Morvan's syndrome

Morvan's syndrome (or fibrillary chorea) is a rare disease characterised by neuromyotonia (involuntary fibrillary contraction of muscles at rest), autonomic nervous system dysfunction, central nervous system dysfunction and endocrine system problems. Major central nervous system problems are sleep disorder, confusion, amnesia, hallucinations and delusions.

The syndrome is named after 19th century French physician Augustin Marie Morvan (1819–1897).

Some cases with this syndrome have been suggested to have an autoimmune origin, depending on associated autoimmune diseases as myasthenia gravis, coexisting thymus tumors, serum antibodies to potassium channels and resolution of symptoms by immunomodulating treatment methods (e.g. plasmapheresis, thymectomy or immunosuppression).