Day # 124: Chronic Pain Syndrome and Fibromyalgia
Today we will continue our current theme of psychosomatic disorders as we discuss chronic pain syndromes (specifically non-cancer pain) and fibromyalgia.
Today's Content Level: Intermediate
Chronic pain is one of the most common reasons patients seek medical attention.
Chronic pain = pain that persists longer than 3-6 months or beyond the duration required for normal tissue healing after an injury.
This leads to impacts on level of function, quality of life, and mood.
These pain syndromes are produced and aggravated from combined biologic, psychologic, and social factors, and typically requires a multifactorial approach to evaluation and treatment.
There are a number of reasons why it is important for us to discuss chronic pain syndromes within psychiatry. One reason is that negative emotions and expectations (ex. fear and catastrophizing) can amplify the perception of pain. Also, individuals with chronic pain are four times as likely to have anxiety or depression. The prevalence of suicidal ideation and suicide attempts are also higher in individuals with chronic pain. Substance use disorders (opioid use disorder and alcohol use disorder in particular) are also associated with chronic pain.
The area(s) of pain and other specific clinical features vary, however common areas of chronic pain include headaches, musculoskeletal pain (back and neck are most common), chronic abdominal pain, chronic pelvic pain, neuropathic pain, and arthritis of any joint (osteoarthritis, rheumatoid arthritis, etc). See below for some examples of specific pain syndromes.
EXAMPLES OF CHRONIC PAIN SYNDROMES 2
Chronic migraines: headache that can cause severe throbbing pain or a pulsing sensation. Usually unilateral but can also be bilateral. Sensitivity to light and sound is common. Nausea or lightheadedness may be seen. Some patients experience an "aura" which are sensations such as flashing lights or zigzag lines that precede the headed or occur concurrently.
Chronic back pain: the majority of back pain is self-limited, however it is a frequent cause of chronic pain. Possible etiologies include muscular strain, herniated disc, spondylolysis (stress fracture through the pars interarticularis of the lumbar vertebrae), spondylolisthesis (vertebra shifts forward due to instability from the pars fracture), connective tissue disease, or idiopathic.
Fibromyalgia: chronic pain syndrome marked by widespread muscle pain and tenderness. It is often accompanied by fatigue and altered mood, memory, and sleep. Current diagnostic criteria, per the American College of Rheumatology, consists of an assessment with the Widespread Pain Index and Symptom Severity Scale. Individuals with fibromyalgia are more likely to have anxiety, depression, OCD, PTSD, chronic headaches, dysmenorrhea, temporomandibular joint pain, irritable bowel syndrome, arthritis, and lupus.
Postherpetic neuralgia: patients may experience chronic neuropathic pain even after resolution of a shingles rash.
Diabetic neuropathy: most common chronic neuropathy worldwide. Symptoms are typically symmetric and start distal (toes) and progressively become more proximal (feet->legs->fingers). Occurs due to chronically elevated blood sugar and subsequent damage to peripheral nerves.
Trigeminal neuralgia: burning or shock-like pain unilaterally along the trigeminal nerve distribution of the face. Often idiopathic or due to an underlying structural lesion.
EPIDEMIOLOGY / PATHOGENESIS 3, 4
Prevalence of chronic pain estimated to be about 30% in the general adult population, while 8% experience major reductions in quality of life. Prevalence of fibromyalgia between 2-8% and is similar across different countries and ethnic groups.
Risk factors include advancing age, female sex, low socioeconomic status, unemployment, history of abuse, smoking, obesity, poor sleep, chronic medical conditions, and psychiatric comorbidity (anxiety, depression, and substance use).
The physiology of pain and pathophysiology of chronic pain is complex and an in-depth discussion is beyond the scope of this post. Keep in mind that there may be disruption/amplification in the peripheral processing of pain signals (peripheral nerve damage, cytokine release, enhanced depolarization, sensitization) as well as central processing of pain signals (transmission from the thalamus to the cortex and emotional amplification in the limbic system).
The evaluation of a patient with chronic pain requires a thorough assessment of the pain itself and a search for a biomedical source of the pain. It should also include assessment of impacts on function (job and/ or life role), a psychological evaluation, sleep evaluation, and determination of social factors that may increase pain severity and worsen clinical outcomes.
Pain description: OPQRST -> onset (what was the patient doing when it started [activity, inactivity, stressed, specific injury, etc]), provocative/palliative factors, quality (sharp, dull, crushing, burning, tearing, throbbing, constant, intermittent), region/radiation, severity (0-10 pain scale, visual analog scale, pain maps), timing (duration how it has changed since onset). Have there been prior patterns of similar presentations? Consider standardized questionnaires such as the Brief Pain Inventory (BPI).
Impact on function: assess for any disability (decreased ADLs) or impact of function on social relationships, work or school, mood, sleep, exercise, and hobbies. Consider using the Defense and Veterans Pain Rating Scale (DVRPS) or the Pain intensity, pain interference with Enjoyment of life and General activity (PEG) score.
Past treatment: discuss prior and concurrent diagnostic studies, relationships with previous providers, medication trials, procedures, non-pharmacologic management, complimentary medicine.
Review of systems (ROS): in addition to the pain are there associated symptoms such as swelling, spasm, temperature or color changes, reduced range of motion, weakness, or fatigue? A "pan-positive" ROS may suggest conditions associated with sensory hypersensitivity and may support a syndromic pain diagnosis such as chronic fatigue, chronic migraines, fibromyalgia, etc.
Medical history: can help determine the etiology of chronic pain if there are comorbid issues such as diabetes, history of cancer, rheumatic disease, etc. It is also important because it may affect the choice of therapy.
Physical examination and diagnostic testing: a comprehensive physical examination (detailed neurological and musculoskeletal exam) should be performed for all patients with chronic pain to identify anatomic and physiologic abnormalities potentially relevant to the pain complaint. Consider lab tests, X-rays, MRI, electromyography, or nerve conduction studies depending the nature of the complaint and abnormalities on physical exam.
Psychological/Psychiatric assessment: perform full psychological screening and comprehensive evaluation if indicated. Individuals with chronic pain are much more likely to have depression, anxiety, substance use, PTSD, OCD and suicidality (prevalence of suicide attempts estimated between 5-14%). Screen for substance use, particularly dependence on alcohol or opioids. Assess for the patients beliefs about the cause of their symptoms and associated thoughts, behaviors, emotions, and impact on function. Examples include the patients sense of hope/hopelessness or self-efficacy/helplessness about their pain, catastrophizing, avoidance behaviors, and problem-solving abilities. Attempt to understand the patients goals and willingness to be an active participant in treatment.
Social factors: assess for strength of social supports as well as any significant stressors that may be exacerbating their condition.
Next lesson we will discuss the treatment of chronic pain and fibromyalgia. If you want more learning resources then check out our recommended resources page.
Resources for today's post include: Pocket Psychiatry and Kaplan and Sadock Synposis of Psychiatry and the articles referenced in the text.