DIAGNOSTIC YIELD OF THE NEUROLOGIC ASSESSMENT OF THE DEVELOPMENTALLY DELAYED CHILD

Objective: The aim of this study was to determine the etiologic yield of the neurologic assessment of a consecutive cohort of developmentall y delayed children. Study design: A retrospective chart review was car ried out on all patients referred to a single university-based pediatr ic neurologist for evaluation of global developmental delay from July 1991 to December 1993. Patients referred because of isolated speech or motor delay or autism or those who had been previously evaluated by a nother neurologist were excluded. Results: A total of 77 patients were identified; 47 were male, and 62 were referred by a pediatrician. Neu rologic evaluation did not confirm global delay in 10, and 8 did not c omplete diagnostic evaluation; one child was included in both groups. Of the remaining 60, an etiologic diagnosis was suspected by the refer ring physician at the time of referral in 13. Although parents suspect ed a delay at a mean age of 0.66 (+/-0.69) year, children were examine d by the neurologist at a mean age of 3.58 (+/-2.42) years. Twenty-fiv e were mildly delayed, 23 were moderately delayed, and 12 were severel y delayed. Diagnostic studies (history, physical examination, and sele cted investigations, including screens for metabolic disease, karyotyp e, fragile X testing, electroencephalography, and neuroimaging) yielde d an etiologic diagnosis in 38 (63.3%) of the 60 patients. Etiologic c ategories included cerebral dysgenesis (16.7%), hypoxic-ischemic encep halopathy (10.0%), chromosomal abnormalities (10%), toxins (8.3%), met abolic disorders (5.0%), and neurocutaneous (3.3%), neuromuscular (3.3 %), genetic/dysmorphic (3.3%), and epileptic (3.3%) syndromes. Etiolog ic yield was equivalent across categories and degree of developmental delay. Conclusion: Referral to a pediatric neurologist and application of a selected battery of investigations yield etiologic findings with important implications with respect to management, prognosis, and rec urrence risk estimate in a significant portion of globally delayed chi ldren.