RESUMO
Case Report: Acute motor and sensory axonal neuropathy (AMSAN) syndrome is a rare subtype of Guillain-Barre syndrome (GBS) with poor recovery [1]. While respiratory and gastrointestinal infections may precipitate AMSAN, an underlying autoimmune disorder is seldom reported in literature. We herein report the complex case of a patient with undiagnosed, asymptomatic mixed connective tissue disease (MCTD) who developed AMSAN syndrome. Case: A 44-year-old Asian male without medical history presented with progressively worsening weakness of both upper and lower extremities and inability to perform daily activities. His symptoms started 12 weeks prior with difficulty standing from a seated position. He felt subjectively better for some time until a week prior, when he became bedbound. He had diarrhea 6 months ago, with 5-6 loose bowel movements a day for a few weeks. Vital signs on admission was normal. On neurological examination, he was alert and oriented, with bilateral upper and lower extremity flaccid paralysis, diffuse muscle atrophy, bilateral hand and foot drop, negative Hoover sign, diffuse areflexia, and intact sensation. Cerebrospinal fluid (CSF) analysis showed WBC 0 and protein level 136. MRI cervical, thoracic, and lumbar spine were normal. EMG revealed sensory involvement with positive sharp waves in proximal muscles along with fibrillations. Intravenous immunoglobulin (IVIG) was initiated at 0.4 mg/kg for 5 days. Infectious workup for COVID-19, stool culture, HIV, TB, RPR and campylobacter jejuni antibody (Ab), was negative. ANA was positive in a speckled pattern with titres 1:1280, with a positive RNP Ab, SS-A, and RF IgM, IgG and IgA. Rest of the autoimmune workup (anti-dsDNA, anti-CCP, SS-B, aldolase, anti-Jo-1, anti-Scl-70, p-ANCA, c-ANCA, anti-GM1, anti-GQ1b, and anti-GD1a ganglioside Ab) was negative. The myositis specific 11 Ab panel was negative. Despite IVIG therapy, he developed dysphagia, respiratory distress, with a negative inspiratory force of -0, requiring intubation. He had a tracheostomy and PEG tube placed and remains quadraplegic nearly 120 days later. Discussion(s): The authors report a unique case of a patient who became progressively weak over 3 months, leading to complete quadriplegia. Interestingly, this is more consistent with chronic inflammatory demyelinating poly-neuropathy (CIDP), as AMSAN typically develops over a short period of 2 to 4 weeks [2]. Despite having negative anti-GM1 and anti-GD1a Ab (in which positive Ab are pathognomonic but not always present in AMSAN syndrome), the patient had weakness that began in the lower extremities, progressing to paralysis, along with albuminocytological dissociation on CSF analysis, pointing to a GBS diagnosis [3]. He had sensory involvement in the EMG, thus making the diagnosis as AMSAN. He had an undiagnosed, asymptomatic autoimmune process most consistent with MCTD. Whether the two disease processes are related to each other is a concept that has not yet been investigated. Pediatric Clinical Case Reports Concurrent Session Saturday February 4, 2023 1:00 PM Copyright © 2023 Southern Society for Clinical Investigation.