The Viral Hypothesis of Mesial Temporal Lobe Epilepsy – Is Human Herpes Virus-6 the Missing Link? A systematic review and meta-analysis. (January 2018)

• Record Type: Journal Article
• Authors: Wipfler, P.; Dunn, N.; Beiki, O.; Trinka, E.; Fogdell-Hahn, A.
• Is Part Of: Seizure. Volume 54(2018)
• Page Start: 33
• Page End: 40
• Publication Date: 2018-01
• Subjects: Epilepsy -- Periodicals; Epilepsy -- Periodicals; Seizures -- Periodicals; Épilepsie -- Périodiques; Electronic journals; Electronic journals; 616.853
• DOI: 10.1016/j.seizure.2017.11.015
• Languages: English
• ISSNs: 1059-1311

Abstract

Highlights: HHV-6 DNA is associated with mesial temporal lobe epilepsy resected brain tissue. Higher HHV-6 DNA rate in temporal lobe epilepsy patients with hippocampal sclerosis. Mechanisms underlying the possible causal relationship are discussed. Results support future studies investigating pathological implications of HHV-6. Abstract: Purpose: Mesial temporal lobe epilepsy (MTLE) is a common epileptic disorder. Although likely multifactorial, the mechanisms underlying the etiology and pathogenesis of the disease remains unknown in majority of patients. Viruses, particularly Human Herpes Virus 6A and B (HHV-6), two neurotropic herpes viruses, have been implicated in MTLE due to their ubiquitous nature and ability to establish lifelong latency with risk of reactivation. However, the results of studies investigating this relationship are conflicting. This systematic review and meta -analysis was conducted to determine the relationship between HHV-6 DNA (not specifying if A or B) in brain tissue and MTLE based on the current evidence. Method: Two independent assessors carried out a comprehensive electronic search to identify all relevant studies. Both fixed- and random-effects models were used to determine the overall odds ratio. Results: A total of 10 studies met the inclusion criteria for the systematic review and eight for the meta -analysis. In 19.6% of all MTLE patients HHV-6 DNA was detected in brain tissue compared to 10.3% of all controls (p > 0.05). The pooled odds ratio of HHV-6 positive cases in MTLE patients was 2.016 [95%-CI: 1.16-3.50] in the fixed effect model. Conclusion: The results of this meta -analysis indicate an association between HHV-6 DNA and MTLE surgically resected tissue samples, unspecified if A or B or both. However, the casual relationship and possible pathological role of HHV-6 in MTLE are yet to be elucidated. This study's results provide a basis for future studies continuing the investigation into pathological implications of HHV-6.