Preface to the 4th MDS Video Challenge Case Supplement for Movement Disorders Clinical Practice

The MDS Video Challenge format is a central tradition of the annual International Congress of Parkinson's Disease and Movement Disorders®. This special issue documents the cases presented at the 2022 MDS Video Challenge that took place in Madrid, Spain along with the respective videos and discussions with key learning points. These cases were shortlisted from a total of 83 submissions (34 from the Asian and Oceanian section, 22 from the European section, 21 from the Pan American section, and 6 from the African section) highlighting challenging phenomenological and etiological associations. The masters of ceremony for 2022 were Drs. Anthony E. Lang and Kailash P. Bhatia, and the panel of discussants comprised Drs. Myriam Carecchio (Italy), Rob De Bie (The Netherlands), Abhimanyu Mahajan (United States), Michele Matarazzo (Spain), and Meenakshisundaram Umairorubahan (India).

This special issue includes 17 submissions, coming from 13 different countries, namely Australia, Brazil, China, India, Italy, Malaysia, Mexico, Spain, Switzerland, Thailand, Turkey, the United Kingdom, and the United States. This is a true explosion of diversity and global participation that is guided by the quality and educational merit of the cases. Indeed, the long‐standing tradition of the MDS Video Challenge continuingly succeeds in fostering a growing international culture of exquisite analytical skills and differential diagnostic thinking, and propels active engagement in clinically motivated translational science. The presented cases cover a very broad spectrum of movement disorders and etiologies, including neurogenetic, infectious, drug‐induced, metabolic, tumor‐related, and autoimmune causes. ¹ , ² , ³ , ⁴ , ⁵ , ⁶ , ⁷ , ⁸ , ⁹ , ¹⁰ , ¹¹ , ¹² , ¹³ , ¹⁴ , ¹⁵ , ¹⁶ , ¹⁷ Importantly, they provide practical take‐home messages and clues to diagnosis, as means to optimize the level of care for our patients.

During the process of putting together this supplement, one striking point became apparent: the imperative of revisiting a given diagnosis. Indeed, several cases here were conclusively diagnosed after several follow‐up examinations owing, for example, to atypical or early presentations that only later evolved to full‐blown and well‐recognized clinical phenotypes, or the discovery of new, previously unknown, etiologies. This highlights the need to thoughtfully re‐evaluate cases considering new developments in our fast‐galloping field. This also includes cases that may have received a functional movement disorder diagnosis, specifically when positive clinical diagnostic signs are absent. ⁵ , ¹¹ Although we acknowledge the increasing complexity between phenotypic and etiologic associations in light of an ever‐expanding number of conditions, as for example, neurogenetic and autoimmune, we see this as a unique opportunity for growth in an era of exciting diagnostic and treatment developments. The cases provided here, but also in the previous supplements over the years (Volume 7, Issue S3; Volume 8, Issue S1; Volume 9, Issue 2), decisively enrich our clinical knowledge and skills and aid our therapeutic decisions. They also stand as a remarkable demonstration of the unwavering dedication exhibited by the MDS Video Challenge hosts, the case reviewers, the Movement Disorder Congress team, the invited panels of expert clinicians, and, of course, all members of our society who actively contribute to this truly unparalleled collaborative international endeavor. Most importantly, the MDS Video Challenge is a testament to the selflessness and strong will of people who seek care in neurology and their families, who together with their movement disorder health professionals synergistically advance education and medical care. We, the editors of this supplement, remain indebted to all of you and wholeheartedly encourage you to continue nurturing this invaluable tradition over the years to come.

Author Roles

1.Research project: A. Conception, B. Organization, C. Execution; 2. Statistical Analysis: A. Design, B. Execution, C. Review and Critique; 3. Manuscript Preparation: A. Writing of the first draft, B. Review and Critique

MM, CG: 3A, 3B.

Disclosures

Funding Sources and Conflicts of Interest: No funding was received for this work, and the authors have no conflicts of interest to declare.

Financial Disclosures for the Previous 12 Months: M.M. has received research funding from The Michael J. Fox Foundation and lecture honoraria from Zambon and Palex. C.G. receives scientific research support from the VolkswagenStiftung (Freigeist) and lecture honoraria from the Movement Disorder Society.