15. Differences between MG & Myasthenic (Eaton-Lamberts) syndrome: MS MG 1.Autoimmune immunological attack on presynaptic membrane limiting the release of ACH. 2.Mosrly paraneoplastic : in 2/3 of cases due to oat cell Ca. of the lungs > 40 ys . of age & 1/3 non neoplastic occuring at any age. 3.Realative sparing of extra ocular & bulbar muscles . 4.Autonomic dysfunction occur in 50% of cases. 5. EMG shows decreases amplitude of contraction with single nerve stimulation , but repetitive stimulation at frequencies > 10htz produces normal amplitude. 6. Treatment: ACH estrase inhibitors has minimal effect. Paraneoplastic type needs management of underlying cancer with guanidine & diaminopyridine having some benefits. For nonneoplastic type steroids + atzathioprine can control immuologocal attack. 1. Postsynaptic ACH receptors Abs. 2.All autoimmune type 3. 3.Common . 4.Not present, 5.Just contrary to that. 6.Good response to ACH estrase inhibitors.
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19. Disease of muscles: MUSCULAR DYSTROPHIES Pseudohypertrophy of calves Cardiomyopathy Gower +ve. Proximal/limb girdle LC/EA XL; deled dystrophin gene Becker Pseudohypertrophy of calves Cardiomyopathy, Gower sign +ve:patient climbs thigh by hand to stand Proximal/ limb girdle 1st 5ys XL; deletd dystrophin gene Duchenne As for DM1 but cognition not affected, Muscle pain Proximal, esp thigh, sometimes muscle hypertrophy Adult AD; chr 3q Proximal myotonic myopathy (PROMM; DM2) Myotonia, cognitive dulling, cardiac conduction abnormalities, lens opacities, frontal balding, hypogonadism Face (ptosis), sternomastoids, distal limb, generalised later Any AD; triplet repeat chr19q Myotonic dystrophy (DM1) Other features Muscles affected onset Genetics Type
20. Disease of muscles: MUSCULAR DYSTROPHIES Contractures early Cardiac involvement leads to sudden death Humero-peroneal, proximal limb girdle later 4-5 years XLR; mutations in emerin gene Emery-Dreifuss Mild lower limb weakness Ptosis, external ophthalmoplegia, dysphagia, tongue weakness 30-50 years AD/AR recessive; chromosome 14q Oculopharyngeal Pain in shoulder girdle common Face/ upper limb girdle 7-30 ys AD; chromosome 4q Facioscapulohumeral (FSH) Some have calf hypertrophy Some have cardiac conduction abnormalities Limb girdle Childhood/early adult AD (type 1) AR (type 2) different chromosomes Limb girdle
I am going to be talking with you today about synaptic transmission. Since, this is a topic that involves many areas in neuroscience, and could easily be made into a semester length course, I am just going to give you a survey of what is involved in synaptic transmission. In later courses, you will go into much greater detail on each topic I discuss today. So, what is synaptic transmission and what does it entail? Well, simply put, it is the method by which neurons communicate with one another. In order for any movement, sensation, thought, or emotion to occur, many neurons have to relay and integrate messages to one another. This involves many processes both on the electrophysiological and molecular levels. If you have any questions along the way, please do not hesitate to ask. I do not mind being interrupted. If you would like background reference information to this lecture please read Part 2 of Principles of Neural Science (Kandel & Schwartz).