Often the impact and course of the current are marked by visible lesions. Sometimes the skin is wounded exposing a bluish black tissue beneath. More commonly there is an area of burnt hair, or straight, radiating or angular lines of raised and frizzled hair marking the course of the current. In a horse killed by an electric light wire in Ithaca recently the current had burned to a depth of several inches in the muscles of the shoulder which rested on the wire.
Lesions are often rather indefinite. There may be no appreciable change in the nervous system. Rigor mortis is slight; it passes off rapidly and decomposition sets in early. The venous system and capillaries are usually filled with liquid blood of a dark bluish black color, and at intervals are points, spots and patches of blood extravasation. The uniformly liquid state of the blood is one of the most marked phenomena of death from electricity. The dark blue congestion of the radical veins is also very pathognomonic, the part struck or traversed by the main current, being the seat of the most elaborate arborescent network. This arborescent appearance of the dark colored veins, and the petechiæ are often marked in the internal organs (brain, kidneys, liver, lungs).
Diagnosis. The environment of the animal will often clear the diagnosis. The patient is found helpless, or dead under a tree, by a pole, or under a hanging wire, and if a tree there are evidences of the electric shock in scattered leaves and branches, stripping off of the bark, or perhaps rending of the tree in pieces. In case of wires attached to or passing near such a tree, the supporting poles show similar splitting and rending. Add to these the fluidity of blood in the carcase, the thickly ramifying network of the minute dark bluish, red veins, the petechiæ and the comparative absence of cadaveric rigidity, and we have a picture very significant of lightning stroke.
Treatment in such cases is according to the condition. The primary unconsciousness is met by inhalations of ammonia or ether, or the injection of brandy or alcohol subcutem. Caffein, atropine or hyoscyamin may be used as substitutes. If consciousness returns recovery is usually rapid and complete. Should paresis or paralysis remain it must be treated like any ordinary case of these affections.
INTRACRANIAL HÆMORRHAGE AND THROMBOSIS. APOPLEXY. SOFTENING OF THE BRAIN.
Definition. Causes: Nature: intracranial rupture, with pressure, serous effusion, excessive congestion, experimental cases, anæmia from pressure, comparative immunity of horse, heart disease, Bright’s disease, atheroma, degeneration, emboli, age, blood tension, severe exertion, excitement, concussion, insolation, venous obstruction, toxins, neoplasms. Lesions: blood clots, small and multiple, large and solitary, brain absorption, cavities, cysts. Symptoms: dullness, swaying, trembling, elevation of head, turning in circle, sudden fall, spasms, unequal dilated or contracted pupils, eyes turned to affected side, congested or anæmic mucosæ, stertor, puffing cheeks except in solipeds, pulse slow, soft, full, vomiting, stupor, coma, unconsciousness, paralysis, monoplegia, hemiplegia, sequelæ. Diagnosis: sudden unconsciousness, with little spasm, but paralysis, history, sign of trauma, deep coma, eyes turned to one side, pupils unequal, stertor, slow breathing and pulse; from uræmia, pulmonary apoplexy, œdema or anthrax. Treatment: bleeding, ice pack, snow, cold water, rest, derivatives to limbs, later purge, bromides, potassium iodide, tonics, open air life.
Definition. Cerebral apoplexy has been defined as a sudden loss of sensation and voluntary motion, from pressure originating within the cranium and followed by paralysis, often unilateral. The definition is somewhat insufficient as regards the early symptoms as the same conditions attend on convulsions and epilepsy (haut mal), and it is only by excluding these by their characteristic features of sudden seizure with clonic spasms and their intermittent and paroxysmal habit that we reach an easy and satisfactory distinction. Later the paralysis tends to identify the apoplectic attack.
Causes and Nature. The immediate cause and essential lesion of apoplexy has been generally held to be the rupture of an intracranial artery and the formation of a considerable blood clot which presses upon (and abolishes the functions of) the brain. There are cases, however, in which the characteristic symptoms are present, and yet a complete recovery ensues at an early date, too early to allow for the absorption of a considerable clot. Moreover, in fatal cases perhaps no blood clot is to be found, but in place a serous effusion, or an internal congestion which exercised the fatal pressure on the brain. So far, therefore, as clinical phenomena are concerned, we must allow that apoplexy may arise from any sudden pressure on the brain substance. Pagenstecher produced the symptoms of the disease by injecting, at a regulated pressure, melted wax and tallow between the skull and dura mater in the dog. In the moderate cases there were drowsiness, psychic depression and general muscular weakness. In the more severe ones there were added sleep and unilateral paralysis. In the more extreme cases death followed in a few hours after coma set in, though in some of these a partial recovery ensued if the waxy mass was scooped out before the fatal symptoms appeared. Cases ended fatally only when the injection pressure equalled that of the blood, and convulsions occurred only when the pressure was unsteady. The temperature fell as it does in apoplexy in man, at the outset, but it continued falling to the fatal issue contrary to what takes place in man.
Duret injected water into the cranium of animals so as to produce great tension of the occipito-atloid membrane causing thereby arrest of the respiration and slowing of the heart’s action. On tearing the membrane so as to allow escape of the water, respiration began anew and consciousness was gradually restored.
Edes sustains the view that apoplexy is directly due to anæmia of a lesser or greater portion of the brain substance, and that this need not be in any one particular seat nor of any definite extent. This anæmia is usually induced by pressure and may be caused by effused blood, or serum, or by the extreme congestion due to narcotic poisons, or other cause. Embolism of a cerebral vessel, however, by cutting off the blood from the part of the brain which it supplies may give rise to the apoplectic phenomena.