Discussion #1 Nervous system
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Guy McKhann, M.D., a neurologist at the Johns Hopkins School of Medicine, describes a ward of Beijing Hospital that he visited on a trip to China in 1986. Dozens of paralyzed children—some attached to respirators to assist their breathing—filled the ward to overflowing. The Chinese doctors thought the children had Guillain-Barré syndrome (GBS), a rare paralytic condition, but Dr. McKhann wasn’t convinced. There were simply too many stricken children for the illness to be the rare Guillain-Barré syndrome. Was it polio—as some of the Beijing staff feared? Or was it another illness, perhaps one that had not yet been discovered? Dr. McKhann decided to perform nerve conduction tests on some of the paralyzed children in Beijing Hospital. He found that although the rate of conduction along the children’s nerves was normal, the strength of the summed action potentials traveling down the nerve was greatly diminished.
Dr. McKhann then asked to see autopsy reports on some of the children who had died of their paralysis at Beijing Hospital. In the reports, pathologists noted that the patients had normal myelin but damaged axons. In some cases, the axon had been com- pletely destroyed, leaving only a hollow shell of myelin. Dr. McKhann named the disease acute motor axonal polyneuropathy (AMAN)—might be triggered by a bacterial infection. He also thought that the disease initiated its damage of axons at neuromuscular junctions.
1. Briefly describe GBS, Which division(s) of the nervous system may be involved in GBS?
2. How can one diagnose GBS?
3. Name other diseases involving altered synaptic transmission.
4. Briefly describe AMAN.
Your response must be between 400 to 500 words.