We previously reported that deep brain stimulation (DBS) of the motor thalamus, in a patient with post-stroke tremor, relieved breathlessness associated with COPD. This raised the question of whether motor thalamus DBS mitigates the ascending dyspnoea signal. We therefore sought to conduct a fully powered cohort study of experimentally induced air hunger, an uncomfortable urge to breathe in patients with motor thalamus DBS "ON" and "OFF".

16 patients (three females) with DBS of the ventral intermediate nucleus (VIM) as treatment for tremor underwent hypercapnic air hunger tests, with DBS ON and OFF. Patients rated air hunger on a visual analogue scale (VAS) every 15 s. Hypercapnia and ventilation were matched for ON and OFF states (end-tidal carbon dioxide tension mean±sd 43±4 and 43±4 mmHg, respectively; ventilation 13.7 and 13.4 L·min^–1, respectively). Participants’ ventilation was constrained to baseline levels by breathing from a 3-L inspiratory reservoir with fixed flow of fresh gas while targeting their resting breathing frequency to a metronome.

Overall steady-state air hunger was 52±28%VAS for ON and 67±20%VAS for OFF (p=0.002; two-tailed paired t-test). The mean reduction in air hunger during VIM DBS was –14.4%VAS. DBS of the motor thalamus relieved air hunger in 13 patients, heightened air hunger in two and caused no change in one.

DBS of the motor thalamus for tremor relief also mitigates the air hunger component of dyspnoea. We posit that DBS of the motor thalamus heightens the gating control of the thalamus modulating the ascending air hunger signal. Extent of relief suggests that thalamic DBS may prove to be a viable therapy for intractable dyspnoea.

我们之前报道过，在中风后震颤患者中，运动丘脑的深部脑刺激 （DBS） 缓解了与 COPD 相关的呼吸困难。这就提出了一个问题，即运动丘脑 DBS 是否减轻了上行性呼吸困难信号。因此，我们试图对实验诱导的空气饥饿进行一项完全有力的队列研究，即运动丘脑 DBS “ON” 和 “OFF” 患者的不舒服呼吸冲动。

16 例腹侧中间核 （VIM） DBS 治疗震颤的患者 （3 例女性） 接受了高碳酸血症性空气饥饿测试，DBS 开启和关闭。患者每 15 秒在视觉模拟量表 （VAS） 上对空气饥饿进行评分。高碳酸血症和通气量在 ON 和 OFF 状态下匹配（呼气末二氧化碳张力平均值分别为 ±43±4 和 43±4 mmHg;通气量分别为 13.7 和 13.4 L·min^–1）。参与者的通气被限制在基线水平，方法是从具有固定新鲜气体流量的 3 L 吸气罐呼吸，同时将他们的静息呼吸频率针对节拍器。

总体稳态空气饥饿为 ON 为 52±28%VAS，OFF 为 67±20%VAS（p=0.002;双尾配对 t 检验）。VIM DBS 期间空气饥饿的平均减少为 -14.4%VAS。运动丘脑的 DBS 缓解了 13 名患者的空气饥饿，2 名患者的空气饥饿加剧，而 1 名患者没有变化。

用于缓解震颤的运动丘脑 DBS 也减轻了呼吸困难的空气饥饿成分。我们假设运动丘脑的 DBS 增强了丘脑的门控控制，从而调节上升的空气饥饿信号。缓解程度表明丘脑 DBS 可能被证明是顽固性呼吸困难的可行疗法。