@misc{SchoeberlIrvingPradhanetal., author = {Sch{\"o}berl, Florian and Irving, Stephanie and Pradhan, Cauchy and Bardins, Stanislav and Trapp, Christoph and Schneider, Erich and Kugler, G{\"u}nter and Bartenstein, Peter and Dietrich, Marianne and Brandt, Thomas and Zwergal, Andreas}, title = {Prolonged allocentric navigation deficits indicate hippocampal damage in TGA}, series = {Neurology : official journal of the American Academy of Neurology}, volume = {92}, journal = {Neurology : official journal of the American Academy of Neurology}, number = {3}, issn = {0028-3878}, doi = {10.1212/WNL.0000000000006779}, pages = {e234 -- e243}, abstract = {Objective 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). Methods 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 [18F]-fluorodeoxyglucose-PET in a subgroup of 8 patients in the postacute stage and compared to those of the controls. Results In the postacute stage, the patients navigated worse and had higher error rates than controls in allocentric (p = 0.002), but not in egocentric, route planning (p = 0.30), despite complete recovery of verbal (p = 0.58) and figural memory (p = 0.11). Until follow-up, allocentric navigation deficits improved, but higher error rates and reduced use of shortcuts persisted (p < 0.0001). Patients still exhibited relatively more fixations of unique landmarks during follow-up (p = 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 (p < 0.005). Conclusions 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.}, language = {en} } @misc{SchoeberlPradhanIrvingetal., author = {Sch{\"o}berl, Florian and Pradhan, Cauchy and Irving, Stephanie and Buerger, Katharina and Xiong, Guoming and Kugler, G{\"u}nter and Kohlbecher, Stefan and Engmann, Julia and Werner, Philipp and Brendel, Matthias and Schneider, Erich and Perneczky, Robert and Jahn, Klaus and Foug{\`e}re, Christian la and Bartenstein, Peter and Brandt, Thomas and Dietrich, Marianne and Zwergal, Andreas}, title = {Real-space navigation testing differentiates between amyloid-positive and -negative aMCI}, series = {Neurology : official journal of the American Academy of Neurology}, volume = {94}, journal = {Neurology : official journal of the American Academy of Neurology}, number = {8}, issn = {1526-632X}, doi = {10.1212/WNL.0000000000008758}, pages = {e861 -- e873}, language = {en} }