nodding spasm nod·ding spasm (nŏd'ĭng)
n.
A falling of the head onto the chest that is most commonly seen in infants and is caused by the loss of tone in the neck muscles, as in epilepsy, or by tonic spasm of anterior neck muscles.
A nodding of the head caused by a clonic spasm of the sternocleidomastoid muscle. Also called salaam convulsion.