The conduction velocity of the ulnar, median and peroneal nerves was studied from birth to adult age in normal infants, children and adolescents. The method allowed measurements of the conduction velocity of the thickest and fastest conducting motor nerve fibres. In newborns the conduction velocity of all 3 nerves was roughly half of that of adults. The value for the ulnar nerve increased rapidly during the first 3 years. After that age it rose only slightly and between adolescence and adult age there was a significant reduction. The value for the median nerve increased
A low white blood cell count usually is caused by: 1  Viral infections that temporarily disrupt the work of bone marrow. 2  Certain disorders present at birth (congenital) that involve diminished bone marrow function. 3  Cancer (or other diseases that damage bone marrow)  Autoimmune disorders that destroy white blood cells or bone marrow cells.
Problems affecting white blood cells. Your white blood cell count can be low for a number of reasonsâwhen something is destroying the cells more quickly than the body can replenish them or when the bone marrow stops making enough white blood cells to keep you healthy. higher-than-normal white blood cell count usually indicates some type of infectionâwhite blood cells are multiplying to destroy an enemy, such as bacteria or a virus. Myelodysplastic syndrome. This condition causes abnormal bone marrow cell production. Cancer of the blood.