Understanding how pain is processed in the brain


About Our Research

We study how pain is processed in the brain and how pain affects the sympathetic nervous system, the branch of the nervous system involved in the control of blood pressure. By inserting a fine needle (microelectrode) into a peripheral nerve we can record the spontaneous bursts of muscle sympathetic nerve activity (MSNA) that originate in the brain and cause constriction of blood vessels in muscle.

People who have high blood pressure (hypertension) have high levels of MSNA. We have shown that infusion of hypertonic saline (sterile salty water) into a muscle for an hour causes long-lasting pain which, in some individuals causes a sustained increase in MSNA and blood pressure and in other individuals a sustained decrease. We have also shown that these patterns are consistent over time, and cannot be explained by differences in resting levels of MSNA, blood pressure, heart rate, gender, anxiety levels or attitudes to pain.

Now, in a new NHMRC-funded grant, we are recording MSNA at the same time as performing fMRI of the brain to identify sites in the brain that lead to either an increase in MSNA and BP or to a decrease. This will improve our understanding of the complex physiological responses to pain and ultimately help us understand why some people with chronic pain develop high blood pressure.

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What is the analgesic effect of EEG neurofeedback for people with chronic pain? A systematic review

Researchers: A/Prof Sylvia Gustin, Dr Negin Hesam-Shariati, Dr Wei-Ju Chang, A/Prof James McAuley, Dr Andrew Booth, A/Prof Toby Newton-John, Prof Chin-Teng Lin, A/Prof Zina Trost Chronic pain is a global health problem, affecting around one in five individuals in the general population. The understanding of the key role of functional brain alterations in the generation of chronic pain has led researchers to focus on pain treatments that target brain activity. Electroencephalographic (EEG) neurofeedback attempts to modulate the power of maladaptive EEG frequency powers to decrease chronic pain. Although several studies provide promising evidence, the effect of EEG neurofeedback on chronic pain is uncertain. This systematic review aims to synthesise the evidence from randomised controlled trials (RCTs) to evaluate the analgesic effect of EEG neurofeedback. The search strategy will be performed on five electronic databases (Cochrane Central, MEDLINE, Embase, PsycInfo, and CINAHL) for published studies and on clinical trial registries for completed unpublished studies. We will include studies that used EEG neurofeedback as an intervention for people with chronic pain. Risk of bias tools will be used to assess methodological quality of the included studies. RCTs will be included if they have compared EEG neurofeedback with any other intervention or placebo control. The data from RCTs will be aggregated to perform a meta-analysis for quantitative synthesis. In addition, non-randomised studies will be included for a narrative synthesis. The data from non-randomised studies will be extracted and summarised in a descriptive table. The primary outcome measure is pain intensity assessed by self-report scales. Secondary outcome measures include depressive symptoms, anxiety symptoms, and sleep quality measured by self-reported questionnaires. Further, we will investigate the non-randomised studies for additional outcomes addressing safety, feasibility, and resting-state EEG analysis.