pseudomyotonic reaction

pseudomyotonic reaction

Myotonoid reaction, pseudomyotonia A myotonia-like reaction characterized by abnormally slow contraction and relaxation in response to mechanical or electrical stimulation of muscles and/or tendons; the PR reaction is typical of hypothyroidism and is attributed to a slowing of the reaccumulation of calcium ions in the endoplasmic reticulum and in the disengagement of thin actin and thick myosin filaments. Cf Myotonia.