|Home | About | Journals | Submit | Contact Us | Français|
Claire T Lundy, Department of Paediatric Neurology, Paul Ward, Royal Belfast Hospital for Sick Children, 180 Falls Road, Belfast BT12 6BE, UK; firstname.lastname@example.org
Gary M Doherty, Elaine M Hicks, Royal Belfast Hospital for Sick Children, Belfast, UK
Jack is a 2.5 year old boy. He has been referred for developmental assessment by his health visitor. His community paediatrician diagnoses speech and language delay. His mother reports he first sat independently at 9 months and walked at 17 months.
In a male child with speech delay who walks prior to 18 months old [patient], does requesting serum creatine kinase [intervention] help diagnose Duchenne muscular dystrophy with reasonable efficiency [outcome]?
PubMed: “Duchenne muscular dystrophy,” “speech delay”, combined with “screening” and “language”. Sixteen references were found in total.
OMIM database and specific journals: The titles and the abstracts were reviewed. Eleven studies were relevant; seven articles were selected as directly related to the question.
Searches were carried out in August 2006.
See table 33.
The early diagnosis of Duchenne muscular dystrophy (DMD) in the male child with developmental delay is a frequent concern in community paediatric practice. Many criteria have been suggested as “triggers” to screen for the condition. Most focus on delayed motor milestones as this has been clearly shown to be symptomatic of DMD. Other criteria have included speech delay.
These parameters appear to be robust when followed prospectively in a cohort of affected boys in the Newborn Screening Study in Wales. Speech problems in boys with DMD have been extensively researched as the mechanism remains unclear. The Welsh cohort demonstrated that 71% of affected boys failed one or both of the speech and language developmental milestones studied (single words at >13.7 months and meaningful sentences at >29 months). The authors point out that there was no clear link between late walking and delayed language development in this group.1
Speech and language delay (SLD) is common and DMD is relatively uncommon. Assuming an incidence of DMD of 1 in 3000 male births7 and a prevalence of SLD of 61% in DMD8 versus 6% in the general preschool population9 10 allows construction of a two‐way contingency table.11 The positive predictive value of SLD as a screening tool for DMD is unsurprisingly low (0.34%) and the negative predictive value unsurprisingly high (99.99%) largely because of the low prevalence of DMD. Approximately 300 children with SLD would have to be tested to identify one child with DMD.
It is important to note that a number of boys with DMD will have normal speech development and up to 70% walk at 18 months. At presentation boys may report more non‐specific symptoms such as cramps, leg pains or clumsy gait; it is worth specific, detailed questioning of parents of boys with speech delay to elucidate these subtle symptoms.