Derrick Boampong

Navigational cue effects in Alzheimer's disease and posterior cortical atrophy

Deficits in spatial navigation are characteristic and disabling features of typical Alzheimers disease (tAD) and posterior cortical atrophy (PCA). Visual cues have been proposed to mitigate such deficits; however, there is currently little empirical evidence for their use.

DIRECTIONAL LIGHTING-BASED INTERVENTIONS TO SUPPORT REAL-WORLD NAVIGATION FOR INDIVIDUALS WITH DEMENTIA-RELATED VISUAL IMPAIRMENT

extended this work to estimate step length, step time walking speed and stride length since early indications of functional loss include change in gait characteristics. Methods: Up to 128 sensors produce a voltage due to a person walking on the carpet. We obtained the walking data from both the smart carpet and the GAITRite [3] mat simultaneously by overlaying the smart carpet over the GAITRite mat. Subjects walked across the carpet and mat for 9 trials each. The data acquisition system of the smart carpet recorded the location of the active sensors, and used to extract the gait parameters. Volunteers performed 9 walks. Data frames read from the data acquisition system provided step counts, walking distance and time. Results: We achieved excellent agreement for walking speed, stride length and stride time between the two systems. The mean percentage error difference for walking speed is 1.43% (SD, 4.4%), stride length is -4.32% and stride time is -5.73%. We compared our work to the work done using a Kinect and web cameras system with excellent agreement. Conclusions: As we showed previously we can detect falls with high accuracy and display this data in real-time. We can now estimate important gait parameter that can lead to an assessment of fall risk. References [1] Alzheimer’s Disease Facts and Figures, 2015. [2] Neelgund R.,“Floor sensor development using signal scavenging for personnel detection system”, University of Missouri, Columbia 2010. Masters thesis for MS Degree. [3] K. E. Webster, J. E. Wittwer, Julian F. Feller, “Validity of GAITRite Walkway System for the Measurement of Averaged and Individual Step Parameters of Gait”, Gait and Posture 22, pp 317-321, 2005.

PRINCIPAL COMPONENT ANALYSIS OF DIFFERENCES IN EYE MOVEMENTS AND LOCOMOTION BETWEEN POSTERIOR CORTICAL ATROPHY AND TYPICAL ALZHEIMER’S DISEASE PATIENTS

and the Euclidian distance from the origin (0, 0, 0) to the score coordinates (ADL, Cognitive function, BPSD) were calculated for evaluations. The Euclidian distances are highly correlated with the scores of MMSE, NPI-D, DAD, CDR sum of box (CDR SOB) and Global CDR of which the correlation coefficients are 0.736, -0.600, 0.717, -0.830 and -0.826, respectively. The specificities and sensitivities to discriminate the severities of AD may be reasonable enough to use practically. For example, the sensitivity and the specificity of probable MCI versus other severities were 0.928 and 0,684, respectively. If the baseline severity was CDR0/0.5, CDR1 or CDR2, the changes of the three dimensional distance between the baseline and 12 weeks were statistically significant. Conclusions: The novel dementia assessment scale can be measured in 10 minutes on average by raters without a special training and qualifications. It can diagnose the severity of AD with high sensitivity and the specificity and detect the changes of the scores by 12 weeks. This scale may be relevant for clinical practice. This research was funded by Daiichi Sankyo Co., Ltd. (Tokyo, Japan). ClinicalTrials.gov Identifier: NCT02667665.

VISUAL SEARCH ABILITIES OF POSTERIOR CORTICAL ATROPHY AND TYPICAL ALZHEIMER’S DISEASE PATIENTS IN REAL-WORLD SETTINGS

Figure 3. A captured scene and a fixation (red circle) from a video of a Ayako Suzuki, Keir Yong, Ian McCarthy, Tatsuto Suzuki, Dilek Ocal, Nikolaos N. Papadosifos, Derrick Boampong, Nick Tyler, Sebastian J. Crutch, University College London, Engineering Sciences, London, United Kingdom; Dementia Research Centre, Institute of Neurology, University College London, London, United Kingdom; University College London, Institute of Neurology, London, United Kingdom. Contact e-mail: a.suzuki@ucl.ac.uk

EFFECTS OF GROUND LIGHTING UNIFORMITY AND CLUTTER ON NAVIGATIONAL ABILITY IN POSTERIOR CORTICAL ATROPHY AND TYPICAL ALZHEIMER’S DISEASE

0.36-0.87) and ARBs (HR 0.60, 95% CI 0.37-0.98) were independently associated with a decreased risk of dementia. The association of CCBs with dementia was most apparent in participants without a history of cardiovascular disease (HR 0.38, 95% CI 0.18-0.81) and with uncontrolled hypertension (HR 0.26, 95% CI 0.11-0.61). Systolic blood pressure was not significantly lower in participants using CCBs or ARBs. Conclusions:Both use of CCBs and ARBs are independently associated with a decreased risk of dementia in older people. der clutter (right) and consistent (A) vs inconsistent (B) lighting.

Locomotion and eye behaviour under controlled environment in individuals with Alzheimer's disease

This study aimed to examine simple locomotion and eye behaviour of individuals with Posterior Cortical Atrophy (PCA) and typical Alzheimers disease (tAD) within a simulated real-world environment. Posterior cortical atrophy (PCA) is a neurodegenerative condition characterised by parietal, occipital and occipito-temporal tissue loss and progressive impairment of higher-order visual function in contrast to relatively spared memory and language. Targeted types of locomotion were walking in a series of corridors, up or down stairs, and across an open room with or without the presence of an obstacle. Eye tracking measures and inertial moment units (IMU) were used in this experiment, and resultant acceleration of left foot and fixation duration were extracted. Findings from three participants are presented as a case series: one control, one PCA and one tAD patient. The averaged resultant acceleration of PCA patient was the slowest in all types of locomotion, especially in stairs. The averaged resultant accelerations of PCA and tAD participants were slower than the control participant. The PCA participant had longer mean fixation durations than the tAD and control participants, however, mean fixation duration was similar between tAD and control participants. Results may help characterise locomotion and eye behaviour in PCA and tAD and may suggest ways to support effective diagnosis and assessment of disease progression.