Published Ahead of Print on June 26, 2020 as 10.1212/WNL.0000000000009901 RESIDENT & FELLOW SECTION Teaching Video NeuroImages: Paroxysmal hyperkinesia with diurnal fluctuations due to sepiapterin-reductase deficiency Tina Mainka, MD, Jessica Hoffmann, Andrea A. Kuhn,¨ MD, Saskia Biskup, MD, and Christos Ganos, MD Correspondence Dr. Ganos Neurology 2020;95:1-e3. doi:10.1212/WNL.0000000000009901 ®
[email protected] A 42-year-old man, born of consanguineous parents, presented with long-standing severe, MORE ONLINE nonepileptic jerky movements of the upper body, pronounced during the second half of the day Video and improving after sleep (video, A and B). There was a history of neurodevelopmental disorder with axial hypotonia, delayed milestones, intellectual disability, and poor speech Teaching slides production. The combination of a neurodevelopmental syndrome and a movement disorder links.lww.com/WNL/ with diurnal fluctuations1 led to targeted exome sequencing for monoamine metabolism dis- B131 orders. A homozygous nonsense variant in the SPR gene was identified (figure), confirmed by Sanger sequencing (figure). Treatment with levodopa led to marked improvement of abnormal movements (video, C). Acknowledgment The authors thank the patient for his participation and support. Study funding Academic research support from the VolkswagenStiftung (Freigeist Fellowship; C. Ganos). Disclosure T. Mainka, J. Hoffmann, A.A. K¨uhn,S. Biskup, and C. Ganos report no disclosures relevant to the manuscript. Go to Neurology.org/N for full disclosures. From the Department of Neurology (T.M., A.A.K., C.G.), Charit´e University Medicine Berlin; Berlin Institute of Health (T.M.); and Center for Genomics and Transcriptomics (J.H., S.B.), Tubingen,¨ Germany.