1. Understanding the individual clinically-relevant mechanisms involved in central and peripheral neuropathic pain.
Following peripheral nerve damage - molecular, morphological and functional changes occur not only in the injured nerve axon, but also in the cell body in the dorsal root ganglion, and within the CNS – particularly in the spinal cord dorsal horn. The combination of these peripheral and central changes (which is highly variable at individual level) contributes to the ongoing pain and sensory changes that the patients experience. The central changes that lead to increased signal amplification at the spinal cord level and decreased descending pain modulation from supraspinal sites are termed “central sensitization” – a phenomenon that has been a subject of increased research and clinical interest recently. We have shown that central sensitization on its own does not generate or maintain chronic neuropathic pain (Haroutounian, 2014), and continue to investigate the individual characteristics that may shed light on the relative contribution of peripheral vs. central mechanisms in driving different types of neuropathic pain.
2. Undertaking pharmacokinetic and sensory phenotyping approach to predict individual response to pharmacotherapy in patients with chronic (predominantly neuropathic) pain.
We have a major interest of investigating individually tailored analgesic pharmacotherapy approaches. By using methodologies that include pharmacogenetics, pharmacokinetic analysis, morphological and functional nerve fiber assessment and psychological evaluation, we aim to identify predictors of individual response to pharmacological interventions in neuropathic pain arising from different conditions such as diabetic neuropathy, chemotherapy induced peripheral neuropathy and HIV sensory neuropathy.
3. Using patient-reported outcomes to guide interdisciplinary pain management in chronic pain.
Chronic pain detrimentally affects patients’ and their families’ quality of life, and is associated with enormous costs. The interdisciplinary approach is considered the best currently available treatment option for chronic pain, as it is aimed to address the physical, emotional and social disability associated with pain. However, there are several important limitations of interdisciplinary pain programs in their current format. One of these is the lack of sufficient tools to allow developing the treatment program around individual patients’ desires, expectations, and preferred outcomes.
An exciting area of research for us is to address what are the preferred study methodology and important outcomes from patients’ perspective, and to investigate whether interdisciplinary care and decision-making guided by patient-reported physical, social, and emotional disability associated with chronic pain (Haroutounian, 2012) improves treatment outcomes.
4. Investigating individual mechanisms, risk factors and intervention methods to prevent chronic pain.
Persistent post-surgical pain (PPSP) is an undesired, quite common consequence of many surgical procedures, such as amputations, thoracic and breast surgeries, and joint replacements. As an iatrogenic condition, it may be possible to reduce its incidence and severity, once we gain enough knowledge on the individual risk factors and mechanisms associated with PPSP. Some of our previous work have addressed the possible mechanisms (Haroutounian, 2013) and preventive approaches (McNicol, 2014), and we continue to learn about the epidemiology and to investigate novel approaches for possible prevention of PPSP.