Teaching NeuroImages: A child with macrocephaly and psychomotor development delay

Summary

  • 12mo M
  • FHx
    • consanguineous parents
  • c/c
    • development delay
    • macrocephaly
  • Ex
    • MR
      • diffuse cerebral WM Hr
      • Tem subcrortical cysts
  • Dx
    • megalencephalic leukoencephalopathy w/ subcortical cysts (MLC)

Background

Terminology

Original

A 12-month-old boy, born to consanguineous parents, presented with developmental delay and macrocephaly. MRI revealed diffuse cerebral white matter T2 hyperintensity and temporal subcortical cysts (figure), leading to a diagnosis of megalencephalic leukoencephalopathy with subcortical cysts (MLC). Diffuse white matter changes and temporal subcortical cysts are hallmarks of this rare disorder1,2; these features, in addition to the lack of basal ganglia involvement, distinguish MLC from other leukodystrophies.1 MLC is caused by MLC1 or GLIALCAM mutations leading to a defect of brain ion and water homeostasis.2 Clinical features include macrocephaly, mild developmental delay, and easily controlled seizures.1

Figure

Figure

Brain MRI
(A) Parasagittal T1-weighted image shows diffuse cerebral white matter hypointensity with temporal subcortical cyst.
(B) Axial T2-weighted image shows increased characteristic diffuse supratentorial white matter signal intensity.
(C) Coronal fluid-attenuation inverse recovery image shows bilateral symmetrical anterior temporal lobe subcortical cysts.

References

  1. Batla A, Pandey S, Nehru R. Megalencephalic leukoencephalopathy with subcortical cysts: a report of four cases. J Pediatr Neurosci 2011;6:74–77.
  2. Van der Knaap MS, Boor I, Estévez R. Megalencephalic leukoencephalopathy with subcortical cysts: chronic white matter oedema due to a defect in brain ion and water homoeostasis. Lancet Neurol 2012;11:973–985.