Table 5.

Data driven and expert opinion approach

Based on the 13 antibodies identified in the systematic review, the table presents associations identified by the data-driven algorithm (grey cells) and expanded panels based on previous literature reviews and expert opinion. It starts with the main movement disorders presentation (chorea, myoclonus, dystonia, parkinsonism, stiff person spectrum disorder [SPSD; includes presentations with prominent myoclonus, such as progressive encephalomyelitis with rigidity an myoclonus], ataxia, peripheral nerve hyperexcitability [PNH], or paroxysmal dyskinesia [PxD]). Antibody test selection takes into consideration the age at onset (for example, NMDAR antibodies are more prevalent in children and young adults, while Caspr2 and IgLON5 antibodies occur later in life) and sex (for example, Caspr2 antibodies occur much more frequently in males). Other associated features may help to narrow the differential diagnosis. Of note, the spectrum of antibodies associated with movement disorders includes antibodies mainly reported in aggregated data (e.g., anti-Ma2 related parkinsonism) and other, rarer antibodies not discussed here. The table is based on typical manifestations, and does not account for the rare occurrence of atypical presentations regarding phenomenology or epidemiology. Opsoclonus-myoclonus syndrome is not included here because there is no syndrome-specific antibody; similarly, tremor is a non-specific finding in antibody-related syndromes

GAD glutamic acid decarboxylase, GlyR glycine receptor, mGluR1 mGluR1 anti-metabotropic glutamate receptor 1, ANNA-2/Ri anti-neuronal nuclear autoantibody type 2, Yo/PCA-1 Purkinje cell cytoplasmic antibody type 1, Caspr2 contactin-associated protein-like 2, NMDAR Anti-N-methyl-D-aspartate receptor, LGI-1 leucine-rich glioma-inactivated 1, CRMP5/CV2 collapsing response-mediator protein-5, ANNA-1/Hu anti-neuronal nuclear autoantibody type 2, IgLON5 immunoglobulin-like cell adhesion molecule 5, DPPX dipeptidyl-peptidase–like protein 6