# Dynamic Handwriting Analysis for Neurodegenerative Disease Assessment: A Literary Review
## 3 Research Directions
### Alzheimer's Disease
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Reference** & **Groups** & **Tasks** & **Main Features** & **Main Findings** \\ \hline _Disease insight_ & & & & \\ \hline [PERSON] et al., 1999 & 16 AD, 16 EC & No-sense word & Kinematic and spatiotemporal & AD patients exhibit less consistent \\ [PERSON] et al., 2003 & 35 AD, 39 MCI, 39 DEP, 40 EC & Circle drawing & Kinematic & AD and MCI patients differ from healthy subjects in automation \\ [PERSON] et al., 2008 & 9 AD, 9 MCI, 10 EC & Handwriting patterns & Kinematic and spatiotemporal & Patients show slow and uncoordinated movements \\  & & & and/or wrist & & \\ [PERSON] et al., 2013 & & SUNIBA & Kinematic & Handwriting in impaired subjects \\  & & & & & \\ [PERSON] et al., 2014 & Not specified & House drawing & Kinematic and pressure & \\  & 2014 & 20 AD, 12 MCI, 16 EC & Line and circle drawing & Kinematic & The degree of motor impairment may help identify those at risk for AD \\ \hline _Disease diagnosis_ & & & & \\ \hline _[PERSON] et al., 2006 & 22 AD, 31 MCI, 41 EC & Functional tasks & Kinematic and spatiotemporal & Handwriting measures, especially those related to in-air movements, are promising for the automatic discrimination \\ [PERSON] et al., 2015 & 29 AD, 30 EC & Signature & Sigma-lognormal-based & Signature deterioration can be a disease predictor \\ [PERSON] et al., 2017 & 23 AD, 12 MCI, 17 EC & Sentence copying and writing, figure copying, and CDT & Kinematic and pressure & Higher specificity in distinguishing between normal and impaired condition and higher sensitivity in distinguishing between AD and MCI \\ [PERSON] et al., 2017 & 37 MCI, 37 EC & Single letter and sentence writing & Spatiotemporal & MCI writing is significantly slower than the normal one \\ [PERSON] et al., 2017a; 20 AD, 30 MCI, 20 EC & House drawing and CDT & Spatiotemporal & In-air time is a good predictor for disease diagnosis \\ [PERSON] et al., 2018 & Different aging conditions & Word and sentence writing & Kinematic and spatiotemporal & Classification based on temporal representations improves \\ [PERSON] et al., 2018 & 15 AD, 13 MCI, 15 EC & Spiral drawing and word & Kinematic and spatiotemporal & Individual variability of \\  & & & writing & & handwriting can be mitigated by noise-robust methods such as \\ [PERSON] et al., 2019 & 36 MCI, 29 EC & Attentional matrices & Kinematic and entropy & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of studies on AD (EC = elderly controls; YC = young controls; DEP = depressed patients). concentric superimposed circles as fast and fluently as possible with the dominant hand; the second task was identical to the first one but, in addition, participants were requested to simultaneously perform a distraction task (pressing a counting device as often as possible) with the nondominant hand. The results obtained showed that kinematic handwriting parameters were effectively related to cognitive status in elderly patients. Patients with MCI and probable AD exhibited a loss of fine motor performance: especially when compared to control subjects, movements of AD patients were significantly less automated, accurate, and regular. [PERSON] et al. [100] investigated whether the decline in fine motor control and coordination characterizes sensorimotor deficiencies of cognitively impaired patients with AD or MCI. Their findings supported this hypothesis. Specifically, when performing handwriting tasks, movement slowing was associated to MCI and AD. When performing fine movements, the AD patients also showed more jerky movement than the other groups. In Reference [44], [PERSON] et al. investigated the relationship between the delta-lognormal and the sigma-lognormal models [49] and the early signs and symptoms of AD. The previously mentioned dataset ISUNIBA was collected and used to perform the analysis.