Muscle pain profoma

Question 1

Define muscle pain

Answer 1

usually only pain on movement. Bone pain is there all the time.

Question 2

Define myopathy

Answer 2

where muscle fibres do not function, causing weakness.

Question 3

Define myositis

Answer 3

a group of conditions causing weak, painful or aching muscles.

Usually a problem w/ immune system where it attacks healthy tissue.
- Polymyositis
- Dermatomyositis
- Inclusion body myositis

Question 4

Presentation of muscle pain?

Answer 4

• Dull or sharp aching pain
• Deep muscle pain in local area or widespread
• Difficulty standing from sitting position.
• Difficulty walking up steps, squatting or lifting overhead.
• Fatigue
• Muscle weakness
• Muscle cramps or spasms
• Bruising - severe strain can cause an intramuscular haematoma.
• Swelling e.g. in muscle strain.

Question 5

Initial investigations for muscle pain?

Answer 5

Blood tests
- Biochemistry - ESR, CRP, creatine kinase, Vitamin D, PTH.
NOTE: Creatinine kinase indicates muscle damage.
- Infections - parvirus, hepatitis B/C, HIV and streptococcus.
- Serology:
1. Serum & protein elctrophoresis
2. ANAs/ENAs e.g. myositis-specific autoantibodies e.g. anti-Jo-1 or anti-Mi-2.
3. Serum ACE - serum antiotensin converting enzyme. Test for Sarcoid.
- Rheumatoid Factor or Complement

MRI - for soft tissue injuries.

CT scan - of chest, pelvis & abdomen for malignancy.

Electromyography (EMG) - measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle. Helps detect neuromuscular abnormalities

Open muscle biopsy - guided by MRI. Can help detect polymyositis or dermatomyositis

Question 6

Key differential diagnosis for muscle pain?

Answer 6

1. Trauma:
   - Muscle strain- muscle fibres are torn.
   - Rhabdomyolysis - muscle breakdown.
   - Cramp
   - Claudication - insufficient blood flow = cramp due to ischaemia.
   - Compartment syndrome
2. Inflammatory
   - Polymyositis - inflammation & weakness in muscles.
   - Dermatomyositis - inflammation & weakness in skin & muscles.
   - Sarcoid- granulomas form in lungs & skin.
   - Other autoimmune connective tissue diseases e.g. SLE, Polymyalgia Rheumatica & Giant Cell Arteritis
3. Neuromuscular:
   - Myasthenia Gravis - involves droopy eyelids, dysphagia & weak arms/legs.
   - Muscular dystrophy - e.g. Duchenne or Becker’s Muscular Dystrophy. A strong family history & onset in childhood or early adulthood suggest muscular dystrophy.
4. Endocrine:
   - Hypothyroidism-↑ CK levels seen.
   - Hyperthyroidism - often thighs & shoulders.
   - Cushing’s syndrome - too much cortisol
   - Addison’s disease- too little cortisol
5. Metabolic
   - Osteomalacia - Vitamin D deficiency
   - Hypokalaemia - too little Potassium
   - Hypercalcaemia - too much Calcium
6. Drugs/ toxins
   - Statins
   - Glucocorticoids- steroids
   - Alcohol - can cause an inflammatory myositis.
   - TNF inhibitors
   - Chemotherapy or radiotherapy
   - High blood pressure medications e.g. ACE inhibitors.
7. Infections
   - Viral infectionse.g. HIV, rubella, Epstein–Barr, flu.
   - Bacterial infections e.g. Clostridium perfringens, staphylococci, TB,Mycoplasma.
   - Parasitic infections e.g. Lyme disease, Malaria.

Question 7

Management for muscle pain- conservative?

Answer 7

• Rest
• Hot or cold treatments
• Muscle strengthening
• Aerobic conditioning (graded exercise)
• Appropriate footwear
• Education
• Physiotherapy

Question 8

Management for muscle pain- pharmacological?

Answer 8

1. Simple analgesics e.g. Paracetamol
2. Topical NSAIDs