Ogle quotes six cases of loss of speech after bites of venomous snakes. Two of the patients recovered. According to Russ this strange symptom is sometimes instantaneous and in other instances it only appears after an interval of several hours. In those who survive the effects of the venom it lasts for an indefinite period. One man seen by Russ had not only lost his speech in consequence of the bite of a fer-de-lance snake, but had become, and still remained, hemiplegic. In the rest of Russ's cases speech alone was abolished. Russ remarks that the intelligence was altogether intact, and sensibility and power of motion were unaffected. One woman who had been thus condemned to silence, suddenly under the influence of a strong excitement recovered her speech, but when the emotion passed away speech again left her.
Ogle accounts for this peculiar manifestation of aphasia by supposing that the poison produces spasm of the middle cerebral arteries, and when the symptom remains a permanent defect the continuance of the aphasia is probably due to thrombosis of arteries above the temporary constriction.
Anosmia, or loss of smell, is the most common disorder of olfaction; it may be caused by cortical lesions, olfactory nerve-changes, congenital absence, or over-stimulation of the nerves, or it may be a symptom of hysteria.
Ogle, after mentioning several cases of traumatic anosmia, suggests that a blow on the occiput is generally the cause. Legg reports a confirmatory case, but of six cases mentioned by Notta two were caused by a blow on the crown of the head, and two on the right ear. The prognosis in traumatic anosmia is generally bad, although there is a record of a man who fell while working on a wharf, striking his head and producing anosmia with partial loss of hearing and sight, and who for several weeks neither smelt nor tasted, but gradually recovered.
Mitchell reports a case of a woman of forty who, after an injury to her nose from a fall, suffered persistent headache and loss of smell. Two years later, at bedtime, or on going to sleep, she had a sense of horrible odors, which were fecal or animal, and most intense in nature. The case terminated in melancholia, with delirium of persecution, during which the disturbance of smell passed away.
Anosmia has been noticed in leukoderma and allied disturbances of pigmentation. Ogle mentions a negro boy in Kentucky whose sense of smell decreased as the leukoderma extended. Influenza, causing adhesions of the posterior pillars of the fauces, has given rise to anosmia.
Occasionally overstimulation of the olfactory system may lead to anosmia. Graves mentions a captain of the yeomanry corps who while investigating the report that 500 pikes were concealed at the bottom of a cesspool in one of the city markets superintended the emptying of the cesspool, at the bottom of which the arms were found. He suffered greatly from the abominable effluvia, and for thirty-six years afterward he remained completely deprived of the sense of smell.
In a discussion upon anosmia before the Medico-Chirurgical Association of London, January 25, 1870, there was an anosmic patient mentioned who was very fond of the bouquet of moselle, and Carter mentioned that he knew a man who had lost both the senses of taste and smell, but who claimed that he enjoyed putrescent meat. Leared spoke of a case in an epileptic affected with loss of taste and smell, and whose paroxysms were always preceded by an odor of peach-blossoms.
Hyperosmia is an increase in the perception of smell, which rarely occurs in persons other than the hysteric and insane. It may be cultivated as a compensatory process, as in the blind, or those engaged in particular pursuits, such as tea-tasting.
Parosmia is a rare condition, most often a symptom of hysteria or neurasthenia, in which everything smells of a similar, peculiar, offensive odor. Hallucinations of odor are sometimes noticed in the insane. They form most obstinate cases, when the hallucination gives rise to imaginary disagreeable, personal odors.
Perversion of the tactile sense, or wrong reference to the sensation of pain, has occasionally been noticed. The Ephemerides records a case in which there was the sense of two objects from a single touch on the hypochondrium. Weir Mitchell remarks that soldiers often misplace the location of pain after injuries in battle. He also mentions several cases of wrong reference of the sensation of pain. These instances cannot be called reflex disturbances, and are most interesting. In one case the patient felt the pain from a urethral injection in gonorrhea, on the top of the head. In another an individual let an omnibus-window fall on his finger, causing but brief pain in the finger, but violent pains in the face and neck of that side. Mitchell also mentions a naturalist of distinction who had a small mole on one leg which, if roughly rubbed or pinched, invariably seemed to cause a sharp pain in the chin.
Nostalgia is the name generally given to that variety of melancholia in which there is an intense longing for home or country. This subject has apparently been overlooked in recent years, but in the olden times it was extensively discussed.