Update from the COVID-19 Related Movement Disorder Study Group
In 2021, MDS formed a new study group with the aim to shed more light on infection-related movement disorders (IRMDs), the Infection Related Movement Disorder Study Group. These disorders, which occur during or after an infectious illness with or without apparent involvement of the nervous system, are one of the major causes of morbidity and mortality globally, albeit with wide geographic variations. Pathogens include bacteria (streptococcal, mycobacterium tuberculosis, treponema pallidum, etc.) and viruses (retrovirus, arbovirus, measles, etc.), parasites (cysticercosis, toxoplasma) and prions.
Yet, the exact pathophysiology beyond the direct involvement of the basal ganglia and extrapyramidal system remains elusive for most forms. The associated disorders have a broad phenotypic spectrum and varying temporal profiles. This includes long-term sequelae in some cases, where the infection may have occurred years prior to the onset of the movement disorder. Examples include subacute sclerosing panencephalitis (SSPE), a progressive neurological complication of the measles virus, and encephalitis lethargica as an aftermath after the Spanish flu. The recent corona virus pandemic also led to concern of delayed neurological/ neurodegenerative sequelae, reigniting interest in this group of movement disorders.
In a first step, the study group members chose to focus on three topics:
An overarching project to formulate diagnostic criteria and define levels of diagnostic certainty for IRMDs (e.g. possible, probable and definite) based on clinical and laboratory findings. Two disease-specific approaches focus on
HIV-related diseases and
COVID-19-related movement disorders.
Regarding the latter, MDS provides valuable up-to-date resources including a repository of published articles that demonstrate the broad phenotypic spectrum (mostly myoclonus/ataxia in the acute phase, but all sorts of organic and pandemic-related functional movement disorders have been reported) and related implications.
To learn more about the long-term outcome of these patients and any potential causal association of the infection and late-life neurodegeneration resulting in disorders such as parkinsonism/dementia, the study group recently initiated a survey where treating physicians can share their observations. Further input from Moving Along readers is welcome.
Further long-term goals of the study group include studying the epidemiology of IRMDs based on geographical regions, the identification of risk factors that predispose to the development of IRMDs, and the creation of an International Resource Database with video-based case studies of common and rare IRMDs.
You can learn more about the Infection Related Movement Disorder Study Group, its board members, the missions and objectives, on the Study Group webpage.