Identifying the real-world challenges of dysplasia surveillance in inflammatory bowel disease: a retrospective cohort study in a tertiary health network.

BACKGROUND: Dysplasia surveillance in inflammatory bowel disease (IBD) is often suboptimal and deviates from guidelines. AIMS: To assess dysplasia surveillance behaviours and adherence to guidelines amongst a large tertiary teaching health network with a specialised IBD unit to identify areas where dysplasia surveillance could be improved. METHODS: A retrospective audit of IBD surveillance colonoscopy practice over an 18-month period was performed using the Provation Endoscopy Database and the hospital's primary sclerosing cholangitis database. RESULTS: The audit identified 115 dysplasia surveillance colonoscopies. A total of 37% of index dysplasia colonoscopies were outside recommended guidelines. A total of 10% had inadequate bowel preparation and only 40% had excellent bowel preparation. A total of 28% of patients underwent dye-based chromoendoscopy and 69% underwent high-definition white-light endoscopy. Dye chromoendoscopy was more likely to be used by IBD specialists than interventional endoscopists (P = 0.008) and other endoscopists (P = 0.004). Only IBD specialists and interventional endoscopists used dye chromoendoscopy. Dysplasia or colorectal cancer was detected in 3.4% of the colonoscopies. Overall, the several dysplasia examinations were lower than expected. CONCLUSIONS: Dysplasia surveillance in the IBD population remains an area of improvement given the current national guidelines. IBD specialists are more likely to perform dye chromoendoscopy than other endoscopists/gastroenterologists. Dysplasia rates in this real-world contemporary setting are less than expected in historical studies and may represent improvements in IBD management principles and medications.

Activity-induced weakness in recessive myotonia congenita with a novel (696+1G>A) mutation.

OBJECTIVE: To investigate the cause of the transient weakness that occurs in recessive myotonia congenita (RMC) following sustained muscle contraction. METHODS: Nerve excitability studies were performed on a 35-year-old male with RMC due to a novel 696+1G>A CLCN1 mutation. The median nerve was stimulated at the wrist and compound muscle action potentials (CMAPs) were recorded from abductor pollicis brevis (APB). Stimulus-response behaviour using two stimulus durations, threshold electrotonus to 100-ms polarizing currents, a current threshold relationship and the recovery of excitability following supramaximal stimulation were recorded at rest. Excitability parameters were also recorded before and after maximal voluntary contraction (MVC) of APB against resistance for 60s. Results were compared to data obtained from 12 normal controls. RESULTS: Baseline axonal excitability parameters were all normal, indicating that axonal function was normal at the point of stimulation. Following one minute of MVC, excitability parameters demonstrated a significant increase in threshold when compared to controls (RMC 54.9%; controls 15.5+/-3.1%). In the RMC patient, this increase in threshold was associated with a 39% reduction in the amplitude of the maximal CMAP, which remained unaffected in controls. CONCLUSIONS: The reduction in maximal CMAP is likely to represent muscle activation failure due to depolarization block, with the increase in threshold possibly reflecting a compensatory attempt by motor axons to overcome prolonged contraction-induced changes in the muscle membrane. SIGNIFICANCE: The prolonged recovery of excitability following sustained muscle contraction is likely to be a contributing factor to symptoms of weakness and fatigue experienced by RMC patients.