Characteristics of intracranial pressure (ICP) waves and ICP in children with treatment-responsive hydrocephalus.

Background: One important goal of modern treatment of pediatric hydrocephalus is to normalize the intracranial pressure (ICP) and ICP volume reserve capacity to optimize normal brain development. Better knowledge of the characteristics of ICP waves/ICP in pediatric hydrocephalus may provide new insight into the mechanisms behind modern hydrocephalus treatment. The aim of the present work was to characterize the ICP waves/ICP in children with either communicating or non-communicating hydrocephalus who improved clinically after surgery. The hydrocephalic children not treated surgically following ICP monitoring served as reference patients.

Methods: The patient material includes all children with hydrocephalus and no previous surgical treatment who underwent diagnostic ICP wave/ICP monitoring during the period 2002-2011. We retrieved the information about the patients from the patient records and the digitally stored ICP waveforms. The ICP wave characteristics amplitude, rise time and rise time coefficient and the mean ICP were determined in the patients treated surgically for their hydrocephalus. The findings were compared with findings in children not treated surgically after ICP monitoring who served as reference patients.

Results: The patient material includes 58 patients. Thirty-one (53%) were treated surgically after ICP monitoring, of whom all improved clinically. As compared to the reference patients, patients treated surgically presented with increased ICP wave amplitudes (MWA) and mean ICP. Alterations were comparable in communicating and non-communicating hydrocephalus. We found no apparent association between the ICP wave/ICP scores and presence of symptoms, indices of ventricular size or age.

Conclusions: Children with either communicating or non-communicating hydrocephalus improving clinically after surgery presented with elevated MWA and mean ICP. In particular, the levels of MWA were raised to a magnitude seen when intracranial compliance is impaired. Hence, the present observations may support the idea that improvement of intracranial compliance can be an important mechanism by which shunts work in pediatric hydrocephalus.