The role of cerebrospinal compensatory parameters in the estimation of functioning of implanted shunt system in patients with communicating hydrocephalus (preliminary report).

Twelve patients presenting with communicating hydrocephalus were studied. In 9 cases where the mean ICP level remained below 10 mmHg the symptoms of normal pressure hydrocephalus were observed. All of the patients were treated by shunt system implantation. The clinical and psychological state, cranial computerized tomography and parameters of the cerebrospinal compensatory mechanisms, evaluated using the constant rate infusion test were compared before and after treatment. In most of the patients (11) the pathologically enlarged ventricles persisted. Only in three cases no clinical improvement was noticed. In this group the resistance to the cerebrospinal fluid absorption and the fluid formation rate were estimated as normal. In the group with improvement the normalization of the resistance (4), decrease in the cerebrospinal fluid formation rate (4) and decrease in the cerebrospinal system elasticity (1) can be pointed out as factors responsible for improvement manifested after shunting. Therefore the resorption resistance and the formation of cerebrospinal fluid should be considered as predictive factors in the shunt implantation in hydrocephalic patients, and play an important role in the diagnosis of this entity.