More bad news for MSers. MS impairs or ability to assess risk. Does this affect MS prognosis? #MSBlog #MSResearch
“Apologies for posting yet again on cognitive function in MS; I am aware that some of you find this topic depressing. However, without keeping our feet on the ground and realising how serious a disease MS how do we take the field forward?”
“This study shows that decision-making processes are impaired in MSers and are linked to MRI markers of gray matter damage. Drawing on my iceberg analogy there clearly more going under the surface that is seen using conventional MRI. What is interesting is that this study shows that MSers who have problems with decision making have difficulty adjusting to levels of risk rather that than showing increased impulsivity. If this correct MSers may on average under estimate the risk that MS poses to them as an individual and play down their own need for more effective treatments. This raises issues in relation to mental competency of MSers in making informed decisions about risk that involves them self. I have always assumed that the reason why people with rheumatoid arthritis (RAers) are in general prepared to take greater personal risks with highly effective therapies, compared to MSers, was down to rheumatologists being more persuasive, and earlier adopters, than MSologists. May be I have gotten this wrong, maybe it is MS that is making MSers risk adverse due to the cognitive impact of the underlying disease?”
“This research paper demonstrates how subtle the cognitive effects of MS can be. It would be interesting to know how these deficits in decision making affect performance in the job market? Are MSers who have deficits in decision making more likely to become employed than those who don’t? Decision making is core to what makes us human and competitive; this is a cognitive task that is vital for optimal occupational and social functioning. How can we simply sit back and accept this fate? Can we prevent the impact MS has on cognition? Can I propose that the preservation of decision-making abilities another reason to promote early effective treatment in MS? To achieve this MSers will have to accept early treatment with highly-effective treatments when they are still well with no overt disability. If you wait until you have disability it may well be too late.”
“This is yet more evidence that MS is a dementing illness.”
Muhlert et al. Impaired decision-making and diffusion orientational complexity in people with multiple sclerosis. J Neurol Neurosurg Psychiatry. 2013 Sep;84(9):e1.
OBJECTIVE: Difficulties with decision-making have been reported in MSers. It is however unclear what aspect of decision making is impaired, for example whether they are more impulsive, and how any impairments relate to grey matter pathology. In this study they assessed grey matter microstructure using a novel measure of the number of diffusion orientations on diffusion MRI “diffusion orientation complexity (DOC)”. They studied DOC in cortical areas known to be associated with decision making and looked at its associations with performance on the Cambridge Gambling Task (CGT).
METHOD: One hundred and five MSers (61 RR, 26 SP, 18 PP; mean age: 45.9 years) and 36 healthy controls (mean age: 39.6 years) were studied. Decision making performance was assessed using the CGT. T1-weighted (T1w) scans (1x1x1mm) and cardiac-gated diffusion scans (2x2x2mm, 61 directions at b=1200s/mm2, 7 at b=0) were acquired on a 3T system. T1w images were registered to diffusion scans and segmented to extract GM. GM regions with a priori evidence of an association with decision-making (caudate, hippocampus, middle frontal gyrus, anterior cingulate, medial prefrontal cortex; all bilateral) were masked using the Oxford-Harvard template and mean DOC was measured in these GM regions.
RESULTS: On the CGT, MSers showed less adjustment of bets to account for the level of risk (t-test, p<0.01) and were significantly slower at making decisions (p=0.01). MSers also showed significantly lower DOC in the caudate (p><0.01), the middle frontal gyrus (p><0.001), the anterior cingulate (p<0.01), and the medial prefrontal cortex (p=0.001), and significantly higher DOC in the hippocampus (p><0.05), relative to controls. In MSers , risk adjustment correlated with hippocampal DOC (r=-.23, p><0.05), the length of deliberation correlated with medial prefrontal DOC (r=-0.22, p><0.05) and the quality of decision-making correlated with DOC in the anterior cingulate (r=0.34, p=0.001).
CONCLUSION: Decision-making deficits in MSers relate to difficulties in adjusting to levels of risk rather than increased impulsivity. Changes in decision-making correlate with DOC in grey matter regions associated with those functions, suggesting a relationship with abnormal grey matter microstructure, such as loss of neurites, which is known to occur in MS.