Challenge Question<

The demonstrated sign can be seen in:

1. Paramyotonia congenita (PMC)

2. Myotonia congenita (MC)

3. Hypokalemic periodic paralysis (HypoKPP)

4. Polymyositis

5. Oculopharyngeal muscular dystrophy

Find the answer and diagnosis in the next edition of Practical Neurology® magazine or online, posted along with the patient video at

Case selected from Dr. Shaibani’s Video Atlas of Neuromuscular Diseases, available from Oxford University Press.

Aziz Shaibani, MD, FACP, FAAN, FANA is Director of Nerve & Muscle Center of Texas. He is also Clinical Professor of Medicine at Baylor College of Medicine in Houston, Texas. He is also an Adjunct Professor of Neurology at Kansas University Medical Center in Kansas City, Kansas.