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.