Neurosurgery, Institut Mondor de recherche biomedicale, Créteil, Île-de-France, France.
Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada.
J Neurol Neurosurg Psychiatry. 2020 May;91(5):547-559. doi: 10.1136/jnnp-2019-322375. Epub 2020 Mar 4.
The fornix is a white matter bundle located in the mesial aspect of the cerebral hemispheres, which connects various nodes of a limbic circuitry and is believed to play a key role in cognition and episodic memory recall. As the most prevalent cause of dementia, Alzheimer's disease (AD) dramatically impairs the quality of life of patients and imposes a significant societal burden on the healthcare system. As an established treatment for movement disorders, deep brain stimulation (DBS) is currently being investigated in preclinical and clinical studies for treatment of memory impairment in AD by modulating fornix activity. Optimal target and stimulation parameters to potentially rescue memory deficits have yet to be determined. The aim of this review is to consolidate the structural and functional aspects of the fornix in the context of neuromodulation for memory deficits. We first present an anatomical and functional overview of the fibres and structures interconnected by the fornix. Recent evidence from preclinical models suggests that the fornix is subdivided into two distinct functional axes: a septohippocampal pathway and a subiculothalamic pathway. Each pathway's target and origin structures are presented, followed by a discussion of their oscillatory dynamics and functional connectivity. Overall, neuromodulation of each pathway of the fornix is discussed in the context of evidence-based forniceal DBS strategies. It is not yet known whether driving fornix activity can enhance cognition-optimal target and stimulation parameters to rescue memory deficits have yet to be determined.
穹窿是位于大脑半球内侧的白质束，连接着边缘回路的各个节点，被认为在认知和情景记忆回忆中发挥着关键作用。作为痴呆症最常见的病因，阿尔茨海默病（AD）极大地降低了患者的生活质量，并给医疗保健系统带来了巨大的社会负担。作为治疗运动障碍的一种成熟方法，深部脑刺激（DBS）目前正在通过调节穹窿活动来进行 AD 患者记忆障碍的临床前和临床研究。然而，仍需确定潜在的治疗记忆缺陷的最佳目标和刺激参数。本综述的目的是整合穹窿在神经调节记忆缺陷方面的结构和功能方面。我们首先介绍了穹窿连接的纤维和结构的解剖学和功能概述。来自临床前模型的最新证据表明，穹窿可以分为两个不同的功能轴：隔核-海马通路和内嗅皮质-丘脑通路。我们介绍了每个通路的目标和起源结构，然后讨论了它们的振荡动力学和功能连接。总的来说，讨论了穹窿每个通路的神经调节在基于证据的穹窿 DBS 策略的背景下。目前尚不清楚是否可以通过驱动穹窿活动来增强认知-最佳的目标和刺激参数还有待确定。
