Related Experiment Videos
Developmental manual dyspraxia: a lesson in mind and brain
1Department of Pediatrics, Washington University School of Medicine, St Louis, MO.
Insights
Pediatric soft neurologic signs in children with learning difficulties do not correlate with IQ in dyspraxic individuals. These motor findings are not indicative of brain damage or fixed motor dysfunction.
Area of Science:
- Pediatric Neurology
- Neurodevelopmental Disorders
- Child Psychology
Background:
- Historically,
- soft neurologic signs
- were documented in children with learning difficulties, but their link to neuropsychological deficits was questioned.
- Epidemiologic studies suggested independence of these signs from other cognitive impairments.
Purpose of the Study:
- To investigate the relationship between motor performance, specifically dyspraxia, and intellectual functioning (IQ) in schoolchildren.
- To determine if
- soft neurologic signs
- correlate with cognitive abilities or indicate specific neurological dysfunction.
Main Methods:
- A standardized dyspraxia battery was administered to 164 schoolchildren aged 5-12 years.
- Intellectual functioning was assessed using the Wechsler Intelligence Scale for Children--revised (WISC-R).
- Correlations were analyzed between dyspraxia subscale scores and WISC-R IQ scores (Full-Scale, Verbal, and Performance).
Main Results:
- A positive correlation was observed between overall motor performance in the dyspraxia battery and IQ in the general cohort.
- Specific subscales of dyspraxia (imitation of gestures, object use) correlated with Performance and Full-Scale IQ.
- Verbal IQ showed a positive correlation only with pantomime tasks.
- In the subgroup of 24 dyspraxic subjects, no correlation was found between dyspraxia scores and IQ.
Conclusions:
- The findings support the view that
- motor soft signs
- are not reliable indicators of fixed brain damage or generalized motor dysfunction.
- Dissociation of specific cognitive and motor deficits is common in individuals with dyspraxia.
- The study highlights the heterogeneity of dyspraxia and challenges the simplistic interpretation of soft neurologic signs.
Abstract:
For decades, pediatricians assiduously documented "soft neurologic signs" in children referred for school learning difficulties, although pediatric neurologists, including Charles F. Barlow, pointed out the dissociation between most neuropsychological abnormalities and the motor findings in question. Later, large epidemiologic studies confirmed the independence of soft signs from other neuropsychological defects. We used a standardized dyspraxia battery to study 164 schoolchildren 5 to 12 years old. We found that in the group as a whole there was a positive correlation between motor performance in the dyspraxia battery and IQ on the Wechsler Intelligence Scale for Children--revised (Full-Scale, Verbal, and Performance). In terms of dyspraxia subscales, we found that Performance IQ and Full-Scale IQ correlated with imitation of nonsense gestures and use of actual objects, whereas Verbal IQ correlated positively only with pantomime on command. In contrast, for the group of 24 subjects whose scores on the battery designated them as dyspraxic, there was no correlation between dyspraxia scores and IQ. Together with the existence of specific, dramatically different, types of dyspraxia among the 24 dyspraxic subjects, present findings uphold the earlier neurologic opinion that "motor soft signs" are not evidence for fixed "brain damage" or even for other types of motor dysfunction, and that dissociation of different specific cognitive dysfunctions is the rule within individual patients.