Fibromyalgia

Question 1

Define fibromyalgia.

Answer 1

• Chronic pain syndrome diagnosed by the presence of widespread body pain (front and back, right and left, both sides of the diaphragm)
• for at least 3 months
• in addition to tenderness (digital palpation at an approximate force of 4 kg)
• of at least 11 out of 18 designated tender point sites as defined by the American College of Rheumatology 1990 classification criteria

Question 2

Where are the Americal College of Rheumatology classification tender point sites?

Answer 2

Question 3

How common is fibromyalgia?

Answer 3

• Prevalence around 0.5-2%
• More common in women (9/10 patients are female)
• Age of onset 20-60 years

Question 4

What is the aetiology of fibromyalgia?

Answer 4

• Could be genetic - strong family component
• Studies show it is different and separable from anxiety and depression - most people with fibromyalgia do not have psychiatric conditions

Question 5

What is the pathophysiology of fibromyalgia?

Answer 5

• CNS pathology that involves pain and/or sensory amplification
• Hallmark of fibromyalgia and its associated conditions (IBS, headache, temporomandibular joint disorder) is that individuals show hyperalgesia* and/or allodynia**
• On neuroimaging studies it appears to be due to imbalances in the levels of neurotransmitter that affect pain and sensory transmission
• Centralisation (to CNS rather than localised pathology) means that other symptoms like fatigue, memory difficulties, sleep and mood disorders are common.

*hyperalgesia - increased pain in response to normally painful stimuli

**allodynia - pain in response to normally non-painful stimuli

Question 6

What types of therapy are given for fibromyalgia?

Answer 6

Pharmacological - drugs that raise anti-nociceptive neurotransmitters such as seritonin and norepinephrine (NA) or lower pro-nociceptive neurotransmitters such as glutamate and Substance P

Non-pharmacological - exercise, CBT

Question 7

What are the symptoms of fibromyalgia?

Answer 7

• Chronic pain - chronic, widespread pain is pathognomonic. Usually descirbed as gnawing, lancinating, nubmness, tingling = “neurpathic” descriptors for pain
• Fatigue unrelieved by rest >90%
• Sleep disturbance
• Mood disturbance - depression/anxiety
• Cognitive dysfunction
• Headaches which extend into neck and shoulders
• Numbness and tingling
• Stiffness accompanied by sensation of swelling without physical exercise
• Sensitivity to bright lights, odours, noises

Question 8

What are the signs of fibromyalgia on examination?

Answer 8

• Diffuse tenderness on examination - as set forth by the ACR in 1990, patients must have excess tenderness to palpation in at least 11 of 18 defined tender points. Must apply so much pressure that examiner nail bed blanches.
• Fluid retention - may be described convincingly by patient but not observed on physical examination

Question 9

What elements must be found in the history for fibromyalgia diagnosis?

Answer 9

Widespread* body pain for at least 3 months

Pain may be myalgia, arthralgia or both.

Widespread = axial plus upper and lower segment, plus left and right sided pain.

Question 10

What investigations would you do for fibromyalgia?

Answer 10

DIAGNOSIS is clinical = but if criteria not met for diagnosis of fibromyalgia:

Bloods: FBC, TFTs, ESR, CRP, Vit D, RF, anti-CCP antibodum ANA

NB: some of these tests have false positive results.