A muscle cramp is also known as charley horse. It is a strong, painful contraction of legs or that comes on suddenly and lasts from a few seconds. It often occurs in the legs. The causes of muscle cramps are because of decreased amounts of minerals like calcium and magnesium, especially in the later months of pregnancy and Exposure to cold temperatures. Quinine is very effective in preventing muscle cramps.
We evaluated the prevalence of focal dystonias in the western area of Tottori Prefecture in Japan. The population of the area was 244,935 on October 1, 1992. Because four patients with blepharospasm and three patients with writer's cramp did not visit any hospitals or clinics in 1993 and did not reply to our question letter, we could not confirm their present condition: with or without focal dystonia in 1993. Four patients with facial dystonia including blepharospasm and oromandibular dystonia, seven with spasmodic torticollis, and four with writer's cramp were observed.