Birth Defects Brain Nervous System Corpus Callosum

The corpus callosum is a prominent communicative pathway of nerves in the brain. Corpus callosum nerve fibers provide a connection between the brain’s hemispheres. When the development of the corpus callosum is incomplete, children may experience a variety of cognitive, physical and behavioral problems. Other connections between the hemispheres are present, but they communicate information far less effectively than the corpus callosum.

No cure exists for these conditions; treatment involves therapy to compensate for reduced levels of functioning.

Corpus Callosum Function

The corpus callosum is a bundle of nearly 200 million nerve fibers in the brain. This pathway connects the right and left hemispheres of the brain, and allows information to travel between hemispheres.

The brain’s hemispheres perform different functions. For example, the left hemisphere is the primary area for language, and the right hemisphere specializes in spatial information. However, both hemispheres control motor movement and process sensory information from the body.

The left hemisphere controls and receives information from the right side of the body, and vice versa. When the left hemisphere receives information from the right side of the body, the corpus callosum allows for transfer of information between hemispheres, which is important for ongoing monitoring of coordinated movements and complex cognitive processes, including information processing.

Diagnosis of Callosal Disorders

The corpus callosum develops by the end of the first trimester of pregnancy. Prenatal tests can detect malformations of the corpus callosum any time after this critical point. The corpus callosum is easily visible on MRI images, and the absence or malformation of the structure is usually obvious.

Several congenital defects of the corpus callosum may occur:

  • Complete agenesis: complete lack of corpus callosum development
  • Dysgenesis: malformation of the corpus callosum
  • Hypoplasia: a thinned corpus callosum with fewer nerve fibers
  • Partial agenesis: incomplete development of the corpus callosum; often only the front of the corpus callosum develops.

Symptoms of Agenesis or Dysgenesis of the Corpus Callosum

Disorders of the corpus callosum affect various functions of the brain. Corpus callosum defects can affect:

  • Achievement of developmental milestones
  • Complex problem-solving skills
  • Higher-level language, including humor, and figurative language
  • Insight into social cues, the behavior of others or the consequences of actions
  • Motor coordination
  • Sensory sensitivity; either hypersensitivity or abnormal insensitivity to various sensory cues, such as pain and texture.

Problems may become more apparent as the child approaches adolescence, as cognitive demands increase, and as the child’s peers become comparatively more adept at using cognitive, motor and social skills. While some individuals with corpus callosum disorders may be of average intelligence, others may experience significant difficulties.

Treatment for Congenital Disorders of the Corpus Callosum

If the corpus callosum does not form properly during fetal development, neural fibers neither generate nor degenerate after birth. That is, the condition does not worsen, but no regeneration occurs among the undeveloped nerves. Thus, the course of treatment for children with corpus callosum defects involves speech, occupational and physical therapy to help improve cognitive processing and physical abilities.

Resources

National Association for Disorders of the Corpus Callosum. (n.d.). Corpus callosum disorders. Retrieved April 24, 2010, from: https://www.nodcc.org/index.php?option=com_content