Upper extremity dual‐task in autosomal dominant Alzheimer disease, PSEN1 E280A

Background Alzheimer’s disease and identification of non‐cognitive preclinical biomarkers is one of the key aspects in research worldwide, in Latin‐American is even more important because the lack of biomarkers in clinical practice. Dual‐task cost have been proposed previously as biomarker in Alzheimer disease. This study aims to create a low‐cost technology using smart phones camera to identify dual‐task in with Early‐onset Autosomal Dominant Alzheimer’s‐Disease carrying PSEN1 – E280A. Method Pilot study creating a low‐cost technology. Procedure: The execution of the motor‐task is recorded with the integrated camera of a smart‐phone and the verbal fluency‐task with the microphone integrated in the headset or an external lavalier type microphone. To determine the angle of elbow‐flexion in the dominant arm, anatomical markers are placed in the acromion (shoulderjoint), lateral epicondyle(elbow) and the ulnar/radial styloid(wrist). After segmenting the markers in the video, the elbow flexion‐angle and the dynamics of the arm movement (angular velocity, range of motion, limb elevation time and number flexions); from the audio recording, the words and quantity named in the task execution and the changes of these with respect to the task execution during the dual task are extracted. The flexion angle was validated with commercial biomechanical‐analysis software and goniometer, also the arm movement dynamics curves were validated with OpenPose. Result 21 controls. The value of the dual‐task cost in verbal fluency in animal category was ‐11.35 % and for arithmetic calculation tasks ‐1, ‐3 was ‐19.09 % and ‐3.13 % respectively. negative values indicating no impairment. 2 Cases with the disease were also evaluated, the results of the dual‐task cost were 28.77 % for the verbal fluency task in animal category and 14.44 % and 38.34 % for the arithmetic calculation (‐1 and ‐3) the latter being the one with the highest load. Conclusion This evaluation method is widely applicable, low cost and time, does not require patient preparation and accessible, since it does not require large space availability or costly and complex instruments in comparison to its analogue, the dual‐task gait. It has great potential to be a non‐cognitive biomarker.