The use of intrathecal chemotherapy is not exempt from generating adverse effects, the appearance of which can vary from a few hours to several weeks. In the spinal cord, progressive myelopathy is a rare but can have a devastating outcome. Three cases are presented, of female patients aged 5 and 6 with a diagnosis of acute lymphoid leukemia and central nervous system involvement, who came to the Fundación Cardioinfantil to start their cancer treatment; After the use of intrathecal chemotherapy, all three patients developed symptoms of progressive myelopathy and MRI of the lumbosacral spine was performed as part of the diagnostic study. It is concluded that the clinical picture is due to chemotherapy- induced toxicity.
