Lambert-Eaton syndrome is an autoimmune disorder in which faulty communication between nerves and muscles leads to muscle weakness. In this syndrome, substances produced by the immune system attack nerve cells. This makes nerves cells unable to release enough of a chemical called acetylcholine. This chemical transmits impulses between nerves and muscles. The result is muscle weakness. Lambert-Eaton syndrome may occur with cancers such as small cell lung cancer or autoimmune disorders such as vitiligo, which leads to a loss of skin pigment. Symptoms may include: weakness or loss of movement that can be more or less severe, difficulty chewing, difficulty climbing stairs, difficulty lifting objects, difficulty talking, drooping head, need to use hands to get up from sitting or lying positions, swallowing difficulty, gagging, or choking. Vision changes can occur such as: blurry vision, double vision, and problems keeping a steady gaze. The symptoms of Lambert-Eaton syndrome may improve by treating the underlying disease, suppressing the immune system, or removing the antibodies. However, not everyone responds well to treatment.