At the Saitama Prefectural Pediatric Medical Center, following an incident involving the misadministration of the chemotherapy drug vincristine, two additional patients were reported to exhibit neurological symptoms after receiving spinal injections. This issue surfaced after three patients experienced adverse effects, eventually leading to the revelation that vincristine, a drug that should not have been used in their treatment, was detected in the cerebrospinal fluid of three of those patients. The medical center disclosed that one patient died as a result, while two others were in critical condition.

During a press conference, the medical center outlined the circumstances of these neurological symptoms, which arose in patients who underwent intrathecal injections intended for spinal application. This troubling phenomenon had not been documented in cases prior to 2024. The center announced that they had investigated the cerebrospinal fluid of five patients who showed symptoms, with vincristine only detected in three. The two patients who did not show any evidence of vincristine were found to experience neurological symptoms characterized by leg issues without cognitive impairment, indicating different underlying causes compared to the first three patients.

The medical center is now under scrutiny regarding their storage practices and the protocols followed during the preparation of vincristine. They report that further tests are underway to determine if other unintended medications contributed to the patients' neurological symptoms. As this situation evolves, it highlights significant concerns regarding the safety and monitoring processes within pediatric medical environments, particularly regarding the handling of potent chemotherapy drugs used in sensitive populations like children with leukemia.