gms | German Medical Science

70. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Skandinavischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

12.05. - 15.05.2019, Würzburg

Paradox dynamics of the optic nerve sheath diameter reveal insight into the pathophysiology of idiopathic normal pressure hydrocephalus – first report

Paradoxe Dynamik der N. Opticusscheide als Manifestation des idiopathischen Normaldruckhydrozephalus – erste Messwerte

Meeting Abstract

  • presenting/speaker Christian Eisenring - Universitätsmedizin Göttingen, Klinik für Neurochirurgie, Göttingen, Deutschland; Insel University Hospital Bern, Neurochirurgie, Bern, Switzerland; Universität Fribourg, Freiburg, Switzerland
  • Jens Fichtner - Insel University Hospital Bern, Neurochirurgie, Bern, Switzerland
  • Sebastian Müller - Universitätsmedizin Göttingen, Klinik für Neurochirurgie, Göttingen, Deutschland
  • Abdelhalim Hussein - Universitätsmedizin Göttingen, Klinik für Neurochirurgie, Göttingen, Deutschland
  • Ingo Fiss - Universitätsmedizin Göttingen, Klinik für Neurochirurgie, Göttingen, Deutschland
  • Björn Sommer - Universitätsmedizin Göttingen, Klinik für Neurochirurgie, Göttingen, Deutschland
  • Lisa-Marie Wittler - Universität Fribourg, Freiburg, Switzerland
  • Veit Rohde - Universitätsmedizin Göttingen, Klinik für Neurochirurgie, Göttingen, Deutschland
  • Christian von der Brelie - Universitätsmedizin Göttingen, Klinik für Neurochirurgie, Göttingen, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 70. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Skandinavischen Gesellschaft für Neurochirurgie. Würzburg, 12.-15.05.2019. Düsseldorf: German Medical Science GMS Publishing House; 2019. DocP021

doi: 10.3205/19dgnc359, urn:nbn:de:0183-19dgnc3591

Veröffentlicht: 8. Mai 2019

© 2019 Eisenring et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objective: The pathophysiology of idiopathic normal pressure hydrocephalus (iNPH) results in reduced brain compliance. The hydrodynamic theory in this context describes sheer forces resulting most probably from inadequate pulsatile CSF waves which successively reduce the elasticity of the brain parenchyma. In addition, the “windkesseleffekt”, which transforms the pulsatility of the blood current into a homogenic laminar flow in the parenchymal capillaries also result in a laminar CSF flow, this is limited in many NPH patients due to a reduced elasticity of the arterial vessels. This results in a higher CSF production. Measuring the optic nerve sheath diameter (ONSD) provides real-time insight into intracranial pressure dynamics. This study addresses the question, whether the basic diameters of the optic sheath as well as the postural dynamics of ONSD measurements are altered in iNPH.

Methods: We prospectively included all patients with iNPH, who had undergone a primary diagnostic workup and were admitted for VP-shunting. We measured ONSD bilaterally in the supine as well as in the upright position. Measurements were repeated three times on each side and the mean values were used for further analysis. After VP-shunt surgery, measurements were repeated. We compared the results with results from a healthy population from patients with spontaneous intracranial hypotension (SIH) with the student T Test to calculate p-values.

Results: N=9/10 of the patients had arterial hypertension. ONSD values in a supine position were larger in iNPH patients and increased in n=10/10 patients after change into upright position (mean: 5.58 mm, SD 0.75mm supine; mean: 6.24 mm, SD: 0.82mm upright, p: 0.06). Compared with a healthy population (mean 5.03mm, SD 0.55mm supine, mean 5.05mm, SD 0.59mm upright) or SIH (mean 5.08mm, SD 0.65mm supine, mean 4.73mm, SD 0.67mm upright), changes in iNPH were different. After VP-shunting, we recorded no relevant postural changes arguing for a more physiological condition (mean 5.69mm, SD 1.21mm supine, mean 5.83mm, SD 1.07mm upright, p=0.79).

Conclusion: The increase of ONSD after postural change argues for an involvement of arterial hypertension and reduced vessel wall elasticity in the pathophysiology of iNPH. Basic enlargement of ONSD might be a pathognomonic situation in iNPH since the increased CSF net-flux might lead to an enlargement of the optical sheath. Basic diameter and dynamic changes of ONSD were more physiologic after VP-shunting.

Figure 1 [Fig. 1]