Characteristics and correlates of cognitive functioning following bone marrow transplantation

Patients who undergo bone marrow transplantation (BMT) often report cognitive problems following treatment. This study used cognitive tests and a self-report measure of subjective cognitive complaints to determine (1) the rate of objective cognitive impairment in a sample of 65 BMT patients, and (2) the correspondence of patients' cognitive complaints to their actual cognitive performance. At 6 months following BMT, patients were assessed in seven cognitive domains--attention, verbal learning, verbal memory, visual memory, simple executive function, complex executive function, and psychomotor speed. Cognitive complaints were likewise assessed. In all, 51% had at least mild impairment (-1 standard deviation (s.d.) below published norms) in one or more cognitive domains, with 28% demonstrating moderate-to-severe impairment (-2 s.d.). Older patients and patients with lower IQ were more likely to score in the impaired range on objective cognitive tests, with males and the less educated showing trends toward scores in the impaired range. Younger patients made significantly more cognitive complaints. Total cognitive complaints were unrelated to average cognitive performance, and complaints in specific cognitive domains were largely unrelated to objective performance on corresponding domains. Findings suggest that patients who complain about their cognitive performance following BMT differ from those who experience actual deficits.