Cerebrospinal compensation in hydrocephalic children.

One hundred and fifteen cases of hydrocephalus in children were analysed. Cerebrospinal compensatory reserve was assessed by a computerized, constant rate, lumbar infusion test. Head circumference and ventricular size were measured and a psychometric examination carried out. A classification of hydrocephalus based on resting cerebrospinal fluid pressure (CSFP) and resistance to cerebrospinal fluid outflow (RCSF) was introduced. Parameters of compensatory reserve were compared in atrophy (low CSFP, low RCSF), normal-pressure hydrocephalus (low CSFP, increased RCSF), non-communicating hydrocephalus (high CSFP, low RCSF) and acute hydrocephalus (high CSFP and increased RCSF). Significant differences were found between the factors describing compensatory ability in these groups. Sixty-two patients could be classified on the basis of resting CSFP and RCSF. Differentiation between the types of hydrocephalus was shown to be more accurate when all variables measured during the pressure-volume test were considered. The patterns of the time courses of CSFP during rate infusion tests in the different types of hydrocephalus are presented.