Which of the following statements about Lambe Eaten Myaesthenic syndrome is true:

Answer is C (Incremental response to repeated electrical stimulation ): Lambe Eaten Myaesthenic syndrome presents with an incremental response to repeated electrical stimulation. Lambe Eaten Myasthenia Syndrome What it is & Associations Paraneoplastic syndrome Associated with - Small cell carcinoma lung - Ceain autoimmune diseases Defect Presynaptic disorder Antibodies to calcium channels (P/Q type) Decrease in presynaptic release of Acetylcholine at Neuromuscular junction is the fundamental defect Presentation Onset usually after 40 years Men > Women (5: 1) Proximal limb muscles and muscles of trunk are the most commonly involved muscles Proximal limb muscles >> extraocular & lid muscles No fatiguability / Incremental response Repeated stimulation causes increased muscle strength Reflexes : Hyporeflexia or absent reflexes Autonomic changes such as dry mouth and impotence are associated Diagnosis Repeated nerve stimulation : incremental response Radioimmune assay : Antibodies against P/Q Ca2+ channels Tensilon test : Negative ( mildly positive in some) Myasthenia Gravis What it is & Associations Autoimmune disorder Associated with - Thymomas - Ceain autoimmune diseases Defect Postsynaptic disorder Antibodies against ACH Receptors Decrease in number of ACH Receptors at post synaptic muscle membrane is the fundamental defect Presentation Onset Often < 40 years Women > Men (4: 3) Craniofascial muscles paicularly lids and extraocular muscles are the most commonly involved. Extraocular & lid muscles > proximal limb muscles Fatiguability / Decremental response Repeated stimulation causes decreased muscle strength Reflexes : Intact No associated autonomic changes Diagnosis Repeated nerve stimulation : Decremental Radioimmune assay : - Anti ACHR antibody response - Anti-Musk antibodies Tensilon test : Characteristically Positive