This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Limbic encephalitis with LGI1 antibodies is a relatively new disease characterized by progressive memory loss, confusion, sleep disturbances, and problems with behaviors and spatial orientation. Seizures are common and frequently precede other symptoms. About half of people with this diagnosis exhibit a specific type of seizure called faciobrachial dystonic seizures, which resemble brief jerks of the face arm. Hyponatremia (low levels of sodium in the blood) may also be present. The disease occurs when antibodies mistakenly attack LGI1 (leucine-rich glioma inactivated 1), a protein found in the brain that binds together two epilepsy-related proteins called ADAM22 and ADAM23. Some people with limbic encephalitis with LGI1 antibodies (5 to 10%) also have a cancer diagnosis (most commonly thymoma and lung cancer), but most do not.
The disease is diagnosed through testing of blood or spinal fluid for LGI1 antibodies. If treatment is started when seizures are first noticed, limbic encephalitis may be prevented. Treatment is intravenous or oral corticosteroids, intravenous immunoglobulin (IVIG), plasmapheresis (a process where antibodies are removed from the blood), or a combination of these. Long-term outcome is mostly favorable, although some people are left with some degree of residual impairment. Relapse occurs in up to one third of patients.
For more information, visit GARD.