Surgical operations for neuralgia are of three kinds—section (neurotomy), removal of a piece of nerve (neurectomy), and nerve-stretching. The two former operations are of course rarely practised, except upon the purely-sensitive fifth pair of nerves, the latter upon mixed nerves also.
Neurectomy is now almost always substituted for simple neurotomy, and sometimes still more effective means are taken to prevent the reunion of the nerve, such as doubling over the cut end, destroying the nerve throughout the length of the bony canal in which it lies, and even plugging the canal with cement.29
29 Heustis (Med. News, Dec. 8, 1883) found that the infraorbital nerve could be readily drilled out with a piece of piano wire.
The inconvenience following nerve-section is as nothing compared to the pain of a severe and intractable neuralgia. It has rarely happened that the disease has been increased by the operation, and under proper antiseptic precautions the surgical risks are not great. There is some chance of permanent cure, and a much greater chance of securing an immunity from pain for a long period.
It is important to remember that when the neuralgia occupies the distribution of several branches of the fifth nerve, an operation on the one primarily or most severely affected may relieve the pain in all. On the other hand, the converse may be true,30 inasmuch as the same district is supplied by recurrent fibres from several different sources. Before any operation is decided on it should be remembered that even in apparently desperate cases of trigeminal neuralgia the persistent and thorough use of tonic and other remedies may in the end be crowned with success, perhaps at the moment when it is least expected.
30 Cartaz, Des névralgies envisagés au point de vue de la sensibilité récurrente.
During the past few years the operation of nerve-section has been to some degree superseded by that of nerve-stretching, as being less serious in its immediate (though not necessarily in its remote) consequences, and sometimes more efficacious. Hildebrandt, indeed, raises the question whether the traction which is apt to be exerted when a nerve is cut is not an important element in bringing about the result. On the other hand, cases are reported where neuralgia which had not been relieved by stretching was cured by resection.31
31 Nocht, Ueber die Gefolge der Nerven-dehnung.
The best showing for the operation is in the treatment of sciatica, but most of the other superficial nerves, including the intercostals, have been successfully treated in the same manner.
On the other hand, this treatment is not without its dangers. Apart from the risks of the operation itself, cases have been reported in which the spinal cord has been injured, so that chronic myelitis has been set up, and a greater or less degree of paralysis—rarely permanent, it is true—may be induced by the direct injury to the nerve.