Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology

Abstract

Movement disorders are a common feature of autoantibody-associated diseases. Balint et al. provide a novel phenotype-oriented algorithmic approach to guide diagnosis. They review the underlying pathophysiology and point out parallels between immune-mediated and genetic conditions presenting with similar phenotypes. They consider future directions such as personalised immunotherapy.

Anti–Glutamic Acid Decarboxylase Encephalitis Presenting With Choreo‐Dystonic Movements and Coexisting Electrographic Seizures

“…GAD is also an important autoantigen in type 1 DM; GAD ab may be detected many years before the clinical onset of DM and detected in about 80% of newly diagnosed DM1 patients . Despite this common association, our patient did not present with endocrine dysfunction.…”

“…The patient also presented with eye movement abnormalities, suggestive of a possible supranuclear gaze involvement. This has been recognized as part of the anti‐IgLON5 syndrome, but in our case, the lack of a sleep disorder made this association more unlikely.…”

“…Besides a well‐known association with Stiff‐person syndrome and ataxia and much rarer progressive encephalomyelitis with rigidity and myoclonus, few cases of movement disorders associated with anti‐GAD have been reported. Sunwoo and colleagues described 2 patients, 1 with oromandibular dyskinesia and limb dystonia and another with blepharospasm, jaw deviation, and face and neck dystonia, whereas Rachanna and Tarannum presented a case of parkinsonism and dysautonomia.…”

“…Glutamic acid decarboxylase (GAD) antibodies (ab) have been associated with rare disorders, such as Stiff‐person syndrome, limbic encephalitis, cerebellar ataxia, and temporal lobe epilepsy . Other systemic autoimmune disorders have been linked to anti‐GAD ab, among them, diabetes mellitus (DM) …”

A Rare Presentation of Paraneoplastic Striatal Encephalitis Associated with Nonsmall Cell Lung Cancer

“…NSCLC, non‐Hodgkin's lymphoma, and renal cell carcinoma are also described . Clinical presentation is variable, often mimicking other disorders . Patients are older (>40 years) presenting with subacute onset of abnormal movements associated with subtle neurological features such as cognitive impairment, agitation, altered behavior, and emotional labiality …”