Intra-Operative Deep Brain Stimulation of the Periaqueductal Grey Matter Modulates Blood Pressure and Heart Rate Variability in Humans

The neuroanatomy of sexual dimorphism in opioid analgesia

“…Indeed, stimulation of the PAG induces a profound analgesic state, such that invasive surgery can be performed in the absence of exogenously administered analgesia [82]. In humans, electrical stimulation of the PAG is used to alleviate intractable pain [39, 59]. …”

Controlling the Lungs Via the Brain: A Novel Neurosurgical Method to Improve Lung Function in Humans

“…We used a 10-minute stimulation washout/wash-in period in this study to minimize any changes in the multiple patient and environmental factors that may have biased the lung function results. Although this period has been seen to be sufficiently long to demonstrate cardiovascular changes in other human studies 9,12,14 and PEFR change in this study, it may not have been sufficient to allow a detectable change in FEV 1 . Therefore, PAG and STN stimulation may be altering upper airway function alone, or perhaps we have not detected lower airway changes owing to the study design or, we suspect more likely, the normal baseline lung function in this patient group.…”

“…The 10-minute period was chosen because, although the motor effects of deep brain stimulation are believed to take minutes to hours and often longer to manifest, the reported changes in cardiorespiratory parameters such as heart rate, blood pressure, and respiratory rate are seen within seconds to minutes. 9,[12][13][14] In this way, many environmental and patient factors could be kept identical between the on and off test periods. This measure also reduced the likelihood that expiratory flow changes were due to skeletal muscle/motor performance rather than airway diameter.…”

“…12,13 Furthermore, PAG stimulation modulates heart rate variability, a surrogate marker of autonomic balance. 14,15 Both the PAG and STN have been implicated in central command, the feed-forward mechanism by which autonomically mediated cardiorespiratory performance is augmented in parallel with motor activity. 16 No invasive, interventional study has been performed in humans to test whether these sites are in fact involved in the electric circuitry of breathing and indeed whether electric manipulation of these sites has a functional effect on lung function.…”

Dysfunctional Brain-bone Marrow Communication: A Paradigm Shift in the Pathophysiology of Hypertension

“…Similarly, chronic carotid baroreceptor activation has been shown to lower blood pressure and sympathetic activity in resistant patients [36-39], prompting initiation of clinical trials with promising long term results [40, 39]. Other more adventurous techniques such as the deep brain stimulation [41-47] and surgical relief of micro-vascular compression [48, 49] have demonstrated promising outcomes, but the invasive nature of these procedures decreases their general therapeutic use and renders them mainly experimental.…”