EpistemisSubacute generalized muscle weakness
Specialty: General.
Why it occurs
- Polymyositis or dermatomyositis (autoimmune inflammatory myopathies that present with lymphocytic inflammatory infiltrate in the skeletal muscle, causing symmetrical proximal weakness)
- Thyrotoxic or hypercortisolism myopathy (accelerated degradation of muscle contractile proteins due to systemic hormonal excesses)
- Chronic inflammatory demyelinating polyneuropathy (CIDP) in the initial progression phase of weeks (autoimmune attack against the myelin of peripheral nerves)
- Multifocal motor neuropathy with conduction blocks (focal demyelination of motor fibers with initial asymmetric progressive weakness that generalizes)
- Chronic metabolic disorders due to uremia or decompensated liver cirrhosis with concomitant disuse atrophy.
Initial workup
Total serum creatine phosphokinase (CPK), serum aldolase, needle electromyography of proximal and distal muscles, muscle MRI of the thighs or shoulder girdle, nerve conduction velocity, and targeted muscle biopsy.
red flags
Difficulty swallowing liquids with reflex cough, dyspnea when lying on the back (muscular orthopnea due to diaphragmatic weakness), bilateral drooping of the eyelids (ptosis), or inability to raise the arms above the shoulders.
Standard management
- Prednisone — 1 mg/kg per day orally in a single morning dose, if polymyositis or another autoimmune inflammatory myopathy is confirmed, monitoring for adverse effects
- Azathioprine — 50 to 100 mg per day orally as a long-term corticosteroid saver under specialist indication
- Calcium and Vitamin D3 supplements to prevent osteoporosis induced by corticosteroids.
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- General
- Listed causes
- 5
- Treatment options
- 3