Motor and visuospatial processing profile in a cross-conditions study: A comparison between developmental coordination disorder and nonverbal learning disability.

BACKGROUND

Neurodevelopmental conditions often exhibit overlapping symptoms, posing challenges for differential diagnosis. Developmental Coordination Disorder (DCD) manifests as fundamental motor impairments, often along with co-occurring visuospatial difficulties. Nonverbal Learning Disorder (NLD) features visuospatial core challenges, with a less consistent characterization of its motor profile. Strikingly, to date no study has directly compared DCD and NLD profiles.

AIMS

The present study aimed to analyze whether DCD and NLD share any characteristics by contrasting their motor and visuospatial performances, comparing them with non-diagnosed (ND) peers.

METHODS AND PROCEDURES

A total of 102 participants (8-16 years; DCD N = 29, NLD N = 29, ND N = 44) completed motor and visuospatial tasks. The groups' performance was compared, and the discriminatory power of the measures administered was analyzed.

OUTCOMES AND RESULTS

Our findings support the substantial motor and visuospatial impairments in DCD and NLD, respectively. Regarding diagnostic efficacy, motor and visuospatial tasks effectively differentiated DCD or NLD from ND, with specificities related to each condition. Balance, and to a lesser extent, Spatial Processing revealed significant predictive power in distinguishing between DCD and NLD.

CONCLUSIONS AND IMPLICATIONS

Our results revealed cross-disorder similarities and highlighted specific hallmarks, corroborating the need of a comprehensive motor and visuospatial assessment for distinguishing between DCD and NLD.