Sensory Profile of TIP-TOE Behavior ASD Subjects

Background: In a previous study we have validated the use of the Short Sensory Profile (SSP) scale in Italy confirming the existence of sensory impairments in ASD subjects that is related to ASD severity, particularly expressed as under-responsiveness or seeking stimuli and an increased or decreased response to auditory stimuli.

Since tip toe behavior (TTB) is likely to be related to sensorial disorders, it is interesting to assess how the sensorial pattern is different in ASD subjects with and without TTB, for which we developed a standardized protocol of the assessment.

Objectives: The aim of this study is to explore the sensory pattern of Severe ASD Subjects with or without TTB through a validated cross-cultural Italian adaptation of the SSP.

Methods: We administered the Short Sensory Profile in a sample of 50 Italian ASD children (7 females; 43 males; mean age 13.9 years). We chose capable special education teachers who carefully and thoroughly reported the children’s behaviors. The ASD diagnosis was done using the DSM V criteria and was confirmed using the ADOS 2. The presence of Tip-Toe Behavior (TTB) was assessed using both direct observation as well as a structured checklist completed during the day by the main caregiver living with the subject through a standardized protocol.

Results: The SSP mean total score of the sample was 149.22 (range 119-182) evidencing the presence of sensory function impairment in our study group (the expected value ranges between 155 and 190). We also found a negative correlation values between ADOS CSS score and total SSP score (r= -0.38). The SSP mean total score of the TTB subgroup was 144.06 (median 142) while the SSP mean total score of the NON-TTB subgroup was 151.65 (median 152): both the TTB and NON-TTB subgroups mean total score ranged in the “probable difference” score. The mean total score values of the two subgroups were not significantly different according to the Mann-Whitney test.Comparing the mean score of SSP subscales between TTB and NON-TTB subgroups using a Mann-Whitney test we found a significant lower score of TTB subgroup only in the “Under-responsive/Seeks sensation” section (p=0.027). Instead the “tactile sensitivity” section was in the “probable difference” score for both TTB and NON-TTB without significant subgroups difference . We also evidenced a significant inverse relationship between toe walking severity and “Under-responsive/Seeks sensation” score ( r= -0.31).

Conclusions: We confirm the existence of sensory impairment in ASD subjects related to ASD severity. TTB ASD subjects show a sensory function impairment when compared with normative values and a more severe sensory impairment in the “Under-responsive/Seeks sensation” section when compared with NON-TTB ASD subjects. This finding seems suggest that TTB subjects show this behavior as an high need of sensations instead of a tactile oversensitivity.