AGENESIS OF THE CORPUS CALLOSUM

 

AGENESIS OF THE CORPUS CALLOSUM

 

DEFINITION:

A disorder of neuronal migration characterized by partial to complete agenesis of the corpus callosum.

EPIDEMIOLOGY:

  • incidence: ?
  • age of onset:
    • infancy to childhood
  • risk factors:
    • an in utero insult to the developing brain (see below)
  • associated anomalies:
    • other migration disorders
      • porencephaly
      • macrogyria
      • microgyria
      • gray matter heterotopias

PATHOGENESIS:

1. Background

  • a toxic insult to the commissural plate during embryogenesis interferes with the migration of cells that eventually form the corpus callosum
  • insults include:
  • 1. Genetic and Chromosomal
    • sporadic, autosomal dominant, and X-linked inheritence patterns
    • Trisomies 18 and 8
  • 2. Syndromes
    • Aicardi Syndrome
    • Crouzon Syndrome
    • FG Syndrome
  • 3. Metabolic disorders
    • Zellweger Syndrome
    • Neonatal Adrenoleukodystrophy (NALD)
    • Nonketotic Hyperglycinemia
    • Menkes (Kinky Hair) Disease
    • Pyruvate Dehydrogenase Deficiency
    • Glutaric Aciduria Type II

TYPES:

1. Type I

  • not associated with other disorders
  • usually associated with no or mild neurologic manifestations

2. Type II

  • associated with other migration, genetic, and chromosomal disorders
  • usually associated with severe neurologic manifestations

CLINICAL FEATURES:

1. Neurologic Manifestations

1. Type I

  • absent to mild findings:
    • normal intelligence to mild/moderate mental retardation
    • seizure disorder
    • impaired visual, motor, and/or bimanual coordination
    • mild impairment of crossed tactile localization and skills requiring matching of visual patterns

2. Type II

  • mental retardation
  • seizure disorder
  • hydrocephaly
  • microcephaly
  • hemiparesis
  • diplegia
  • spasticity
  • failure to thrive

INVESTIGATIONS:

1. Imaging Studies

1. CT/MRI

  • absence of corpus callosum
  • widely-spaced frontal horns
  • upward displacement and enlargement of the 3rd ventricle
  • evidence of other migration disorders

MANAGEMENT:

1. Team Approach

  • periodic multidisciplinary follow-up:
    • Paediatrics, Neurology, Ortho, OT, PT

2. Supportive

  • anticonvulsants
  • genetic counselling

 

Pediatric Database - AGENESIS OF THE CORPUS CALLOSUM

Pediatric Organization - Pedbase [at] Gmail.com