Triggers of myotonic episodes

Myotonic dystrophies are disorders that feature myotonia (persistent contracture of skeletal muscle) after voluntary contraction or external stimulation
Pathophys: Ca released but does not efficiently return to SR → causes sustained muscle contraction
Triggers:
Hypothermia → shivering
Neostigmine (acetylcholinesterase inhibitor)
Succinylcholine (depolarizing NMB)
Direct surgical stimulation of muscle (esp via electrocautery)
Treatment:
Phenytoin, quinine, procainamide
Direct infiltration of affected muscle with local anesthetic
High concentration of volatile anesthetic
Paralytics don’t work