A Case of Adynamia Episodica Hereditaria

Four members of a family suffering from frequent attacks of flaccid paralysis with asymptomatic myotonia were evaluated. There was an autosomal dominant pattern of inheritance and their earliest symptoms were noticed between 1-3 years of age. The plasma potassium level rised during the attack and an EMG demonstrated myotonic discharge. Treatment with acetazolamide was beneficial. These findings were consistent with adynamia episodica hereditaria. The clinical features and pathogenesis were also described.