Morphia. This drug is undoubtedly beneficial in its results, but the habitual use thereof is strongly contra-indicated, not only because of the temporary benefit received, but also because of the necessary increase in the quantity required to alleviate the pain. If persistently used the patient gradually develops the morphia habit.
Some of these remedies suffice for the neuralgias minor, but with regard to their action in cases of neuralgia major, their effect may be summed up as follows: ‘True tic doloreux has been the therapeutic despair of most physicians and surgeons,’[70] and ‘too often the operation is put off till the patient is addicted to the morphia habit, depleted in strength and vitality by drugs, sleepless nights, and years of intense suffering’.[71]
Until quite recently, with the exception of these medicinal remedies, the only other methods at our disposal in the treatment of trigeminal neuralgia were Gasserian ganglion removal and other intracranial operations on the three divisions of the fifth nerve. In 1906, however, Schlösser[72] of Munich advocated the injection of alcohol into the region of those foramina at the base of the skull through which the nerve trunks emerged. As the result of these injections it was stated that, although some slight degree of cutaneous anæsthesia frequently resulted, yet that it was usually of an unimportant and transient character, and that the pain subsided and finally ceased, remaining absent for a variable period of time, usually about ten months. In the event of recurrence the injection was repeated, each period of recurrent pain being less intense and less prolonged, whilst the periods of remission increased proportionately.
Whilst it is clear from the results obtained by those who have followed in Schlösser’s footsteps, that alcohol injections are, as a rule, reasonably satisfactory, yet it must be clearly understood that beneficial results are not always observed, and that in the event of failure the more radical intracranial operations must be carried out.
The technique of alcohol injections.
Question of anæsthetic. Freezing of the skin or other method of local anæsthesia suffices to allow of the painless introduction of the needle. A general anæsthetic should be avoided wherever possible, as the burning sensation experienced by the patient when the nerve-trunk is encountered greatly assists the accuracy of introduction.
The needle. The needle should be stout—10 cm. long, 1·5 cm. in diameter, and graduated in centimetres up to 5 cm., and provided with a blunt stilette.
Introduction. The skin is cleansed, the stilette slightly withdrawn, and the needle introduced. After puncture of the skin the stilette is pushed home, all further introduction being carried out with the blunt advancing point. When in position, the stilette is withdrawn, and a glass syringe, ready filled with alcohol, fitted to the needle and the injection made.
The solution. Purves Stewart recommends the injection of 1-1·5 c.cm. of the following solution:—
Beta eucaine, 2 grains
Absolute alcohol, 6 drs.
Distilled water to the ounce.