Autoimmune Atypical Parkinsonism Profile, Serum

Autoimmune atypical parkinsonism is characterized by parkinsonian symptoms accompanied by neuron-specific antibodies, often presenting with abnormal cerebrospinal fluid (CSF) findings and a notable response to immunotherapy. Atypical parkinsonism, also referred to as Parkinson plus syndromes, encompasses a diverse group of neurological disorders marked by bradykinesia, rigidity, tremor and postural instability, along with a poor response to levodopa and additional distinguishing clinical features. 

In some cases, autoimmune parkinsonism has been identified as a paraneoplastic condition, with varying responses to treatment. It has been linked to specific antibodies, including glutamic acid decarboxylase (GAD) 65, voltage-gated potassium channel (VGKC) complex, leucine-rich glioma-associated protein (LGI1) and contactin-associated protein-like 2 (CASPR2), though not all antibody-associated cases present with parkinsonism. 

Furthermore, autoimmune parkinsonism has been associated with systemic autoimmune disorders such as Sjögren’s syndrome and systemic lupus erythematosus. In children, it has been observed in encephalitis lethargica syndrome, which is characterized by sleep disturbances, lethargy and parkinsonian symptoms.