$Unique_ID{BRK04039}
$Pretitle{}
$Title{Nelson Syndrome}
$Subject{Nelson Syndrome Pituitary Tumor after Adrenalectomy }
$Volume{}
$Log{}

Copyright (C) 1987, 1989 National Organization for Rare Disorders, Inc.

484:
Nelson Syndrome

** IMPORTANT **
It is possible the main title of the article (Nelson Syndrome) is not
the name you expected.  Please check the SYNONYMS listing on the next page
to find alternate names and disorder subdivisions covered by this article.

Synonyms

     Pituitary Tumor after Adrenalectomy

General Discussion

** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.

Nelson Syndrome is a disorder characterized by abnormal hormone secretion
and enlargement of the pituitary gland (hypophysis).  It occurs in 5 to 10
percent of patients following surgical removal of the adrenal glands for
Cushing Disease (for more information on this disorder, choose "Cushing" as
your search term in the Rare Disease Database).  Symptoms include intense
skin discoloration (hyperpigmentation), headaches, visual field disturbances
and the cessation of menstrual periods in women.

Symptoms

Symptoms of Nelson Syndrome include intense skin pigmentation, headaches,
visual field disturbances and the cessation of menstrual periods in females.
Blood levels of the pituitary hormones adrenocorticotrope hormone (ACTH) and
beta-melanocyte stimulating hormone (beta-MSH) are abnormally high.  The
pituitary gland gets abnormally large in Nelson Syndrome, causing headaches
and visceral symptoms.

Causes

Nelson Syndrome can be caused by surgical removal of the adrenal glands on
both sides of the body.  Removal of the adrenal glands is a treatment for
Cushing Syndrome.  Following removal of these glands 5 to 10% of cases will
develop Nelson Syndrome.  Growth of a pre-existing or a concealed (occult)
tumor of the pituitary gland may also cause this disorder.

Affected Population

Nelson Syndrome affects approximately 5 to 10% of people who have undergone
surgical removal of their adrenal glands.  It affects males and females in
equal numbers.  Cases caused by tumors are very rare.

Therapies:  Standard

Treatment for Nelson Syndrome consists of radiation to limit abnormal growth
of the pituitary gland.  If the pituitary gland increases so much in size
that it encroaches on surrounding brain structures, it may be surgically
removed.

Therapies:  Investigational

Microsurgical removal of Nelson Syndrome's ACTH adenomas through the bone at
the base of the skull (transsphenoidal) is an experimental treatment for
Nelson Syndrome.  More research is needed before this procedure will be
deemed acceptable for general use.

In another study it was found that treatment with the drugs bromocriptine
(a dopamine agonist) and cyproheptadine (a serotonin antagonist) caused a
marked drop in plasma ACTH levels stimulated by corticotropin-releasing
factor (CRF).  However, after a longer period of treatment with
cyproheptadine, plasma ACTH levels rose again.  Thus the usefulness of the
drug appears limited.  More research is necessary to determine the safety and
effectiveness of these drugs for Nelson Syndrome.

This disease entry is based upon medical information available through
June 1989.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Nelson Syndrome, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     (203) 746-6518

     NIH/National Institute of Neurological Disorders & Stroke (NINDS)
     9000 Rockville Pike
     Bethesda, MD  20892
     (301) 496-5751
     (800) 352-9424

References

TRANS-SPHENOIDAL MICROSURGICAL TREATMENT OF NELSON'S SYNDROME:  T.
Fukushima; Neurosurg Rev (1985:  issue 8(3-4)).  Pp. 185-194.

EFFECTS OF BROMOCRIPTINE AND CYPROHEPTADINE ON BASAL AND CORTICOTROPIN-
RELEASING FACTOR (CRF)-INDUCED ACTH RELEASE IN A PATIENT WITH NELSON'S
SYNDROME:  Y. Hirata, et al.; Endocrinol Jpn (October 1984:  issue 31(5)).
Pp. 619-626.