The 2023 Movement Disorder Society congress was hosted in true Scandinavian style in the Danish capital. Whilst delegates may have been distracted by Copenhagen’s beautiful waterfront and stunning architecture, the programme was more than enough to keep everyone in the conference centre. Over 5,200 delegates from more than 100 countries shared the latest advances in pathophysiology, diagnosis, and management.
Results from numerous important clinical trials in Parkinson’s disease were presented. Follow up data from the UK’s PD-MED study compared patients who were initiated on Levodopa versus Levodopa-sparing agents. This confirmed that that, despite increased levels of dyskinesia, quality of life remained higher in the patients in the Levodopa group 15 years later. Importantly, in the Levodopa sparing group, the MAO-B inhibitors were not inferior to dopamine agonists .
The relationship between the gut and the brain is a hot topic in PD. A study of 74 patients found that after 12 weeks of probiotic therapy, patients showed significant reduction in ‘time to on’ and NMS scale scores and objective changes in their gut flora compared to placebo. How long might it be before we are routinely prescribing probiotics alongside dopaminergic drugs ?
Following on from the exciting recent Exenatide studies, a phase II study of another injectable GLP-1 agonist, Lixisenatide, demonstrated significant improvement in UPDRS-III scores in 156 patients with early onset PD .
In the presidential lectures, Dr Caroline Tanner gave an excellent overview of ‘prevention’ in Parkinson’s focusing on early detection, and exposure risk within different US cohorts. Dr Andy Singleton presented work from the GP2 genetic Parkinsons’s collaboration highlighting the lack of knowledge about sub-Saharan Africa Parkinson’s cohorts with high prevalence of GBA mutations.
The award for the best research article of the year from Movement Disorders went to Zappia et al. for a fascinating study  showing a synergistic effect of long duration Levodopa alongside motor learning inducing neuroplasticity and adaptive changes to basal ganglia networks.
Since the pandemic, tic disorders referrals have been on the increase. Pringsheim et al. were presented with the Movement Disorders Clinical Practice article of the year award for their article describing the demographic and phenomenological characteristics of the Calgary tic registry . This highlighted how similar current tic presentations were to historical cohorts and showed slight differences between male and female presentations with the later having more intense and frequent motor tics. Becker et al. presented interesting data which used machine learning to distinguish movements in Tourette’s syndrome from health controls with accuracy of 83% .
The MDS congress enjoys emphasising the importance of clinical skills in its Grand Rounds section where selected clinicians are invited to take a history and examine a few local cases in front of a packed auditorium. Our Danish and Swedish colleagues provided a clinical smörgåsbord of fascinating cases, which prompted discussion and debate. The congress had many interactive video sessions in which clinical phenomenology was carefully explained and taught. Highlights included sessions on functional movement disorders chaired by Alberto Espay, a ‘Tics, Tourette’s and stereotypies’ session chaired by Lis Gitte and Christos Ganos and a hyperkinetic movement disorder session chaired by Mark Stacy.
The congress is famed for its evening Video Challenge with movement disorder legends Tony Lang and Kailash Bhatia sharing master of ceremonies duties across a marathon of 29 complex cases. This session is always educational and highlights interesting genetic, autoimmune, or metabolic presentations with videos submitted from around the world. There was an excellent atmosphere as the audience tried to piece together the clues and arrive at the correct diagnosis.
The final day saw entertaining discussions around controversies in movements disorders. First up was the topic of safety and efficacy of bilateral lesioning for Parkinson’s disease. Maria Rodriguez was speaking for and Elena Moro against with her impassioned argument around the lack of data on bilateral lesioning winning over the crowd. Secondly Alastair Noyce argued in favour of genotyping in Parkinson’s disease patients with Jonathan Carr speaking against. An honest but forward-looking argument from Professor Noyce narrowly won against Professor Carr’s more pragmatic approach in an area with a lack of disease modifying treatments.
In the final session, Giulietta Riboldi and Sanjay Pandey presented research highlights from the past year in both hyperkinetic and hypokinetic movement disorders. They discussed how a new candidate gene for dystonia, ATP5F1B, has been identified with variants in 2 families giving rise to an autosomal dominant early onset phenotype . There has been excitement about emerging treatments for Huntington’s disease; data was shown from a recent Phase II trial of Pepinemab, a semaphorin 4D (SEMA4D)-blocking antibody, that failed its primary outcome, but met several secondary outcomes that will provide hope . Furthermore, recent data has shown Velbanizine is both effective and safe for use for chorea in Huntington’s disease . Lastly there was interest in the results of a recent phase II trial of Sodium Oxybate which was shown to be efficacious in treating vocal tremor in patients with essential tremor .
There has been much discussion of seed amplification assays for α-synuclein in PD. More evidence appears to be emerging about the specificity of CSF assays, but there is also excitement around serum sampling, although a cross-sectional study highlighted false negative results in LRRK2 patients . In the area of disease modification for Parkinson’s, a recent phase II of Venglustat in GBA1-associated Parkinson’s showed a positive safety profile but no benefit against placebo . Lastly there was an important message from a recent paper on the remote assessment of movement disorders highlighting the technical limitations of video conferencing programmes .
Overall, there was much for delegates to digest in this packed meeting. It was closed by the incoming President Victor Fung with delegates asked to put the dates in their diary for the 2024 congress in Philadelphia.
- Clarke C. et al. 15-year effects of initiating treatment for Parkinson’s disease with dopamine agonists or monoamine oxidase B inhibitors compared with levodopa: final results of PD MED early disease randomisation [abstract]. Mov Disord. 2023;38 (suppl 1).
- Leta V. et al. Efficacy of a four-strain probiotic on gut dysbiosis, motor and non-motor symptoms in Parkinson`s disease: a multicentre randomised controlled trial [abstract]. Mov Disord. 2023;38 (suppl 1).
- Meissner WG. et al. Multicenter, randomized, placebo-controlled, double-blind, parallel-group proof-of-concept study of lixisenatide in patients with early Parkinson’s disease (PD): the LIXIPARK trial (NCT03439943) [abstract]. Mov Disord. 2023;38 (suppl 1).
- Sciacca G. et al. Long‐Duration Response to Levodopa, Motor Learning, and Neuroplasticity in Early Parkinson’s Disease [abstract]. Mov Disord. 2023;38:626–635. https://doi.org/10.1002/mds.29344
- Nilles C. et al. Have We Forgotten What Tics Are? A Re-Exploration of Tic Phenomenology in Youth with Primary Tics. Mov Disord Clin Pract. 2023;10:764–773. https://doi.org/10.1002/mdc3.13703
- Becker L. et al. New machine learning approaches in tic detection: Seeking to learn more about the characteristic of tics [abstract]. Mov Disord. 2023;38 (suppl 1).
- Nasca A. et al. Variants in ATP5F1B are associated with dominantly inherited dystonia. Brain. 2023;146:2730–2738. https://doi.org/10.1093/brain/awad068
- Feigin A. et al. Pepinemab antibody blockade of SEMA4D in early Huntington’s disease: a randomized, placebo-controlled, phase 2 trial. Nat Med. 2023;28:2183–2193. https://doi.org/10.1038/s41591-022-01919-8
- Furr Stimming E. et al. Safety and efficacy of valbenazine for the treatment of chorea associated with Huntington’s disease (KINECT-HD): a phase 3, randomised, double-blind, placebo-controlled trial. Lancet Neurol. 2023;22:494–504. https://doi.org/10.1016/S1474-4422(23)00127-8
- O’Flynn, LC. et al. Sodium Oxybate in Alcohol-Responsive Essential Tremor of Voice: An Open-Label Phase II Study. Mov Disord. 2023. https://doi.org/10.1002/mds.29529
- Siderowf A. et al. Assessment of heterogeneity among participants in the Parkinson’s Progression Markers Initiative cohort using α-synuclein seed amplification: a cross-sectional study. Lancet Neurol. 2023;22:407–417. https://doi.org/10.1016/S1474-4422(23)00109-6
- Giladi N. et al. Safety and efficacy of venglustat in GBA1-associated Parkinson’s disease: an international, multicentre, double-blind, randomised, placebo-controlled, phase 2 trial. Lancet Neurol 2023;22:661–671. https://doi.org/10.1016/S1474-4422(23)00205-3
- Park KW. et al. Potential Pitfalls of Remote and Automated Video Assessments of Movements Disorders. Mov Disord 2023;38:504–506. https://doi.org/10.1002/mds.29325