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Injuries of nerves and their consequences - Reflex Sympathetic ...

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176 INJURIES OF NERVES.<br />

in the limbs. As regards these latter, it is likely that the<br />

have some<br />

utter absence <strong>of</strong> muscular movement may<br />

influence in causing lowered temperature, but a far larger<br />

share may be due to atrophic changes in vasal muscles<br />

<strong>and</strong> to <strong>their</strong> subsequent contraction. As the voluntary<br />

muscles <strong>and</strong> other parts waste away, the general calibres<br />

<strong>of</strong> the greater trunks, both arteries <strong>and</strong> veins, must be<br />

diminished, <strong>and</strong> the circulation lose all <strong>of</strong> those hastening<br />

influences which every muscular movement occasions, so<br />

that in time the general temperature comes at last to be<br />

distinctly lessened. The slight rise <strong>of</strong> the thermometer<br />

which is seen in parts <strong>of</strong> the body suffering from glossy<br />

skin <strong>and</strong> burning,<br />

is<br />

probably due to localized palsies <strong>of</strong><br />

vessel walls, owing either to direct nutritive changes or<br />

to reflected impressions, competent to bring about such a<br />

condition.<br />

There is a curious <strong>and</strong> interesting discrepancy between<br />

the physiological <strong>and</strong> the clinical results as to the local<br />

temperatures observed after nerve sections. Bernard has<br />

shown that section <strong>of</strong> the anterior or posterior spinal<br />

nerve roots, or, indeed, <strong>of</strong> both, does not materially alter<br />

the temperature <strong>of</strong> the related tissues, while, on the other<br />

h<strong>and</strong>, division <strong>of</strong> the main nerve <strong>of</strong> a limb, as the sciatic<br />

after it has been joined by sympathetic filaments from<br />

the pelvis, results in considerable elevation <strong>of</strong> temperature<br />

in the leg. Schifi" believes, however, that portions<br />

<strong>of</strong> the vaso-motor <strong>nerves</strong> pass with the spinal nerve roots,<br />

<strong>and</strong> that <strong>their</strong> division causes slight elevation <strong>of</strong> the thermometer,<br />

while a higher temperature is to be attained by<br />

section <strong>of</strong> the main nerve <strong>of</strong> the limb. Neither physiologist<br />

has considered the influence <strong>of</strong> partial section or<br />

<strong>of</strong> irritation <strong>of</strong> <strong>nerves</strong>. I am aware <strong>of</strong> no clinical observation<br />

which records the early rise in temperature after<br />

total section <strong>of</strong> the main nerve <strong>of</strong> a member; but this<br />

may be due to the fact that the temperature examinations

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