Safety of transcutaneous auricular vagus nerve stimulation (taVNS): a systematic review and meta-analysis.

Transcutaneous auricular vagus nerve stimulation (taVNS) has been investigated as a novel neuromodulation tool. Although taVNS is generally considered safe with only mild and transient adverse effects (AEs), those specifically caused by taVNS have not yet been investigated. This systematic review and meta-analysis on taVNS aimed to (1) systematically analyze study characteristics and AE assessment, (2) characterize and analyze possible AEs and their incidence, (3) search for predictable risk factors, (4) analyze the severity of AE, and (5) suggest an evidence-based taVNS adverse events questionnaire for safety monitoring. The articles searched were published through April 7, 2022, in Medline, Embase, Web of Science, Cochrane, and Lilacs databases. In general, we evaluated 177 studies that assessed 6322 subjects. From these, 55.37% of studies did not mention the presence or absence of any AEs; only 24.86% of the studies described that at least one adverse event occurred. In the 35 studies reporting the number of subjects with at least one adverse event, a meta-analytic approach to calculate the risk differences of developing an adverse event between active taVNS and controls was used. The meta-analytic overall adverse events incidence rate was calculated for the total number of adverse events reported on a 100,000 person-minutes-days scale. There were no differences in risk of developing an adverse event between active taVNS and controls. The incidence of AE, in general, was 12.84/100,000 person-minutes-days of stimulation, and the most frequently reported were ear pain, headache, and tingling. Almost half of the studies did not report the presence or absence of any AEs. We attribute this to the absence of AE in those studies. There was no causal relationship between taVNS and severe adverse events. This is the first systematic review and meta-analysis of transcutaneous auricular stimulation safety. Overall, taVNS is a safe and feasible option for clinical intervention.

Treatment of Cryptogenic Stroke with Active Cancer with a New Oral Anticoagulant.

BACKGROUND: Low-molecular weight heparin (LMWH) was shown to be effective and safe in treating venous thromboembolism, and generally used for stroke in cancer patients, but its effects on stroke are unclear. We compared clinical outcomes between LMWH and new oral anticoagulant (NOAC) in patients with cancer-related stroke. METHODS: We enrolled patients with cryptogenic ischemic stroke with active cancer who were treated with LMWH or NOAC between May 2012 and June 2015. The clinical outcomes, including early neurologic deterioration, early radiologic recurrence, 3-month modified Rankin scale score, 90-day mortality, cardio-cerebrovascular recurrence, and bleeding complications, were compared. RESULTS: Among 48 patients, 7 patients were treated with NOAC, and the remaining 41 patients with LMWH. Overall, the participants presented poor outcomes, including 20 (42%) early neurologic deteriorations, 28 (58%) early radiologic recurrences, 34 (71%) poor modified Rankin scale scores, 27 (56%) 90-day mortality events, 24 (50%) cardio-cerebrovascular recurrences, and 18 (38%) bleeding complications, that led to a change or temporary hold in medication in 12 cases. No statistical differences were found between the 2 groups in terms of demographic, clinical, or cardiovascular risk factors and clinical outcomes. CONCLUSIONS: NOAC showed the similar clinical outcomes and safety compared with LMWH in the treatment of cryptogenic ischemic stroke in active cancer patients.