[Clinical spectrum of anti-glycine receptor antibody-associated disease]

Anti-glycine receptor (anti-GlyR) antibodies were first reported in 2008 in a case of progressive encephalomyelitis with myoclonus and rigidity (PERM), which is a variant of stiff-person syndrome (SPS). After that, the antibodies have been studied extensively. At least 40 patients have been reported or presented until May 2013. We reviewed 28 patients (median age 47 years, range 1 to 75 years), whose clinical data are available. Seventeen patients (60%) were male. We classified clinical phenotype into PERM (17), classic SPS (5), variant SPS (5), and others (1: progressive optic atrophy). Nine patients (32%) had ant-GAD antibodies. Accompanied diseases included thyroiditis (5), diabetes mellitus (3), thymoma (3), and Addison's disease (2). Twenty-one patients (75%) treated with immunotherapy or thymectomy improved, but two of six patients without immunotherapy died or developed cardiac arrest. The clinical features suggested that antibody-mediated inhibition of the GlyR on the brainstem nuclei or spinal inhibitory interneurons may cause continuous firing of α motor neurons and paroxysmal excessive response to a variety of afferent impulses, leading to increased stiffness, brainstem signs, trismus, myoclonus, painful spasms or hyperekplexia. Phenotype associated with the anti-GlyR antibodies may be broader than previously thought, but among those PERM is the most common phenotype.