From the Department of Neurology (F.S., C.T., M.D., A.Z.), German Center for Vertigo and Balance Disorders (F.S., S.I., C.P., S.B., C.T., E.S., G.K., P.B., M.D., T.B., A.Z.), Graduate School of Systemic Neuroscience (S.I., M.D., T.B.), Department of Nuclear Medicine (P.B.), and Clinical Neurosciences (T.B.), Ludwig Maximilians University, Munich; and Munich Cluster of Systems Neurology (P.B., M.D.), SyNergy, Munich, Germany.
Neurology. 2019 Jan 15;92(3):e234-e243. doi: 10.1212/WNL.0000000000006779. Epub 2018 Dec 14.
To investigate long-term recovery of allocentric and egocentric spatial orientation as a sensitive marker for hippocampal and extrahippocampal network function in transient global amnesia (TGA).
A group of 18 patients with TGA performed an established real-space navigation paradigm, requiring allo- and egocentric spatial orientation abilities, 3 days (postacute stage) and 3 months (follow-up) after symptom onset. Visual exploration behavior and navigation strategy were documented by a gaze-controlled, head-fixed camera. Allo- and egocentric spatial orientation performance was compared to that of 12 age-matched healthy controls. Navigation-induced brain activations were measured using [F]-fluorodeoxyglucose-PET in a subgroup of 8 patients in the postacute stage and compared to those of the controls.
In the postacute stage, the patients navigated worse and had higher error rates than controls in allocentric ( = 0.002), but not in egocentric, route planning ( = 0.30), despite complete recovery of verbal ( = 0.58) and figural memory ( = 0.11). Until follow-up, allocentric navigation deficits improved, but higher error rates and reduced use of shortcuts persisted ( < 0.0001). Patients still exhibited relatively more fixations of unique landmarks during follow-up ( = 0.05). PET measurements during the postacute stage showed increased navigation-induced brain activations in the right hippocampus, bilateral retrosplenial, parietal, and mesiofrontal cortices, and cerebellar dentate nucleus in patients compared to controls ( < 0.005).
Patients with TGA show selective and prolonged deficits of allocentric spatial orientation. Activations in right hippocampal and extrahippocampal hubs of the cerebral navigation network functionally substitute for the deficit in creating and updating the internal cognitive map in TGA.
研究以自我为中心和以客体为中心的空间定位的长期恢复情况，作为瞬态全球失忆症（TGA）中海马和海马外网络功能的敏感标志物。
一组 18 名 TGA 患者在症状发作后 3 天（急性期后）和 3 个月（随访）进行了既定的真实空间导航范式，该范式需要自我和以客体为中心的空间定位能力。通过视线控制、头戴式相机记录视觉探索行为和导航策略。将患者的自我和以客体为中心的空间定位表现与 12 名年龄匹配的健康对照组进行比较。在急性期后，对 8 名患者中的亚组进行了 [F]-氟脱氧葡萄糖-PET 测量，以测量导航诱导的大脑激活，并与对照组进行比较。
在急性期后，患者的自我和以客体为中心的路线规划表现均比对照组差，错误率更高（=0.002），但以自我为中心的路线规划错误率（=0.30）无差异。尽管言语（=0.58）和图形记忆（=0.11）完全恢复，但直到随访时，以客体为中心的导航缺陷仍在改善，而错误率更高且使用捷径减少（<0.0001）。患者在随访期间仍表现出相对更多地注视独特地标（=0.05）。急性期后测量的 PET 显示，与对照组相比，患者右侧海马体、双侧后扣带回、顶叶和中额叶皮质以及小脑齿状核的导航诱导大脑激活增加（<0.005）。
TGA 患者表现出以自我为中心和以客体为中心的空间定位选择性和持久缺陷。在 TGA 中，右侧海马体和海马外大脑导航网络的枢纽激活功能替代了创建和更新内部认知图的缺陷。
