Neuropathic pain in endometriosis

Thesis

Chronic pelvic pain is one of the main symptoms of endometriosis which affects 1 in 10 women of reproductive age. Historically, despite the prevalence of this condition and the impact it has on those affected, endometriosis-associated pain (EAP) has been poorly understood. In this thesis I explore endometriosis-associated pain, specifically the presence of neuropathic pain (pain due to lesion/disease of the somatosensory system). To do this, I use a variety of different techniques including questionnaires, functional magnetic resonance imaging (fMRI) and quantitative sensory testing (QST).

To determine the prevalence of neuropathic pain in a large population is difficult. In this thesis I use an online questionnaire on patient support websites to give an estimation of the proportions of women experiencing neuropathic pain. I investigate differences between those with and without neuropathic pain with respect to pain symptoms, psychological and cognitive function, number of surgeries to the abdomen and duration of pain. I also sub-divided women further based on their sensory symptom profiles. I replicate these findings in a novel cohort and relate them to treatment response.

Central nervous system changes have been demonstrated in people with neuropathic pain. In this thesis I investigate the association between neuropathic pain features and functional connectivity of the brain in women with endometriosis-associated pain.

Sensory testing is an important aspect of neuropathic pain research and in this thesis I use QST to investigate sensory perception. A range of stimuli are used to determine whether there are changes in sensory processing in women with endometriosis-associated pain.

Overall, the aims of the research described in this thesis are to advance knowledge regarding the prevalence of neuropathic pain in endometriosis; how women can be stratified using questionnaires and whether that relates to treatment response; what changes associated with neuropathic pain can be seen in the activity of the brain at rest; and the sensory profiles of women with EAP. Research in the area of EAP is critical to inform clinical practice and improve treatment.

Authors: Coxon, L

• DOI: 10.5287/ora-5zgrppaqq
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: resting state functional connectivity; painDETECT; chronic pelvic pain; quantitative sensory testing QST; fMRI; neuropathic pain; endometriosis
• Subjects: Pain; Endometriosis