More movements in neuroimmunology

Abstract

Detection of antibodies to neuronal cell surface antigens has become an essential component of the diagnostic work-up of unexplained forms of encephalitis in association with epilepsy or movement disorders. One, now well-established, development is the finding of antibodies to N -methyl-d-aspartate receptors in a form of encephalopathy that often includes neuropsychiatric features and a variety of hyperkinetic and hypokinetic movements. This disorder was first described mainly in younger women and children, but subsequently also in men and less frequently in older patients of both sexes (reviewed in Dalmau et al ., 2011 and Vincent et al ., 2011), and responds to immunotherapies, although improvement can be slow. Another new entity is the disorder characterized by brief dystonic seizures, which often affect the face and arm (‘faciobrachial dystonic seizures’), associated with antibodies directed towards LGI1, a major component of the voltage-gated potassium channel complex (Irani et al ., 2010, 2011). Patients with faciobrachial dystonic seizures usually, if not always, develop typical limbic encephalitis, but immunotherapies are highly effective in suppressing the seizures and may prevent the progression to cognitive involvement. Finally, although much less common, glycine receptor antibodies are now being detected in patients with syndromes encompassing excessive startle reactions, spasms, rigidity, phobias and autonomic and brainstem dysfunction (reviewed in Vincent et al ., 2011). As a result of the success in detecting each antibody in patients with these complex disorders, there is a growing acceptance that immune-mediated CNS diseases exist and are not uncommon; moreover, several reports suggest that early recognition and immunotherapies reduce hospitalization and improve …