Touchscreen typing-pattern analysis for detecting fine motor skills decline in early-stage Parkinson's disease

Dimitrios Iakovakis, Stelios Hadjidimitriou, Vasileios Charisis, Sevasti Bostantzopoulou, Zoe Katsarou, Leontios J. Hadjileontiadis
2018 Scientific Reports  
Parkinson's disease (PD) is a degenerative movement disorder causing progressive disability that severely affects patients' quality of life. While early treatment can produce significant benefits for patients, the mildness of many early signs combined with the lack of accessible high-frequency monitoring tools may delay clinical diagnosis. To meet this need, user interaction data from consumer technologies have recently been exploited towards unsupervised screening for PD symptoms in daily
more » ... Similarly, this work proposes a method for detecting fine motor skills decline in early PD patients via analysis of patterns emerging from finger interaction with touchscreen smartphones during natural typing. Our approach relies on low-/higher-order statistical features of keystrokes timing and pressure variables, computed from short typing sessions. Features are fed into a two-stage multi-model classification pipeline that reaches a decision on the subject's status (PD patient/control) by gradually fusing prediction probabilities obtained for individual typing sessions and keystroke variables. This method achieved an AUC = 0.92 and 0.82/0.81 sensitivity/specificity (matched groups of 18 early PD patients/15 controls) with discriminant features plausibly correlating with clinical scores of relevant PD motor symptoms. These findings suggest an improvement over similar approaches, thereby constituting a further step towards unobtrusive early PD detection from routine activities. Parkinson's disease (PD) is a common progressive neurodegenerative disorder 1 , characterised primarily by motor symptoms that contribute to significant disability 2,3 . The pathological hallmark of the disease is the loss of dopaminergic neurons in the substantia nigra, a basal ganglia structure of the human brain, and the presence of Lewy body-containing alpha-synuclein 3 , a protein widely distributed in the brain. The clinical spectrum of the disease is more extensive covering also a wide range of non-motor symptoms 4 due to the degeneration of other dopaminergic and non-dopaminergic regions of the brain, spinal cord and peripheral nervous system 5-7 . The resultant decreased availability of dopamine in the basal ganglia leads to the motor symptomatology 3,8 . Due to the mildness of many early signs, including motor symptoms 2 , patients may not undergo clinical examinations for PD during early stages and therefore, the disease may be undiagnosed for many years 9 . When PD is screened non-instrumentally -that is the majority of cases -the procedure traditionally involves the evaluation of subject's overall condition according to standardised scales and questionnaires, such as the commonly used Unified Parkinson's Disease Rating Scale (UPDRS) 10 . Motor status in particular, is often assessed by an expert based on the individual scoring and aggregated score of UPDRS Part III items 10 , which cover a broad range of PD motor symptoms, including among others, tremor (resting and action), rigidity, and bradykinesia. The latter examination, as is the case with other scales/questionnaires, requires a movement disorders specialist and the presence of the subject at the clinic. These factors limit the frequency of evaluation and monitoring of PD symptoms, while results are often of subjective nature as they rely on the expert's experience or subject's self-reports 11 . On the other hand, the development of more accessible tools that provide objective information Published: xx xx xxxx OPEN www.nature.com/scientificreports/ 2 SCIENTIfIC REPORTS | (2018) 8:7663 |
doi:10.1038/s41598-018-25999-0 pmid:29769594 pmcid:PMC5955899 fatcat:qntomj3cujeehkwore5jul22ci