Neurological soft signs in comorbid learning and attention deficit hyperactivity disorders.

The present study aimed to examine whether neurological soft signs identified in children with attention deficit hyperactivity disorder (ADHD), learning disorders (LD), comorbid ADHD-LD and children with no known disorders could be grouped and whether these groups of soft signs would differentiate between the clinical groups and the non-clinical group. A total of 148 children (114 boys, 34 girls) participated in the study, with a mean age of 8.84. The exploratory factor analysis for Neurological Examination for Subtle Signs (NESS) items revealed five factors, explaining 81.7% of the variation. Multivariate analysis of variance showed that these factors of NESS were significantly different between the clinical groups and the non-clinical group. The discriminant functional analysis also yielded significant canonical discriminant functions, correctly classifying 85% of the clinical and non-clinical groups of children. Certain factors of NESS such as speed of movement, dysrhythmia and overflow with timed movements, provide important information that may enhance our understanding of the neurobiological bases of ADHD and LD and the clinical implications of neurological soft signs.