Clinical features of Herpes Simplex Virus Reactivation after Microvascular Decompression for Trigeminal Neuralgia: Experience of 200 patients and a literature review

Abstract Background and Objective: Herpes simplex virus (HSV) reactivation occasionally develops in the early postoperative period after microvascular decompression (MVD) for trigeminal neuralgia (TN). Therefore, the present study investigated the clinical features of this phenomenon. Methods: The study cohort comprised 200 patients with 125 (63%) women aged between 17 and 90 years (median age, 66 years) who underwent MVD for TN between January 2010 and December 2020. Characteristics were compared between patients with and without HSV reactivation and clinical features were analyzed. Results: Twenty patients had HSV reactivation: herpes labialis in 18; herpes zoster (final diagnosis) in 2. A multivariate analysis revealed independent correlations between postoperative HV reactivation and a previous history of herpes labialis (OR:6.32, p=0.0003) and re-operation for recurrent or persistent pain (OR:5.06, p=0.0211). No significant differences were observed in pain relief, postoperative facial numbness, or BNI Pain Intensity/Facial Numbness Scores in the last follow-up between patients with and without HSV reactivation. HSV reactivation manifested at a median of the 4th postoperative day (1-10 days) and its location was not related to the preoperative distribution of facial pain. All patients were treated with local acyclovir and were completely cured within 1-2 weeks. Conclusions: HSV reactivation occurred in 10% of patients after MVD including 1% of herpes zoster. A previous history of herpes labialis and re-operation were identified as risk factors for reactivation. Symptoms were completely cured by antiviral drugs within 1-2 weeks. It is important to note that cases of herpes zoster may be confused with cases of herpes simplex virus after MVD.