Evaluation of the effects of central nervous system complications and radiological findings on survival after hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is a curative treatment which has been increasingly used for the many malign and benign hematologic childhood disorders, metabolic and genetic diseases and immune deficiencies. It has been shown by many studies that central nervous system (CNS) complications are seen in 11-59% of the patients after HSCT. Early diagnosis, treatment and successful management of the patients have remarkable effect on survival. Radiologic evaluation is one of the most important methods in early diagnosis for neurological complications. We evaluated the relation between positive radiological findings and patient survival among patients who had HSCT in our institution. We aimed to provide information that may be helpful in decreasing HSCT related mortality and morbidity. We retrospectively evaluated records of all the patients who had HSCT between August 1998 - January 2014. There were total 489 patients who had HSCT in this period and 91 (18,6%) of them had developed neurologic symptoms and neuroradiologic evaluation. Patients were divided into two groups according to presence of positive radiologic findings. Forty-seven (51,6%) patients had positive findings and 44 (48,3%) patients had no radiologic findings. Patients' ages, sexes, presence of neurologic finding before HSCT, intrathecal treatment history, CNS radiotherapy history had no significant effect on positive radiological findings. Mean duration between HSCT and appearance of neurologic symptoms was 87,4±14,4 days. Shortest duration was 1 day and longest duration was 912 days. It was noted that neurologic complications could be observed even years after HSCT. There was no significant effect of preparatory regimen, type of graft versus host disease prophylaxis, source of stem cells, and engraftment status on positive radiologic findings. Most frequent neurologic complaint was convulsions, which was seen on 34 (37,4%) cases, whereas most frequent radiologic finding was white matter lesions, which was seen on 22 (46,8%) cases. Posterior reversible encephalopathy syndrome (PRES) accounted for 18 (81,8%) of all white matter lesions. When final neurologic diagnoses were considered, PRES was the most frequent (19,8%) and intracranial bleeding was the second (11%). In the patients who died after transplantation, the reason of death was also evaluated. In the patients with positive radiologic findings, the ratio of death due to neurologic complications was significantly higher than the patients with no radiologic findings (p < 0,05). The mean patient survival was 52,5±7,2 months in patients who had HSCT and developed neurologic complications. Survivals were also evaluated according to presence of radiologic findings. In the group of patients with positive findings, mean survival was 30,5±4,5 months, whereas in patients with no findings, mean survival was 68,6±10,1 months. The presence of radiologic findings was significantly decreasing the mean survival (p < 0,05). When the findings were divided into three groups as cerebrovascular complications (bleeding, ischemia and infarction), white matter involvement (including PRES) and infections, the shortest mean survival was in the cerebrovascular complication group (p < 0,05). In conclusion, neurologic complications are not rare in patients who had HSCT. In these patients, prompt neuroradiologic evaluation is mandatory. In the management of these patients, it should always be kept in mind that positive neuroradiologic findings may considerably shorten the patient survival.