Manford M, Andermann F
Department of Clinical Neurology, Addenbrooke's Hospital, Cambridge, UK.
Brain. 1998 Oct;121 ( Pt 10):1819-40. doi: 10.1093/brain/121.10.1819.
Complex visual hallucinations may affect some normal individuals on going to sleep and are also seen in pathological states, often in association with a sleep disturbance. The content of these hallucinations is striking and relatively stereotyped, often involving animals and human figures in bright colours and dramatic settings. Conditions causing these hallucinations include narcolepsy-cataplexy syndrome, peduncular hallucinosis, treated idiopathic Parkinson's disease, Lewy body dementia without treatment, migraine coma, Charles Bonnet syndrome (visual hallucinations of the blind), schizophrenia, hallucinogen-induced states and epilepsy. We describe cases of hallucinosis due to several of these causes and expand on previous hypotheses to suggest three mechanisms underlying complex visual hallucinations. (i) Epileptic hallucinations are probably due to a direct irritative process acting on cortical centres integrating complex visual information. (ii) Visual pathway lesions cause defective visual input and may result in hallucinations from defective visual processing or an abnormal cortical release phenomenon. (iii) Brainstem lesions appear to affect ascending cholinergic and serotonergic pathways, and may also be implicated in Parkinson's disease. These brainstem abnormalities are often associated with disturbances of sleep. We discuss how these lesions, outside the primary visual system, may cause defective modulation of thalamocortical relationships leading to a release phenomenon. We suggest that perturbation of a distributed matrix may explain the production of similar, complex mental phenomena by relatively blunt insults at disparate sites.
复杂视幻觉可能会在一些正常人入睡时出现，在病理状态下也较为常见，且常与睡眠障碍相关。这些幻觉的内容引人注目且相对刻板，通常涉及色彩鲜艳、场景戏剧性的动物和人物形象。导致这些幻觉的病症包括发作性睡病 - 猝倒综合征、脑桥幻觉症、经过治疗的特发性帕金森病、未经治疗的路易体痴呆、偏头痛昏迷、查尔斯·博内综合征（盲人的视幻觉）、精神分裂症、致幻剂所致状态以及癫痫。我们描述了由其中几种病因导致的幻觉症病例，并在以往假说基础上进行拓展，提出复杂视幻觉背后的三种机制。（i）癫痫性幻觉可能是由于直接刺激作用于整合复杂视觉信息的皮质中枢。（ii）视觉通路病变导致视觉输入缺陷，可能因视觉处理缺陷或异常皮质释放现象而引发幻觉。（iii）脑干病变似乎会影响上行胆碱能和5-羟色胺能通路，帕金森病中也可能涉及。这些脑干异常通常与睡眠障碍有关。我们讨论了这些位于初级视觉系统之外的病变如何导致丘脑皮质关系调节缺陷，从而引发释放现象。我们认为，分布式矩阵的扰动或许可以解释不同部位相对轻微损伤如何产生相似的复杂心理现象。
