An unusual case of tight ...

26/M, graduate, married with 01 male healthy child, presented with complaints of- • Difficulty in releasing hand grip (Difficulty in releasing knives, door knobs, pens)  Tightness of jaw muscles and tongue while eating (Jaw would get stuck while chewing. Tongue would get stuck to floor of mouth on putting morsel of food. It would improve with continued eating)  Fatigue Since 03 years. On evaluation, he had scalloped concave temporalis, handgrip myotonia, percussion myotonia over bilateral abductor pollicis brevis and tongue, Eyelid myotonia. He had normal tone, bulk, power, reflexes, sensory and cerebellar function. Lab investigation showed impaired glucose tolerance (FBS- 108 mg/dl), Raised CK Nac – 206 IU/L, EMG – fibrillation and positive sharp waves seen. Myotonic discharges + (dive bomber sound) Genetic testing- 77 CTG repeats at DMPK gene locus A diagnosis of Myotonic Dystrophy Type 1 was made. Started on Mexiletine 150 mg BD. Response awaited.