In the insidious variety the resemblance to tuberculous meningitis may be so great, that only careful examination of the aspirated cere brospinal fluid prevents errors, which otherwise would be unavoidable. This error probably has often CaUSed the publication of cures of tubercu lous meningitis. when the cases really- were simple serous meningitis. The mistake is more readily made when the child which presents symp toms of meningitis, has some other tuberculous affections; although even such cases not exceptionally- are only serous meningitis.
Acute inflammatory hydrocephalus attains especial clinical significance in that, if the child lives, it becomes chronic and then either exhibits the progressive course of the common chronic hydrocephalus and ends fatally, or becomes stationary after moderate deyelopment, but is still ominous for the afflicted children.
In the first place these comparative recoveries often occur after the mental or motor functions of the brain have already suffered and in the second place the existence of a limited chronic hydrocephalus is a constant danger, a point of lowerecl resistence for the remainder of life. To Quincke belongs the credit of haying called especial attention in his studies of serous meningitis to those cases which on account of trauma, physical or mental overexertion or excesses, or infectious diseases before puberty have acute or subacute exacerbations of the exudative process, which may be a menace to life. Infections, which are the chief primary etiologic factor, are no doubt rarely the cause of these exacerba tions; as Quincke says aseptic angioneurotic processes are more likely the cause. Indicative of this fact are the rather slow onset, the feverless course, the absence of bacteria in the aspirated cerebrospinal fluid, which always is evacuated at high pressure; and, not least important, the result of lumbar puncture is decidedly more favorable than is seen in other meningitides.
Finally of great theoretical interest is the fact 1101V firmly established, that in a number of affections (gastro-enteritis, pneumonia, etc.), bacteria are demonstrable in the cerebrospinal fluid which may cause symp toms of cerebral irritation of more or less pronounced meningeal type merely by toxic action upon the cortical parenchyma without histo logic changes of the meninges or of the superficial supportive structures. It is impossible to say how frequently this occurs or presents clinical symptoms.
All that is important concerning the diagnosis and prognosis of serous meningitis has 110W been touched upon.
Treatment.—Its therapy is more promising inasmuch as generally we have to deal with a secondary condition which, after the subsidence of the primary focus of infection, recovers. Therefore the therapy should primarily be directed toward the basic disease, gastro-enteritis, pneu monia, etc. Finkelstein places above all other considerations the necessity of careful examination and treatment of the ear, by which he often secured surprisingly rapid disappearance of the cerebral symptoms.
Favorable measures in the form of cold packs or hot baths (highly recommended in cerebrospinal meningitis), and which perhaps should be repeated several times daily, have good effect.
Inunctions of gray ointment are recommended especially by Quincke, because of his good experiences, and have been successfully employed by others. On the other hand Quincke's recommendation to cause a pyogenic process as a counterirritant by applying unguentum tartari stibiati (P.G.) to the scalp has met with little favor.
The most important therapeutic measure is without doubt lumbar puncture, which by diminishing pressure secures more favorable con ditions for circulation and absorption. This especially is the case in the ventricular form.