Reflexes; Inflammation

February 16, 2008 at 5:05 pm

[COLOR=black]My neurologist and I were discussing reflexes. He said that a lack of reflexes is more sensory than motor. I am not sure I agree completely, but his argument makes sense.[/COLOR]
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[COLOR=black]It might be helpful to review how a reflex occurs:[/COLOR][COLOR=black][/COLOR]
[COLOR=black]a stimulus is received by the nerve endings, [/COLOR][COLOR=black][/COLOR]
[COLOR=black]the signal travels to the spinal cord,[/COLOR][COLOR=black][/COLOR]
[COLOR=black]the spinal cord reroutes the signal to a different set of nerves,[/COLOR][COLOR=black][/COLOR]
[COLOR=black]the signal travels back, and[/COLOR][COLOR=black][/COLOR]
[COLOR=black]the resulting response happens.[/COLOR]
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[COLOR=black]My neurologist’s argument was that a missing reflex was a result of the stimulus not getting to the spinal cord; in other words, the sensory nerves were the main culprits. Still, if any of these steps is slow or absent, then the reflex will be slow, weak, or missing. But to answer your question, poor reflexes does not have to imply motor involvement.[/COLOR][COLOR=black][/COLOR]
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[COLOR=black]As to the question about predominantly sensory CIDP causing weakness, it could be what Kelly said, that both sets are demyelinated. Another possibility is that the sensory nerve demyelination has led to inflammation. Still, why should an inflamed sensory nerve affect the motor nerves? Part of the reason is that the nerves are distributed in bundles. If one or several nerves in the bundle are inflamed, the others are likely to be affected by the products and results of the inflammation, perhaps severely enough to have clinical presentation. Part of the reason that prednisone, Ig, and plasmapheresis can work so quickly is that they all help to reduce inflammation.[/COLOR]