Elsevier

Neurochirurgie

Volume 63, Issue 6, December 2017, Pages 444-448
Neurochirurgie

Original article
Role of serial ultrasonic optic nerve sheath diameter monitoring in head injury

https://doi.org/10.1016/j.neuchi.2017.06.001Get rights and content

Abstract

Objectives

To compare optic nerve sheath diameter (ONSD) measurements in head injury patients with a group of normal subjects and investigate the significance of serial ONSD monitoring in head injury patients.

Methods

All patients with a head injury admitted to our hospital with a program of conservative management at the time of admission were included in this prospective study. On admission, the patient was assessed using the Glasgow Coma Scale (GCS), orbital ultrasound for optic nerve sheath diameter (ONSD), and CT brain scan. CT scan findings were tabulated with Marshall and Rotterdam scores. The patient was serially assessed with ONSD every 24 to 48 hours. If the patient deteriorated, repeat CT and ONSD measurements were performed. A control group consisting of normal subjects was used for comparison.

Results

The case group consisted of 40 patients and the control group included 16 volunteers. The mean age of the case group was 38.9 years and the control group 36.3 years. The mean ONSD was 4.8 mm in the case group as compared to 3.4 mm in control group (P < 0.0001). In the case group, we found a significant correlation between GCS and ONSD, GCS and radiological scores and ONSD and radiological scores. The change in serial recordings of ONSD measurements were termed ascending, descending or static. All the patients with descending trend in serial ONSD values had good outcome and required no surgical intervention.

Conclusions

Ultrasound ONSD measurement is a useful investigation tool in a setting where invasive ICP monitoring is not available. Serial recording of ONSD is valuable and provides valuable information regarding decision making.

Introduction

Orbital ultrasound to measure optic nerve sheath diameter (ONSD) is an innovative procedure which is useful to detect increased intracranial pressure (ICP) [1], [2], [3], [4], [5]. It is also a non-invasive method and a very useful technique to monitor the ICP in head injury patients. As this technique is not as accurate as invasive ICP monitoring, serial recordings might be more useful than depending only on a single value. The ONSD measurements of head injury patients were in fact, compared to healthy subjects. We also investigated the significance of serial ONSD monitoring in head injury patients.

Section snippets

Methods

This prospective study was carried out in Department of Neurosurgery over a period of 21 months from September 2013 to May 2015. All patients with a head injury admitted in our hospital with a program of conservative management at the time of admission were included in the study. Head injury patients with no parenchymal injury, ocular trauma or requiring polytrauma management were excluded from the study. On admission the patient was assessed based on a Glasgow Coma Scale (GCS), ultrasound

Results

The mean right-left ONSD of patients and healthy subjects, 4.8 mm and 3.4 mm respectively, were different (P < 0.0001) (Table 1). Out of 40 patients, there were 18 mild, 17 moderate and 5 severe head injury patients. The mean ONSD values of the mild, moderate and severe head injury patients were 4.4, 4.9 and 5.7 mm, respectively (Table 1).

The statistical correlation between GCS, ONSD and radiological scores in the case group are shown in Table 2. Average right-left ONSD was higher for lower GCS (P = 

Discussion

Orbital ultrasound to detect ONSD is becoming increasingly popular as an adjuvant modality of neuro-imaging tools in the neurology ICU. Although it has some limitations, it is non-invasive, safe, easily reproducible, repetitive, and a cost-effective examination when compared to invasive intracranial pressure monitoring. It is efficient and the examination takes approximately 5 minutes per patient [8]. In head injury patients, associated orbital trauma with optic nerve injury the application of

Conclusions

The results of our study suggest that orbital ultrasound to measure ONSD can be a useful adjunct to making clinical decisions and CT scan findings in a setting, where invasive ICP monitoring is not available. Serial recordings of ONSD is thus a valuable tool and offers important and basic information regarding decision making. Normal ONSD values should be recorded in each institute in order to define the normal range.

Financial support

Institutional.

Disclosure of interest

The authors declare that they have no competing interest.

Acknowledgement

The authors are grateful to Mrs. Naga Saritha Kolli, lecturer in Statistics at NRI Academy of Sciences, Chinakakani for her help regarding the statistical analysis of the study.

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