The Myotonic Plot Thickens: Electrical Myotonia in Antimuscle-Specific Kinase Myasthenia Gravis

Table 1

Differential diagnosis of electrical myotonia
Myotonic dystrophies (1 and 2)	Severe subacute denervation
Myotonia congenita	Welander myopathy
Schwartz-Jampel syndrome	Myotubular myopathy
Paramyotonia congenita	Centronuclear myopathy
Hyperkalemic periodic paralysis	Hereditary vacuolar myopathy
Pompe disease/acid maltase def.	Branching enzyme deficiency
Polymyositis	Debranching enzyme deficiency
Cholesterol lowering agent myopathy	Chronic progressive external ophthalmoplegia
Colchicine myopathy	Monocarboxylic acid myotonia
Hypothyroidism	20,25-Diazacholesterol myotonia