Neurotoxicology of chemotherapy in relation to cytokine release, the blood-brain barrier, and cognitive impairment.

PURPOSE/OBJECTIVES To review the effects of chemotherapeutic agents on the blood-brain barrier as related to cytokine release and cognitive impairment. DATA SOURCES PubMed database. DATA SYNTHESIS The recent findings that standard doses of chemotherapy agents reach higher than expected levels in the brain and cerebral spinal fluid are being investigated as a potential etiology for the cognitive impairment seen in patients receiving chemotherapy for cancer. Chemotherapy and chemotherapy-related neurotoxicity are associated with the release of proinflammatory cytokines, substances related to sickness behavior (e.g., decreased ability to concentrate). Chemotherapy-related oxidative stress is an additional mechanism hypothesized to induce cognitive impairment. Cognitive impairment from chemotherapy is estimated to occur in 17%-75% of patients, and 17%-35% may suffer from long-term effects. CONCLUSIONS Further research is needed to identify the patients most at risk for cognitive impairment from chemotherapy. Prospective studies that evaluate appropriate interventions and control for age, intelligence quotient, education level, hormonal status, fatigue, anxiety, depression, chemotherapy regimen, and genetic status are needed. IMPLICATIONS FOR NURSING Changes in cognitive function are associated with significant effects on patients' quality of life. Oncology nurses must be aware of chemotherapy's effects on the brain to appropriately assess and educate patients and their families. In addition, nurses should develop plans of care to prevent or manage chemotherapy-related cognitive impairment after more intervention information is obtained.