Introduction

We analyzed group differences in visual processing speed tests, namely Trail Making Test (TMT) A and B, between amnestic (A) and non-amnestic (nA) subtypes for converters to probable Alzheimer’s Disease dementia (MCI-Ac and MCInAc, respectively), nonconverters (MCI-Anc and MCInAnc) and healthy controls (HC)

Method

In this retrospective stddy, participants were divided into five groups: 12 MCI-Ac, 8 MCI-nAc, 16 MCI-Anc, 15 MCI-nAnc y 13 HC. Pairwise comparisons were used to detect differences between groups in TMT-A, B and in the difference between TMT-B and A (TMT B-A), in ACE III, IFS and across demographic data (age, years of education, depressive symptoms and activities of daily living).

Results

Amnestic converters had a significantly lower score in ACE III than MCI-nAnc and HC (p = 0.01, p = 0.005). No significant differences were observed between amnestic converters and non-amnestic converters in TMT-A. However, both of them differed significantly from amnestic non-converters (p = 0.004 and p = 0.026, respectively), from non-amnestic nonconverters (p = 0.002 and p = 0.02), and from HC (p = 0.0009 and p = 0.008). For TMT-B, no differences were found between converter subtypes, but they non-converters and HC (p = 0.029, p = 0.03, and p = 0.0005, respectively).

Conclusions

TMT-A might be an effective measure to differentiate both amnestic and non-amnestic MCI converters to Alzheimer’s Dementia from those who do not. Additionally, TMT-B may be useful for differentiating mainly between MCIAc and MCI-nc. Future studies should consider a larger sample for each subgroup and compare its effectiveness against non AD pathologies.