White matter of cerebrum

Explanation:

No neurological manifestations [Ref: Internet reference]

• Agenesis of corpus callosum is a rare birth defect (congenital disorder) in which there is complete or partial absence of corpus callosum.
• Corpus callosum is a band of tissue connecting the two hemispheres of the brain. Fibres of corpus callosum arise from the superficial layers of the cerebral cortex and they project to the homotypic regions of the contralateral cortex by passing through the corpus collosum while crossing the midline.

Clinical features of Agenesis of corpus callosum

• Signs and symptoms of agenesis of corpus callosum vary greatly among individuals.
• Patients usually do not have any neurological manifestations.
• However, some features common in agenesis of corpus callosum are:­- Vision impairment

– Low muscle tone (hypotonia)

Poor motor coordination

– Delay in motor milestones such as sitting and walking.

Low perception of pain

– Delayed toilet training

– Chewing and swallowing difficulties

– Early speech and language delays

Social difficulties

• Other characteristics sometimes associated with callosal disorders are:­- Seizures

– Spasticity

– Early_, feeding difficulties and or gastric reflux-.

– Hearing impairments

– Abnormal head and facial features

– Mental retardation

Investigation

• CT and MRI reveal “Bat wing” deformity of the ventricles.

Treatment

• There are currently no specific medical treatments for callosal disorders.

An important point

• The neurological abnormalities associated with corpus callosum are not caused by absence of corpus callosum per se.

– These conditions are believed to be caused due to associated cerebral anomalies rather than in corpus callosum per sc.

– The most common associated brain anomalies with absent corpus callosum are

– Dandy walker malformation

– lnterhenfispheric cyst with hydrocephalus

– Migrational disorder

– Absence of the inferior vertnis

– The children who had the best prognosis without any significant neurological sequale were those with isolated agenesis of corpus collosum.

– The children with the worst prognosis and neurological sequale were those with agenesis of corpus callosum and migrational disorder with or without Dandy — walker malformation.

– Hence prognosis is determined primarily by the underlying or associated malformation.

Explanation:

The corpus callosum is a large bundle of myelinated and non-myelinated fibers, the great white commissure that crosses the longitudinal cerebral fissure and interconnects the hemispheres. The body of the corpus callosum is arched; its anterior curved portion, the genu, continues antero ventrally as the rostrum. The thick posterior portion terminates in the curved splenium, which lies over the midbrain.

Also Know:
The corpus callosum is the largest of the interhemispheric commissures and is largely responsible for co-ordinating the activities of the two cerebral hemispheres.

Explanation:

Corpus callosum is the largest commissure of the brain. It connects the two cerebral hemispheres. It connects all part of the cerebral cortex of the two sides, except the lower and anterior parts of the temporal lobes which are connected by the anterior commissures.

• It is approximately 10 cm long, with an anterior end approximately 4 cm from the frontal lobes and posterior end approximately 6 cm from the occipital lobe.
• The superior surface of callosal trunk is covered by a thin layer of grey matter, the indusium griseum.
• Connection that link the same, or similar area on each side are termed homotopic connections. The corpus callosum also interconnects heterogeneous cortical areas on the two sides (heterogenous connections).

Fibres of corpus callosum

1. The rostrum connects the orbital surfaces of the two frontal lobes.
2. The forceps minor is made up fibres of genu that connects the two frontal lobes.
3. The forceps major is made up of fibres of the splenium connecting the occipital lobes tapetum.

Functional significance:
The corpus callosum helps in co-ordinating activities of the two hemispheres.
  

Explanation:

A i.e. Unite far area of two sides of brain; B i.e. Connect two frontal lobe ; C i.e. Unite two hemisphere