This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
It is only by stimulating the paralyzed part, or the nervous centre or nervous trunk supplying it, that electricity operates in the cure of palsy. It is obvious, therefore, that it is wholly inapplicable to cases in which the affection depends upon high vascular congestion, inflammation, or other organic disease of the nervous centres. It is not less obvious that it can be of no use, when similar disease in the connecting nerves prevents the transmission of influence from the centres, even though these may be in a healthy state. Under these circumstances, so far from being serviceable, it may do serious harm, not only when applied directly to the diseased centres or nerves, but even when limited to the para-i part; for any excitement in this part reacts upon the nervous centres, and of course upon the nerves which convey impressions to them But, when all excitement in nervous centres or trunks has subsided. when the organic injury baa been repaired, and the continuance of the palsy is owing simply to debility in the centres, or the habit of inertia. or defective nutrition in the paralyzed part, the electric influence is strongly indicated, and often does great service.
The same remark is applicable to cases of palsy from wounds or other mechanical injuries of the nervous centres or trunks. It is vain to stimulate the palsied part until the wound has healed, or the injury been repaired. But after this event, it not unfrequently happens that the palsy persists, and sometimes seems as if it would persist indefinitely, unless the sluggish centre be stimulated, or the paralysed part restored, by suitable excitation, to its proper organic condition and due sensibility. Perhaps, under these circumstances, no one agent is so efficient as electricity, because no one can be brought to bear so accurately upon the seat of the disease.
It must be observed that, in thus limiting the power of electricity in paralytic affections, I have reference to the excitant power of the remedy over the muscle. But, as will be shown directly, electricity may sometimes be used with great effect in the cure of certain chronic cases of inflammation; and thus, in cases of palsy dependent on chronic inflammatory thickening of the supplying nerve, a cure may be hoped for by the antiphlogistic power of the agent directed to the diseased part of the nerve.
In all cases of palsy arising from simple debility or depression of the centres, and all those of local origin, not dependent on irreparable loss of parts, or other organic injury, much good may be hoped for from electricity.
In relation to the precise circumstances under which, in the cases above mentioned as indicating this agent, it may be used with tin-greatest benefit, to the precise modes, moreover, in which it may be most effectually employed, and the probable results in each case, nothing has appeared which, so far as I am able to judge, approaches in value the recent contributions of M. Duchenne to this branch of therapeutics. In the following remarks on the use of the remedy in palsy, the reader will please to ascribe to that author most of the credit of what be may find in them that is meritorious.
In palsy, the sensibility and power of motion may both be lost, or either, without the other.
In reference to the condition of the muscles, palsies may be classified according to the mode in which the part affected is influenced by the electric current; and, by attention to these differences, great assistance is gained, not only in diagnosis, but in the proper application of the remedy. There are two classes of the affection; one in which the muscle does not contract, or contracts but slightly and inefficiently, under the electric stimulus, and the other in which it responds readily to the stimulus, and contracts whenever it is applied. In one case the electro-contractility is lost or impaired, in the other it remains untouched. To the former class belong palsies depending on lesions, traumatic or otherwise, of the spinal marrow or nervous trunks proceeding from it, and the palsy of lead; to the latter all the purely cerebral palsies, whether proceeding from hemorrhage, inflammation, or other lesion, the palsies denominated rheumatic and hysterical, and those dependent on atrophy or fatty degeneration of the muscle itself, which exhibits this property so long as any of the muscular fibre is left. The electro-sensibility, or susceptibility to painful impression from electricity, is somewhat differently modified. Generally speaking, a loss or diminution of electro-contractility is accompanied with the same condition of electro-sensibility; but with integrity of the electro-contractility, the sensibility may be normal, increased, diminished, or quite lost. Having made these preliminary observations, we will proceed to the consideration of the special palsies. The reader will remember that it is the electricity of induction, the form, namely, developed by the magneto-galvanic or magneto-electric machines, that is employed, unless the fact is otherwise specially stated. We may sometimes use M. Duchenne's term of faradisation, to signify this mode of applying electricity.