Pseudomyotonia

Pseudomyotonia

The term pseudomyotonia has been used to describe the clinical appearance of myotonia (slow muscular relaxation after contraction) in the absence of myotonic discharges on electromyography. Pseudomyotonia is most commonly observed as the slow-relaxing or "hung-up" tendon reflexes (Woltman’s sign) of hypothyroidism, although other causes are described.
Pseudomyotonia has also been used to describe difficulty opening the hand in cervical osteoarthritis, although muscle relaxation is normal; finger flexion on attempted extension has been explained as aberrant regeneration of the C7 root.

The term pseudomyotonia has also been used to describe neuromyotonia and myokymia (as, for example, in Isaacs syndrome), to distinguish it from myotonia.

References

Satoyoshi E, Doi Y, Kinoshita M. Pseudomyotonia in cervical root lesions with myelopathy. A sign of the misdirection of regenerating nerve. Archives of Neurology 1972; 27: 307-313

Cross References

Myotonia; Neuromyotonia; Woltman’s sign