Brugman F, Scheffer H, Wokke JH, Nillesen WM, de Visser M, Aronica E, Veldink JH, van den Berg LH. Paraplegin mutations in sporadic adult-onset upper motor neuron syndromes. Neurology. 2008 Nov 04;71(19):1500–5. doi: 10.1212/01.wnl.0000319700.11606.21. PMID: 18799786.