Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Curr Opin Psychiatry. 2020 May;33(3):206-211. doi: 10.1097/YCO.0000000000000586.
The association between hallucinations and sensory loss, especially vision- and hearing-impairment, has been firmly established over the past years. The deafferentation theory, a decrease of the threshold for activation in the brain and the consequential imbalance between excitatory and inhibitory brain networks, is hypothesized to underly this relationship. Here we review the studies investigating this theory with a focus on the most recent literature to better understand the contribution of sensory loss to hallucinations.
A large cross-sectional study has recently confirmed the relationship between auditory impairment and deafferentation. However, the underlying mechanisms of deafferentation are still under debate, with hyperexcitability and deviations in bottom-up and top-down processes being the most likely explanations. Social isolation following sensory impairment increases the risk for hallucinations. Better knowledge and awareness about the contribution of deafferentation and loneliness would benefit diagnosis and treatment of hallucinations.
Studies imply activity in higher order areas, corresponding to the functional mapping of sensory system, and a general state of higher excitability as neurobiological explanation. Auditory deafferentation, tinnitus and other auditory hallucinations, likely lie on a continuum. Social isolation mediates psychotic symptoms in sensory-impaired individuals. Currently, there is no standard treatment for deafferentation hallucinations.
近年来，幻觉与感觉缺失（尤其是视觉和听觉损伤）之间的关联已得到明确证实。去传入（deafferentation）理论，即大脑激活阈值降低以及兴奋性和抑制性脑网络之间的失衡，被假设为这种关系的基础。本文重点回顾了研究该理论的相关研究，以更好地了解感觉缺失对幻觉的影响。
最近一项大型横断面研究证实了听觉损伤与去传入之间的关系。然而，去传入的潜在机制仍存在争议，过度兴奋以及自上而下和自下而上过程的偏差最有可能解释这种关系。感觉损伤后社交孤立会增加幻觉的风险。更好地了解去传入和孤独感的作用将有助于幻觉的诊断和治疗。
研究表明，较高阶区域的活动与感觉系统的功能映射相对应，以及更高的兴奋性状态是其神经生物学解释。听觉去传入、耳鸣和其他听觉幻觉可能处于同一连续谱上。社交孤立在感觉损伤个体的精神病症状中起中介作用。目前，针对去传入性幻觉尚无标准治疗方法。
