Cognitive dysfunction in adult survivors of allogeneic marrow transplantation: relationship to dose of total body irradiation.

Bone marrow transplant (BMT) patients are exposed to several potential sources of neurologic damage including the neurotoxicity of pre-BMT preparative regimens. The latter generally include a combination of total body irradiation (TBI) and high-dose chemotherapy. Cognitive functioning in 30 adult allogeneic BMT patients (mean of 47 months post-BMT) treated for either acute or chronic leukemia was assessed by two standardized self-report questionnaires. Consistent with hypothesis, results of both univariate and multivariate analyses indicated that increased dose of TBI was associated with increased cognitive dysfunction. Furthermore, this relationship remained even after the impact of psychological distress upon cognitive functioning was accounted for. TBI-related cognitive impairment primarily involved slowed reaction time, reduced attention and concentration, and difficulties in reasoning and problem-solving. These results complement previous findings of an inverse association between dose of TBI and self-perceptions of health and physical functioning in BMT survivors and indicate the importance of including quality of life measures in clinical trials of therapeutic innovations in the field of BMT.