THE PATHOLOGIC MECHANISM OF TREMOR
Journal of the American Medical Association (JAMA)
New Jersey, Illinois and Michigan, covering a population of over thirty-four millions. The prosecutions have not been numerous and still more rarely have midwives been severely punished for neglect in this respect. But the very existence of this law has had an admirable effect, and wherever a midwife has thus been brought to a sense of her duty, even by arrest, that has had a better effect upon the remainder of her class than all the lectures given and pamphlets published. We call attention to
... call attention to this law for the reason that it should be passed also by the legislatures of other States and we trust that ophthalmologists, who most frequently see these sad results of ignorance and delay of midwives, will take the matter in hand, and also that medical journals in States without this pro¬ vision will agitate the subject, so that when their legislatures convene, as most of them do about this time of the year, some move may be made to extend still further the effects of this beneficent law. THE PATHOLOGIC MECHANISM OF TREMOR. Although it is one of the most common of morbid motor symptoms and a very general accompaniment of states of weakness the phenomenon of tremor has not yet received a perfectly adequate or satisfactory explanation. We can conjecture of course its mechanism and assume, with Dana, that it is a derangement in the rhythm and force of the tonic influences proceeding from the brain to the muscles, or that it is in some way connected with impaired nervous conduction, but the underlying states that give rise to these lesions of function have not been made clear, nor has this been generally seriously attempted in the works treating of nervous disorders. We can say therefore with Landon Carter Gray, in Dercum's text-book of nervous diseases, that the intimate pathology of tremor has been so far an unknown quantity, notwithstanding all the clinical studies and pathologic investigations of the various disorders of which it is a characteristic symptom. While it is true that as yet we have had no perfectly satisfactory theory of tremor, as regards, at least, its ultimate cause, one thing can be assumed as tolerably certain, that it is of central, and probably cerebral, rather than of peripheral origin. Some authorities have admitted the possibility of lesions of the peri¬ pheral motor tracts participating in its production, but this must be from interference with cerebral impulses rather than from the local lesions themselves and were conduction altogether interrupted it is not probable that tremor would occur. In a recent paper in the Wiener medicinische Wochenschrift, Adamkiewicz reports the results of a clinical and experimental study of this subject, which seem to throw a certain possible light upon the possible pathologic mechanism of the symp¬ tom. He starts with the assumption that the phe¬ nomenon is of cerebral origin; there is no tremor that continues during sleep and from this it may be inferred that it is a phenomenon of active central innervation, over which however the will appears to have prac¬ tically no control. It may be defined as a series of involuntary muscular movements of very brief dura¬ tion, of central origin, and independent of the will. To demonstrate its character Adamkiewicz employed the following experiment: A piece of laminaria was introduced under the dura mater of a rabbit, and its gradual expansion in that situation caused first spasm followed later by paralysis and spontaneous tremor. Tremor, therefore, he concludes is only a higher grade of spasm, and both, in spite of the pathologic increase of muscular tonus in spasm, are alike paralytic phe¬ nomena.