The movement disorder of Nicolas Poussin (1594-1665) [historical article].

Nicholas Poussin (1594–1665) is a key figure in the classic tradition of European visual art. From around 1630 onward his drawings develop a shaky quality, and in a letter dated 1650 he says “le tremblement de mes membres augmente comme les ans.” In the absence of detailed evidence, Poussin’s movement disorder has been variously ascribed to Parkinson’s disease or to neurosyphilis. A retrospective analysis and diagnosis of Poussin’s movement disorder presents some interesting challenges to the modern scientist. First, the only available data for studying his behavior is the record left by the pen tip as he moved it across the page over 350 years ago. Second, this data is purely spatial, yet most conventional analyses of movement disorders focus on their temporal characteristics. Third, there is no clear and unambiguous way to distinguish between voluntary modulations of Poussin’s pen movement from involuntary tremors. In principle, geometrically identical segments of pen motion could be made as part of the artistic process in one drawing, yet be a consequence of tremor in another drawing. Retrospective tremor analysis thus contrasts with the highly constrained tasks studied in the modern tremor laboratory. Knowing the specific hallmark or kinematic sign of Poussin’s movement disorder could assist in authenticating works thought to be by him. To address these challenges, we have analyzed several features of Poussin’s movement in lines taken from selections of Poussin’s drawings spanning the period 1625 until 1664. We know from Poussin’s own letters that his movement disorder was degenerative, and that it made writing, drawing, and painting progressively harder. Identifying a degenerative trend over this period in a specific parameter of the drawing movement would therefore help to reveal the primary features of Poussin’s disorder. These could then be correlated with more detailed kinematic knowledge from modern studies.