Reversible cerebral vasoconstriction syndrome due to teprotumumab: two case reports.

Background: Reversible Cerebral Vasoconstriction Syndrome (RCVS) involves cerebral vasculature constriction and dilation. While the exact pathophysiology of RCVS is still not fully understood, there are multiple etiological factors suggested to be implicated in triggering RCVS. We report two RCVS cases potentially linked to teprotumumab. Case 1: A 59-year-old female with Graves' eye disease (GED) developed leg weakness and headache after initiating teprotumumab, and neuroimaging studies revealed multifocal cerebral vasospasm (CVS). Verapamil mitigated vasospasm and the patient overall improved. Case 2: A 71-year-old female with GED developed thunderclap headache two months after starting teprotumumab, with subarachnoid hemorrhage (SAH) and CVS revealed on neuroimaging studies. The patient improved on verapamil and was discharged without deficits. Conclusions: The temporal correlation between teprotumumab initiation and RCVS's symptom onset raises concern for the potential involvement of teprotumumab in triggering RCVS via disrupting cerebrovascular modulation. Further research is needed to investigate this proposed association. [ABSTRACT FROM AUTHOR]