VOLUME 29, ISSUE 3 • SEPTEMBER 2025.

Rare disorder symposium focuses on immune-mediated movement disorders

In India, the healthcare professionals and affected families face several hurdles in managing rare movement disorders. In 2020, a group of experts who recognized these challenges established the Indian Rare Movement Disorders Consortium (IRMDC). In 2024, it became an integral part of the Movement Disorders Society of India (MDSI).

With the objectives of improving care and advancing research in this field through multi-disciplinary collaboration, the IRMDC organizes two types of academic activities in India: monthly online video case sessions and a yearly symposium. The monthly online video case session provides a platform for discussion on the phenomenology, interpretation of investigations, and therapeutic strategies. The yearly symposium updates the existing knowledge and identifies avenues of research and improvement. The first symposium drew attention to the genetic as well as non-genetic rare movement disorders relevant to the Indian population. The second and third symposiums focused on genetic disorders. The IRMDC decided that there should be a symposium to catch up with the growing field of neuroimmunology and revise immune-mediated movement disorders, which are rare but potentially treatable.

The 4th Indian Rare Movement Disorders Symposium: Autoimmune Chapter (June 21-22, 2025) was hosted by the Vadodara Neurological Association in the Western India. It was endorsed by the International Parkinson and Movement Disorder Society (MDS). Reflecting its name, the two-day symposium engaged national as well as international faculty in didactic lectures, interactive case discussions, and video-case presentations on the immune-mediated movement disorders. The course director, Dr. Suvorit S Bhowmick, ensured balanced representation of experts in related fields (movement disorders neurology, neuroradiology, neuropathology, and neuroimmunology) to share knowledge and foster inter-disciplinary collaboration. The symposium was attended by 160 delegates (neurologists, residents, and fellows) across the country.

In the inaugural session, Dr. Angela Vincent (widely considered a pioneer in the field of neuroimmunology) inspired the audience through a virtual lecture on the fundamental concepts of immune-mediated movement disorders. Dr. Pramod Pal (President of the MDSI) gave an overview on the phenomenology of movement disorders. Dr. Vikram Holla’s lecture on parallels in immune-mediated and genetic movement disorders was outright captivating; besides discussing shared pathophysiology and genetically determined autoinflammatory disorders, he showed examples where genetic disorders can be misdiagnosed as immune-mediated movement disorders and vice versa. Dr. Ajay Garg (Professor of Neuroradiology) summarized the role of neuroimaging in suspecting autoimmune etiology.

There were two sessions (named Phenomenology Plunge 1 and 2) on the phenomenology of immune-mediated movement disorders; they included lectures on immune-mediated parkinsonism, cerebellar ataxia, stiff person spectrum disorders, chorea/dystonia, myoclonus, and peripheral hyperkinetic disorders by national experts Dr. Roopa Rajan, Dr. Jacky Ganguly, Dr. Sreenivas M, Dr. Hrishikesh Kumar, Dr. Sanjay Pandey, and Dr. Divya KP, respectively. Another session (named Immunological Meltdown) had lectures on movement disorders in systemic autoimmune diseases by Dr. Niraj Kumar, pediatric immune-mediated movement disorders by Dr. Sayoni Roy Chowdhury, and paraneoplastic movement disorders by Dr. Divyani Garg. Each of these three sessions incorporated discussion on two relevant challenging video cases, wherein an ‘anchor’ interacted with a ‘master’ on the phenomenology, approach to diagnosis, and management. Young neurologists, residents, or fellows presented the video cases. The anchors (Dr. Sarika Patil, Dr. Narendra Barad, Dr. Ashish Susvirkar, Dr. Heli Shah, Dr. Mitesh Chandarana, and Dr. Harshadkumar Chovatiya), relatively new in the field of the movement disorders, had reviewed the videos and diagnosis before the session. The masters (Dr. Asha Kishore, Dr. Mohit Bhatt, Dr. Rukmini M Kandadai, Dr. Charulata Sankhla, Dr. Vijayashankar Paramanandam, and Dr. Ravi Yadav) approached the cases systematically to reach the final diagnosis.

The organizing committee had invited submissions of interesting video cases of immune-mediated movement disorders from India for discussion or presentation during the symposium. Out of a total of 24 submissions, a jury of experts selected six challenging cases for travel grant award and discussion. The rest of the video cases were presented in the ‘Knowledge Splash I’ session. The moderators (Dr. Soaham Desai, Dr. Ajith Cherian, and Dr. Suvorit S Bhowmick) summarized the learning pearls from each case. The audience also participated through an interactive application, which projected pertinent poll questions on their mobile devices after each video case presentation. The session showcased a wide variety of immune-mediated movement disorders (chorea in antiphospholipid antibody syndrome and systemic lupus erythematosus, MOG antibody-associated parkinsonism, catatonia, and focal myoclonus, paroxysmal dysarthria-ataxia in multiple sclerosis, anti-NMDAR encephalitis, anit-Caspr2 associated chorea, anti-Ri rhombencephalitis, anti-Ma2 rhombencephalitis, anti-IgLON5 disease, anti-amphiphysin encephalitis, anti-KLHL11 rhombencephalitis, anti-Yo paraneoplastic cerebellar degeneration, etc.).

The subsequent sessions had mixture of virtual and in-person presentations by the international and national faculty. Dr. Bryan Ceronie talked about the basic science behind immune-mediated movement disorders. Dr. Carles Gaig, through his presentation on the borderland between immune-mediated movement disorders and neurodegeneration, shared his 10 years of experience on anti-IgLON5 disease and emphasized the importance of recognizing distinct phenotypes and sub-specialty collaboration in investigating unresolved cases. Dr. Alberto Vogrig gave a presentation on the novel immune-mediated movement disorders. Dr. Anita Mahadevan (Professor of Neuropathology) recapitulated different methods of antibody testing, along with their pitfalls. Dr. Netravathi M spoke on the principles of immunotherapy, including the available and upcoming therapeutic strategies and agents. The fellows from University of Toronto and Western University, Canada, presented interesting video cases in the final ‘Knowledge Splash II’ session.

There are several limitations in diagnosing and managing immune-mediated movement disorders in resource-limited countries like India. These disorders are potentially treatable, hence there is a low threshold for antibody testing. While several laboratories offer testing of individual antibodies as well as panels of antibodies for movement disorders (parkinsonism, ataxia, stiff person spectrum, paraneoplastic antibody panels), a large number of affected people can not afford these commercially available tests. A very few laboratories that offer tests at subsidized rate are not able to meet the high demand of such tests. There is no designated referral laboratory in India for replication of results through alternative test methods. There are insufficient means for discovery of newer antibodies. Furthermore, there are critical knowledge gaps, such as prevalence of antibodies in the population, antibodies of unknown significance, pathogenicity of several known and newly discovered antibodies, diagnosis of immune-mediated disorders without detectable antibodies, alternative biomarkers for neuronal autoimmunity, etc. Hopefully, the symposium ignited minds towards taking the necessary measures and filling the existing gaps. The recently established Consortium for Infection- and Immune-mediated movement disorders in India is a welcome step in this direction.