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
Underlying causes for a low white blood cell count can range from benign disorders, such as vitamin deficiencies, to more serious blood diseases, such as leukemia or lymphoma. A truly low white blood cell count also puts you at higher risk for infections â typically bacterial infections.
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) 4  Autoimmune disorders that destroy white blood cells or bone marrow cells.