brain, spinal cord, and nerve disorders
Hereditary Neuropathy With Liability to Pressure Palsies (HNPP)
Introduction
Hereditary neuropathy with liability to pressure palsies is a hereditary disorder in which nerves become increasingly sensitive to pressure, injury, and use. In this disorder, nerves are easily damaged by slight pressure or injury or by repetitive use. Numbness, tingling, and weakness occur in the affected area. Electromyography and genetic testing help establish the diagnosis. People should avoid or modify activities that cause symptoms, and wrist splints and elbow pads may help by reducing pressure on the affected nerves. (See also Overview of the Peripheral Nervous System .) In this Hereditary Neuropathies , Usually, this neuropathy starts during adolescence or young adulthood, but it may start at any age. It affects both sexes equally. Hereditary neuropathy with liability to pressure palsies is usually inherited as an Dominant disorders . That is, only one gene from one parent is required for the disease to develop. In this neuropathy, nerves lose their myelin sheath (called Overview of Demyelinating Disorders ) and do not send nerve impulses normally. (The myelin sheath functions somewhat like insulation around electrical wires, enabling nerve impulses to travel quickly.) 