Research Scientist 2 University of Washington Seattle, Washington, United States
Introduction: Patients with aneurysmal subarachnoid hemorrhage (aSAH) are at risk for cerebral vasospasm and delayed cerebral ischemia, which cause disability or death in nearly 20% of patients who survive the hemorrhagic ictus. The mechanism and risk factors for development of cerebral vasospasm in aSAH are unclear. Arterial vasospasm is associated with herpesvirus reactivation after latent infection and may play a role in the development of post-aSAH vasospasm.
Methods: Tears, saliva, and blood (serum) were collected from 38 aSAH patients. Serum was tested for Herpes Simplex Virus Type 1 (HSV-1) Glycoprotein G-Specific Antibody. HSV-1 DNA was detected by quantitative, real-time PCR in tears and saliva sampled at five timepoints up to 14 days after aSAH. Vasospasm was assessed via the ratio of mean flow velocities in the middle cerebral artery and ipsilateral extracranial internal carotid artery, measured by transcranial Doppler ultrasonography (TCD), collected daily for 14 days post-aSAH.
Results: 87% (33/38) of post-aSAH subjects developed vasospasm by TCD criteria. Of these, 97% (32/33) were HSV-1 seropositive, compared with 13% (5/38) who did not develop vasospasm. 100% of patients with moderate to severe vasospasm (ratio >3) were HSV-1 seropositive. Shedding was detected in 31% of patients with vasospasm (13/33 saliva, 1/33 tears), but no shedding was detected in patients without vasospasm. Of the 5 patients who did not develop vasospasm, 3 (60%) were HSV-1 seropositive.
Conclusion : Preliminary analysis suggests possible correlation between HSV-1 shedding and development of moderate to severe vasospasm after aSAH. Factors related to HSV-1 reactivation or arterial spasm, including the role of other herpesviruses and specific reservoirs for latency, warrant further investigation. Because anti-viral agents are generally well-tolerated and effective in suppression or treatment of herpesvirus reactivation, anti-viral agents could be studied in the treatment of aSAH patients.
