Progressive encephalomyelitis with rigidity and myoclonus initially diagnosed as an anxiety disorder associated with anti-glycine receptor antibodies: A case report

Progressive encephalomyelitis with rigidity and myoclonus is a rare neurological disorder predominantly associated with anti-glycine receptor antibodies. It is characterized by rigidity, painful muscle spasms, sensory disturbances, brainstem and spinal cord involvement, autonomic dysfunction, respiratory distress, and sudden, spontaneous, or stimulus-induced myoclonus. A Chinese woman in her early 50s was admitted with acute-onset dysphagia, dysarthria, and stiffness in both lower limbs. Her initial symptoms included anxiety, recurrent myoclonic episodes, swallowing difficulties, and lower limb rigidity. The condition was initially diagnosed as an anxiety disorder, but the diagnosis was reconsidered after the patient's symptoms progressed despite adequate treatment for almost a year. Diagnostic workup on admission revealed anti-glycine receptor antibodies in the serum, which, along with the clinical presentation, confirmed the diagnosis of progressive encephalomyelitis with rigidity and myoclonus. The patient demonstrated improvement and clinical stabilization after treatment with intravenous immunoglobulin and immunotherapy. This case represents a rare instance of anti-glycine receptor antibody-positive progressive encephalomyelitis with rigidity and myoclonus that initially manifested as an anxiety disorder, later progressing to seizures, myoclonus, brainstem and spinal cord involvement, and autonomic dysfunction. We aim to raise awareness of the psychiatric clinical presentations of progressive encephalomyelitis with rigidity and myoclonus.