TY - JOUR TI - Network-wide abnormalities explain memory variability in hippocampal amnesia AU - Argyropoulos, Georgios PD AU - Loane, Clare AU - Roca-Fernandez, Adriana AU - Lage-Martinez, Carmen AU - Gurau, Oana AU - Irani, Sarosh R AU - Butler, Christopher R A2 - Colgin, Laura L A2 - Olsen, Rosanna VL - 8 PY - 2019 DA - 2019/07/08 SP - e46156 C1 - eLife 2019;8:e46156 DO - 10.7554/eLife.46156 UR - https://doi.org/10.7554/eLife.46156 AB - Patients with hippocampal amnesia play a central role in memory neuroscience but the neural underpinnings of amnesia are hotly debated. We hypothesized that focal hippocampal damage is associated with changes across the extended hippocampal system and that these, rather than hippocampal atrophy per se, would explain variability in memory between patients. We assessed this hypothesis in a uniquely large cohort of patients (n = 38) after autoimmune limbic encephalitis, a syndrome associated with focal structural hippocampal pathology. These patients showed impaired recall, recognition and maintenance of new information, and remote autobiographical amnesia. Besides hippocampal atrophy, we observed correlatively reduced thalamic and entorhinal cortical volume, resting-state inter-hippocampal connectivity and activity in posteromedial cortex. Associations of hippocampal volume with recall, recognition, and remote memory were fully mediated by wider network abnormalities, and were only direct in forgetting. Network abnormalities may explain the variability across studies of amnesia and speak to debates in memory neuroscience. KW - hippocampus KW - memory KW - amnesia KW - MRI KW - limbic encephalitis KW - cingulate JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -