Neurological events associated with the infusion of cryopreserved bone marrow and/or peripheral blood progenitor cells

Reports of neurological toxicity of cryopreserved stem cell infusion are infrequent, Three of 179 consecutive patients experienced significant neurological events in this context. Transient global amnesia developed following infusion in one patient and in the other two, cerebral infarction occurred. Profound hypotension, bradyarrhythmias or hypoxia were not associated with any of these episodes. These events may have been related to infused DMSO, which in the non-transplant setting has been associated with neurological toxicity and local infusion of which has resulted in acute vasospasm in animal models. These cases suggest that infusion of cryopreserved stem cells may result in cerebrovascular ischaemia.