Isaac's Syndrome
Information Page |
NINDS is part of the
National Institutes of
Health
Table of Contents (click to jump to sections)
What is Isaac's Syndrome?
Is there any treatment?
What is the prognosis?
What research is being done?
Organizations
What is Isaac's Syndrome?
Isaac's syndrome (also known as neuromyotonia, Isaac-Mertens syndrome, continuous muscle fiber activity syndrome, and quantal
squander syndrome) is a rare neuromuscular disorder caused by continuous signaling of the end regions of peripheral nerve
fibers that activate muscle fibers (motor neurons). Symptoms, which include progressive muscle stiffness, continuous vibrating
or twitching muscles, cramping, increased sweating, and delayed muscle relaxation, occur even during sleep or when patients
are under general anesthesia. Many patients develop weakened reflexes and muscle pain, but numbness is relatively uncommon.
Although symptoms can be limited to cranial muscles, in most patients stiffness is most prominent in limb and trunk muscles.
Speech and breathing may be affected if pharyngeal or laryngeal muscles are involved. Age of onset is between ages 15 and
60, with most patients experiencing symptoms before age 40. There are hereditary and acquired forms of the disorder. The acquired
form may develop in association with peripheral neuropathies or as an autoimmune condition.
Is there any treatment?
What is the prognosis?
What research is being done?
Select this link to view a list of studies currently seeking patients.
National Organization for Rare Disorders (NORD) P.O. Box 1968 (55 Kenosia Avenue) Danbury, CT 06813-1968 orphan@rarediseases.org http://www.rarediseases.org Tel: 203-744-0100 Voice Mail 800-999-NORD (6673) Fax: 203-798-2291 |
Prepared by:
Office of Communications and Public Liaison
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892
NINDS health-related material is provided for information purposes only and does not necessarily represent endorsement by or an official position of the National Institute of Neurological Disorders and Stroke or any other Federal agency. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient's medical history.
All NINDS-prepared information is in the public domain and may be freely copied. Credit to the NINDS or the NIH is appreciated.
Last updated January 14, 2008