Leprosy

by G. Armauer Hansen; Carl Looft

The interosseous muscles, of the hands and feet atrophy, so that the interosseous spaces appear as furrows. The thenar and hypothenar muscles also disappear, and the first interosseous space becomes a depression. The muscles of the forearms and calves also atrophy and lose their power, but complete paralysis is never developed; the patients can always move their hands and walk. In the face, all the muscles atrophy and lose their power, and thus all expression is lost. The masseter muscles occasionally, though very rarely, become so atrophic, that the lower jaw drops, and must be retained in position by a bandage. Paralysis of the Orbicularis Oris leads to dropping of the under lip, and to extreme difficulty in closing the mouth, and consequent escape of saliva. (See [Plate V]—a case of maculo-anæsthetic form completely cured and anæsthetic. The maculæ were developed in 1857, and the patient is still alive.) Paralysis of the Orbicularis Palpebrarum renders the closure of the eyes impossible, and paralytic ectropion of the lower lid is developed. The results of this on the eye we will refer to later. The muscular atrophy is by no means always symmetrical; one hand may present marked atrophy, while the other is tolerably useful. This indicates the peripheral development of the paralysis, as does the fact that the muscular sense is preserved, and in particular that no ataxic symptoms appear. The patients can do fine knitting and needle-work with their paretic hands. Their gait has a peculiar character, from the difficulty with which the weakened muscles raise the feet, but they can both stand and walk quite well with closed or bandaged eyes. As we shall see later, this clinical observation corresponds with the results of the anatomical examination of the cord.

Along with the paralysis and atrophy of the muscles, there appear also, as the result of the destruction of the nerve trunks, trophic affections of the bones and of the skin. The changes in the skin have been already described; when the anæsthesia is advanced, there always appear ulcerations under the heel and the ball of the foot. Most of these owe their origin simply to pressure; the weight of the body is too much for the atrophic skin. They are always callous, heal with great difficulty, and so long as the patient goes about, not at all. The ulcers are not usually deep, but it may happen that they penetrate as far as the bone, and lead to necrosis. But usually necrosis of the bones is preceded by periostitis, and when the pus makes its way out, an ulceration leading down to necrotic bone is formed. We have sometimes seen the formation of a blister precede the ulceration, but it is rare, and it is certainly not true, as stated by many authors, that ulceration of the sole is always preceded by a bulla. Not only on the feet but also on the hands, necrosis with exfoliation of bone takes place; the phalanges are especially attacked. When the atrophy of the muscles is advanced, the fingers are always claw-like, with extension of the first phalanx. The joints consequently often appear swollen, although no joint affection is present. The phalanges and the metacarpals undergo simple atrophy, becoming very thin at the middle, and since the joints retain almost their normal thickness, they appear swollen by contrast. As already noted, this clawing of the fingers is accompanied by no disease of the tendon sheaths. The bones in the feet undergo the same form of atrophy.

If, in addition to this atrophy of the bones, which was first noted and demonstrated by Prof. Hjalmar Heiberg, there ensues necrosis with exfoliation of whole phalanges or metacarpals (the carpal bones very rarely necrose), there is great mutilation of the hands and feet; all the fingers of the hand may go, and there remain on the diminished carpus only small, soft processes, each supplied with a nail—the remnants of the fingers. The toes disappear from the feet, the metatarsal bones atrophy, and several of the tarsal bones may exfoliate; so that ultimately there remains of the foot only a pyramidal cushion at the lower end of the leg. In most cases we must regard external injury as the cause of these necroses. The patients feel nothing when they injure themselves; they may burn their hands at a stove without noticing it. Under such circumstances it is not to be wondered at, that inflammation is readily excited, especially as the vitality of the parts evidently diminished. But it is remarkable how well operation wounds heal. One may do pretty extensive necrotomies, and the wounds heal well and quickly, either by granulation or by first intention. In such operations it is a frequent experience that the bone is reached before the patient feels anything, but he immediately feels pain when the periosteum is scraped or the bone attacked with forceps or saw. We believe, however, that it is only nervous individuals who complain of pain; though it is certain that when the bone is meddled with, something is felt. Probably in this connection may be explained the statement of the patients, that when walking they feel the ground. It is easy to demonstrate that a patient who is quite unconscious of any irritation on his skin, can perceive deep pressure fairly well.

These necroses and trophic disturbances, together with the muscular contraction, cause the mutilation characteristic of the last stage of the disease, which was at one time described as a special form, Lepra mutilans.

We said above that the finger joints appear enlarged on account of the atrophy of the shaft of the bone. In some cases, however, the joints, especially the ankle, show changes which must either be regarded as the remains of the rheumatoid affections of the eruptive period, or as trophic articular changes, corresponding to those seen in Tabes dorsalis. We have seen ankles and knees, but especially ankles, presenting such an appearance. In some cases post mortem examination shows widespread tuberculosis of the synovial membrane and of the ends of the bones, which we shall refer to more particularly under the pathological anatomy.

As we have already mentioned, the eyelids can no longer be closed on account of the paralysis of the orbicularis palpebrarum, and consequently the under part of the cornea remains uncovered during sleep. This leads to a punctiform drying of the epithelium of the cornea, and further, to an injection of the conjunctivæ at the under margin of the cornea; then the vessels gradually attack the cornea, which becomes opaque, at first around the xerotic spots, and later in its whole under part. It may go on to ulceration with rupture of the cornea and prolapse of the iris, and finally to complete atrophy of the globe. As a result of the paralysis, the lower lid is always ectropic, at first at its inner end, and later, completely. As the lower punctum is thus drawn away from the bulb, the tears run down over the cheeks, and the paralysed countenance looks still more woe-begone.

In the later stages, when the facial paralysis is very pronounced, the senses of smell and taste may be very much diminished, or completely lost.

We often see symptoms which are not proper to the disease itself developing during its course, such as obstinate cardialgia, acid pyrosis, and vomiting of a slimy nature indicating gastric catarrh. Diarrhœa or chronic obstruction is by no means rare, nor is albuminuria dependant on parenchymatous, interstitial or amyloid nephritis.

The course of maculo-anæsthetic leprosy is essentially chronic. Cases usually last between ten and twenty years; some may even exceed forty.

The patients often die cachectic, without one being able to find on the post mortem table any definite cause of death, or they may—though in our aseptic and antiseptic times more and more rarely—perish from septicæmia or pyæmia. Pulmonary or general tuberculosis was formerly a frequent cause of death, which, however, usually takes place from some intercurrent disease.