An Unusual Case of Two Paraneoplastic Neurological Syndromes in a Patient With Lung Cancer

Abstract

Paraneoplastic immune-mediated disorders have been well described in the literature. However, it is still relatively rare. The incidence has increased over the past decade due largely to the discovery of more autoantibodies. With a better understanding of the pathophysiology of different autoantibodies and clinical phenotypes, we are often able to diagnose clinically some specific paraneoplastic autoimmune neurological syndromes. We may also predict the response to treatment based on the autoantibody class. We are presenting a very unusual case of two completely different paraneoplastic syndromes with two different autoantibodies, gamma-aminobutyric acid-B (GABA B ) and collapsin response mediator protein 5 (CRMP5), in a patient with underlying small-cell lung cancer. We will discuss the differences in the two antibody syndromes, their significance, and their management.

A Case Report of a Clinically Suspected Diagnosis of Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS) Syndrome With Cardiac Impairment

“…MELAS is a maternally inherited condition that results from mitochondrial gene mutations, causing a wide range of multi-organ affectations and mainly causing mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes. The commonest genetic mutation associated with this condition is the m.3243A>G pathogenic variant in the mitochondrial gene MT-TL1, and this accounts for 80% of MELAS occurrence [ 5 ].…”

An Unusual Case of LGI1 (Leucine-Rich Glioma-Inactivated Protein 1) Limbic Encephalitis With Anti-acetylcholine Receptor and Anti-striational Autoantibodies

“…This ties into the patient's underlying thymoma as myasthenia gravis antibodies are produced in small amounts in the thymus [14]. The presence of multiple types of autoantibodies indicated a higher chance of an underlying malignancy [15].…”

Unraveling RNA Conformation Dynamics in Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like Episode Syndrome with Solid-State Nanopores

“…Its maternally inherited nature makes MELAS a poignant intersection of genetics and clinical pathology. With an incidence rate of 1 in 4000, approximately 80% of patients with MELAS have the mt-DNA A3243G substitution that is mapped to mt-Leu­(UAA), − representing the most common single-point pathogenic mutation in human populations . Another 10% of patients with MELAS have the T3271C substitution that is mapped to the U40C mutation in mt-Leu­(UAA) .…”