Eaton-Lambert syndrome

Lambert-Eaton syndrome, also known as Lambert-Eaton myasthenic syndrome, is a rare neuromuscular disorder in which IgG antibodies attacks the neuromuscular junctions — the areas where human nerves and muscles connect.

The weakness in patients with the Eaton-Lambert syndrome results from a presynaptic abnormality that results in a decrease in the quanta of acetylcholine released by the passage of the nerve impulse, although each quantum released is normal.

It seems that the Eaton-Lambert syndrome is caused by antibody-mediated autoimmune response that down-regulates the voltage-gated calcium channel and thereby impairs the calcium-dependent release of acetylcholine from the presynaptic active zone.

Muscle weakness in Eaton-Lambert syndrome tends to be symmetrical and is most pronounced in the lower extremities. Altered gait after prolonged walking usually is the initial symptom. This weakness may progress to inability to rise from a chair or walk up stairs.
Eaton-Lambert syndrome