Letter to the Editor. Do bacteria contribute to formation and rupture of intracranial aneurysms?

Torque Teno virus DNA is found in the intracranial aneurysm wall-Is there a causative role?

Objective

Torque Teno virus (TTV) is a recently discovered virus with high prevalence worldwide, that has been associated with vascular diseases. The aim of this study is to investigate the prevalence of TTV molecular DNA in the intracranial aneurysm (IA) artery walls.

Method

Samples of IA walls were collected after microsurgical clipping from 35 patients with IA (22 ruptured/13 unruptured cases). The samples were submitted to molecular DNA extraction using the EasyMag automatized extractor and performed with Qiagen DNA extraction Minikit 250. The samples underwent PCR examination with primers for β-globin as internal control using the Nanodrop ^® 2000 spectrophotometer. A quantitative (real-time) PCR with TTV-specific primers was performed. Clinical and radiological data of patients included was collected.

Results

TTV was detected in 15 (42.85%) cases, being 10 (45.4%) ruptured and 5 (38.4%) unruptured (p = 0.732) lesions. Multiple IAs accounted for 14 (40%) cases. Five cases (17.2%) had TTV+ and multiple aneurysms (p = 0.73). Association between presence of virus and aneurysm rupture was not statistically significant (p = 0.96).

Conclusion

This study demonstrated a relatively high prevalence of viral DNA in the walls of IAs. This is the first study to identify the presence of TTV DNA in IA's samples, which was found more often in ruptured lesions. This is an exploratory study, therefore, larger studies are required to clarify the relationships between inflammation, viral infection, IA formation and rupture.

Human herpesvirus DNA occurrence in intracranial aneurysmal wall: illustrative case

BACKGROUND

Subarachnoid hemorrhages secondary to intracranial aneurysms (IAs) are events of high mortality. These neurological vascular diseases arise from local and systemic inflammation that culminates in vessel wall changes. They may also have a possible relationship with chronic viral infections, such as human herpesvirus (HHV), and especially Epstein–Barr virus (EBV), which causes several medical conditions. This is the first description of the presence of HHV deoxyribonucleic acid (DNA) in a patient with IA.

OBSERVATIONS

A 61-year-old woman with a downgraded level of consciousness underwent radiological examinations that identified a 10-mm ruptured aneurysm in the anterior communicating artery. A microsurgery clip was performed to definitively treat the aneurysm and occurred without surgical complications. Molecular analysis of the material obtained revealed the presence of EBV DNA in the aneurysm wall. The patient died 21 days after admission due to clinical complications and brain swelling.

LESSONS

This is the first description of the presence of herpesvirus DNA in a patient with IA, presented in 2.8% of our data. These findings highlight that viral infection may contribute to the pathophysiology and is an additional risk factor for IA formation, progression, and rupture by modulating vessel wall inflammation and structural changes in chronic infections.