Objective

Micrographia and bradygraphia are classic features of Parkinson’s disease (PD). However, the relevance of quantifying them in the clinical exam with pen and paper is unclear.

Materials/patients and methods

Twenty-five patients with PD (72 ± 8 years, 8F; time since diagnosis 9.8 ± 5.1 years; Hoehn and Yahr 2.5 ± 0.6) and 26 age-matched healthy controls (HC, 71 ± 16 years, 8F) wrote three times the same standard sentence in the OFF state. We measured changes from sentence 1 (S1) to sentence 3 (S3), in writing speed (WS), sentence length (SL), heights of first and last Ps (H1P, H3P), mean inter-words interval (IWI) and ratio total inter-word interval/sentence length (TIWI/SL). We also explored correlation with classical parameters of parkinsonism, including delay since diagnosis (DSD), UPDRSIII, and gait parameters such as the coefficients of ambulation speed increase (CSI) on a modified 20-meter up and go test.

Results

Raw values were: WS, 7.6 ± 2.4 (S1) and 8.8 ± 2.6 mm/s (S3) in HC (S1 vs S3, p = 0.000003) vs 6.4 ± 2.8 and 6.5 ± 3.0 mm/sec in PD (S1 vs S3, p = 0.65); H3P, 8.2 ± 2.4 (S1) and 8.4 ± 2.9 mm (S3) in HC (S1 vs S3; NS) vs 7.2 ± 3.2 and 6.3 ± 3.1 mm in PD (S1 vs S3, p < 0.05); IWI, 5.0 ± 1.4 (S1) and 4.8 ± 1.3 mm (S3) in HC (S1 vs S3, p < 0.05) vs 4.8 ± 1.7 and 4.2 ± 1.5 mm in PD (S1 vs S3, p < 0.001). The between-group differences in changes from S1 to S3 involved: WS, increased in HC (+ 15%) more than in PD (+ 2%; p = 0.003, ANCOVA); H3P, decreased in PD (–13.5%) while increased in HC (+ 2.6%; p = 0.012); IWI, decreased more in PD (–11.5%) than in HC (–4.5%; p = 0.048). WS, H3P and IWI did not correlate with time since diagnosis or UPDRS III. However, the coefficient of writing speed increase correlated negatively to CSI (r = –0.52, p = 0.006).

Discussion/Conclusion

From first to last sentence, the lack of speed increase seems to best distinguish PD patients from healthy subjects. It also correlates with markers of parkinsonism in ambulation.