A disorder in which acetylcholine cannot be released from the nerve endings in the brain to cross the synapse and stimulate muscles to contract; also known as Lambert-Eaton syndrome, myasthenic-myopathic syndrome, and Eaton-Lambert myasthenic syndrome. This disorder differs from myasthenia gravis, in which acetylcholine is released but cannot bind with muscles to allow them to respond. Eaton-Lambert syndrome is most often associated with lung cancer, but can be caused by other forms of cancer or autoimmune diseases. People with Eaton-Lambert syndrome describe muscle weakness and severe fatigue (usually of muscles of the legs, arms, and trunk first). Unlike myasthenia gravis, facial weakness is rarely a symptom; dry mouth, loss of bowel or bladder control, muscle aches, and decreased reflexes may occur. The treatment of choice is to treat any present cancer. Immune suppressive therapy can sometimes be helpful.
A neuromuscular condition arises when nerve cells do not release an adequate quantity of the neurotransmitter acetylcholine. This disorder is frequently linked to a form of lung cancer called small cell carcinoma. The primary symptom manifests as severe muscle weakness affecting both the torso and limbs.