The effect of chronic hemodialysis on the kinematic analysis of handwriting with Arabic language. A prospective cross sectional study.

Background: Handwriting results from a complex network made up of cognitive, kinesthetic, and perceptual-motor abilities. Patients with chronic hemodialysis are more likely to have metabolic abnormalities, myopathies, and cognitive impairment so it can affect the quality of the handwriting. This study aimed to investigate the changes of the kinematics of handwriting in a sample of renal disease patients on chronic hemodialysis. Patients and methods: This study included fifty end-stage renal disease patients on chronic hemodialysis. Their previous handwritings were obtained from their hospital's records and their previous documents prior to chronic hemodialysis. The obtained handwriting was examined for pen pressure, mean speed of handwriting, tremors, alignment, direction of handwriting, writing skill level, slanting angle , word size, inter-letter connections, inter-word spacing, initial stroke, terminal stroke, pen drags, word shape, and writing errors. Results: After chronic hemodialysis, 84% of patients had reduced pen pressure, 90% showed slow mean speed of handwriting, 82% with tremors in down strokes, 48% with minimal word alignment, 58% with deteriorated writing skill level, 56% with increased word size, 86% with semi regular inter-letter connections, 78% with wide and irregular inter-word spacing, 44% with disturbed word shape, and 84% with writing errors in the form of overwriting. No statistically significant findings were found regarding slanting angle, retrace and thickness of both initial and terminal strokes between pre and post dialysis. Conclusion: Chronic hemodialysis therapy could affect patients’ handwriting characteristics which may be misdiagnosed as non-genuine documents.