Comorbidities in Chronic Neuropathic Pain

Abstract

Neuropathic pain arises from a lesion or dysfunction within the nervous system; the specific mechanisms that elicit neuropathic pain symptoms are the subject of ongoing research. It is generally acknowledged that neuropathic pain is extremely difficult to treat, and a major factor impacting outcomes is the presence of comorbidities such as poor sleep, depressed mood, and anxiety. Patients who suffer from chronic pain experience difficulties in initiating and maintaining sleep. Sleep deprivation has been associated with a decreased pain threshold, muscle aches, and stiffness in normal volunteers. The interrelationship of these factors is complex: Many chronic pain patients are depressed and anxious; sleep deprivation can lead to anxiety; and depression can be both the cause and the result of sleep disturbances. Thus, physicians must evaluate all aspects of pain, sleep, and mood in chronic pain patients. Several instruments have been developed to aid physicians in gathering qualitative and quantitative information from chronic pain patients. This triad of chronic pain, sleep disturbances, and depression/anxiety must be fully addressed if the patient is to be restored to optimal functionality. A multidisciplinary team approach allows for treatment of the whole patient. Nonpharmacologic interventions include relaxation therapy, sleep restriction therapy, and cognitive therapy. Strategies for pharmacologic interventions should attempt to maximize outcomes by employing, where possible, agents that address both the pain and the comorbidities. In this way, functionality may be restored and the patient's quality of life improved.

Applicability of the Brazilian version of the McGill pain questionnaire in elderly patients with chronic pain

“…This category consists of words related to the individual's emotional state, and can translate the perception of tiredness, the feeling of fear and punishment and autonomic reactions. These data confirm the idea that individuals with neuropathic pain present emotional factors related to the perception of this symptom 41 .…”

“…When the reliability of the Sensory Pain Classification Index was assessed, it showed to be almost perfect, demonstrating the importance of this category to qualify pain in this specific elderly group. It is noteworthy that the sensory characteristics of pain are the main criteria to define the presence of neuropathic pain 40,41 . There are several mechanisms to develop neuropathic pain, such as direct stimulation of the sensitive neurons by compression or chemical irritation, by nervous injury or deafferenting and maintenance of pain by constant sympathetic stimulation [42][43][44] .…”

Rethinking chronic pain in a primary care setting

“…[61] Although chronic pain can contribute to the development of depression, anxiety, stress, and sleep disorders, these factors exhibit a bi-directional relationship with pain and their presence can lower pain thresholds, influence perception, and increase the risk of developing chronic pain. [62][63][64][65][66][67][68] Even basic steps to assess and address an individual's psychological and social factors can significantly increase the likelihood of treatment success. This requires an individualized treatment approach that shifts from predominantly biomedical strategies (i.e.…”

Migraine and Reward System—Or Is It Aversive?

“…Pain and reward are considered opponent processes, but are processed within overlapping or interacting brain structures (e.g., anterior cingulate cortex, dorsal and ventral striatum, and amygdala). It has been demonstrated that rewarding stimuli such as food and pleasurable music decrease pain sensitivity [12], whereas pain can impair reward processing, which can lead to an anhedonic state [13,14]. The negative affect, or how much the pain is 'bothersome,' significantly impacts the quality of life of the sufferer, and leads to the common comorbidities of psychiatric disorders such as depression.…”

“…The negative affect, or how much the pain is 'bothersome,' significantly impacts the quality of life of the sufferer, and leads to the common comorbidities of psychiatric disorders such as depression. Comorbidity between chronic pain and Axis I disorders of the DSM-V (including depression, anxiety disorders, bipolar disorder, ADHD, autism spectrum disorders, and schizophrenia) has been well documented, where depression is the most common comorbidity, with some studies finding a prevalence rate approaching 100 % among clinical chronic pain samples [14]. In fact, chronic pain is second only to bipolar disorder as the major cause of suicide among all medical illnesses, and the high comorbidity of migraine with depression further highlights the importance of negative affect [15][16][17].…”