Leg scissoring has historically been considered a hallmark of ‘spasticity’, and characterizing the dominant phenotype of CP. Scissoring is driven by a tonic Labyrinthine response.

Our hypothesis is that scissoring and clonus are mutually exclusive. We aim to demonstrate that TLRs is a hallmark of dystonia and not of spasticity.

160 patients were screened from the query analysis.  A total of 93/160 cases that had both “scissoring” and “clonus” and were distributed as following:  17 (18%) had both scissoring and clonus; 45 (48%) had scissoring alone without clonus; 11 (12%) had clonus alone without scissoring; 20 (22%) had neither scissoring nor clonus. This latter group was eliminated from the analysis because they represent neurological normal phenotype patients. Considering the hypothesis of having either clonus or scissoring, but not both together, we simplified the analysis into two groups: either scissoring 76/93 (82%) versus clonus and scissoring in 17/93 (18%). Statistical analysis revealed that having either scissoring alone or clonus alone is statistically significantly more frequent than having both. We compared the presence of scissoring to the gestational age and and found a statistically significant association (p=0.012) between gestational age lower than 30 weeks and the presence scissoring. We also found a statistically significant correlation between the presence of scissoring acquired dystonia compared to idiopathic and inherited dystonias respectively.

We have demonstrated from a retrospective analysis of a large cohort of children that a scissoring is associated with dystonic signs and not with spasticity signs.