Clinical Variables Correlated with Numbers of Intra-arterial Nimodipine Infusion in Patients with Medically Refractory Cerebral Vasospasm

OBJECTIVE The objective of this study was to find out the clinical variables correlated with repeated intra-arterial (IA) nimodipine infusions in patients with medically refractory cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH). MATERIALS AND METHODS During the 36 months between January 2011 and December 2013, 275 patients were treated at our institute for SAH due to a ruptured intracranial aneurysm. Of the 275 patients, 26 patients (9.5%) met the inclusion criteria. For each patient, a retrospective review of their medical records was conducted. RESULTS Eleven patients underwent a single IA nimodipine infusion and 15 patients underwent more than two IA nimodipine infusions. Multiple IA nimodipine infusion patients had poor improvement (2 of 15 patients, 13.3%) in Glasgow coma scale (GCS) scores after the first IA nimodipine infusion compared to patients of single IA nimodipine infusion (6 of 11 patients, 54.6%) (p = 0.038). The mean middle cerebral artery (MCA) Lindegaard ratio of multiple IA nimodipine infusion patients was 4.3 ± 1.1 after the first IA nimodipine infusion (p = 0.039). In multiple IA nimodipine infusion patients, CV occurred more often bilaterally (p = 0.035) and distally (p = 0.001). More vessel segments were affected in multiple IA nimodipine infusion patients (3.1 ± 1.0) (p < 0.001). CONCLUSION The following factors correlated with multiple IA nimodipine infusions: 1) no improvement in GCS after the IA nimodipine infusion; 2) no decrease of MCA velocity on transcranial doppler over 50 cm/s or Lindegaard ratio over 4.3 after the IA nimodipine infusion; 3) distal, bilateral, or diffuse involvement of CV.