L-8 Fibromyalgia

• Patrick E. Barry, DO, Associate Professor, Osteopathic Principles & Practice, is the presenter of these notes

Definition

• Fibromyalgia (FM) is the most common cause of chronic widespread musculoskeletal pain.
• FM is often accompanied by fatigue, cognitive disturbance ("fibro fog"), psychiatric symptoms, and multiple somatic symptoms.
• FM is more prevalent in women than men with a ratio of 6:1.
• FM commonly presents between the ages of 20-55 years.
• The prevalence of FM increases with age.
• FM is commonly under-recognized in clinical practice.
• The average time to diagnosis is approximately 5 years.

Etiology

• FM is thought to be neurogenic in origin.
• The exact pathogenesis of FM is still unknown.
• Central sensitization may be the main pathophysiologic change.
• There is increased CNS response to stimulation and decreased conditioned pain modulation (CPM).
• CPM involves activation of specific neurotransmitters such as serotonin and noradrenaline.
• Medications that target these neurotransmitters may be a successful management method.

Causes

• Evidence indicates a dysregulation of pain processing.
• Increased levels of substance P and glutamate in the spinal cord and muscles are physiological abnormalities.
• Low levels of blood flow to the thalamus is a physiological abnormality.
• HPA axis hypofunction is a physiological abnormality.
• There are low serotonin and tryptophan levels (inhibitory) physiological abnormalities.
• Abnormalities in cytokine function is a physiological abnormality.
• Genetics may play a role.
• Small-Fiber Neuropathy may be a cause

Genetics

• Genetics and epigenetics insights may provide diagnostic biomarkers.
• COMT gene polymorphisms (involved in pain transmission) may predispose individuals to FM.
• FM is pathogenetically involved through adrenergic mechanisms.
• The ability to inactivate catecholamines and catecholamine-containing drugs may be affected.
• There can be altered inflammatory pain.
• There can be altered mu-opioid receptor expression.
• Altered outcomes may occur with long-term morphine treatments.
• There can be changes to the pain threshold.
• Alteration in the maintenance of skeletal muscle integrity may occur.

Sensitization

• Peripheral sensitization occurs at the level of the peripheral nerve terminal.
• Central sensitization occurs at the level of the dorsal horn of the spinal cord.
• Damage to or inflamed tissues can cause sensitization.
• Inflammatory mediators activate intracellular signal transduction in nociceptors leading to:
  • Increased production, transport, and membrane insertion of chemically gated and voltage gate ion channels
  • Increased excitability of nociceptor terminals
  • Lowered nociceptor threshold for activation from stimuli
• Direct activation by intense pressure and consequent cell damage causes sensitization. -Cell damage induces lower pH (H+), leads to release of potassium (K+), synthesis of prostaglandins (PGs) and bradykinin (BK) -PGs increase the sensitivity of the terminal to BK and other pain-producing substances.
• Impulses generated in the stimulated terminal propagate to spinal cord and terminal branches as a secondary activation. -Results in release of peptides, including substance P (SP). -Substance P causes vasodilation and neurogenic edema with further accumulation of BK. -Substance P causes release of histamine (H) from mast cells and serotonin (5HT) from platelets.

Diagnostic Criteria

• 1990 American College of Rheumatology diagnostic criteria includes tenderness in 11 of 18 standardized tender points on palpation
• Widespread pain is needed in all four quadrants of the body for a minimum of 3 months
• 2010 Fibromyalgia Clinical Diagnostic Criteria includes Widespread Pain Index (WPI)
  • How many areas has patient had pain in last week? (Score = 0-19). - Includes: Shoulder: Lt, Rt. Upper arm: Lt, Rt. Lower arm: Lt, Rt. Jaw, Lt, Rt. Neck, Buttock, hip trochanter: Lt, Rt., Upperleg: Lt. Rt. Lowerleg: Lt, Rt., Upperback, Lowerback, Chest, and Abdomen
• Symptom severity scale (SS): What is level of severity in last week?
  • 0(No problem) 1(slight prob) 2(Moderate) 3(Severe)
  • Includes: Fatigue, Waking unrefreshed, Cognitive disturbances, and General somatic symptoms
  • SS Score = 0-12
• A patient should satisfy the 2010 fibromyalgia clinical diagnostic criteria if WPI > 7 and SS score > 5 OR WPI between 3-6 and SS score > 9
• The AAPT diagnostic criteria for fibromyalgia includes:
  • MSP defined as 6 or more pain sites from a total of 9 possible sites includes Head, Left/ Right arm, Chest, Abdomen, Upper/ Lower back, and Left/ Right leg
  • Moderate to severe sleep problems or fatigue exists
  • MSP plus fatigue or sleep problems must have been present for at least 3 months
  • The presence of another pain disorder or related symptoms does not rule out a diagnosis of FM

Fatigue

• Begins on rising.
• Patients report more fatigue than when going to bed.
• Patient: "No matter how much sleep I get, it feels like a truck ran me over in the morning."
• Patient does not reach stage 4 for prolonged periods of time.
• Symptoms include "alpha-delta sleep" and constant interruptions of sleep with awake-like brain activity.

Other Symptoms

• Can include stiffness.
  • Lasts all day.
  • Severe enough to limit activities.
  • Does not diminish with activity.
• Migraine headaches
• Temporomandibular joint disorder
• Urinary frequency
• Paresthesias in hands/feet
• Irritable bowel syndrome

Psychosocial Factors

• Jobs involving physical labor
• Poor coping strategies
• Feeling helpless
• Involvement in litigation
• Vulnerability issues as the brain develops
• Persistent stress
• Anxiety
• Poor coping skills
• Generalized decreased pain perception threshold

Aggravating Factors

• Cold/humid weather
• Non-restorative sleep
• Physical and mental fatigue
• Excessive physical activity
• Physical inactivity
• Anxiety
• Stress

Things to Rule Out

• Must rule out other conditions
• Chronic fatigue syndrome (ME/CFS)
• Complex regional pain syndrome (CRPS)
• Depression
• Hypothyroidism
• Thoracic outlet syndrome
• Peripheral neuropathy
• Autoimmune disorder
• Polymyalgia rheumatica
• RA
• OA

Labs

• Conduct the following labs
• CBC (chronic infection with elevated WBC)
• CRP/ESR
• CPK
• Liver/Renal function panels for Hep C, myositis, lupus, rheumatoid arthritis, other autoimmune diseases
• TSH
• B12 (bowel resection, malnourished, excessive alcohol intake)
• Hep C titer
• Lyme's titer

Treatment

• Improvement of current symptoms, functioning, and quality of life
• Secondary prevention of worsening presenting chronic complex condition
• Analgesics can be used to relieve pain
• Acetaminophen (Tylenol)
• NSAIDS
• Tramadol (Ultram, Ultracet)
• Low dose antidepressants
• TCA'S
• SSRI's (Prozac, Zoloft, Paxil)
• SNRI'S

FDA Approved Treatments

• FDA approved drugs for FM:
  • Pregabalin (Lyrica)
  • Duloxetine (Cymbalta)
  • Milnapracin (Savella)
• Local anesthetic injections can be used Acupuncture can also be used as a treatment
• Exercise can be a treatment
  • Aerobic
  • Heated pool therapy
  • Gentle stretching

OMT

• Multiple studies have shown that OMT can augment treatment
• Counterstrain
  • Correlation of FM tender points with counterstrain points
• Myofascial release techniques
• Lymphatic techniques
• Stretching with or without gentle muscle energy
• HVLA generally is not directly effective
• Patients can be given OMT alone or combined with Gabapentin and it displays clinical improvements in the pain scale scores

Other Therapies and the Future

• These may include Meditative Movement Therapies
  • Tai chi
  • Yoga
  • Qigong
• Acupuncture
• Brain neuromodulation
  • Transcranial direct current stimulation
  • Transcranial magnetic stimulation
  • Occipital and C2 nerve stimulation
  • Transcutaneous electrical nerve stimulation (TENS)

Prognosis

• Prognosis for FM is chronic and not progressive.
• Some studies reporting no change in symptoms occur over long term.
• Other studies report 25–35% of patients show “some improvement” over time.
• An estimated 30–40% of patients have stopped working or changed jobs secondary to FM.