NEURAL SOURCES OF DYSGEUSIA

味觉障碍的神经源

• 批准号: 2391129
• 负责人: LINDA MAY BARTOSHUK
• 金额: $ 11.78万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2391129
• 关键词: anesthesia; chorda tympani; clinical research; facial nerve; functional magnetic resonance imaging; histology; human subject; nerve injury; neuroanatomy; neurosurgery; phantom model; psychophysiology; sensory disorder chemotherapy; taste; taste buds; taste disorders; tongue; video microscopy; wallerian degeneration

Dysgeusia, an unwanted, chronic taste (akin to chronic pain), is a disorder that diminishes the quality of life. The evaluation of patients with dysgeusia has led to the development of a diagnostic protocol intended to highlight variations in the characteristics of dysgeusias which may provide clues concerning their causes. The protocol uses a spatial taste test designed to evaluate the integrity of the cranial nerves subserving taste and a topical anesthesia test designed to reveal inhibitory relations among those cranial nerves (first discovered by Halpern and Nelson in an animal model). Three groups of studies are proposed which concern dysgeusias (usually salty or metallic) that originate within the taste nervous system (in this case the dysgeusias are referred to as taste phantoms). The first group of studies are to be conducted on patients in whom cranial nerve VII is unavoidably sacrificed during surgery. Surgeries involving cranial nerve VII offer an experimental opportunity to study taste phantoms produced by cutting VII both central to and peripheral to the geniculate ganglion, which contains the cell bodies that keep the neurons in VII viable. When VII must be sacrificed during acoustic neuroma surgery, the cut is central to the geniculate ganglion. This causes Wallerian degeneration from the cut to the brain and thus denervates the central neurons. When VII must be sacrificed during stapedectomy or mastoidectomy, the cut is peripheral to the geniculate ganglion. This causes Wallerian degeneration from the cut to the tongue. Sprouting from the central side of the cut may lead to the formation of a neuroma. One goal of the proposed research is to quantify any differences between the phantoms from these two sorts of nerve cuts that might be attributable to the nature of the pathology induced by the cut. Anatomical evaluation of samples of VII from patients in whom it has been sacrificed may provide additional relevant information. The second group of studies will investigate a new type of taste phantom that has been produced in the laboratory. The chorda tympanic nerve (a branch of VII) innervates the anterior tongue. When this nerve is unilaterally anesthetized at the tympani membrane (via an injection in the ear canal), a taste phantom occurs (in about half of the subjects so anesthetized) contralateral to the side anesthetized on the rear of the tongue (innervated by the glossopharyngeal nerve, IX). The phantoms produced vary in quality across subjects and are abolished if anesthesia is placed directly on the area from which the phantom appears to arise. This kind of phantom may occur in patients who suffer localized damage to taste. Taste phantoms are subjective experiences, but a third group of studies using functional magnetic resonance imaging (fMRI) may provide an objectively measured correlate. Since the side of the brain activated by the anesthesia-induced taste phantoms can be varied, these phantoms offer important experimental advantages in fMRI studies.

味觉障碍，一种不想要的慢性味觉（类似于慢性疼痛），是一种疾病 降低了生活质量。患者的评价 味觉障碍导致了一种诊断方案的发展， 强调味觉障碍特征的变化， 关于他们的原因的线索。该方案使用空间味觉测试 设计用于评估影响味觉的脑神经的完整性 和一个局部麻醉试验，旨在揭示抑制关系， 这些脑神经（首次由Halpern和纳尔逊在动物身上发现 模型）。 提出了三组关于味觉障碍的研究（通常 咸的或金属的），其起源于味觉神经系统（在此 在这种情况下，味觉障碍被称为味觉幻觉）。第一组 研究将在脑神经VII受损的患者中进行。 手术期间不可避免地牺牲了。累及颅神经的脑膜炎 VII提供了一个实验性的机会来研究味觉幻象， 切割膝状神经节的中央和外周的VII， 它包含了维持VII区神经元存活的细胞体。当 在听神经瘤手术中必须牺牲VII，切口位于中央 到膝状神经节这会导致切口处的沃勒变性 从而切断了中枢神经第七，必须 在镫骨切除术或乳突切除术中牺牲，切口位于周边， 膝状神经节这会导致沃勒变性， 舌尖从切口的中央侧发芽可能导致 形成神经瘤。这项研究的一个目标是量化 这两种神经切断的幻象有什么不同吗 这可能归因于由药物引起的病理学性质。 切.来自具有VII的患者的VII样品的解剖学评价 可以提供额外的相关信息。 第二组研究将调查一种新型的味觉幻象 已经在实验室里生产出来了。鼓索神经（a VII的分支）支配前舌。当这条神经 在鼓膜处单侧麻醉（通过在鼓膜中注射）。 耳道），味觉幻象发生（在大约一半的受试者中， 麻醉）对侧的背面麻醉的一侧， 舌（由舌咽神经支配，IX）。幽怪 产生的质量在受试者之间存在差异，如果麻醉被取消， 直接放置在幻影出现的区域。这 味觉局部受损的病人可能会出现这种幻觉。 味觉幻象是主观体验，但第三组研究 使用功能性磁共振成像（fMRI）可以提供一个 客观测量的相关性。因为大脑的一侧被激活， 麻醉诱导味觉幻象可以变化，这些幻象提供 在fMRI研究中的重要实验优势。