Neuropediatrics 2008; 39 - P068
DOI: 10.1055/s-0029-1215837

Diagnostic value of magnetic resonance imaging and morphometry of the corpus callosum in children with isolated mental retardation

I Sanchez-Albisua 1, A Merten 1, H Mayrhofer 1, W Grodd 2, I Krägeloh-Mann 1
  • 1Universiätsklinikum Tübingen, Klinik für Kinder- und Jugendmedizin, Neuropädiatrie, Tübingen, Germany
  • 2Universitätsklinikum, Neuroradiologie, Tübingen, Germany

There are few data on the diagnostic value of the magnetic resonance imaging (MRI) in children with unclear isolated mental retardation (IMR). We performed a retrospective study with two questions:

  • How often are pathogenetic/aetiologic factors found? and

  • Is there a correlation between the size of the corpus callosum (CP) and the cognitive development of a child?

Methods: We evaluated MRIs of 64 children with IMR and of 18 normal controls. Inclusion criteria for the IMR children were: Age>3 years, independent walking at <3 years, normal neurological examination, no progression of the illness, no epilepsy, no perinatal risk factors, no dysmorphic syndromes. The MRI findings were classified as "normal", „questionably pathological“ and „surely pathological". Also, we measured some features of the CP (absolute length, total area, perimeter, surfaces and perimeters of its segments). We collected data on anamnesis, findings of the physical examination and diagnoses.

Results: MRI results were considered as „normal“ in 54.7% of the patients and 61.1% of the controls. MRIs were considered „questionably pathological“ in a similar rate of patients (37.5%) and controls (38.9%). „Surely pathological“ findings were found in 5 patients (7.8%), but 2 (3.1%) did not explain sufficiently the mental retardation; 3 „certainly pathological findings“ (4.7%) did explain the mental retardation. Pathological findings were proportionately found in more microcephalic than in normocephalic patients; but the difference was not statistically significant (maybe due to the small sample size). With regard to the characteristic features of the CP we found, with the exception of the length of CP, no statistically significant differences between the case and the control groups.

Conclusion: An MRI is indicated in the diagnosis of children with unclear IMR. Nevertheless, the probability to find specific pathological and explanatory findings is low (8%). There is no correlation between the size of the CP and the cognitive development of a child.