2784 Steroid Responsive Gastric Dysmotility - Seronegative Autoimmune Autonomic Neuropathy

Abstract

INTRODUCTION: Gastrointestinal motility disorders are complex conditions manifesting with a wide array of symptoms. In recent years, the increasing discovery of autoantibodies targeting the nervous system has led to the recognition of new neurologic autoimmune disorders (NAD) which present with the subacute development of profound neurological impairment and gastrointestinal motility disorders which when promptly treated with immunotherapy, may show dramatic improvement. CASE DESCRIPTION/METHODS: A 32 year old woman with a history of undifferentiated connective tissue disease presented to establish care for known gastroparesis Her symptoms started following an upper respiratory infection the age of 15 years, which was followed by development of arthralgia, rash, raynaud's, tonic pupils, and distal sensory symptoms. She also developed orthostatic intolerance and was diagnosed with severe gastroparesis with over 40 lb weight loss. Her medications included Plaquenil and methotrexate, as well as Zofran. She underwent extensive testing with autonomic function testing showing moderate sympathetic adrenergic dysfunction and distal sudomotor impairment which indicated a limited autonomic neuropathy and skin biopsy showed small fiber neuropathy. Paraneoplastic antibody testing, GAD antibody and ganglionic Acetylcholine receptor (gAChR ab) was negative. A trial of IVIg was started for suspected autoimmune GI dysmotility but this was complicated with pancytopenia. On exam she was malnourished with a BMI of 15, normal reflexes, and decreased distal sensations. She underwent repeat autonomic function testing which was normal. A 4 hour solid gastric emptying was performed which showed delayed emptying at 4 hr of 80%. She was underwent a 5 day infusion of IV Solumedrol at 1000 mg daily for suspected autoimmune dysmotility. A daily GCSI-DD ( gastroparesis cardinal symptom index- daily diary) score showed a >50% improvement in scores on Day 0 to Day 5 and normalization of 4 hour solid GES and was then started on IV Rituximab. DISCUSSION: This case highlights that importance of considering a diagnosis of neurologic autoimmune disorders which can present with as solitary GI dysmotility. Seronegative autoimmune autonomic neuropathy is a clinical entity which shows prominent sympathetic failure, sensory symptoms and is steroid responsive.