Blistering by Cantharidin is a favourite routine, the plaster, collodion or liquor being employed. The plaster is decidedly to be preferred, as the duration of its application can be so gauged as to produce a mild degree of vesication after 2 or 3 hours, when the blister may be removed to another spot.over the painful nerve and the application continued for a longer period. In this manner a series of so-called " flying blisters " may be employed in the treatment of sciatica, the skin over the nerve being irritated from the notch to the heel.
Anstie applied the blister over the posterior branch of the spinal nerve trunk, from which the affected intercostal branch springs. In facial neuralgia a small circular blister may be applied over the temple, behind the ear or over a tender point till complete vesication occurs. A combina tion of counter-irritation and local anodyne treatment may be tried by rapidly blistering the skin over a neuralgic nerve with a few drops of strong Ammonia on cotton-wool covered in by a watch-glass. After snipping the bulla, any alkaloid, as Aconitine, Veratrine, Atropine, Morphia or Cocaine in minute amount, may be dusted over the abraded surface, or this may be dressed by an ointment containing the alkaloid. Mustard as a counter-irritant often aggravates neuralgic pain.
Capsicum, as Chili Paste or Calorific Wool, is sometimes valuable when employed in very chronic cases. Strong Iodine preparations may be similarly used. Leeching has occasionally proved useful in very acute cases when applied over a tender point or where the nerve issues from a dense fascia or through a bony canal; probably the cases relievable in this manner are always examples of acute neuritis and not of true functional neuralgia. Any form of counter-irritation which requires friction should never be attempted in acute neuralgia.
Various forms of apparatus for producing mechanical vibrations are in use. The best of these are driven by the electric current such as the Ruk, Barker, or Granville machines. By a suitably shaped applicator laid over the skin a series of minute regular strokes may be employed to set the nerve and underlying tissues into vibration without causing pain or jarring effects. The benefits obtainable are comparable to those effected by massage without the danger of irritating the nerve.
Electricity has been employed in endless ways. As a rule the best results are obtainable from the continuous or galvanic current of low tension produced by a battery of several cells, and the Leclanche element is the most convenient. A large wet-cell battery may be easily rigged up in the patient's house by any intelligent hellhanger. The stabile anodal method of application is the most soothing and sedative, and,by a careful attention to the switching on and off of the current no shock or painful sensation need be experienced. The negative pole (kathode) should be attached to a large moistened rheophore and applied to the skin over an indifferent part and the positive electrode placed over a sensitive or tender spot in the course of the nerve. When thus employed the nerve in the region of the anode is in a condition of decreased excitability after the current is slowly turned on. 3 to 8 milliamperes may be permitted to pass for io to Is minutes, and the applications may be repeated daily for a few weeks, care being taken to keep the skin and the electrodes quite moist throughout the whole of each séance. The labile method may be employed in chronic cases, the anode being moved along the course of the nerve, without, however, breaking contact.
In sciatic and brachial neuralgia the kathode may be dropped into a bath and the anode applied as before, or the 4-cell bath of Schnee may he used.
The interrupted current may be tried when the continuous fails, but as a rule it should not be used in acute cases. A strong current in chronic cases may be employed as a counter-irritant.
Static electricity is used in various ways. The best is to place the patient in an insulated chair connected with the positive pole of the machine, and after he has been charged with electricity, the operator approaches a conducting material towards the affected region, so as to produce " the electric breeze " without withdrawing sparks.
11 igh-frequency currents may he employed in a manner similar to the above and the condensing electrode (a pointed electrode enclosed in a glass tube and insulated by a glass handle) may he permitted to approach closely to the skin over the affected nerve so as to produce a " breeze " without sparking.