Fetal Acetylcholine Receptor Inactivation Syndrome and Maternal Myasthenia Gravis

Antibodies to voltage-gated potassium channels (VGKC-Abs) have been recognized in neuromyotonia, limbic encephalitis (LE), and Morvan syndrome (MoS), 1,2 a rare condition with insomnia, peripheral, and central and autonomic nervous system involvement. Clinical progression in MoS is variable, but potentially fatal. We describe a patient with VGKC-Abs-positive MoS who showed prominent compulsive behaviors, basal ganglia hypermetabolism, increased catecholamine and serotonin secretion, epileptic seizures, and cardiac and endocrine circadian rhythm suppression. A striking response to immunotherapy paralleled a marked reduction in VGKC-Abs over 15 months.