Prospective evaluation of neurological complications after allogeneic bone marrow transplantation.

OBJECTIVE: To determine the spectrum and frequency of neurologic sequelae after allogeneic bone marrow transplantation (BMT) and to define a risk profile of the patients.

METHODS: A prospective follow-up of 71 allogeneic bone marrow recipients 14 +/- 3 months after transplantation. Patients underwent a neurologic examination, a neuropsychological test battery, and cranial MRI before and after BMT.

RESULTS: A large proportion of patients (65%) developed sequelae after BMT. Acute complications of defined etiology occurred in 18% of the patients and led to death in 9% of the study population. A total of 47% of the patients developed new neurologic abnormalities of undefined origin that were mild and subacute and predominantly affected the peripheral nervous system. The cognitive and neuroradiologic outcome was favorable in a majority of these patients, but a small subgroup exhibited cognitive deterioration and white matter lesions. Risk factor analysis identified acute graft-versus-host disease (GvHD) and other variables partly related to GvHD such as long-lasting immunosuppression as the main predictors of sequelae after allogeneic BMT. The authors have established an association with various factors but, owing to the observational character of this study, conclusions about the etiology of the findings are unclear.

CONCLUSION: Neurologic complications significantly contribute to the morbidity and mortality of patients receiving allogeneic BMT. Subclinical abnormalities, cognitive deficits, and white matter lesions detected 1 year after BMT in a subgroup of patients may be related to more extensive CNS changes observed after transplantation in an earlier retrospective study and may be associated with the risk factor chronic GvHD/immunosuppression.