Compensatory parameters of intracranial space in giant hydrocephalus.

Background And Purpose: The main goal of the present study is to examine compensatory parameters of intracranial space in giant hydrocephalus. We also assess the early and late outcome and analyse complications in shunted cases.

Material And Methods: Nine cases of giant hydrocephalus characterised by the value of Evans ratio > 0.5, ventricular index > 1.5, and the width of the third ventricle > 20 mm were considered. Using the lumbar infusion test and developed software we analysed the intracranial compensatory parameters typical for hydrocephalus. Based on the Marmarou model, the method depended on a repeated search for the best fitting curve corresponding to the progress of the test was used. Eight out of nine patients were therefore shunted. Patients were followed up for 9 months.

Results: Five out of eight shunted patients undoubtedly improved in a few days after surgery (62%). Complications (subdural hygromas/haematomas and intracerebral haematoma) developed in 5 (62%) cases in longer follow-up. A definite improvement was noted in 4 out of 8 operated cases (50%).

Conclusions: To get the stable values of compensatory parameters, the duration of the infusion test must at least double the inflexion time of the test curve. All but one considered cases of giant hydrocephalus were characterized by lack of intracranial space reserve, significantly reduced rate of CSF secretion and by various degrees of elevated value of the resistance to outflow. Due to the significant number of complications and uncertain long-term improvement, great caution in decision making for shunting has to be taken.