Montreal Cognitive Assessment May Hold Promise for Assessing Cognitive Impairment in SCD

A new pilot study is suggesting that a cognitive assessment tool commonly used across chronic diseases can potentially be used to screen for cognitive impairment in patients with sickle cell disease (SCD).

Among their sample cohort of 49 patients, the researchers, writing in the British Journal of Haematology, found that scores on the Montreal Cognitive Assessment (MoCA) correlated with measures of both literacy and health literacy. According to the researchers, their findings are the first to draw a connection between MoCA scores and literacy and health literacy in a US cohort.

“Future studies should also assess the relationship between MoCA scores, other cognitive domains, and advanced activities of daily living in adults with SCD. There are no norms guiding interpretation of MoCA scores among adults with SCD,” urged the researchers, emphasizing the limited sample size of their pilot study.“Future studies should compare MoCA scores to the gold standard of neuropsychological testing and examine the utility of adjusting for educational attainment. In the interim, our work adds to the limited literature describing the performance of adults with SCD on the MoCA, which helps clinicians and researchers interpret results.”

In their study, median MoCA scores were associated with the reading subset of the Wide Range Achievement Test, fourth edition (WRAT-4) literacy testscores (𝛽 = 0.13; 95% CI, 0.06–0.21, P = 0.002) and the Shortened Test of Functional Health Literacy in Adults (S-TOFHLA) health literacy test scores (𝛽 = 0.44; 95% CI, 0.20–0.68, P = .001).

Associations between MoCA scores and scores of the sentence comprehension subset of WRAT-4 neared significance (𝛽 = 0.09; 95% CI, −0.01 to 0.19, P = .07).

Exploring the impact of various clinical characteristics with scores, the researchers found that median MoCA scores were associated with overt stroke (P = .03) but not with baseline hemoglobin (P = .20), acute chest syndrome (P = .21), or clinical ischemia (P = .54).

With a maximum score of 30, the median MoCA score across the patients was 25, falling short of the score many research groups classify as normal (26). With that cutoff score of 26, 65% of patients had an abnormal score on at least 1 test. While patients with higher education tended to have higher MoCA scores, the researchers found that that higher educational attainmentdid not always translate into higher cognitive performance.

“Scores on most cognitive tests, including the MoCA, are correlated with educational attainment, and our data were consistent with these previous findings. Since education improves cognitive performance, any sensitive cognitive test is likely to be associated with educational attainment,” explained the researchers. “However, SCD patients with high educational attainment are still vulnerable to cognitively deleterious disease process. In our sample, 18 participants with post-secondary education, including nine college graduates, had abnormal scores on at least one cognitive test.”

All patients who had at least some college experience and a history of a neurologic event had at least 1 abnormal test, though the difference did not reach statistical significance. There were 2 patients who presented for neuropsychological testing in the years prior to the study due to changes in cognition and another patient who recently screened positive for moderately severe depression.

Reference

Early M, Linton E, Bosch A, et al. The Montreal cognitive assessment as a cognitive screening tool in sickle cell disease: associations with clinically significant cognitive domains. BR J Haematol. Published online April 6, 2022. doi:10.1111/bjh.18188