Tocilizumab and the reversible cerebral vasoconstriction syndrome

Background/Aims Reversible cerebral vasoconstriction syndrome (RCVS) describes a group of conditions characterised by thunderclap headache and radiographic evidence of multifocal cerebral artery vasoconstriction. While typically following a benign course to resolution within a period of days to weeks, a small proportion of patients experience complications such as stroke, seizure or cerebral oedema. While a wide range of aetiological factors have been implicated in the clinical literature, there is, to our knowledge, only one prior publication reporting an association between tocilizumab and RCVS. Methods Here, we describe the case of a patient who developed RCVS following treatment with tocilizumab for rheumatoid arthritis. Results A 41 year old lady presented to her local emergency department after waking from sleep with sudden onset thunderclap headache with associated photophobia and vomiting. There was no prior history of headache. Her past medical history included rheumatoid arthritis and depression. At time of admission, her prescribed medications included folic acid, sertraline, methotrexate and tocilizumab. For the past 5 years, her rheumatoid arthritis had been controlled with a combination of methotrexate and etanercept, but, with her disease flaring, the etanercept was switched for tocilizumab six weeks prior to admission. Initial evaluation with CT head, CT venogram and lumbar puncture did not reveal any underlying abnormalities. A subsequent CT angiogram of the head and neck revealed multiple smooth stenoses bilaterally within the anterior cerebral arteries (ACA), middle cerebral arteries (MCA) and posterior cerebral arteries (PCA). A diagnosis of RCVS was made and tocilizumab was discontinued. Conclusion In patients taking tocilizumab, particular consideration should be given to the possibility of RCVS when performing a diagnostic evaluation of thunderclap headache. Tocilizumab may be an aetiological factor in this condition and its discontinuation may prevent the development of more serious complications. Disclosure B. Corney: None. C. Rhys-Dillon: None.