[A] The kathode, or negative electrode, is attached to the zinc rod; the anode, or positive electrode, to the copper or carbon.
As the nerve lesion passes away, the voluntary contraction generally begins to return before the nerves show any reaction to electrical stimulus.
The following three cases in which the electrical reactions of the muscles were determined, give examples of typical cases of lead paresis. In No. 3, owing to the fact that the case was treated immediately the paralysis occurred, complete recovery had taken place, and, as will be seen, the electrical reactions have again become normal.
Case 1.—Litharge and blast-furnace worker. Employed in lead works, where a large number of different metallurgical processes associated with the recovery of lead from the ore were carried on. Double wrist-drop, existing for eight years, untreated until some four years after paralysis took place, when slight improvement occurred. The electrical reactions show that the extensor communis digitorum on the right side is completely degenerated, whilst the first interosseous of the right side show reactions of degeneration. On the left side the extensor communis digitorum showed normal but very feeble reaction. This latter point is one of considerable importance if early hæmorrhage accounts for lead paralysis, for if the nerve itself was completely destroyed, or if, as was the case, the muscle appeared completely paralyzed on inspection, obviously the nerve-supply must be completely cut off if the lesion was due to destruction of the nerve of the spinal cord or to the destruction of the lower motor neuron. On the other hand, the presence of small localized fibrillar contraction, found by the galvanic current, together with the presence of a slight reaction to faradism, suggests that some small portion of the nerve has remained unaffected, and that for this reason certain portions of the muscle have not undergone degeneration—a circumstance which can hardly be expected if the cause of the paralysis is in the destruction of the whole of the nerve-supply.
| ELECTRICAL REACTIONS IN LEAD PARALYSIS. (CASE 1.) | |||||||
|---|---|---|---|---|---|---|---|
| Muscle. | Galvanism. | Faradism. | Remarks. | ||||
| M.A. | M.A. | ||||||
| R. Deltoid (anterior portion) | K.C.C. | 8 | A.C.C. | 8 | Good | Evidently extensor communis digitorum on right side is completely degenerated.First interosseous on right side show reactions of degeneration. On left side extensor communis digitorum showsnormal but feeble contractions | |
| L. Deltoid (anterior portion) | K.C.C. | 6 | A.C.C. | 9 | Good | ||
| R. Deltoid (posterior portion) | K.C.C. | 6 | A.C.C. | 9 | Good | ||
| L. Deltoid (posterior portion) | Good | ||||||
| R. Supinator longus | K.C.C. | 6 | A.C.C. | 10 | Reaction brisk | Good | |
| L. Supinator longus | K.C.C. | 5 | A.C.C. | 6 | Reaction brisk | Good | |
| R. Extensor communis digitorum | No reactions either A.C.C. orK.C.C.[15] | No reaction | |||||
| L. Extensor communis digitorum | K.C.C. | 8 | A.C.C. | 12 | Brisk, but feeble | Feeble reaction | |
| R. Extensor primi internodii pollicis | K.C.C. | none at 13 | A.C.C. | 13 | Brisk | Good | |
| L. Extensor primi internodii pollicis | K.C.C. | 6 | A.C.C. | 12 | Reaction brisk | Good (but less than right) | |
| R. Extensor carpi ulnaris | K.C.C. | 8 | A.C.C. | 8 | Brisk Contraction | Good | |
| L. Extensor carpi ulnaris | K.C.C. | 8 | A.C.C. | 12 | Brisk Contraction | Good | |
| R. First interosseous | K.C.C. | 8 | A.C.C. | 6 | Contraction slow | No reaction | |
| L. First interosseous | K.C.C. | 6 | A.C.C. | 6 | Brisk contraction | Good | |
| R. Second interosseous | K.C.C. | 8 | A.C.C. | 10 | Brisk Contraction | Slight reaction | |
| L. Second interosseous | K.C.C. | 6 | A.C.C. | 8 | Brisk Contraction | Good | |
| R. Third interosseous | K.C.C. | 9 | A.C.C. | 6 | Brisk Contraction | Slight reaction | |
| L. Third interosseous | K.C.C. | 6 | A.C.C. | 8 | Brisk Contraction | Slight reaction | |
| R. Fourth interosseous | K.C.C. | 8 | A.C.C. | 6 | Brisk Contraction | Slight reaction | |
| L. Fourth interosseous | K.C.C. | 10 | A.C.C. | 9 | Brisk Contraction | Good | |
| ELECTRICAL REACTIONS IN LEAD PARALYSIS.(CASE 2.) | |||||||
| Muscle. | M.A. | Galvanism. | Faradism. | Remarks. | |||
| R. Deltoid | 9 | Slow reaction A.C.C. > K.C.C. | No reaction | Reaction of degeneration | |||
| L. Deltoid | 9 | Slow reaction A.C.C. > K.C.C. | Slow reaction | ||||
| R. Extensor communis digitorum | 9 | Slow reaction A.C.C. > K.C.C. | No reaction | ||||
| L. Ditto | 9 | Slow reaction | No reaction | ||||
| Ante brachial and brachial groups give normal reaction | |||||||
| ELECTRICAL REACTIONS IN CASE OF RECOVERED WRIST-DROP. (CASE 3.) | |||||||
| Muscle. | M.A. | Galvanism. | Faradism. | Remarks. | |||
| R. Extensor communis digitorum | 9 | Good reaction K.C.C. > A.C.C. | Good reaction | All muscles react well to both currents; no sign of any reaction of degeneration | |||
| L. Ditto | 9 | Good reaction K.C.C. > A.C.C. | Good reaction | ||||
| R. Extensor ossis metacarpi pollicis | 9 | Good reaction K.C.C. > A.C.C. | Good reaction | ||||
| L. Ditto | Good reaction K.C.C. > A.C.C. | Good reaction | |||||
| R. Deltoid | Good reaction K.C.C. > A.C.C. | Good reaction | |||||
| L. Deltoid | Good reaction K.C.C. > A.C.C. | Good reaction | |||||
| R. Extensor carpi ulnaris | Good reaction K.C.C. > A.C.C. | Good reaction | |||||
| L. Extensor carpi ulnaris | Good reaction K.C.C. > A.C.C. | Good reaction | |||||
| R. Interossei | Good reaction K.C.C. > A.C.C. | Good reaction | |||||
| L. Interossei | Good reaction K.C.C. > A.C.C. | Good reaction | |||||
This case is a typical one of the anterior brachial type, showing partial recovery of function. The man is able to grasp, although the wrist becomes strongly flexed in so doing.
Case 2.—We are indebted to Dr. Gossage for this case, which was presented at the Out-patients of the Westminster Hospital; and to Dr. Worrell, who made the electrical investigations. We are further indebted to Dr. Worrell for the reports which are given in tabular form of the electrical reactions of these three cases.
This is a case of brachial type, with weakness of both deltoids, and the patient was unable to raise his right arm at the shoulder. It will be seen that there is here also evidence that the electrical contractility diminishes before the entire loss. It will be also noticed that the supinators are unaffected.
Case 3.—These are the electrical reactions of a case which had recovered. This man showed the ordinary anterior brachial type, which came on suddenly, although he had shown distinct weakness of wrists when forcible flexion was performed for nine months previously, but there had been no obvious increase in the weakness. He was immediately removed from his work, and within seven days paralysis, which at first only affected the extensor communis digitorum, had spread to the minimi digiti and the extensor indicis, the opponens pollicis being also involved on the right side. He was treated from the start with faradic current, and was instructed to use the battery himself, which he did twice a day for a year. At the end of two months he was sufficiently recovered to be given light work, and at the time of taking the reactions his wrists have so far recovered their power that we were unable to flex them forcibly.
The progressive weakness noted in the three cases has already been referred to, and may be a prodrome of paralysis, but there may be recovery without paralysis supervening.