Crohn’s beyond the digestive tract: could the disease influence cognition?

Written by Mollie Spindler

A computer-based study of cognitive response times, conducted by researchers at Monash and RMIT Universities (both VIC, Australia) and published in the United European Gastroenterology (EUG) Journal, has indicated that sufferers of Crohn’s disease have slower response times than healthy controls. The authors state that these new findings highlight the multisystemic consequences of Crohn’s disease, as well as the importance of a multidisciplinary approach to research into the disorder.
The highly sensitive Subtle Cognitive Impairment Test  undertaken on patients at the Box Hill Hospital Inflammatory Bowel Disease (IBD) Clinic, Australia, revealed that Crohn’s sufferers had response times up to 10% slower than matched healthy individuals. Furthermore, patients demonstrated a slower average response times than individuals whom had blood alcohol content above that of the EU’s legal drink drive limit.

The results coincide with the recurrent complaints by Crohn’s sufferers of concentration difficulties, memory loss and clouding of thought; symptoms often overlooked by clinicians. The lead researcher on the study, Daniel van Langenberg of Monash University, explained: “These results reinforce the notion that Crohn’s has a wide range of multi-systemic consequences with the impact of the disease affecting patients not only within but well beyond the digestive tract.”

C-reactive protein titers from the blood of the study group, amongst other tests of inflammatory marker proteins, revealed a noteworthy correlation between the slower response times of Crohn’s sufferers and a higher level of inflammation in the body. The findings of this computer-based study are thus consistent with other experiments that link the bowel inflammation characteristic of Crohn’s disease to that of increased inflammatory hippocampal activity in the brain, which may be the causative factor of the impaired cognitive function seen in the Crohn’s sufferers.

It is also interesting to note how other IBS symptoms such as disturbed sleep, co-morbid depression and anxiety also correlate with an increased risk of subtle cognitive impairment. The slower response times in this study, therefore, may be attributed to a wide combination of Crohn’s symptoms; thus, further research is necessary to further investigate the impact of the discussed cognitive impairment on the daily lives of Crohn’s sufferers.

UEG inflammatory bowel disease expert, Gigi Veereman concludes: “This research highlights the need for regular interventions with multi-disciplinary IBD teams to address the wide issues that are presented with Crohn’s disease. This will enable a greater understanding of this complex condition and therefore improve the service and care offered to each patient.”

Sources: van Langenberg DR, Yelland GW, Robinson SR, Gibson PR. Cognitive impairment in Crohns disease is associated with systemic inflammation, symptom burden and sleep disturbance. United European Gastroenterology J. doi: 10.1177/2050640616663397 (2016) (Epub ahead of print);