J Neurol Surg A Cent Eur Neurosurg 2016; 77(03): 258-263
DOI: 10.1055/s-0035-1566117
Technical Note
Georg Thieme Verlag KG Stuttgart · New York

Telemetric Intracranial Pressure Measurement: A Graphical Approach to Data Analysis

Michele Maeske
1   Department of Neurosurgery, Armed Forces Hospital, Ulm, Germany
Simon Mayer
1   Department of Neurosurgery, Armed Forces Hospital, Ulm, Germany
Sebastian M. Blanc
2   Department of Economics and Management, Karlsruhe Institute of Technology, Karlsruhe, Germany
Chris Schulz
1   Department of Neurosurgery, Armed Forces Hospital, Ulm, Germany
Ulrich Kunz
1   Department of Neurosurgery, Armed Forces Hospital, Ulm, Germany
Uwe Max Mauer
1   Department of Neurosurgery, Armed Forces Hospital, Ulm, Germany
› Author Affiliations
Further Information

Publication History

06 February 2015

11 May 2015

Publication Date:
20 November 2015 (online)


Purpose In recent years, radiofrequency identification has been used for the continuous measurement of intracranial pressure (ICP) in patients with a cerebrospinal fluid (CSF) shunt for hydrocephalus . Unlike ICP monitoring in an inpatient setting, measurements in mobile patients outside the hospital provide ICP data that take into account the everyday activities of each individual patient. Common methods of ICP monitoring and analysis cannot be used for those patients. In addition, ICP measurements in mobile patients require considerably longer observation times than in-hospital monitoring. For this reason, ICP measurements over a period of 7 to 10 days must be analyzed effectively and efficiently.

Methods A possible approach is to analyze ICP data graphically. Pathologic changes can be expected to be associated with specific patterns that can be detected graphically (e.g., Lundberg A waves). Patients without pathologic ICP values and without intracranial pathologies usually show an approximately normal distribution of ICP data. By contrast, patients with pathologic ICP values are likely to show major deviations from a normal distribution such as changes in minimum and maximum values and multimodal distributions. Against this background, we present a new graphical method for detecting pathologic conditions. This novel method is based on the distribution of ICP data that is assessed using GNU R, a free software package for statistical computing and graphics.

Results A left-skewed distribution indicates CSF shunt overdrainage and a right-skewed distribution suggests CSF shunt underdrainage. In addition, an additive analysis of the number of physiologic ICP values can be helpful in detecting possible causes of CSF shunt overdrainage or underdrainage. The approach presented here shows that patients with hydrocephalus objectively benefited from ICP-guided adjustments of the opening pressure of a shunt valve or the insertion of a valve. This objective improvement was confirmed by the patients' subjective perception of well-being.

Conclusions Further investigations should be performed to examine the influence of multimodal ICP distributions and to assess how data analysis is affected by a drift that can occur when a sensor has been in place for an extended period of time.

  • References

  • 1 Miyake H, Ohta T, Kajimoto Y, Matsukawa M. A new ventriculoperitoneal shunt with a telemetric intracranial pressure sensor: clinical experience in 94 patients with hydrocephalus. Neurosurgery 1997; 40 (5) 931-935
  • 2 Frim DM, Lathrop D. Telemetric assessment of intracranial pressure changes consequent to manipulations of the Codman-Medos programmable shunt valve. Pediatr Neurosurg 2000; 33 (5) 237-242
  • 3 Atkinson JR, Shurtleff DB, Foltz EL. Radio telemetry for the measurement of intracranial pressure. J Neurosurg 1967; 27 (5) 428-432
  • 4 Olsen ER, Collins CC, Loughborough WF, Richards V, Adams JE, Pinto DW. Intracranial pressure measurement with a miniature passive implanted pressure transensor. Am J Surg 1967; 113 (6) 727-729
  • 5 Citerio G, Piper I, Cormio M , et al; BrainIT Group. Bench test assessment of the new Raumedic Neurovent-P ICP sensor: a technical report by the BrainIT group. Acta Neurochir (Wien) 2004; 146 (11) 1221-1226
  • 6 Kiefer M, Antes S, Schmitt M, Krauss I, Eymann R. Long-term performance of a CE-approved telemetric intracranial pressure monitoring. Conf Proc IEEE Eng Med Biol Soc 2011; 2011: 2246-2249
  • 7 Freimann FB, Sprung C, Chopra SS, Vajkoczy P, Wolf S. Large-scale referencing of the telemetric neurovent-P-tel intracranial pressure sensor in a porcine model. Pediatr Neurosurg 2013; 49 (1) 29-32
  • 8 Schmitt M, Eymann R, Antes S, Kiefer M. Subdural or intraparenchymal placement of long-term telemetric intracranial pressure measurement devices?. Acta Neurochir Suppl (Wien) 2012; 113: 109-113
  • 9 Welschehold S, Schmalhausen E, Dodier P , et al. First clinical results with a new telemetric intracranial pressure-monitoring system. Neurosurgery 2012; 70 (1, Suppl Operative): 44-49 ; discussion 49
  • 10 Czosnyka M, Pickard JD. Monitoring and interpretation of intracranial pressure. J Neurol Neurosurg Psychiatry 2004; 75 (6) 813-821
  • 11 Kiefer M, Antes S, Leonhardt S , et al. Telemetric ICP measurement with the first CE-approved device: data from animal experiments and initial clinical experiences. Acta Neurochir Suppl (Wien) 2012; 114: 111-116
  • 12 Freimann FB, Schulz M, Haberl H, Thomale UW. Feasibility of telemetric ICP-guided valve adjustments for complex shunt therapy. Childs Nerv Syst 2014; 30 (4) 689-697