Writing Error May Be a Predictive Sign for Impending Brain Atrophy Progression in Amyotrophic Lateral Sclerosis: A Preliminary Study Using X-Ray Computed Tomography

<i>Aim:</i> To investigate whether writing errors are predictive of longitudinal brain atrophy progression in patients with amyotrophic lateral sclerosis (ALS). <i>Methods:</i> The frequency of writing errors in 6 ALS patients without dementia was compared with longitudinal changes in lateral ventricular areas of the bilateral anterior and inferior horns on X-ray computed tomography scans. The increase in area per month for the anterior and inferior horns was used as a measure of longitudinal brain atrophy progression, and was calculated as: (area on the initial scan – area on the follow-up scan)/scan interval (month). <i>Results:</i> The longitudinal rate of increase in the area of the anterior horns showed significant associations with the rates of total writing errors (<i>r</i> = 0.886, p = 0.0152), kana errors (<i>r</i> = 0.887, p = 0.0148) and kana omission (<i>r</i> = 0.856, p = 0.0268), whereas that for the inferior horns size showed no significant association with any writing errors. <i>Conclusion:</i> The increased area of the anterior horns indicates frontal-lobar atrophy, and writing errors may be a predictive sign for impending brain atrophy progression in the frontal lobes, which reflects the development of anterior-type dementia.