Early nimodipine treatment in reversible cerebral vasoconstriction syndrome: A serial transcranial Doppler study

Although nimodipine is commonly used to treat reversible cerebral vasoconstriction syndrome (RCVS), its disease-modifying effects are not yet understood. We prospectively investigated the effect of nimodipine and treatment initiation timing on the prevention of worsened vasoconstriction in patients with angiogram-proven RCVS.

In this prospective cohort study, we recruited patients with angiogram-proven RCVS who visited a single headache clinic between June 2019 and November 2021. To evaluate the mean flow velocities (MFVs) of the middle cerebral arteries, patients underwent transcranial Doppler at baseline and were then serially followed up after 10, 20, 30, and 90 days. Oral nimodipine treatment was initiated after the baseline transcranial Doppler study. We estimated the worsening of vasoconstriction using the area of total time spent with MFVs above the baseline value ("MFV area").

A total of 32 patients (51.5 ± 10.3 years old, 91% female) completed this study. During nimodipine treatment, MFVs gradually decreased in 94% (n = 30/32) of patients (p < 0.001). The MFVs in the early treatment group (<7 days after onset) were lower than the untreated baseline MFVs of the late treatment group (≥7 days) at the same time point after onset (69.8 ± 19.4 vs. 86.1 ± 23.7 cm/s, p = 0.032). Earlier treatment with nimodipine correlated with reduced MFV area (r = 0.37, p = 0.038), and this relationship remained significant after adjustment for covariates (β = 58.46, 95% confidence interval = 2.31-114.62, p = 0.041).

Our study shows an independent association between the timing of oral nimodipine administration and exacerbation of cerebral vasoconstriction in patients with RCVS, suggesting that early administration of nimodipine may have a role in mitigating vasoconstriction. A potential disease-modifying role of nimodipine should be tested in future studies using a hypothesis-testing design.