Wilfred Harris[69] collected 265 cases, and showed that the disease was slightly more common in men than in women—144 to 131. There appeared to be some predilection for the disease to involve the right side in preference to the left—179 to 80. In 6 cases the affection was bilateral.
Trigeminal neuralgia does not in itself lead to fatal results, but the continuous pain, the want of sleep, and the difficulty experienced in taking sufficient nourishment soon reduce the patient to such a miserable condition that, unless relieved by the surgeon, amelioration is sought in morphia or release in death.
Before proceeding further it will be convenient to enumerate certain points aiding in the differential diagnosis between the true and hysterical forms of trigeminal neuralgia.
| True Neuralgia. | Hysterical Neuralgia. |
|---|---|
| Patient old, probably over 50, and more commonly of the male sex. | Patient young, more commonly of the female sex. |
| Pain paroxysmal. | Pain severe for long periods together. |
| Vaso-motor, trophic and sensory changes common. | All these changes very rare. |
| Pain strictly unilateral and constant in site. | Pain variable in distribution, radiating irregularly to the opposite side of the face. |
The pathology of tic doloreux is most obscure. The parts requiring examination are the peripheral nerve-trunks, the ganglion, the sensory root, and the central nervous system. The last two regions may be excluded, not only on the ground that research has failed to show any constant structural changes, but also because the removal of the ganglion may be regarded as curative of the disease. The ganglion itself and the peripheral nerve-trunks remain for investigation.
In the peripheral nerve-fibres no constant material changes have been observed. The epineurium, on the other hand, is almost invariably shrunken and sclerosed. Considerable stress might be laid on this fact unless it were also taken into consideration that the nerves were examined in patients who had suffered from major neuralgia for prolonged periods of time. Similar changes have also been observed in patients who have never exhibited neuralgic symptoms.
In the ganglion itself the following changes have been observed:—(1) arterio-sclerosis; (2) alteration in the character of the nerve-fibres traversing the ganglion; and (3) adhesions between the ganglion and the surrounding parts. All these changes, however, are so inconstant that but little importance can be attached to them.
At the present time there is a disposition to regard trigeminal neuralgia in the light of an ascending neuritis, originating peripherally and ascending towards the Gasserian ganglion. Sir Victor Horsley first pointed out that the ganglion acts as a barrier to the further upward spread of the affection. This is proved by the success obtained in the removal of the ganglion.