Lettsomian Lectures on Syphilis as a Cause of Disease of the Nervous System
Authors: W. H. Broadbent
Journal: BMJ (1874)

Syphilitic Ceremal Tuwuvor.-Among the most interesting examples of syphilitic disease of the brain, are those in which the morbid deposit takes the form of a distinct tumour.The symptoms common to nearly all cerebral tumours, when any symptoms at all are present, are, severe pain in the head, vomiting, and double optic neuritis, the pain being fixed in seat or radiating from one point, but variable in intensity at different times.Cases, however, are on record in which tumours have attained a large size without giving rise to abnormal phenomena of any kind; and, although the concurrence, for any long time, of the three symptoms men- tioned would be almost conclusive of the existence of tumour, the absence of one or other would not necessarily be conclusive to the con- trary.Superadded to these general symptoms may be hemiplegia, motor or sensory, if the central ganglia be involved, or paralysis of indi- vidual nerves if' the tumour be situate at the base of the brain, or con- vulsions if the grey matter of the surface of the hemispheres be affected.The symptom of greatest importance is unquestionably the double optic neuritis; and, as Dr. HughlingsJackson, in particular, has pointed out, it may for some time be the only symptom; or, if not quite alone, it may be associated with symptoms so slight as to have no significance independently of it.We must not wait till vision begins to suffer before examining the eyes.It is with constantly renewed astonishment, notwithstanding the frequent illustrations brought forward by Dr. Jackson, and exhibited to this Society and elsewhere, and my own experience, that I see the ex- tensive changes in the disc compatible with good vision.We are as yet in uncertainty as to the immediate mode of production of optic changes, and of the chain of causation by which they are connected with tumours.It may, perhaps, be taken as certain that one way in which changes in the optic disc are produced is by increased intracranial pressure; and it appears probable, moreover, that this intracranial pressure operates through fluid being forced along the sheath of the optic nerve between its two layers, which bulges out the sheath near the eye, and compresses the nerve and its vessels.But the optic changes may be entirely absent, or having appeared may subside, when we have every reason to suppose, from examination after death, that intracranial pressure must have ex- isted; and they may be present when we can see no cause of intracranial pressure.If the existence of fluid in a position to be carried into the optic sheath be a condition required for the production of strangulation of the nerve, the absence of effusion in the membranes at the base of the brain may explain some cases in which optic changes have not appeared.But it is riot even a settled point whether there is, or is not, a distinction between ischremia of the disc, a vascular strangulation or obstruction due to intracranial pressure, and neuritis descendens, an inflammation propagated to the disc by the continuity of the neurilemma with the pia mater; or, admitting the distinction, whether the difference can be made out by ophthalmoscopic characters.Till this is decided, we can- not so much as pass the threshold of the inquiry as to the mode of pro- duction of optic changes in diseases of the brain.If I were not held back by the doubts of men such as Dr. Hughlings Jackson and Mr. Hutchinson, whose opinion in this matter I hold to be far higher than my own, I should consider my own experience warranted me in ollowing Dr. Clifford Allbutt in recognising a difference between optic isclhamia