Pain Syndromes Flashcards
Fibromyalgia
Fibromyalgia is a syndrome characterised by widespread pain throughout the body with tender points at specific anatomical sites. The cause of fibromyalgia is unknown.
Epidemiology
women are 10 times more likely to be affected
typically presents between 30-50 years old
Fibromyalgia - Features
Features
chronic pain: at multiple site, sometimes ‘pain all over’
lethargy
sleep disturbance, headaches, dizziness are common
Fibromyalgia - Diagnosis
Diagnosis is clinical and sometimes refers to the American College of Rheumatology
classification criteria which lists 9 pairs of tender points on the body. If a patient is tender in at least 11 of these 18 points it makes a diagnosis of fibromyalgia more likely
Fibromyalgia - Mx
The management of fibromyalgia is often difficult and needs to be tailored to the individual patient. A psychosocial and multidisciplinary approach is helpful. Unfortunately there is currently a paucity of evidence and guidelines to guide practice. The following is partly based on consensus guidelines from the European League against Rheumatism (EULAR) published in 2007 and also a BMJ review in 2014.
- explanation
- aerobic exercise: has the strongest evidence base
- cognitive behavioural therapy
- medication: pregabalin, duloxetine, amitriptyline
The evidence base for pharmacological treatment of fibromyalgia includes many trials with small participant numbers and short follow-up periods. In addition, many trials have exclusion criteria (such as co-morbid psychiatric illness or chronic physical illness) that make generalisation to patients seen in clinical practice difficult.
Recent network meta-analysis has demonstrated that once trials with fewer than 50 participants are excluded then there is only evidence of effectiveness of duloxetine and pregabalin to improve pain and quality of life. Current recommendation is to use an agent at an effective dose for at least four weeks then assess response. If no response obtained then initial treatment should be held before new agent started.
Fibromyalgia - Diagnosis: Example Question
A 45 year old woman was referred to Rheumatology clinic after experiencing widespread aches and pains felt throughout her body. The pains were felt particularly in her arms and legs in addition to significant pain throughout the patients spinal column. The patient could not recall a precise onset of her symptoms but she felt they had been present for at least 12 months, possibly longer. In addition, the patient reported on-going feelings of tiredness and lethargy. Despite going to bed around 10 pm each evening, the patient reported waking in the morning still feeling exhausted. She denied any history of hot or tender joints, skin rashes, hair loss, swallowing difficulties or dry eyes. The patients appetite was described as normal for her with no significant change in weight.
There was no previous past medical history and the patient took no regular medications except for a non-prescription multi-vitamin. Family history was remarkable for hypothyroidism affecting her mother and elder sister. The patient worked as an accountant and lived with her two teenage children. She had separated from her ex-husband 18 months previously.
Examination did not demonstrate any evidence of active sinovitis of the hands or feet with no other inflamed or deformed joints. Palpation of the muscles of the upper arms and legs as well as the paraspinal muscles was exquisitely tender. Neurological examination of the arms and legs was unremarkable. Cardiovascular and respiratory examination was unremarkable with no skin rashes.
During clinic interaction the patient appeared tired and stressed but had good rapport and maintained good eye contact. She denied any significant low mood but was anxious that her symptoms represented a serious underlying illness.
Investigations requested following clinic are listed below.
Haemoglobin 12.9 g / dL White cell count 7.2 * 109/l Platelets 332 * 109/l Mean cell volume 87 fL Sodium 140 mmol / L Potassium 3.6 mmol / L Urea 3.5 mmol / L Creatinine 68 micromol / L Erythrocyte sedimentation rate 11 mm / h Rheumatoid factor Negative Anti-nuclear antigen Weak positive B12 324 pmol / L (reference 74-516) Folate 30 nmol / L (reference 7-36) Serum immunoglobulin Normal electrophoresis strip Thyroid stimulating hormone 0.9 microU / mL (reference 0.4-5.0)
X-rays of hands: some minor degenerative change in right index proximal interphalangeal joint but otherwise unremarkable with no boney erosion or deformity
What is the cause for the patients pain?
> Fibromyalgia Systemic lupus erythematous Chronic regional pain syndrome Generalised anxiety disorder Depression
The patient has chronic widespread pain (>3 months) associated with lethargy, non-refreshing sleep and multiple tender points on palpation. Basic blood tests are essentially normal and there is no history or examination to suggest connective tissue disease or other pathology. This presentation is consistent with fibromyalgia, the diagnostic label used to describe chronic widespread pain associated with multiple muscular tender points or associated symptoms of fatigue, non-refreshing sleep or cognitive dysfunction.
Please note that many healthy individuals have weakly positive anti-nuclear antigen results and this does not imply a diagnosis of systemic lupus erythematous in the absence of symptoms and signs of the disease. It may be that requesting immunological tests was inappropriate in this patient given the lack of clinical evidence of connective tissue disease.
Chronic regional pain syndrome is associated with persistent burning pain in one limb, usually after a minor injury. The brief mental state examination documented does not suggest evidence of significant depression or generalised anxiety.
Fibromyalgia: Diagnosis - Example Question
A 37 year old woman with known rheumatoid arthritis was reviewed at her annual follow-up at rheumatology clinic. The diagnosis of rheumatoid arthritis had been made ten years previously after the patient experienced severe inflammation of her meta-carpal phalangeal joints of both hands. Symptoms had been controlled with an initial reducing course of oral steroids and had been subsequently maintained on 15 mg of subcutaneous methotrexate weekly. She had experience one significant flare of her symptoms 18 months previously that had necessitated a single intra-muscular dose of corticosteroids.
On this occasion the patient reported no further swelling, pain or redness of the joints of her hands or other joints. She did report however that over the past 6 months she had experienced on-going severe pains throughout her body. In addition, she had been feeling tired and lethargic and had been finding it hard to concentrate on her work at as a computer programmer. She denied any history of skin rashes, photosensitivity, hair loss, swallowing difficulties or dry eyes and she had not lost any weight.
Examination did not demonstrate any evidence of active sinovitis. A minor ulnar deviation of the digits of both hands was noted which the patient denied caused her any functional impairment. The patient was noted to be tender on palpation of the muscles of her arms, legs and paraspinal muscles. However, there was no associated muscle weakness with patient able to rise unaided from a chair without using the assistance of her arms. There was no thickening of the skin of the hands or face. Cardiovascular, respiratory and abdominal examination was unremarkable and there were no skin rashes.
Investigations requested following clinic review are listed below.
Haemoglobin 13.4 g / dL White cell count 6.6 * 109/l Platelets 198 * 109/l Sodium 139 mmol / L Potassium 4.3 mmol / L Urea 4.8 mmol / L Creatinine 75 micromol / L Erythrocyte sedimentation rate 15 mm / h Rheumatoid factor Positive Anti-nuclear antigen Negative Anti-citrullinated protein antibodies 37 units (reference < 20)
What is the likely cause of the patients new symptoms?
Flare of rheumatoid arthritis Mixed connective tissue disease Chronic regional pain syndrome Inclusion body myositis > Fibromyalgia
The patient has chronic widespread pain associated with lethargy and difficultly concentrating and multiple tender points on palpation. The patient has immunological results consistent with her previous diagnosis of rheumatoid arthritis but no clinical or biochemical evidence of a flare of this disease or the development of a new connective tissue disease or myositis. Chronic regional pain syndrome is associated with persistent burning pain in one limb, usually after a minor injury.
The patients symptoms are consistent with the diagnostic entity known as fibromyalgia. It is important to be aware that fibromyalgia is not a diagnosis of exclusion and can co-exist with other diseases as in this case.
Fibromyalgia - Mx: Example Question
A 40 year old woman was diagnosed with fibromyalgia 6 months previously following review in Rheumatology outpatient clinic. She was subsequently discharged from clinic with a recommendation for trial of pregabalin therapy. The patient has now returned to her General Practitioner to report on-going symptoms of severe widespread body pain, severe fatigue and difficulty in concentrating on daily activities. The patient did not feel that starting pregabalin 6 months previously had offered any improvement in her symptoms. In fact, her symptoms had been causing more problems and she had recently been unable to attend her work as a teaching assistant.
The patients past medical history included a duodenal ulcer five years previously, induced by the combination of non-steroidal anti-inflammatory drug use and alcohol consumption. She also had a previous diagnosis of irritable bowel disease and had a tendency to become severely constipated. There were no known allergies to medications. The patient lived alone and in addition to her teaching assistant job was her elderly mothers primary carer.
On assessment by her General Practitioner, there was no evidence of inflammatory arthritis but multiple tender spots were demonstrated across the patients body. The patient was clearly distressed and frustrated with her on-going symptoms and had concerns for her ability to continue in paid employment. The patients affect was otherwise unremarkable with a good rapport maintained throughout. She denied any symptoms of low mood or thoughts of self-harm.
Following further discussion, the patient was keen to try a further pharmacological therapy as treatment for her fibromyalgia symptoms. She was reluctant to engage with suggested psychological therapies.
What is appropriate next line pharmacological treatment for the patients fibromyalgia?
Continue pregabalin, start duloxetine Continue pregabalin, start ibuprofen as required > Stop pregabalin, start duloxetine Stop pregabalin, start amitriptyline Continue pregabalin, start fluoxetine
The evidence base for pharmacological treatment of fibromyalgia includes many trials with small participant numbers and short follow-up periods. In addition, many trials have exclusion criteria (such as co-morbid psychiatric illness or chronic physical illness) that make generalisation to patients seen in clinical practice difficult.
Recent network meta-analysis has demonstrated that once trials with fewer than 50 participants are excluded then there is only evidence of effectiveness of duloxetine and pregabalin to improve pain and quality of life. Current recommendation is to use an agent at an effective dose for at least four weeks then assess response. If no response obtained then initial treatment should be held before new agent started, for example stopping pregabalin before trial of duloxetine as in this case.
Using ibuprofen (ulcer) or amitriptyline (constipation) would likely be inappropriate in this patient given previous history of peptic ulceration and constipation.
Fibromyalgia and Aerobic Exercise
Many non-pharmacological therapies for fibromyalgia have been tried although evidence for their effectiveness is limited. Aerobic exercise has the strongest evidence of benefit with a Cochrane review showing that regular aerobic exercise improved wellbeing, aerobic capacity, tenderness and pain compared with no exercise. Strength training has also been show to have some benefit but with a lower quality of evidence than for aerobic exercise.
There is only weak evidence to support passive physical therapies such as electrotherapy or balneotherapy (hot spa treatments). Acupuncture is often used in fibromyalgia although evidence of long-term benefit is available
