Dyscognition in chronic pain. A systematic approach to cognitive complaints, cognitive performance, metamemory and malingering in patients suffering from chronic pain

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Although chronic pain states are highly prevalent, the underlying neurobiological mechanisms of pain chronification are still incompletely understood. Increasing evidence suggests that chronic pain is associated with (maladaptive) neuroplastic changes in the brain. Chronic pain patients often suffer from additional complaints and symptoms, such as depressive episodes, chronic fatigue and cognitive deficits. The latter, also termed dyscognition, is increasingly recognized to add significantly to the degree of suffering and malfunctioning in chronic pain patients. On the other hand there is evidence that memory complaints (as estimated by the patients themselves) exceed the actual deficits as determined by neuropsychological testing. As such other mechanisms such as a dysfunction of meta-memory and malingering might also play a role. Dyscognition has been investigated in some depth in fibromyalgia patients, however more work is needed in other chronic pain states, such as chronic headaches, chronic neuropathic pain and chronic backpain (among others) to determine similarities and differences in dyscognitive profiles across pain syndromes. Furthermore neural correlates of dyscognition, i.e. the interaction between chronic pain and cognitive functions such as attention, working memory and long-term memory, have only sparsely been investigated. Current theories, here referred to as neuroplasticity theory, limited resource theory and neurotransmitter theory provide a conceptual framework, however further corroborations and refinements are needed. The aims of the current proposal are threefold. First of all more research is needed to profile dyscognition in chronic pain states (other than fibromyalgia). The question is whether patients with chronic headaches, chronic neuropathic pain and chronic back pain also show cognitive deficits, and, if so, in which domains. Furthermore modern brain imaging enables the investigation of neural correlates of both pain perception and cognitive performance. The current proposal aims at using modern brain imaging techniques, such as structural and functional MRI, to investigate changes in brain structure and/or function associated with pain that might influence/interfere with cognitive functioning. We will also investigate meta-memory processes in chronic pain paints and neural correlates thereof, trying to determine how chronic pain patients judge their cognitive performance and whether there is a negative bias that possibly leads to an overestimation of cognitive dysfunction. Finally we will investigate whether cognitive, deficits (if present) resolves, as pain improves.