Ideomotor limb apraxia as a staging tool in individuals with Alzheimer's disease (ILIAD)

Ideomotor apraxia (IMA) is known to affect individuals with Alzheimer's disease (AD). Combined with impaired cognitive function, IMA can support evidence of probable AD. However, apraxia is a condition that is difficult to diagnose. The Postural Knowledge Test (PKT), developed by Mozaz et al, was designed to easily identify limb apraxia in multiple sclerosis yet demonstrated potential utility for AD. ILIAD is a pilot study to investigate correlation between the PKT and Mini-Mental State Examination (MMSE).

Participants with mild, moderate, and severe AD were administered the MMSE by 1 examiner, followed by the PKT by a second blinded examiner.

Seventy-seven participants with mild (25), moderate (26), and severe AD (26) met study criteria. Correlation was demonstrated between the MMSE and PKT at 0.835 among all AD groups. Correlation between MMSE and PKT-1 (transitive) and PKT-2 (intransitive) separately was 0.819 and 0.793.

There is significant correlation between the MMSE (memory loss) and PKT (IMA). This suggests the PKT may be used in conjunction with the MMSE to aid in staging AD and to monitor disease severity. Correlation between the MMSE and separate PKT tests suggests that administration of only 1 test may be necessary clinically, saving valuable time.