1. Yuliarni Syafrita Bagian Neurolog FK Unand
POLIMIOSITIS
Yuliarni Syafrita
Bagian Neurolog
FK Unand

2. Polymyositis is an idiopathic inflammatory myopathy
causes symmetrical, proximal muscle weakness
elevated skeletal muscle enzyme levels

3. Polymyositis/Dermatomyositis
General
group of disorders
proximal muscle weakness
nonsuppurative inflammation skeletal muscle
prevalence
5 cases/mil/year
2 to 1 F>M
40-60 yrs
pediatric variant 5-15-yrs

4. Epidemiology
Idiopathic inflammatory myopathies are relatively rare diseases.
incidence in the United States that ranges from cases per million population.
more common in the US within the black population, with the estimated black-to- white incidences for polymyositis and dermatomyositis being 5:1 and 3:1, respectively.
Internationally, polymyositis is less common among Japanese persons.

5. usually affects adults older than 20 years, especially those aged 45-60 years.
Polymyositis rarely affects children.
observed in children, usually those aged years
In most patients, polymyositis responds well to treatment, although residual weakness occurs in approximately 30% of patients

6. Physical Examination
usually present with symmetrical, proximal muscle weakness in the upper and lower extremities.
Patients with polymyositis may report muscle pain and tenderness, which may be confused with symptoms of polymyalgia rheumatica.
all of the muscles usually involved
Muscle weakness may fluctuate from week to week or from month to month.

7. Dysphagia secondary to oropharyngeal and esophageal involvement occurs in about one third of patients with polymyositis and is a poor prognostic sign.
Facial and bulbar muscle weakness is extremely rare in individuals with polymyositis.

8. Etiology :
Polymyositis is an immune-mediated syndrome .
secondary to defective cellular immunity
commonly associated with other systemic autoimmune diseases

9. Myositis General criteria proximal muscle weakness elevated serum CPK
myopathic changes on EMG
muscle biopsy inflammation
definitive with four, probable with three, possible with two
dermatomyositis skin rash with above

10. Myositis General labs up to 20% associated with malignancy
anti-tRNA synthetases
up to 20% associated with malignancy
lung, ovary, breast, stomach
parotid, tonsil reported
dermatomyositis with nasopharyngeal carcinoma, endemic areas

11. Myositis Head and Neck Manifestations weakness neck muscles
difficulty phonation, deglutition, nasal regurgitation
dysphagia from upper esophagus
may result in aspiration pneumonia

12. Enzyme levels Serum creatine kinase (CK) levels are usually elevated in persons with polymyositis, ranging from 5-50 times the reference range. A level greater than 100 times the reference level is rare and is a signal of other diagnoses.

13. Other muscle enzymes that may be elevated include the following:
Lactic dehydrogenase
Aspartate aminotransferase
Alanine aminotransferase
Aldolase - In practice, usually only the CK and aldolase levels are determined

14. Electromyography
Electromyographic findings are abnormal in almost all patients (90%) with polymyositis. Various abnormalities consistent with polymyositis may be found, depending on the stage of disease

15. Biopsy
Muscle biopsy is crucial in helping to diagnose polymyositis and in excluding other rare muscle diseases
Inflammatory changes are seen at muscle biopsy (eg, deltoid or quadriceps femoris).

16. Myositis Treatment steroids if symptomatic
methotrexate, immunosuppresives nonresponders
H2 blockers
metoclopromide

17. Therapy Corticosteroids
Prednisone is the first-line treatment of choice for polymyositis. Typically, the dose is 1 mg/kg/day, either as a single or divided dose. This high dose is usually continued for 4-8 weeks, until the CK level returns to reference ranges. Taper prednisone by 5-10 mg on a monthly basis until the lowest dose that controls the disease is reached.

18. Monitor response to therapy based on improvement in muscle strength and muscle endurance and decrease in CK levels.

19. Immunosuppressants
Immunosuppressive agents are indicated in patients who do not improve with steroids within a reasonable period (ie, 4 wk) or in whom adverse effects from corticosteroids develop
Patients with poor prognostic indicators, such as dysphagia or dysphonia, are likely to require immunosuppressive agents.

20. Other agents
Intravenous immunoglobulin (IVIG) has been used for the short-term treatment of steroid- resistant cases of polymyositis.
Diet
Patients with polymyositis may benefit from a high-protein diet. Monitor patients to avoid excessive weight gain due to corticosteroid use.

21. Activity
During the acute stage of polymyositis, patients may benefit from heat therapy, passive range-of-motion exercises, and splints to avoid contractures.

22. Miopati Etiologi : Pemakaian kortiko steroid
Gangguan metabolik (hipoglikemi kronik, myiglobinuria miopatik, penyakit penimbunan glikogen)
Gangguan endokrin (tirotoksikosis, sindroma cushing, penyakit addison)