Pre-operative and Post-operative Thyroid Function in Patients Undergoing Vagus Nerve Stimulation for Epilepsy: A Single-Center Pilot Study
EANS Congress 2026, Hamburg, Almanya, 30 Eylül - 04 Ekim 2026, ss.4227675, (Özet Bildiri)
- Yayın Türü: Bildiri / Özet Bildiri
- Basıldığı Şehir: Hamburg
- Basıldığı Ülke: Almanya
- Sayfa Sayıları: ss.4227675
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Eskişehir Osmangazi Üniversitesi Adresli: Evet
Özet
Background: Vagus nerve stimulation (VNS) is an established neuromodulation therapy for drugresistant epilepsy. Beyond seizure control, neuromodulation may influence systemic physiological pathways, including autonomic and endocrine regulation. Given the modulatory role of thyroid hormones in neuronal excitability, understanding perioperative thyroid function profiles may be clinically relevant for neurosurgeons performing functional procedures. This study aimed to evaluate the distribution and longitudinal changes of thyroid function tests (TFTs) in patients undergoing VNS implantation.
Methods: We retrospectively reviewed 13 consecutive patients who underwent VNS implantation between 2016 and 2024 at a single tertiary neurosurgical center. Demographic data, baseline endocrine history (including hypothyroidism), surgical dates, and serum thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) levels were recorded. Laboratory values were categorized as normal, low, or high according to institutional reference ranges. Post-operative TFTs were defined as the first available stable measurements obtained during follow-up; due to heterogeneous follow-up intervals, the surgery-to-test time was additionally documented. Paired longitudinal comparisons were performed in patients with available data.
Results: The mean age was 24.6 ± 5.9 years, and 54% of patients were female. Five patients (38%) had a known history of hypothyroidism. The median post-operative TFT assessment occurred approximately 9 months after surgery, with a wide range of follow-up intervals. Pre-operative TSH levels were within the normal range in 76.9% (n=10), low in 15.4% (n=2), and elevated in 7.7% (n=1) of patients. Among 11 patients with post-operative TSH evaluation: 90.9% (n = 10) remained within the normal range 9.1% (n = 1) showed elevated levels Paired longitudinal analysis demonstrated: Normal → normal in 8 patients, Low → normal in 2 patients, High → high in 1 patient. No new clinical thyroid disorder developed during follow-up, and no patient required initiation of thyroid medication. Both fT3 and fT4 levels remained within reference ranges in the pre- and postoperative periods. No thyroid-related adverse effects attributable to VNS were observed.
Conclusions: In this pilot neuromodulation cohort, thyroid function largely remained within the euthyroid range following VNS implantation. Some pre-operative subclinical deviations normalized during follow-up, and no clinically relevant thyroid dysfunction emerged. These findings suggest that VNS does not appear to be associated with clinically significant endocrine alterations in patients with drug-resistant epilepsy. The small sample size and heterogeneous follow-up intervals represent important limitations. Larger prospective neurosurgical studies are warranted to further clarify the systemic physiological effects of VNS.