J Ludwig, P Remien, C Guballa, et al. Effects of subthalamic nucleus stimulation and levodopa on the autonomic nervous system in Parkinson's disease (J Neurol Neurosurg Psychiatry 2007;78:742–5). In figure 1, panels B, D and F, the symbols for “before levodopa” and “after levodopa” should be interchanged—that is, the triangles should be named “before levodopa” and the squares “after levodopa”.