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a lethargic, typhoid, or semi-intoxicated condition, from which they can be temporarily roused dition which is, however, frequently combined with a purposeless, hazy motor delirium, not of a purely automatic character. Even in the lesser degrees of obnubilation of consciousness, there are certain criteria of special significance; thus a patient may be roused to more or less correctly answer questions in a slow, drawling, dreamy, sleepy manner. He may even perform complex acts in response to requests or demands, yet be unable to respond to the calls of nature, and he passes urine and fæces in the bed, or evacuates his excreta in the room. Occasionally the patient may shamelessly masturbate. The mind may again become clear and he may regain control, but not infrequently this loss of control over the sphincters persists, and this denotes usually a permanent state of dementia. The dementia of syphilitic brain disease is characterized by being partial and recurring in attacks; it does not alter the character and personality of the individual to the same extent as in the dementia of general paresis. He preserves his autocritical faculties and is conscious of his intellectual deficit, and he is by no means indifferent to his mental and bodily condition. He may suffer with loss of memory, especially of recent events, and his knowledge of time and place may be defective. He is subject to sudden fits of excitation with motor restlessness or of depression with suicidal tendencies."1

1 F. W. Mott. Syphilis of the Nervous System. A System of Syphilis, edited by D'Arcy Power and J. K. Murphy, Vol. IV. London, 1910.

Gummatous type. This type is comparatively infrequent. It is characterized anatomically by the presence of one or more large gummata originating in the meninges and extending into the brain substance. The physical symptoms are apt to be those of brain tumor together with hemianopsia, aphasia, convulsions, hemiplegia, etc., according to the location of the gummata. The mental symptoms are much like those of the diffuse meningitic type.

Endarteritic type. This is perhaps the commonest type of cerebral syphilis, especially if we take account of the circumstance that many cases are difficult to distinguish from cerebral arteriosclerosis and are often classified as such. The clinical manifestations are, in fact, essentially those of cerebral arteriosclerosis. Even post mortem the differentiation cannot always be made with certainty; the characteristic finding in cerebral syphilis is a proliferative endarteritis accompanied by more or less marked lymphoid and plasma cell infiltration of the adventitial sheaths and, perhaps, patches of similar infiltration in the pia.

Various combinations, forms of the three abovementioned types of cerebral syphilis, are found in practice.

Diagnosis. Cerebral syphilis often has to be differentiated from brain tumor, general paresis, and cerebral arteriosclerosis.

In cases of brain tumor the presence of the cardinal symptoms and focal symptoms and the absence of lymphocytosis in the cerebral-spinal fluid and of the

Wassermann reaction both in the blood and in the fluid will exclude cerebral syphilis.

When the clinical differentiation from general paresis is uncertain, some help may be gained from an examination of the cerebro-spinal fluid; the Wassermann reaction is positive in from 75 to 90% of cases of general paresis and in but 30 or 35% of cases of cerebral syphilis;1 in the latter condition it is most apt to be positive in cases of the diffuse meningitic type and negative almost as a rule in the gummatous and endarteritic types; lymphocytosis is almost invariably present in general paresis, the usual finding being from 15 to 50 cells per cubic millimeter, while in cerebral syphilis it is inconstant and extremely variable in degree, being very often slight or absent in the gummatous and endarteritic types and as a rule extremely marked in the diffuse meningitic type-from 100 to 1500 cells or more per cubic millimeter;2 the typical reaction obtained in the colloidal gold test in cases of general paresis is not apt to be obtained in cerebral syphilis, there being, instead, as a rule, but a slightly marked precipitation in the first one or two tubes, a mere change of color in the next two or three, a more intense reaction again in the next one, two, or three tubes, and no change at all in the remaining ones—the so-called luetic curve which may be represented by the formula, 3321122200.3

1 D. M. Kaplan. Serology of Nervous and Mental Diseases. Philadelphia and London, 1914, p. 191.

2 D. M. Kaplan. Loc. cit., p. 157.

3 Swalm and Mann. The Colloidal Gold Test on Spinal Fluid in Paresis and Other Mental Diseases. N. Y. Med. Journ., Apr. 10, 1915.

The test of treatment is of value in many cases, improvement or recovery under salvarsan or mercury and iodides with reduction or disappearance of the lymphocytosis indicating cerebral syphilis and not general paresis.

In cerebral arteriosclerosis the findings in the cerebro-spinal fluid are negative, so that a difficulty in differentiation arises only in connection with those cases of the endarteritic type of cerebral syphilis in which the findings are likewise negative, and in such cases, as already stated, the differentiation cannot always be made with certainty even post mortem. A history of syphilitic infection will, naturally, turn the probability toward cerebral syphilis. The age of the patient may help in the differentiation; cases occurring in persons under 45 are almost surely syphilitic; in persons between 45 and 60 the probability is still strongly in favor of syphilis; after 60 this probability diminishes with advancing senility.

Prognosis. Cerebral syphilis is a grave affection; untreated cases progress more or less rapidly with tissue destruction and often a fatal termination. Treatment, however, if instituted early may result in a quick and perfect cure; the most favorable cases from this point of view are those of the diffuse meningitic type; cases of the gummatous type are often stubbornly resistant to treatment; in most cases of the endarteritic type recovery cannot be expected owing to the tissue destruction which occurs early in the course of the disease, but some relief may be secured through abatement or arrest of the syphilitic process.

Treatment. This is that of syphilis in general. The special points to be emphasized in connection with cerebral syphilis are: (1) the treatment must be intensive and instituted promptly upon the development of the symptoms in order to forestall, as far as possible, tissue destruction; (2) it should be controlled by repeated examinations of the blood and cerebro-spinal fluid, and it should be persisted in after clinical recovery until the findings in the blood and cerebro-spinal fluid become permanently negative; (3) intra-spinal medication may be of value in some cases which have resisted other methods of treatment; (4) every case in which the differentiation between general paresis and cerebral syphilis has not been made with certainty should be submitted to the test of a thorough course of treatment; (5) Horsley recommends that if improvement does not occur in a case of cerebral gumma after six weeks' medicinal treatment, the growth be removed by operation.