In neuroanatomy, the corona radiata is a white matter sheet that continues ventrally as the internal capsule and dorsally as the centrum semiovale. This sheet of axons contains both descending and ascending axons that carry nearly all of the neural traffic from and to the cerebral cortex. The corona radiata is associated with the corticospinal tract, the corticopontine tract, and the corticobulbar tract.
Structure
Projection fibers are afferents carrying information to the cerebral cortex, and efferents carrying information away from it. The most prominent projection fibers are the corona radiata, which radiate out from the cortex and then come together in the brain stem. The projection fibers that make up the corona radiata also radiate out of the brain stem via the internal capsule. Cerebral white matter is commonly regarded today as an intricately organized system of fasciculi that facilitate the highest expression of cerebral activity.
Function
Motor Pathway
Evidence from subcortical small infarcts suggests that motor fibers are somatotopically arranged in the human corona radiata. Following subtotal brain damage, localization of the corticofugal projection in the corona radiata and internal capsule can assist in evaluating a patient's residual motor capacity and predicting their potential for functional restitution. Data suggests that the corona radiata and superior capsular lesions may correlate with more favorable levels of functional recovery. Lesions seated inferiorly are likely to correlate with poorer levels of recovery regarding upper limb movement. Findings also suggest that motor deficit severity is likely to increase as a lesion occupies progressively more posterior regions of the internal capsule.
Speculative Analysis
It appears that the white matter sheet of the corona radiata is one of the first cells to formulate in embryos, making this region more capable of functional motor recovery following damage. An intact corona radiata has been correlated with higher rates of fertility and increased math scores as well. The internal capsule is more closely associated with the brainstem and the central nervous system indicating that you would see less functional recovery from damage in that region when compared to the corona radiata, a region further from the brain stem more closely associated with complex cerebral activity deeper in the brain and more capable of restitution or cerebral reorganization.
Clinical significance
The corona radiata may be affected by diseases affecting the cerebral white matter, including ischemic leukoencephalopathy, multiple sclerosis, and progressive leukoencephalopathy. These may have major effects on intellectual, social, and emotional functioning.
In normal pressure hydrocephalus, expansion of the lateral ventricles causes distortion of the fibers of the corona radiata. This contributes to the urinary incontinence seen with NPH.