spasmodic torticollis

spasmodic torticollis [Gk, spasmodes + L, tortus, twisted, collum, neck] , a condition in which the head is inclined to one side as a result of episodes of spasms of the neck muscles. It is often transient, and examination seldom reveals a physical cause. In some cases, it may be brought on by severe stress.

Spasmodic torticollis: characteristic head posture (Perkin et al, 2011)