Archived Public Lecture: Understanding Human Pain, Relief and Altered States of Consciousness Using Brain Imaging

About This Lecture 

The ability to experience pain is old in evolutionary terms. It is an experience shared across species. Acute pain is the body’s alarm system, and as such it is a good thing. Pain that persists beyond normal tissue healing time (3-4 months) is defined as chronic – it is the system gone wrong and it is not a good thing. Chronic pain has recently been classified as both a symptom and disease in its own right. It is one of the largest medical health problems worldwide with one in five adults diagnosed with the condition. Chronic pain is more prevalent in the elderly and in women for reasons we do not yet understand. It is associated with comorbid depression and anxiety, which combined produces untold suffering and a major financial burden to society (e.g. the cost of chronic pain in the USA is thought to be over $600 billion per annum). Most of our treatments don't work very well and, in part, the consequent burden of suffering has led to the opioid epidemic witnessed in the USA and other parts of the world. We must do better.  

The brain is key to the experience of pain and pain relief. This is the place where pain emerges as a perception. So, relating specific brain measures using advanced neuroimaging to the changes patients describe in their pain perception induced by peripheral or central sensitization (i.e. amplification), psychological or pharmacological mechanisms has tremendous value. Identifying where amplification or attenuation processes occur along the journey from injury to the brain (i.e. peripheral nerves, spinal cord, brainstem and brain) for an individual and relating these neural mechanisms to specific pain experiences, measures of pain relief, persistence of pain states, degree of injury and the subject's underlying genetics, has neuroscientific and potential diagnostic relevance. This is what neuroimaging has afforded – a better understanding and explanation of why someone’s pain is the way it is. Researchers can go ‘behind the scenes’ of the subjective report to find out what key changes and mechanisms make up an individual’s particular pain experience. A key area of development has been pharmacological imaging where objective evidence of drugs reaching the target and working can be obtained. This is invaluable information that improves analgesic drug development that oftentimes is hampered by over-reliance on subjective pain ratings. We even now understand the mechanisms of placebo analgesia – a powerful phenomenon known about for millennia. More recently, researchers have been investigating through brain imaging whether there is a pre-disposing vulnerability in brain networks towards developing chronic pain; in short, what makes you the 1 in 5?

So, advanced neuroimaging studies can powerfully aid explanation of a subject’s multidimensional pain experience, pain relief (analgesia) and even what makes them vulnerable to developing chronic pain. The application of this goes beyond the clinic and has relevance in courts of law, and other areas of society, such as in veterinary care. All of these issues will be discussed in Dr. Tracey's talk.

Relatively far less work has been directed at understanding what changes in the brain occur during altered states of consciousness induced either endogenously (e.g. sleep) or exogenously (e.g. anaesthesia). However, that situation is changing rapidly. For example, recent multimodal neuroimaging work in Dr. Tracey's lab explores how anaesthetic agents produce altered states of consciousness such that perceptual experiences of pain and awareness are degraded. This is bringing fascinating insights into the complex phenomenon of anaesthesia, consciousness and even the concept of self-hood. Dr. Tracey will describe some of these latest experiments too during her presentation.

Additional Details 

This is a free event hosted by Dr. Michael Friedlander and the Fralin Biomedical Research Institute. For more information, please call 540-526-2059 or send an e-mail. 

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