Sun Lihua, Peräkylä Jari, Hartikainen Kaisa M
Behavioral Neurology Research Unit, Tampere University Hospital, Tampere, Finland.
Turku PET Center, University of Turku, Turku, Finland.
Front Hum Neurosci. 2017 Dec 4;11:584. doi: 10.3389/fnhum.2017.00584. eCollection 2017.
Neuromodulation techniques targeting limbic circuits can be used to treat refractory psychiatric or neurological disorders. However, objective measure for the impact of neuromodulation on affective brain circuits is lacking. Deep brain stimulation at a key node of the limbic circuit, the anterior thalamic nuclei (ANT-DBS), is used to treat refractory epilepsy. While effective in reducing seizures, patients have reported subjective depressive symptoms as a side effect. In line with potential vulnerability to depression, we have previously shown ANT-DBS to increase attention allocation to threat evidenced by behavior and brain physiology. Rightward frontal alpha asymmetry with greater right hemispheric activation is thought to reflect brain physiology linked with depression and anxiety. To that end, we investigated whether high-frequency electric stimulation at ANT influences frontal alpha asymmetry. Furthermore, we explored the impact of DBS on emotional modulation of frontal alpha asymmetry and whether it is linked with emotional modulation of response speed. Electrical stimulation at ANT led to an increased rightward frontal alpha asymmetry compared to situations where stimulation was off ( = 14.09, = 0.003) or the thalamic control location was stimulated ( = 10.19, = 0.008), along with prolonged reaction times in the context of emotional distractors ( = 16.66, = 0.005). The change was specifically driven by increased activity in the right hemisphere. Furthermore, we found a correlation between the emotional modulation of frontal alpha asymmetry and emotional interference of response speed due to ANT stimulation ( = 0.78, = 0.02). In conclusion, DBS at ANT increased relative right hemispheric activity and this was linked with emotional modulation of behavior. Previous studies have linked frontal alpha asymmetry with emotion related symptoms and furthermore, Vagus Nerve Stimulation (VNS) has been shown to modulate alpha asymmetry. Thus, in the light of the previous literature and the current findings, we suggest that frontal alpha asymmetry along with emotional interference of response speed might be a feasible biomarker for the effects of neuromodulation on brain's affective circuitry in general.
针对边缘系统回路的神经调节技术可用于治疗难治性精神或神经疾病。然而，目前缺乏对神经调节对情感脑回路影响的客观测量方法。在边缘系统回路的一个关键节点——丘脑前核进行深部脑刺激（ANT-DBS），用于治疗难治性癫痫。虽然它能有效减少癫痫发作，但患者报告出现了主观抑郁症状作为副作用。鉴于存在抑郁的潜在易感性，我们之前的研究表明，ANT-DBS会增加对威胁的注意力分配，这在行为和脑生理学上都有体现。右侧额叶α波不对称且右半球激活增强被认为反映了与抑郁和焦虑相关的脑生理学特征。为此，我们研究了ANT处的高频电刺激是否会影响额叶α波不对称。此外，我们还探讨了深部脑刺激对额叶α波不对称的情绪调节的影响，以及它是否与反应速度的情绪调节有关。与刺激关闭（t = 14.09，p = 0.003）或刺激丘脑对照部位（t = 10.19，p = 0.008）相比时的情况相比，ANT处的电刺激导致右侧额叶α波不对称增加，同时在存在情绪干扰因素的情况下反应时间延长（t = 16.66，p = 0.005）。这种变化是由右半球活动增加特异性驱动的。此外，我们发现额叶α波不对称的情绪调节与ANT刺激导致的反应速度的情绪干扰之间存在相关性（r = 0.78，p = 0.02）。总之，ANT处的深部脑刺激增加了右半球的相对活动，这与行为的情绪调节有关。之前的研究已将额叶α波不对称与情绪相关症状联系起来，此外，迷走神经刺激（VNS）已被证明可调节α波不对称。因此，鉴于先前的文献和当前的研究结果，我们认为额叶α波不对称以及反应速度的情绪干扰可能是神经调节对大脑情感回路影响的一种可行的生物标志物。
