Spectrum and prognosis of neurologic complications after hematopoietic transplantation

Objective: To describe the neurologic complications after hematopoietic progenitor cell transplantation (HPCT) in order to design rules for their management. Methods: We reviewed 361 consecutive patients over 6 years, including 245 autologous and allogeneic HPCT recipients for hematologic malignancies (87%) and solid cancers (13%). Results: Fifty-seven patients developed 65 symptomatic neurologic complications (16%), with a higher incidence in allogeneic than in autologous HPCT recipients (p = 0.01) and in chronic myelogenous leukemia (42%) than in Hodgkin disease (2.5%) (p < 0.001). CNS infections (4.2%) were the main complications, marked by an early onset (within the first 4 months) after HPCT (87%), diagnostic difficulties, and a high mortality rate (47%). They mainly included cerebral toxoplasmosis, fungal infections, and viral encephalitis. Their incidence was markedly higher in allogeneic than in autologous HPCT recipients (p = 0.002). However, two CD34(+) selected autologous HPCT recipients developed cerebral toxoplasmosis. Other CNS complications included recurrent tumors (3.6%), metabolic encephalopathies (2.8%), and cerebrovascular events (1.7%). Seizures occurred in 5% of patients, most often associated with cerebral lesions. Peripheral nervous system manifestations occurred in 3.3%. Twenty-one patients (5.8%) died directly of neurologic complications. The 4-year probability of survival was markedly lower in the case of neurologic events than in the absence thereof (12% vs 58%, p < 0.0001). Conclusions: Severe neurologic complications after hematopoietic progenitor cell transplantations are common, vary according to the underlying disease and type of transplantation, and are associated with poor survival rates. Better prophylactic protocols and therapy for CNS infections are required in future studies.