Yamaguchi fox–pigeon imitation test (YFPIT) for dementia in clinical practice

Abstract

Background: In out-patient clinics, having simple procedures to check for signs of dementia is invaluable. In the present study, we evaluated the imitation of hand gestures to detect visuomotor deficits in dementia in clinical practice. Methods: In all, 1219 subjects were enrolled in the present study, including 497 with Alzheimer's disease (AD), 98 with dementia with Lewy bodies (DLB), 71 with other types of dementia diseases, 175 with a Clinical Dementia Rating (CDR) of 0.5, and 378 normal controls. All subjects were aged 65 years or older. Subjects were recruited from 10 clinics and two communities. Visuomotor function was evaluated by the Yamaguchi fox-pigeon imitation test (YFPIT), which consists of a simple one-handed sign for 'fox' and a complex two-handed sign for 'pigeon', a rapid, game-like test with low psychological burden. Results: The success rate (successful/total) for imitating the 'pigeon' hand gesture was reduced as the severity of the dementia increased: 85.7% in normal controls, 60.6% in CDR 0.5 (mild cognitive impairment), 39.2% in CDR 1 (mild dementia), 21.2% in CDR 2 (moderate dementia), and 5.7% in CDR 3 (severe dementia). The success rate for imitating the 'pigeon' hand gesture was higher in patients with DLB than AD within the CDR 1 group (51.2% vs 35.4%, respectively), but lower for patients with DLB than AD within the CDR 2 group (12.5% vs 24.4%, respectively). The success of imitating the hand gesture for 'fox' was similar for patients with AD and DLB. Of those subjects who failed to imitate the hand gesture for 'pigeon', 49.5% of those with AD showed the palm-palm pattern (both palms facing outward), suggesting deficits of perspective conversion from the first-person to the third-person. Conversely, 52.8% of patients with DLB showed a dorsum-dorsum pattern (both dorsa facing outwards), suggesting deterioration of visual attention and recognition. Conclusion: In conclusion, the YFPIT is a useful test to detect visuomotor deficits in dementia that can differentiate between AD and DLB.

The Yamaguchi fox/pigeon-imitation test, a brief cognitive performance rating tool, in a community-dwelling population: normative data for Japanese subjects – a preliminary study

“…There was a sex difference in the correct-answer rate in this study, in contrast with the results of a previous study 13. This sex difference may have been influenced by the type of dementia causing the CI.…”

“…There was a difference in the correct-answer rate for the pigeon gesture between a previous report13 (85.7%) and the present study (75.3%). We cannot clearly explain the reason for this difference, but it may have resulted from the difference in the areas assessed, ie, a farm/village area versus a mid-sized city.…”

“…Based on these principles, the Yamaguchi fox/pigeon-imitation test (YFPIT) was developed in Japan 13. This test is composed of a simple one-hand sign for “fox” and a two-hand sign for “pigeon”, providing a simple, enjoyable test for AD and dementia of Lewy bodies with a low psychological stress.…”

“…This test is composed of a simple one-hand sign for “fox” and a two-hand sign for “pigeon”, providing a simple, enjoyable test for AD and dementia of Lewy bodies with a low psychological stress. One study reported associations between the percentage of correct answers on the YFPIT and the Clinical Dementia Rating scale score 13. Although the detection of prodromal and preclinical states is important, there is little information on the utility of the YFPIT in preclinical populations.…”

Impaired imitation of gestures in mild dementia: comparison of dementia with Lewy bodies, Alzheimer's disease and vascular dementia

“…Unlike previous studies,6 7 13 19 finger gestures were presented in an anatomically congruent manner (ie, not as if looking into a mirror) in the present study. Anatomical congruency of the limb between the model and the performer (congruent vs incongruent) can affect the task complexity.…”