[Central nervous system toxicity caused by bortezomib: five case reports and a review of literature]

Objective: To investigate the clinical features, diagnosis, and treatment of the central nervous system (CNS) toxicity caused by bortezomib. Methods: This study reports five new cases of CNS toxicity caused by bortezomib to elucidate its characteristics along with a review of the literature. Results: CNS toxicity caused by bortezomib presents in three clinical forms: syndrome of inappropriate antidiuresis (SIAD) , posterior reversible encephalopathy syndrome (PRES) , and central fever, which is the most common clinical manifestation. Four of our five patients developed central fever after the administration of bortezomib, manifested as persistent high fever, anhidrosis, and absence of infective foci; the symptom could be improved by discontinuance of bortezomib. Of these patients, three concurrently presented with refractory hyponatremia and one was clearly diagnosed with SIAD. The bortezomib could have caused damages to the hypothalamus and induced both central fever and SIAD. In addition, one patient was diagnosed with PRES due to disturbance of consciousness and epilepsy after taking bortezomib. After discontinuation of bortezomib, the symptoms disappeared and did not recur. We also found that thrombocytopenia may be related to the severity of the CNS toxicity of bortezomib. Conclusion: Cases of CNS toxicity of bortezomib are extremely rare and present as SIAD, PRES and central fever. Early detection and treatment of bortezomib are very important to prevent irreversible neurological complications.