Can infusion tests be recommended for patients with giant hydrocephalus

Background : The problem of adequate diagnosis of hydrocephalus followed by administration of an effective treatment has not yet been properly solved. Specifically, this pertains to the decision about the surgical insertion of a flow diverting device. Aims : A lumbar infusion test was used to examine the compensatory parameters of intracranial space in giant hydrocephalus. The early and late results of shunt implantation were analyzed together with complications after surgery. Settings and Design : In-house software was used offline to adjust the dynamic intracranial pressure (ICP) response to infusion. Patients and Methods : Nine patients with giant hydrocephalus were the subjects for the study. We analyzed recordings of the response in ICP to the 2 ml/min infusion of saline. We performed computerized identification of outflow resistance and intracranial compliance based on the truncated (30- 100) ICP response and assessed the stability of estimates over time. Eight out of nine patients were shunted. Monitoring of patients was followed for a period of up to 9 months. Results : Five out of eight shunted patients improved within a few days of surgery. During follow-up five patients developed various complications. A definite improvement was noted in four patients. The improvement rate did not correlate with any of the compensatory parameters. Most of the patients studied exhibited a lack of intracranial space reserve, a significantly reduced rate of CSF secretion, and a slightly elevated value of outflow resistance. Conclusions : The infusion test showed itself to be more useful as a way of revealing the compensatory parameters of the intracranial space than as a prognostic tool. The outcome of shunted patients with giant hydrocephalus was uncertain, owing to the relatively high rate of complications. We may therefore suggest that the diagnosis of giant hydrocephalus is a relative contraindication to implantation, as well as to the performance of an infusion test.