J Neurol Surg A Cent Eur Neurosurg 2018; 79(04): 302-308
DOI: 10.1055/s-0037-1608841
Original Article
Georg Thieme Verlag KG Stuttgart · New York

How Reliable Is Pupillary Evaluation Following Subarachnoid Hemorrhage? Effect of Oculomotor Nerve Degeneration Secondary to Posterior Communicating Artery Vasospasm: First Experimental Study

Cengiz Ozturk
1  Family Medicine, Osmangazi Health Center, Erzurum, Turkey
,
Nuriye Guzin Ozdemir
2  Department of Neurosurgery, Istanbul Training and Research Hospital, Istanbul, Turkey
,
Ayhan Kanat
3  Department of Neurosurgery, Medical Faculty, Recep Tayyip Erdogan University, Rize, Turkey
,
Mehmet Dumlu Aydin
4  Department of Neurosurgery Medical Faculty, Ataturk University, Erzurum, Turkey
,
Huseyin Findik
5  Department of Ophthalmology, Recep Tayyip Erdogan University, Rize, Turkey
,
Nazan Aydin
6  Psychiatry Clinic, Bakirkoy Training and Research Hospital for Psychiatry, Neurology and Neurosurgery, Istanbul, Turkey
,
Mehmet Esref Kabalar
7  Department of Pathology Clinic, Regional Training and Research Hospital, Erzurum, Turkey
,
Hizir Kazdal
8  Department of Anesthesiology and Reanimation, Recep Tayyip Erdogan University, Rize, Turkey
,
Coskun Yolas
9  Department of Neurosurgery, Regional Training and Research Hospital, Erzurum, Turkey
,
Orhan Baykal
10  Department of Ophthalmology, Medical Faculty, Ataturk University, Erzurum, Turkey
,
Muhammet Calik
11  Department of Pathology, Medical Faculty, Ataturk University, Erzurum, Turkey
› Author Affiliations
Further Information

Publication History

08 February 2017

27 June 2017

Publication Date:
14 December 2017 (online)

Abstract

Background and Study Aim  Basic neurophysiologic principles of the light reflex are well known. However, the effects of degenerated axon densities of oculomotor nerves (OMNs) secondary to posterior communicating artery (PComA) vasospasm following subarachnoid hemorrhage (SAH) have not been investigated. Our aim was to study this subject.

Methods This study was conducted on 19 rabbits. There was a control group of five animals, a sham group of five animals in which saline was injected into the cisterna magna and a study group of nine animals in which homologous blood was injected into the cisterna magna. Pupillary diameters were measured for 1 week, then the animals were decapitated. The normal and degenerated axon densities of the OMNs were examined by stereological methods. Vasospasm indexes (VSIs) of posterior communicating arteries (PComAs) supplying OMNs were estimated and analyzed statistically.

Results The pupillary diameter was 5.439 ± 368 µm, and the mean axon density of the OMNs was 0.924 ± 324/mm3 in the control group. The pupillary diameter and degenerated axon density of the OMNs in animals of the sham group were 6.980 ± 0.370 µm and 36 ± 8/mm3, respectively. The pupillary diameter was 9.942 ± 653 µm, and degenerated axon density of the OMNs was 265 ± 57/mm3 in animals with SAH. The mean VSI values of PComAs were 0.927 ± 0.224 in the control group, 1.542 ± 0.257 in the sham group, and 2.321 ± 0.324 in the SAH group.

Conclusion We found a linear relationship between the axon density of the OMNs and pupillary diameters. High degenerated neuron density in the OMNs may be responsible for an unresponsive pupillary that has not been mentioned in the literature.