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
Low blood counts can have many causes, including vitamin deficiencies, bleeding, and rare bone marrow failure diseases like aplastic anemia, MDS and PNH. If your blood tests are abnormal, your doctor may do other blood tests or take a sample of your bone marrow to find out why.
Causes. A low white blood cell count usually is caused by one of the following: 1  Viral infections that temporarily disrupt bone marrow function. 2  Congenital disorders characterized by diminished bone marrow function. 3  Cancer or other diseases that damage bone marrow.