Systemic Lupus Erythematosus and Sjögren's Syndrome Complicated by Conversion Disorder: a Case Report

Conversion disorder (CD) is sometimes accompanied by motor and sensory impairments, such as muscle weakness, paralysis, sensory hypersensitivity, and sensory loss. Sjögren's syndrome (SS) complicates 5-10% of cases of systemic lupus erythematosus (SLE). Patients with SS or SLE present with various neurological symptoms and psychiatric manifestations. When neurological symptoms are present, it is important to distinguish whether the symptoms are caused by a neurological or a mental disorder because the former requires early intensive intervention, such as methylprednisolone pulse therapy (MPT), whereas psychotherapy or antidepressant drugs are recommended for mental disorders. We noticed SS- and SLE-like symptoms just after a diagnosis of idiopathic thrombocytopenic purpura in a 14-year-old girl. At approximately the same time, paralysis started in her lower limbs and subsequently spread to her upper limbs. An examination for neurological symptoms revealed no abnormalities. Because of the conversion reaction between her neurological symptoms and her disease state, CD was suspected as the etiology of her physical symptoms. Nevertheless, because of the progressive nature of the neurological symptoms, MPT was initiated with concurrent administration of intravenous immunoglobulin, but it failed to achieve a good outcome. The patient's symptoms eventually improved after she underwent psychotherapy treatment for a few months. Because early diagnosis of the cause of neurological symptoms accompanying SS and SLE is difficult, it may be necessary to combine the two lines of treatment in the early stages. However, when a mental disorder is suspected, psychotherapy should be started early to minimize the use of unnecessary neurological treatment.