Exploring variables associated with brain volume changes in women with endometriosis-associated pain

Thesis

Endometriosis is o,en a painful gynaecological disease characterised by the growth of uterine issue in other parts of a woman's pelvic and body, leading to inflammaion, pain, and inferility. The chronic pain associated with endometriosis, or endometriosisassociated pain (EAP), is highly complex; treatment o,en involves both hormonal and surgical therapies. Other chronic pain conditions are well-known for being linked to structural alteraions in the brain's grey maHer volume, and in white maHer microstructure, paricularly in established pain modulatory areas.

To synthesise the current literature on structural alteraions and EAP, I conducted a broad systematic review of the neuroimaging literature of women with EAP but also including other patients with either abdominal and pelvic chronic pain conditions, o,en comorbid with endometriosis. The review included 41 papers and narratively summarised the most common structural alterations found in patients compared to controls and other pain conditions, as well as any associations with clinical variables such as pain intensity or duration. This systematic review highlighted the limited nature of EAP, as only two cross-sectional studies among the included papers examined EAP, both focusing on grey maHer. No papers were found that investigated EAP and white maHer microstructure.

Using participants from a completed study, I proceeded to investigate grey maHer volumetric alterations in this cohort of women with suspected and confirmed EAP in a cross-sectional comparison with healthy controls, as well as pre- and post-surgery in a ongitudinal subgroup. This revealed several areas of volumetric grey maHer differences between EAP patients and controls, which are dynamic, showing signs of normalisation in the longitudinal subgroup. The same approach was also taken to investigate white maHer microstructure, uncovering anatomo-functional correspondence in grey and white maHer alterations both at baseline and post-surgery.

Overall, this thesis expands the currently limited research on brain structural abnormalities and changes in patients with EAP by relating these structural differences to clinical variables. This work also provides novel investigations of white maHer structure and grey and white maHer alterations in a longitudinal cohort, both pre- and post-surgery. 

Understanding alterations in brain structure advances our comprehension of the central pathological mechanisms of EAP, thereby improving the chances of developing effective treatments for patients.

Authors: Szabo, M

• DOI: 10.5287/ora-zodad44mn
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: clinical research; voxel-based morphometry; grey matter volume; endometriosis; longitudinal; pain mechanisms; neuroimaging
• Subjects: Brain volume changes in women with endometriosis-associated pain