Delorme C, Gras D, Roze E. Spasmus nutans: more than meets the eye. Pediatr
Neurol. 2015 Oct;53(4):367-8.
“Spasmus nutans is a rare transient movement disorder of early childhood, defined by the clinical triad (1) nystagmus, (2) head nodding, and (3) torticollis, in the absence of any associated ophthalmological or neurological condition.  This condition might be difficult to recognize and is rarely reported in the literature.”