Figure 5From: Extrapyramidal signs in normal pressure hydrocephalus: an objective assessmentTone analysis in NPH versus control subjects. Plots of the slope of the line of force: angular displacement about the elbow (stiffness constant k) for control and NPH subjects at baseline during repose. Solid diamonds represent each individual subject, and horizontal lines denote mean values. As a group, NPH patients displayed significantly increased tone versus controls (p < 0.02) with a majority of subjects demonstrating tone outside the range of controls.Back to article page