Objectively Investigating Memory and Attention in Individuals Living with Endometriosis

Endometriosis is a chronic inflammatory disease experienced by approximately 10% of people assigned female at birth, which translates to around 200 million women and adolescents globally (As-Sanie et al., 2019) Scant research has focused on potential deficits in cognitive functioning including difficulties with information processing, attention, problem solving and executive functioning (Sherwin, 2003). The current research indicates that individuals living with endometriosis may experience cognitive dysfunction, specifically through two qualitative studies, in which a participant reported “mental fatigue” and another participant reported “no mental clarity” (DiBenedetti et al., 2020). In addition, neuroimaging studies have identified reduced gray matter volume in areas of the brain important for cognition, suggesting potential cognitive difficulties (Maulitz et al., 2022). In order to explore this potential relationship in detail, a mixed-methods study completed as part of the student researchers’ Honours thesis was conducted. An online survey collecting both qualitative and quantitative measures was distributed in 2021 (n=1239), finding that the sample reported significantly lower cognitive functioning than a sample of cancer survivors (Kiang et al., 2016) and 80% of the sample were classified as cognitive impaired (Van Dyk et al., 2017). Participants also reported qualitatively the negative impacts of their endometriosis on their cognition, particularly reporting the negative influences of endometriosis-related pain, fatigue and treatments and depression on cognition, and the negative impacts of these cognitive impairments on their ability to function, particularly in their occupation. A wide range of impairments were qualitatively reported by participants including issues with concentration, memory and communication skills. This study demonstrated for the first time that individuals living with endometriosis experience significant cognitive deficits, yet this relationship needs to be explored in further detail Thus, there is current cross-sectional evidence of widespread subjective cognitive deficits in individuals with endometriosis. However, these cognitive complaints were subjectively measured and as such, there is a need to use neurocognitive tests to objectively measure cognitive functioning in individuals with endometriosis. These objective measures have been utilised in many other chronic health populations to measure potential cognitive deficits, including in Fibromyalgia (Tesio et al., 2015; Wu et al., 2018), chronic fatigue syndrome (Cockshell & Mathias, 2010), chronic pain (Higgins et al., 2018; Oosterman et al., 2011) and multiple sclerosis (Chiaravalloti & DeLuca, 2008; Patti, 2009). Thus, this project aims to explore cognitive difficulties in individuals with endometriosis, measured using objective neurocognitive tests. Neurocognitive domains tested will be: memory, attention, processing speed, learning and verbal fluency. Two separate studies will be conducted to explore separate aims of the over-arching project: 1) Case Control Study: To determine whether participants show cognitive deficits, a case control study design will be utilised, with participants with endometriosis compared to healthy matched controls. Thus, performance on neurocognitive tests, and a subjective measure of cognition will be compared with matched healthy controls, which is commonly utilised in other chronic health populations; in fibromyalgia (Gelonch et al., 2018; Tesio et al., 2015; Wu et al., 2018); chronic fatigue syndrome (Cockshell & Mathias, 2010); multiple sclerosis (Chiaravalloti & DeLuca, 2008; Patti, 2009) and chronic pain (Berryman et al., 2013; Oosterman et al., 2011). Participants will be matched on age, sex and education level, which allows for controlling of these variables in the study, which are commonly associated with cognitive functioning (Boscher et al., 2020; Chiaravalloti & DeLuca, 2008; Lenehan et al., 2015). 2) A cross-sectional study: There is a need to investigate associations of pain, fatigue and depression with objective measures of cognitive functioning, which builds upon previous research demonstrating their links with subjective measures of cognition. This cross-sectional design will explore these associations between pain, fatigue, and depression with objective measures of cognitive functioning.