistic hypothesis may be the epigenetic regulation of gene expression. Gross structural and functional anomalies are mirrored by cellular and molecular abnormalities that suggest decreased or faulty innervation and/or dysregulation of intracellular signaling. These reflect, in part, a genetically mediated neurodevelopmental etiology. ![]() Convergent data indicate that structural and functional abnormalities extend from the cortex to the most peripheral elements of the olfactory system. In this article, we review the evidence supporting a primary olfactory sensory disturbance in schizophrenia. Olfactory dysfunction may therefore be a sensitive indicator of schizophrenia pathology and may even serve as an "early warning" sign of disease vulnerability or onset. Perhaps more importantly, to the extent that early sensory afferents are also disrupted in schizophrenia, the olfactory system-owing to its strategic anatomic location-may be especially vulnerable to such disruption. ![]() Olfactory probes may therefore be ideal tools through which to assess the structural and functional integrity of the neural substrates that underlie disease-related cognitive and emotional disturbances. Changes in the characteristics of the signal and the misinterpretation of visual stimuli associated with them may, as a result, contribute to the development of schizophrenic disease.Īmong the sensory modalities, olfaction is most closely associated with the frontal and temporal brain regions that are implicated in schizophrenia and most intimately related to the affective and mnemonic functions that these regions subserve. This review describes the precortical circuit and the key changes in biochemistry and pathophysiology that affect the creation and characteristics of the retinal signal as well as its subsequent modulation and processing in other parts of this circuit. Searched databases included Google Scholar, PubMed, and Web of Science. Articles were chosen with respect to topic relevance. ![]() A web-based comprehensive search of peer-reviewed journals was conducted based on various keyword combinations including schizophrenia, saliency, visual cognition, visual pathways, retina, and LGN. So far, there has been no clear answer as to whether the disruption occurs primarily within the brain or in the precortical areas of visual perception (the retina, visual pathways, and lateral geniculate nucleus ). However, in schizophrenia, this modality is disrupted. Visual perception is one of the basic tools for exploring the world.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |