Objective:

To conduct a comparison of non-invasive intracranial pressure waveform (nICPw) data from patients with asymptomatic shunts and those with shunt dysfunction resulting in overdrainage or underdrainage.

Background:

Accurate diagnosis of shunt malfunction in hydrocephalus patients is essential, as this condition can present with severe complications. Modern devices have emerged as promising tools for nICPw monitoring, and by analyzing the waveform and the relationship between pressure peaks (P2/P1 ratio) and time to peak (TTP), they estimate intracranial compliance.

Design/Methods:

The study included 37 patients diagnosed with cerebral hydrodynamic disorders treated with CSF shunts, divided into three groups: asymptomatic patients (n=19) and those with shunt dysfunction resulting in overdrainage (n=9) or underdrainage (n=9). nICPw was monitored in sessions lasting from 5 to 30 minutes, with patients placed in three positions: supine, 30° bedrest, and standing. The data was analyzed to extract the P2/P1 and TTP and compared between patient groups. Kruskal-Wallis test was used to assess variation within groups.

Results:

Regarding the average P2/P1 across positions, significant differences were observed between groups, indicating varying distributions for overdrainage, underdrainage, and asymptomatic patients. For TTP average, significant differences were noted in the supine and 30° positions, but not in the standing position (p-value = 0.0665), suggesting no significant group differences in TTP in this position. Variability between positions was small and not significant within groups, although variability between groups was evident, especially in overdrainage, where responses varied across positions.

Conclusions:

These results indicate that physiological characteristics measured by the P2/P1 ratio and TTP vary significantly between asymptomatic patients with CSF shunts and patients experiencing either underdrainage or overdrainage, except for TTP in the standing position. These findings suggest nICPw monitoring may be a valuable tool in the diagnosis and management of different cerebral hydrodynamic disorders.