Polyglucosan Inclusion Myopathy as Gastrointestinal Neuromuscular Disease: A Challenge to Diagnosis and Treatment

Background: The polyglucosan inclusion myopathy is a very rare condition that belongs to the gastrointestinal neuromuscular diseases. The accumulation of polyglucosan bodies in the smooth muscles of the gastrointestinal tract can cause intestinal motility disorders up to intestinal failure. The diagnostic and therapeutic pathway of this disease is often tortuous and complex. Case presentation: A 54-year-old caucasian woman presented with a 30-year history of diarrhea, vomiting, malnutrition and intermittent ileus. She had no response to conservative (prucalopride, octreotide, 5-HT agonists) as well as surgical treatment (subtotal colectomy, small bowel resection). Endoscopy revealed a dilated small intestine with duodenal manometry demonstrating gastrointestinal dysmotility. A fecal transplant resulted in temporary improvement only. During laparoscopic placement of a gastric pacemaker full thickness small bowel wall biopsy was performed finally, evidencing the presence of polyglucosan bodies. The gastric pacemaking and the introduction of a Glucagon-like-2 agonist resulted in clinical and nutritional improvement. The latter however, did require discontinuation due to side effects. Conclusion: After thorough routine diagnostic work-up full thickness biopsy with histopathological analysis should be considered in cases of longstanding gastrointestinal neuromuscular disorders of unclear origin. Polyglucosan inclusion myopathy is one of the potential rare etiopathogenesis unmasked by this approach. Treatment of polyglucosan inclusion myopathy is extremely difficult and refractory to common prokinetic therapeutics. Experimental utilization of FMT or off-label use of GLP-2-analogs can be considered but did not deliver long-term benefit in the presented case.