EXTREMITIES OF THE NERVES.
541
seat, not in those parts, but in the spinal marrow or brain. It is the
first symptom of the affections of the spinal marrow and brain which
show themselves during the attack. Should an epileptic fit be occa¬
sionally arrested by the application of a ligature to the limb above
the seat of the aura epileptica, it must be owing, not to the ligature
preventing the transmission of any morbid matter, but to its pro¬
ducing a strong impression on the sensorium. It must be remarked,
however, that in the form of epilepsy which is dependent on tumours
of the nerves, a ligature applied to the limb really arrests the propa¬
gation of the irritation to the spinal cord.
If a tourniquet is applied to the arm above the elbow-joint, the
first effect is the sensation of pins and needles in all parts of the hand,
then gradually numbness and the sensation of cold ensue, and at last
insensibility to external stimuli. If now the nerves in the axilla and
arm, above the tourniquet, are irritated mechanically by means of
the fingers, the sensation of an electric shock will be felt in the hand
as distinctly as when the nerves of the fore-arm and hand are not
paralysed by pressure.
VIII. When a limb has been removed by amputation, the re-
maining portion of the nerve ivhich ramified in it may still be the
seat of sensations, which are referred to the lost part.—This is a
fact known to all surgeons, and is subject to no exception. It is
usually said that the illusion continues for some time, namely, as long
as the patient is under the care of the surgeon; but the truth is, that
in most cases it persists throughout life: of this it is easy to convince
oneself by questioning a person whose limb has been amputated, at
any period after the operation. The sensations are most vivid while
the surface of the stump and the divided nerves are the seat of in¬
flammation, and the patient then complains of severe pain felt, as if
in the whole limb which has been removed. When the stump is
healed, the sensations which we are accustomed to have in a sound
limb are still felt; and frequently throughout life tingling, and often
pains, are felt, which are referred to the parts that are lost. These
sensations are not of an undefined character; the pains and tingling
are distinctly referred to single toes, to the sole of the foot, to the
dorsum of the foot, to the skin, &e. These important phenomena
have been absurdly attributed to the action of the imagination, &c.
They have been treated merely as a curiosity; but I have convinced
myself of their constancy, and of their continuance throughout life,—
although patients become so accustomed to the sensations that they
cease to remark 'them. The feeling of tingling or creeping of ants
in the hand, foot, or whole extremity, with the same distinctness as
when the limb is still present, may be excited much more vividly by
applying a ligature or tourniquet to the stump, or by exerting pressure
on its nerve; hence patients have the feeling of their lost limb most
distinctly, when from any cause the application of the tourniquet is
again necessary. If the patient have suffered before amputation
from a local painful affection of the limb, the whole limb will still be
felt as if in pain after its removal; and pain will be felt as if in the
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