If, on examination, loss or impairment of knee-jerk be shown, contraction of the pupil with Argyll-Robertson phenomenon and defective station, but little doubt can exist.

The discovery by the ophthalmoscope of some degree of beginning optic neuritis would make assurance more sure, and this can often be detected in a very early stage of the disease.
Much controversy has been spent on the question of the share of syphilis in producing tabes, and out of the battle but two facts emerge fairly certain, the one that syphilis often precedes the disease, the other that anti-syphilitic medication is commonly of no service.

But syphilis is so frequently antecedent that a history of that infection may make certain the diagnosis when doubt exists.

This may be an important point, for some of the cardinal symptoms are occasionally absent; cases are seen with no incooerdination, sometimes with the station unaffected, even, though rarely, with the knee-jerk preserved.
The diagnosis established, treatment will somewhat depend upon the stage which the disease has reached.
In the pre-ataxic stage, where slight unsteadiness, often not troublesome except in the dark or with closed eyes, sharp stabbing pains here and there, numbness of the feet, girdle-sense in the region of chest, waist, or belly, some recurrent difficulty in emptying the bladder, a fugitive partial palsy of the external muscles of the eye, are the chief or, perhaps, the only complaints, it would not be justifiable to put the patient to bed at complete rest.

This early stage calls for a different plan of treatment, to be presently described.
In the middle or more distinctly ataxic period long rest in bed should be prescribed, and will be gratefully accepted by a patient whose sufferings from incooerdination, pains, and numbness of the extremities are often so great as to incapacitate him.
The bladder muscles share in the ataxia, and the consequent retention of urine frequently causes cystitis, and may endanger life by the involvement of the kidneys.
The bowels cannot be emptied or are moved without the patient's knowledge, and these annoyances combine with the pain and nervous apprehension to drive the victim into a melancholic or neurasthenic state.