Prospective Study of Video Hand Opening Time as a Quantitative Measurement of Myotonia in Patients With Myotonic Dystrophy Type 1.

Leeuwenberg KE, Sansone VA, Hamel J, Hung M, Dekdebrun JM, Lizio A, Eichinger K, Gagnon C, Roxburgh RH, Subramony SH, Statland JM, Elsheikh BH, Turner C, Matthews EL, Ragole TE, Sampson JB, Schoser B, Takahashi MP, Wicklund MP, Swenson AJ, Laverty CG, Shieh PB, Greene EP, Raymond J, DeSpain E, Thornton CA, Mul K, Johnson NE; Myotonic Dystrophy Clinical Research Network.