Background We have shown that over 50% of transient ischaemic attack (TIA) and stroke patients with MMSE≥27, score below the cut-off for normal cognitive function on the Montreal Cognitive Assessment (MoCA). However, it is uncertain whether these patients have clinically relevant cognitive problems. We therefore aimed to determine the clinical, functional and neuropsychological characteristics of this group.

Methods Consecutive patients with transient ischaemic attack (TIA) or stroke had the MMSE, MoCA, Rankin score, Addenbrooke's cognitive examination-revised (ACE-R) and neuropsychological battery (trail test, Hopkins verbal learning test (HVLT), digit symbol substitution test (DSST), Boston naming test) at least 6 months after the index event. Patients with MMSE≥27 were grouped as MoCA-normal (MoCA≥26), or MoCA-impaired (MoCA<26).

Results The MoCA-impaired group (n=162) were more likely than the MoCA-normal group (n=122) to have had a stroke rather than a transient ischaemic attack (TIA) (97/162 vs 50/122, OR 2.15, p=0.0016) and had higher Rankin scores (p<0.0001). All neuropsychological battery test scores and total ACE-R score were significantly (p<0.01) worse in the MoCA-impaired group than in the MoCA-normal group. Differences were greatest for the DSST (executive function/attention) and the HVLT (memory).

Conclusion In patients with normal MMSE, impairment on the MoCA is associated with stroke vs TIA, with greater dependency, and with worse performance on neuropsychological battery.