Freund Brin E, Greco Elena, Okromelidze Lela, Mendez Julio, Tatum William O, Grewal Sanjeet S, Middlebrooks Erik H
Departments of1Neurology.
2Radiology, and.
J Neurosurg. 2022 Sep 9;138(4):1008-1015. doi: 10.3171/2022.7.JNS221116. Print 2023 Apr 1.
The authors hypothesized that the proximity of deep brain stimulator contacts to the anterior thalamic nucleus-mammillothalamic tract (ANT-MMT) junction determines responsiveness to treatment with ANT deep brain stimulation (DBS) in drug-resistant epilepsy and conducted this study to test that hypothesis.
This retrospective study evaluated patients who had undergone ANT DBS electrode implantation and whose devices were programmed to stimulate nearest the ANT-MMT junction based on direct MRI visualization. The proximity of the active electrode to the ANT and the ANT-MMT junction was compared between responders (≥ 50% reduction in seizure frequency) and nonresponders. Linear regression was performed to assess the percentage of seizure reduction and distance to both the ANT and the ANT-MMT junction.
Four (57.1%) of 7 patients had ≥ 50% reduction in seizures. All 4 responders had at least one contact within 1 mm of the ANT-MMT junction, whereas the 3 patients with < 50% seizure improvement did not have a contact within 1 mm of the ANT-MMT junction. Additionally, the 4 responders demonstrated contact positioning closer to the ANT-MMT junction than the 3 nonresponders (mean distance from MMT: 0.7 mm on the left and 0.6 mm on the right in responders vs 3.0 mm on the left and 2.3 mm on the right in nonresponders). However, proximity of the electrode contact to any point in the ANT nucleus did not correlate with seizure reduction. Greater seizure improvement was correlated with a contact position closer to the ANT-MMT junction (R2 = 0.62, p = 0.04). Seizure improvement was not significantly correlated with proximity of the contact to any ANT border (R2 = 0.24, p = 0.26).
Obtained using a combination of direct visualization and targeted programming of the ANT-MMT junction, data in this study support the hypothesis that proximity to the ANT alone does not correlate with seizure reduction in ANT DBS, whereas proximity to the ANT-MMT junction does. These findings support the importance of direct targeting in ANT DBS, as well as imaging-informed programming. Additionally, the authors provide supportive evidence for future prospective trials using ANT-MMT junction for direct surgical targeting.
作者推测，在药物难治性癫痫中，脑深部刺激器触点与丘脑前核-乳头丘脑束（ANT-MMT）交界处的距离决定了对ANT深部脑刺激（DBS）治疗的反应性，并开展本研究以验证该假设。
这项回顾性研究评估了接受ANT DBS电极植入且根据直接MRI可视化将设备编程为在最接近ANT-MMT交界处进行刺激的患者。比较了有反应者（癫痫发作频率降低≥50%）和无反应者中活性电极与ANT及ANT-MMT交界处的距离。进行线性回归以评估癫痫发作减少的百分比以及与ANT和ANT-MMT交界处的距离。
7例患者中有4例（57.1%）癫痫发作减少≥50%。所有4例有反应者在距离ANT-MMT交界处1毫米内至少有一个触点，而癫痫发作改善<50%的3例患者在距离ANT-MMT交界处1毫米内没有触点。此外，4例有反应者的触点定位比3例无反应者更靠近ANT-MMT交界处（有反应者距MMT的平均距离：左侧0.7毫米，右侧0.6毫米；无反应者左侧3.0毫米，右侧2.3毫米）。然而，电极触点与ANT核内任何点的距离与癫痫发作减少无关。癫痫发作改善程度更大与更靠近ANT-MMT交界处的触点位置相关（R2 = 0.62，p = 0.04）。癫痫发作改善与触点到任何ANT边界的距离无显著相关性（R2 = 0.24，p = 0.26）。
本研究通过直接可视化和ANT-MMT交界处的靶向编程相结合获得的数据支持以下假设：在ANT DBS中，仅与ANT的距离与癫痫发作减少无关，而与ANT-MMT交界处的距离相关。这些发现支持了ANT DBS中直接靶向以及影像引导编程的重要性。此外，作者为未来使用ANT-MMT交界处进行直接手术靶向的前瞻性试验提供了支持性证据。
