Transplant-associated Altered Mentation and Encephalopathy (TAME): A New Classification for Acute Neurocognitive Changes Associated with Hematopoietic Cell Transplantation from the ASTCT Committee on Practice Guidelines

Acute encephalopathy, manifesting clinically as delirium, is a common but often unrecognized complication of hematopoietic cell transplant (HCT). Delirium is found in patients of any age and observed after autologous or allogeneic HCT. While primarily studied during initial transplant hospitalizations among recipients of myeloablative conditioning, recent HCT investigations have identified delirium later posttransplant and among those who received reduced intensity conditioning. Acute encephalopathy can be driven by infectious complications, medications, tissue damage and/or organ dysfunction. Altered consciousness, either mild or profound, is often its only clinical manifestation. Identifying delirium is essential to overall HCT care because patients who experience delirium have longer hospitalization and recovery times and are at risk for other poor post-HCT outcomes. Given the critical nature of this common complication and expansion of HCT into more vulnerable populations, the American Society of Transplantation and Cellular Therapy (ASTCT) recommends that it is time to intensify research into post-HCT cognitive changes and to establish standardized definitions that encompass the full spectrum of altered consciousness for clinical care purposes and to provide benchmark endpoints for future research studies. To capture a range of acute neurocognitive changes specifically found in HCT patients (often referred to as acute encephalopathy), ASTCT propose a new diagnosis, Transplant-associated Altered Mentation and Encephalopathy (TAME). The TAME diagnosis includes HCT patients who meet DSM-5 criteria for delirium and those with acute neurocognitive changes who do not meet full DSM-5 criteria for delirium (subsyndromal delirium). Early TAME is defined as occurring during conditioning or ≤100 days post-HCT, while late TAME occurs >100 days post-HCT in patients with additional HCT-related complications. This manuscript will establish clear diagnostic criteria and discuss factors that can potentially impact the development of TAME, as well as work-up and management of TAME.