Common sensation was reported by Notta as affected in only three cases out of a hundred and twenty-eight; but my own experience has afforded a much larger proportion of instances in trigeminal neuralgia. Indeed, in all situations neuralgia appears to me to involve this effect, in the larger number of instances, in the early stages; later, it is supplanted in part by great tenderness on pressure in the well known _points douloureux_, and sometimes the tenderness becomes diffused over a considerable surface. I agree with Eulenburg in thinking that anæsthesia is more frequent in sciatica than in other neuralgias.
6. Secretion is often very notably affected in neuralgia; the phenomena are necessarily more easily observed in connection with affections of the trigeminal than of other nerves. In the great majority of cases the affection is in the direction of increase; at least, the watery elements of secretion are often poured out in profusion. Thus, profuse lachrymation is exceedingly common in ophthalmic neuralgia; in a large number of cases there is also copious thin nasal flux on the affected side; sometimes, however, the secretion, though copious, is semi-purulent, or bloody. Increased salivation has been noticed, by a large number of observers, in neuralgia involving the lower division of the fifth. In a smaller number of instances, the secondary effect on secretion is precisely opposite; thus both Notta and myself have observed complete dryness on the nostril on the affected side in ophthalmic neuralgia.
I might expand this chapter on the complications of neuralgia to a very much greater length; but, as regards the clinical history of these affections, it is perhaps better not to occupy more time and space. It will, however, be necessary to return to the consideration of the subject in connection with Pathology.
[15] Archiv fur Ophthalmologie, B. xii., Abth. 1, 1866.
The pathology and the etiology of neuralgia cannot be considered apart; they must be discussed together at every step. I do not mean to say that neuralgia is singular among diseases in this respect; it seems to me merely a case in which the intrinsic defects of the conventional system of separating the "causes" of disease from its pathology happen to be more glaring and more easily demonstrable than usual.
