Numerous neurological disorders affecting the central and peripheral nervous system can be attributed to the immune system through multiple effector mechanisms. However, current treatments could be drastically improved by faster and more accurate diagnosis. The sample collection will benefit to patients with rare neuroimmune syndromes such as Autoimmune Encephalitis (AE) and Paraneoplastic Neurological Syndromes (PNS) leading to a better and early diagnosis, as well as treatment improvement.