Repeated claims have been made that inactivation of the subthalamic nucleus (STN) is a neuroprotective measure.^1–3 It was postulated that by suppression of the glutamatergic STN, glutamate mediated excitotoxicity exerted on the substantia nigra could be reduced, if not abolished. The paper by Hilker et al in this issue (see page 1217) deals with this topic by looking longitudinally at patients who have undergone successful STN stimulation. The investigators have taken the approach of using objective functional imaging employing ¹⁸F-DOPA positron emission tomography (PET), an established objective measure of biological progression in Parkinson’s disease, which was then correlated with clinical progression. They were able to show convincingly that STN stimulation did not halt the progression of Parkinson’s disease.

They have also shown …