Antibodies to calcium channel are seen in -

Ans. is 'a' i.e., Eaton lamberi syndrome Lambert Eaton Mvesthenic syndromeo It is a paraneoplastic syndrome associated with small cell cancer of lung.o It is a disorder of neuromuscular junction transmission (presynaptic).Pathogenesis : -o Autoantibodies are present against voltage sensitive calcium channels.These IgG autoantibodies against voltage sensitive calcium channels reduce the number of functioning channels.# 773 is causes decrease in release of presynaptic acetylcholine.Difference between Myaesthenia Gravis & Eaton Lambert SyndromeMyaesthenia GravisEaton Lambert Syndromeo Postsynaptic Q defect (Autoantibodies direct against acetyle choline receptors)o Decrease in number of acetylcholine receptors0 at post synaptic muscle membraneMuscular involvemento Occular muscle is most Q commonly involvedo Occular muscle > proximolQ limb musclso Tendon reflexes ate intact Qo No autonomic changes Qo Presynaptic Q defecto (Antibodies directed against P/Q typeo of calcium channels')o Decrease in presynaptic release of acetylcholine QMuscular involvemento Proximal muscles of lower limb Qo are most commonly involvedo Proximal muscles > occular Q muscleso Tendon reflexes are depressed or absent Qo Slow autonomic changes such as dry Q mouth and impotenceDiagnosisDiagnosiso DecrementalQ response on repeated nerve stimulationo Antibody against acetylcholine receptoro IncrementalQ response on repeated nerveo stimulationo Antibody against P/Q channel