Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 26 3 2004 10 22 Two Cases of Isaac’s Syndrome Associated with Charcot – Marie – Tooth Neuropathy as a Hereditary Disorder 99 103 EN OSHIB NATTAJ A RAHBAR M Journal Article 2013 07 28 A 21-year-old man and a 16-year-old girl (sibling) developed generalized relatively slow , undulating and worm - like movements of the muscles (myokymia), cramps and stiffness since childhood. Myokymia was continued during sleep. Symptoms exacerbated with unoptimal temprature of enviroment (cold , warm), physical activity and sleep awakening at morning. They had excessive sweating and limited physical activity. The male patient developed a diffuse subcutaneous nodules and symmetric muscular hypertrophy (quadriceps and calf) and carpopedal spasm. There was ankle joint contracture, without significant sensory and motor abnormalities, absent ankle reflex and reduced other deep tendon reflexes, high arch feet and normal laboratory tests. Nerve conduction study showed low amplitude and slowing of sensory and motor responses, F waves and H-reflexes with repetitive-after-discharge, especially in lower limbs and normal repetitive stimulation test. Electromyography displayed a significant spontaneous activity including myokymic, neuromyotonic, doublet, triplet discharges with neurogenic motor unite action potentials. Significant improvement was seen with carbmazepine.