15 Lehrbuch der Speciellen Pathologie und Therapie, p. 193, vol. ii.
16 It should be designated as static ataxia, in distinction from locomotor or motor ataxia, which is manifested in unskilled movements.
The important part played by eye symptoms in the early stages of tabes has been already referred to. Reflex iridoplegia is one of these early and persisting features; it is sometimes complicated with mydriasis, and occasionally with paralysis of accommodation of one eye. In the majority of my cases there was spinal myosis, often of maximum intensity; in a large number there was in addition irregularity of the outline of the pupil; and where there was mydriasis I found it to be quite symmetrical, in this respect differing from the experience of Müller17 and Schmeichler.18
17 Centralblatt für die Gesammte Therapie.
18 Loc. cit.
Atrophy of the optic nerve is a common and sometimes, as stated, the initial symptom of tabes. It is rarely found in its incipient phase in advanced stages. The patient who escapes involvement of the optic nerve in the pre-ataxic stage is very apt to escape it altogether. It is more frequently found either to precede the pre-ataxic period by months and even years, or to develop during this period, leading to complete atrophy in the ataxic period, and sometimes before. Erb calculates that 12 per cent. of tabic patients have optic-nerve atrophy; he probably includes only such cases in which the atrophy was marked or led to amblyopia. Including the lesser degrees of atrophy, it is found in a larger number of patients. Schmeichler claims as high as 40 per cent.19 If we regard those cases in which there is noted progressing limitation of the color-field of the retina as beginning optic-nerve atrophy, the majority of tabic patients may be said to have some grade of this disorder. The ophthalmoscopic changes are quite distinctive: at first there is noted a discoloration of the papilla and apparent diminution of the number of arterial vessels; the veins then become dilated; and finally the papilla becomes atrophied, the vessels usually undergoing a narrowing after their previous dilatation. In the first stages of this process visual power is not gravely impaired, but as soon as shrinkage has set in visual power sinks rapidly to a minimum, decreasing till only quantitative light-perception remains. This limited function usually remains throughout, but in a few cases complete amaurosis ensues. As the field of vision becomes diminished, the concentric extinction of quantitative perception is preceded by concentric extinction of color-perception, the color-field for green being the first to suffer; red follows, and blue remains last.
19 Archives of Ophthalmology and Otology, 1883.
In a large number of cases the only symptoms attributable to a disturbance of the cerebral functions are those connected with the motor relations of the eyeball and pupil, and the function and appearance of the optic nerve. The special senses other than those of sight and touch are rarely affected. Sometimes there is obstinate tinnitus, exceptionaly followed by deafness, attributed to atrophy of the auditory nerve. The development of symptoms resembling those named after Ménière is not referable with certainty to a disturbance of the same nerve.
The sexual functions become involved in all cases of tabes sooner or later. In the majority of cases there is a slow, gradual extinction of virile power; in a large minority this extinction is preceded by irritative phenomena on the part of the genital apparatus. Some patients display increased sexual desire and corresponding performing powers, but mostly they suffer from erections of long duration which may be painful, and loss of the normal sensations attending the sexual orgasm. There is no constant relationship between the intensity of the general affection and the diminution of sexual power. It is retained to a limited degree by patients who are barely able to walk, and it may be entirely destroyed in those who have but entered the initial period.