Older individuals with phenylketonuria often have some degree of nerve demyelination (destruction of the myelin sheath that surrounds nerve fibres) that causes progressive symptoms of cognitive dysfunction, including mental retardation, epileptic seizures, and abnormal brain activity.
Inflammation associated with nerve cell destruction often alters the color and appearance of the gray matter in the spinal column, causing it to appear reddish and swollen.
Time course studies on lesion development in NMO patients revealed that astrocytes are destroyed first, but that this is followed by profound demyelination and oligodendrocyte, axons and nerve cells destruction [ 127, 128, 158].
However, in more slowly developing lesions, acute nerve cell destruction is rare or absent, similar to what has been described in the cortex of Alzheimer's disease patients (Stadelmann et al., 1998).
But Dr. Ross also suggested that caffeine might somehow protect against the nerve-cell destruction that causes Parkinson's.
Eventually, however, most malignant tumours cause pain by the direct invasion of nerves or the destruction of bone.
The capability of MRI in depicting such phenomena is unsurpassed: a combination of signs (enlargement and abnormal enhancement of named nerves, remodelling and destruction of foramina and fissures, denervation atrophy of muscles) allows sensitivity and specificity as high as 100%and85%5%, respectively (Fig. 11).
With the destruction of nerve cells, the muscles no longer receive signals from the brain or spinal cord; without nerve stimulation, the muscles atrophy, becoming weak, floppy and poorly controlled, and finally completely paralyzed.
