Fibromyalgia and Brain Function
If you have Fibromyalgia there have likely been many times where you’ve experienced what we call “Fibro Fog“, but you’ve likely also noticed other issues with your cognitive function, for instance you may no longer be able to multi-task, to learn game rules quickly, to understand what you are reading, to have music playing in the background while you work. You are not alone as these are all fairly common issues for all of us who live with Fibromyalgia; it’s common to wonder if there’s a connection between Fibromyalgia and brain function.
Results from a study by Verdejo-García et al (2009) confirmed that there is a link between Fibromyalgia and reduced cognitive function. They used two tasks to measure cognitive ability and emotion-based decision-making. The Wisconsin Card Sorting Task (WCST) requires participants to sort a deck of cards along a specific rule, but they are not told what the rule is. Instead, they have to figure it out as they go along based on feedback. Once the participants correctly place 10 cards, the rule changes testing the participant’s ability to learn and maintain a new rule. This task measures the subject’s ability to switch tasks, learn new rules, and deal with distractions while monitoring multiple sources of information.
The second task, the Iowa Gambling Task (IGT) is a computer-based simulation where the participants are given with four decks of cards and asked to choose a card. Each card provides either a reward or punishment (increase or decrease in play money); two decks offer higher reward values but higher punishment values (leading to lower overall earnings), while the other two decks offer lower rewards and lower punishments (leading to higher overall earnings). The participants are tested on their ability to learn which decks are provide the highest payouts and make correct decisions despite competing emotions from pain, and that may occur from winning or losing. A second form of the IGT was also used which provided an instant punishment on all decks, paired with a matched reward later. Two decks paired a high initial punishment with a high reward later, while the other two decks paired a lower initial punishment with a lower reward later. Subjects were not aware of this pairing at the beginning and were only told that most decks would contain a punishment and few would issue a reward.
Results for the study by Verdejo-García et al indicated a significant difference in cognitive function for the Fibromyalgia patients as compared to the healthy controls. In the WCST Fibromyalgia patients were able to complete significantly fewer categories (rule changes), and showed more errors. However, perhaps surprisingly, the errors that the Fibromyalgia group showed were not related to their ability to learn or remember a new rule.
Results for the IGT indicated that Fibromyalgia patients had a significant decrease in ability to make positive decisions while dealing with emotions. The Fibromyalgia group showed an inability to learn which deck was most advantageous to choose. In the alternative version of the IGT Fibromyalgia patients were more likely to choose the decks that provided the high initial punishment, indicating that they may be more willing to tolerate punishment in hopes of a higher reward later (big surprise!).
Higher self-reported pain scores correlated to the differences between the Fibromyalgia group and healthy controls. Fibromyalgia patients showed higher levels of distractibility and emotion-based decision making in the WCST and the IGT. Fibromyalgia patients did not show any decrease in flexibility or ability to learn a new rule.
Previous studies have indicated that the differences in the IGT may be a result of an increased need for reward in the Fibromyalgia group. This has been evidenced by a decrease in dopamine uptake in those with Fibromyalgia. Dopamine is the neurotransmitter that is responsible for providing a feeling of reward in the brain. A lack of dopamine has been examined in Fibromyalgia and it is the reason why drugs like Memantine are being considered for potential treatment of Fibromyalgia.
What was unclear from this study was whether it was specifically the pain that caused the differences between the Fibro and the healthy groups, or if co-morbid issues such as sleep disturbance, fatigue, or even medication may cause some of the differences. However, another study (Dick et al, 2008) has indicated the regular consistent use of opioid analgesics can actually improve cognitive function.
So, the next time you are feeling like your brain isn’t working like it used to, now you know that you are probably right. The pain is likely getting in the way.Study shows that #Fibromyalgia does decrease brain function. #fibro #chronicpain Click To Tweet