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Background: After ventriculoperitoneal shunt surgery for idiopathic normal pressure hydrocephalus (iNPH) with adjustable gravitational valves, a certain proportion of patients develop secondary clinical worsening after initial improvement of clinical symptoms. The aim of this study was to analyze this group of patients with secondary deterioration and to evaluate the performed shunt management. Methods: For this investigation, we retrospectively reviewed our NPH registry for patients included between 1999 and 2013 with a decrease by a minimum of two points in the Kiefer score in the first year of follow up and an increase of two points in the Kiefer score between the second and the fifth year after shunt surgery (secondary deterioration). Then, we analyzed the patient's shunt management (adapting the valve pressure setting, shuntography, valve replacement, catheter replacement, implant an adjustable gravitational unit). Additionally, we searched for risk factors for secondary deterioration. Results: Out of 259 iNPH patients, 53 (20%) patients showed secondary deterioration on an average of 2.7 (2-4 years) years after shunt surgery. Fourteen (26%) patients with secondary deterioration improved after shunt or valve management and 58% remained without clinical benefit after management. We had a drop-out rate of 15% due to incomplete datasets. Our shunt management reduced the rate of secondary deterioration from 20 to 15%. On the basis of our findings, we developed an algorithm for shunt management. Risk factors for secondary deterioration are the age of the patient at the time of shunting, newly diagnosed neurodegenerative diseases, and overdrainage requiring adjusting the valve to higher-pressure levels. Conclusion: Twenty percent of patients with iNPH were at risk for secondary clinical worsening about 3 years after shunt surgery. About one-fourth of these patients benefited for additional years from pressure level management and/or shunt valve revision. Our findings underline the need for long-term follow-ups and intensive shunt management to achieve a favorable long-term outcome for patients with iNPH and VPS.

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Objectives Measurement of intracranial pressure (ICP) plays an important role in long-term monitoring and neuro-intensive treatment of patients with a cerebral shunt. Currently, only two complete telemetric implants with different technical features are available worldwide. This prospective pilot study aims to examine patients who had both probes implanted at overlapping times for clinical reasons and represents the first in vivo comparison of both measurement methods. Materials and methods Patients with a primary subarachnoid hemorrhage or a spontaneous intracerebral hemorrhage with ventricular hemorrhage who had received a telemetric ICP probe (Raumedic® NEUROVENT®-P-tel) were included in the study. Conventional external ventricular drainages (EVD) and ventriculoperitoneal shunts with a telemetric ICP probe (Miethke Sensor Reservoir) were implanted in patients with hydrocephalus who required CSF (cerebrospinal fluid) drainage. Absolute ICP values from all systems were obtained. Due to the overlapping implantation time, parallel ICP measurements were performed via two devices simultaneously. ICP measurements via the sensor reservoir were repeated after 3 and 9 months. Differences between the absolute ICP values measured via the NEUROVENT®-P-tel probe, the Miethke sensor reservoir®, and the EVD were analyzed. Results Seventeen patients were included in the present study between 2016 and 2018. 63% of all patients were male. In 11 patients the ICP measurements were followed up with both devices for 3 months. ICP measurements of the sensor reservoir showed corresponding trends in 9 cases compared to ICP measurement via the telemetry probe or EVD. Difference in absolute ICP values ranged between 14.5 mmHg and 0.0 mmHg. The average difference of the absolute ICP values in 8 cases was ≤ 3.5 mmHg. Conclusion ICP measurements with both systems continuously showed synchronous absolute ICP values, however absolute values of ICP measurement with the different systems did not match.

Background Mechanical obstruction of ventriculoperitoneal shunt (VPS) during the first year after shunt implantation is a common complication and is widely described in the literature. In this paper, we evaluated the suitability of the shuntography for the diagnosis of mechanical complications of the VPS in patients with idiopathic normal pressure hydrocephalus (iNPH). Methods We retrospectively identified 49 patients with pathologic shuntography over of a period of 20 years in our hospital. The percentage of procedure-associated complications was determined. Results Ninety-eight percent (n = 48) of the patients who underwent shuntography showed clinical and radiographic signs of underdrainage prior to examination. Shuntography revealed mechanical complications of the VP shunt in 37% (n = 18) as a cause of clinical deterioration and following revision operation. During shuntography, mechanical obstruction was discovered in 78% (n = 14) and disconnection of shunt components in 22% (n = 4). In the obstruction group, in 50% (n = 7) the closure was detected in the ventricular catheter, in 29% (n = 4) in the distal catheter of the VPS, and in 21% (n = 3) in both sides of the VPS. In the case of an inconspicuous shuntography (63%, n = 31), the patients received symptomatic therapy (32%, n = 10) or re-adjustment of the valve setting (68%, n = 21). Fifty-seven percent of the patients who underwent surgical treatment improved clinically by at least one point according to the Kiefer score. Conclusion Shuntography can produce valuable clinical information uncovering mechanic complications after implantation VPS in patients with idiopathic normal-pressure hydrocephalus. Patients with mechanical complications of their VPS needed revision surgery and showed clinical benefit after treatment.