Webster's New World Medical Dictionary

neuroendocrinology
A branch of medicine
concerned with the interactions between the nerv-
ous system and the endocrine system. The nervous
and endocrine systems often act together to regulate
the physiologic processes of the human body.
neurofibromatosis
A genetic disorder of the
nervous system that primarily affects the develop-
ment and growth of neural (nerve) cell tissues,
causes tumors to grow on nerves, and may produce
other abnormalities. Neurofibromatosis consists of
two very different disorders: neurofibromatosis type
1 (NF1) and neurofibromatosis type 2 (NF2).
neurofibromatosis type 1
A genetic disorder
that is characterized by a number of skin character-
istics, including multiple café au lait (coffee with
milk) spots, multiple benign tumors called neurofi-
bromas on the skin, plexiform neurofibromas
(thick and misshapen nerves due to the abnormal
growth of cells and tissues that cover the nerve),
and freckles in the armpit and groin. Abbreviated
NF1. The café au lait spots increase in number and
size with age. The skin neurofibromas appear later,
usually in the second decade of life. Patients with
NF1 have an increased risk of scoliosis, optic
gliomas (benign tumors on the optic nerve),
epilepsy, and learning disabilities. The risk of malig-
nant degeneration of neurofibromas is lower than
5 percent. NF1 is inherited in an autosomal domi-
nant manner and is due to mutation of the NF1 gene
on chromosome 17 that encodes a protein called
neurofibromin. Half of cases are due to new muta-
tions in the NF1 gene. Prenatal testing is available.
Also known as von Recklinghausen disease.
neurofibromatosis type 2
A genetic disorder
that is characterized by the growth of benign tumors
of both acoustic nerves (the nerves to the ears).
These tumors, called acoustic neuromas, cause tin-
nitus (ringing in the ears), hearing loss, and prob-
lems with balance. Abbreviated NF2. Other findings
in NF2 include similar benign tumors of other
nerves, meningiomas, and juvenile cataracts. NF2 is
inherited in an autosomal dominant manner and is
due to mutation in the NF2 gene on chromosome
22. About half of people with NF2 have a 
new gene mutation. Prenatal testing is available.
Also known as bilateral acoustic neurofibromatosis
and central neurofibromatosis.
neurogenic
Giving rise to or arising from the
nerves or the nervous system. For example, neuro-
genic pain is pain that originates in the nerves, as
opposed to muscle pain, bone pain, etc.