Features of developmental dyspraxia in the general speech-impaired population?

A typical clinical population with speech impairment was investigated to determine the extent of the presence of features of developmental dyspraxia and its interaction between the severity of impairment. Thirty diagnostic features of developmental dyspraxia were identified from the post-1981 literature and two scales of severity were devised. First the severity of these 30 features was measured (feature severity rating, FSR), and secondly severity of speech impairment was based on percentage of consonants correct (PCC). Using these features and severity ratings a retrospective file audit was conducted of 50 paediatric clients aged 2-8 years with impaired articulation or phonology. It was found that many characteristics regarded as diagnostic for developmental dyspraxia occur in the general speech-impaired population. The relationship between the variables was analysed, and support was found for the hypotheses that: (a) there is a relationship between the number of dyspraxic features expressed and the severity of impairment of speech production and (b) developmental dyspraxia is not characterized by severe impairment, but may occur in a range of severities from mild to severe.