[Non-reabsorptive communicating hydrocephalus: surgical results according to the diagnostic procedure]

Both ex-vacuo and non-reabsorptive hydrocephalus can present with a similar clinical triad of dementia, gait disturbances and incontinence. From a prognostic point of view, however, a great difference exists due to the possibility of surgical treatment with cerebrospinal fluid shunting in non-reabsorptive hydrocephalus. The difficulty lies in a correct preoperative diagnosis. In this study 37 patients aged from 60 to 72 with a clinical history suggestive of non-reabsorptive communicating hydrocephalus were evaluated; the diagnostic tests applied to them were: computerized axial tomography, infusion test with Nelson's technique and intracranial pressure monitoring. A clear correlation was observed between the clinical improvement obtained after a cerebrospinal fluid shunt had been placed and the presence of pathological computerized axial tomography (hydrocephalus without increased sulci with or without trans-ependymal edema) or the pathological infusion test (intracranial pressure increase over 2 mm Hg/min and no decrease back to the basal level once the infusion had ended). No correlation was observed between the different recordings obtained from the intracranial pressure monitoring and the surgical results. The clinical data which most easily revert are the gait disturbance, dementia and incontinence in this order and, more so, in patients with known etiology. Since non-reabsorptive hydrocephalus and ex-vacuo hydrocephalus may co-exist, mostly in elderly patients, it is important to further develop the dynamic studies of intracranial pressure with the aim of offering a more reliable surgical prognosis.