Effect of a cervical collar on optic nerve sheath diameter in trauma patients

BACKGROUND:As advocated in advanced trauma life support and prehospital trauma life support protocols,cervical immobilization is applied until cervical spine injury is excluded.This study aimed to show the difference in optic nerve sheath diameter(ONSD)between patients with and without a cervical collar using computed tomography(CT).METHODS:This was a single-center,retrospective study examining trauma patients who presented to the emergency department between January 1,2021,and December 31,2021.The ONSD on brain CT of the trauma patients was measured and analyzed to determine whether there was a difference between the ONSD with and without the cervical collar.RESULTS:The study population consisted of 169 patients.On CT imaging of patients with(n=66)and without(n=103)cervical collars,the mean ONSD in the axial plane were 5.43±0.50 mm and 5.04±0.46 mm respectively for the right eye and 5.50±0.52 mm and 5.11±0.46 mm respectively for the left eye.The results revealed an association between the presence of a cervical collar and the mean ONSD,which was statistically significant(P<0.001)for both the right and left eyes.CONCLUSION:A cervical collar may be associated with increased ONSD.The effect of this increase in the ONSD on clinical outcomes needs to be investigated,and the actual need for cervical collar in the emergency department should be evaluated on a case-by-case basis.

Bedside ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure in nontraumatic neurocritically ill patients

BACKGROUND Delay in treatment of raised intracranial pressure(ICP)leads to poor clinical outcomes.Optic nerve sheath diameter(ONSD)by ultrasonography(US-ONSD)has shown good accuracy in traumatic brain injury and neurosurgical patients to diagnose raised ICP.However,there is a dearth of data in neuro-medical intensive care unit(ICU)where the spectrum of disease is different.AIM To validate the diagnostic accuracy of ONSD in non-traumatic neuro-critically ill patients.METHODS We prospectively enrolled 114 patients who had clinically suspected raised ICP due to non-traumatic causes admitted in neuro-medical ICU.US-ONSD was performed according to ALARA principles.A cut-off more than 5.7 mm was taken as significantly raised.Raised ONSD was corelated with raised ICP on radiological imaging.Clinical history,general and systemic examination findings,SOFA and APACHE 2 score and patient outcomes were recorded.RESULTS There was significant association between raised ONSD and raised ICP on imaging(P<0.001).The sensitivity,specificity,positive and negative predictive value at this cut-off was 77.55%,89.06%,84.44% and 83.82% respectively.The positive and negative likelihood ratio was 7.09 and 0.25.The area under the receiver operating characteristic curves was 0.844.Using Youden’s index the best cut off value for ONSD was 5.75 mm.Raised ONSD was associated with lower age(P=0.007),poorer Glasgow Coma Scale(P=0.009)and greater need for surgical intervention(P=0.006)whereas no statistically significant association was found between raised ONSD and SOFA score,APACHE II score or ICU mortality.Our limitations were that it was a single centre study and we did not perform serial measurements or ONSD pre-and post-treatment or procedures for raised ICP.CONCLUSION ONSD can be used as a screening a test to detect raised ICP in a medical ICU and as a trigger to initiate further management of raised ICP.ONSD can be beneficial in ruling out a diagnosis in a low-prevalence population and rule in a diagnosis in a high-prevalence population.

Analyses on the misdiagnoses of 25 patients with unilateral optic nerve sheath meningioma

AIM：To investigate clinical features of optic nerve sheath meningioma（ONSM） that was misdiagnosed,and to find methods to reduce the misdiagnoses.METHODS：Retrospective series study.Twenty-five misdisgnosed patients with unilateral ONSM were collected from Jan.2008 to Jan.2015 and the clinical records reviewed.RESULTS：Patients were misdiagnosed with acute papillitis most frequently（P=17）,immediately followed by optic atrophy（P=8）,ischemic optic neuropathy（P=5）,acute retrobulbar optic neuritis（P=5）,optic disc vasculitis（P =3）.For each patient,the minimum frequency of misdiagnoses was once and the maximum was 4 times.As for the lasting time of being misdiagnosed,the shortest was 1.5mo and the longest was 45 mo.Twentyone cases（84%） were once treated with glucocorticoids,and its side effects was found in seventeen patients.Twenty patients（80%） complained with varying degree of vision loss.When a definite diagnosis was made,sixteen cases（64%） showed slight exophthalmos and eighteen cases（72%） had the tubular ONSM.CONCLUSION：ONSM without loss obvious exophthalmos is easily misdiagnosed in clinic,and for most of these ONSMs are tubular.

Optic nerve sheath diameters in healthy adults measured by computer tomography

AIMTo measure optic nerve sheath diameters (ONSD) in different locations by computer tomography (CT) and to recommend the best location for cases when ONSD is used for intracranial pressure monitoring.METHODSIn a prospective cohort study, CT data of 300 healthy adults were analyzed (600 eyes). In all cases, the CT investigation was performed at the Emergency Department because of the various conditions that proved not to be connected with ophthalmological or neurological pathology. The ONSD were measured at 3 mm and 8 mm distance from the globe, and 3 mm from the anterior opening of the optic canal. The correlation analysis was performed with gender, age, and ethnic background.RESULTSThe right/left ONSD are 4.94&#x000b1;1.51/5.17&#x000b1;1.34 mm at 3 mm, 4.35&#x000b1;0.76/4.45&#x000b1;0.62 mm at 8 mm from the globe, and 3.55&#x000b1;0.82/3.65&#x000b1;0.7 mm at 3 mm from the optic canal. No significant differences correlated with gender of the patients, their age, and ethnic background were found.CONCLUSIONIn healthy persons, the ONSD varies from 5.17&#x000b1;1.34 mm to 3.55&#x000b1;0.82 mm in different locations within the intraorbital space. The most stable results with lesser standard deviation can be obtained if it is measured 8-10 mm from the globe.

Prognostic values of optic nerve sheath diameter for comatose patients with acute stroke:An observational study

BACKGROUND Optic nerve sheath diameter(ONSD)measurement is one of the non-invasive methods recommended for increased intracranial pressure(ICP)monitoring.AIM This study aimed to evaluate the roles of optic nerve sheath diameter(ONSD)and ONSD/eyeball transverse diameter(ETD)ratio in predicting prognosis of death in comatose patients with acute stroke during their hospitalization.METHODS A total of 67 comatose patients with acute stroke were retrospectively recruited.The ONSD and ETD were measured by cranial computed tomography(CT)scan.All patients underwent cranial CT scan within 24 h after coma onset.Patients were divided into death group and survival group according to their survival status at discharge.The differences of the ONSD and ONSD/ETD ratio between the two groups and their prognostic values were compared.RESULTS The ONSD and ONSD/ETD ratio were 6.07±0.72 mm and 0.27±0.03 in the comatose patients,respectively.The ONSD was significantly greater in the death group than that in the survival group(6.32±0.67 mm vs 5.65±0.62 mm,t=4.078,P<0.0001).The ONSD/ETD ratio was significantly higher in the death group than that in the survival group(0.28±0.03 vs 0.25±0.02,t=4.625,P<0.0001).The area under the receiver operating characteristic curve was 0.760(95%CI:0.637-0.882,P<0.0001)for the ONSD and 0.808(95%CI:0.696-0.920,P<0.0001)for the ONSD/ETD ratio.CONCLUSION The mortality increased in comatose patients with acute stroke when the ONSD was>5.7 mm or the ONSD/ETD ratio was>0.25.Both indexes could be used as prognostic tools for comatose patients with acute stroke.The ONSD/ETD ratio was more stable than the ONSD alone,which would be preferred in clinical practice.

The clinical value of dynamic ultrasound measurement of optic nerve sheath diameter in the treatment of patients with moderate and severe craniocerebral injury

Objective:To explore the clinical value of dynamic ultrasound monitoring of optic nerve sheath diameter(ONSD)in the treatment of patients with moderate and severe head injury(CI).Methods:A total of 160 patients with moderate and severe CI admitted to the First Affiliated Hospital of Hainan Medical University from January 2018 to January 2020 were selected and divided into observation group(80 cases)and control group(80 cases)a Januaryccording to the random number table.Patients in control group and observation group were dehydrated to reduce intracranial pressure(ICP)according to clinical symptoms/brain CT and ONSD monitoring guidance.National Institutes of Health Stroke Scale(NIHSS),Acute Physiology and Chronic Health EvaluationⅡ(APACHEⅡ),Glasgow Coma Scale(GCS),complications,prognosis,ICU stay time and mechanical ventilation time were compared between the two groups.Results:NIHSS score[control group:(19.58±3.19)points vs(37.98±5.75)points,observation group:(10.33±2.42)points vs(38.05±5.83)points]and APACHE II score[control group:(14.55±2.17)points vs(19.87±3.50)points,observation group:(8.71±2.03)points vs(20.12±3.56)points]of the two groups at 1 month after injury were significantly lower than those at admission(P<0.05),GCS score[control group:(10.78±1.66)points vs(8.03±1.34)points,observation group:(13.10±1.72)points vs(7.99±1.32)points]were significantly higher than that at admission(P<0.05).At 1 month after injury,NIHSS score[(10.33±2.42)points vs(19.58±3.19)points],APACHE II score[(8.71±2.03)points vs(14.55±2.17)points]in the observation group were significantly lower than those in the control group(P<0.05),and GCS score[(13.10±1.72)points vs(10.78±1.66)points]in the observation group was significantly higher than that in the control group(P<0.05).The proportion of hydrocephalus(2.50%vs 12.50%),total complication rate(5.00%vs 21.25%),proportion of severe disability(5.00%vs 17.50%),proportion of survival in plant man(3.75%vs 15.00%),mortality rate(2.50%vs 12.50%),ICU stay time[(5.01±1.25)d vs(8.38±2.29)D],mechanical ventilation time[(2.18±0.75)D]in observation group were lower than those in the control group,and the good rate(56.25%vs 32.50%)and the total effective rate(93.75%vs 72.50%)in the control group were significantly higher than those in the control group(P<0.05).Conclusion:Dynamic ultrasound monitoring ONSD is effective in guiding dehydration treatment of patients with moderate and severe CI,it can significantly reduce ICP and complications,improve prognosis,which is worthy of promotion and application.

Sonographic Measurement of the Optic Nerve Sheath Diameter (ONSD) and Eyeball Transversal Diameter (ETD) in Benin Healthy African Adults

Background: Measuring optic nerve sheath diameter (ONSD), a relatively re-cent technique, allows an indirect and non-invasive diagnosis of intracranial hypertension. The ONSD ratio to eyeball transverse diameter (ETD) increases this reliability of the technique. The objective of this study was to determine the normal ONSD and its ratio with ETD in black African adults in Benin. Methods: A descriptive cross-sectional study was conducted between May 2019 and August 2019. Ultrasound ONSD and ONSD/ETD ratio were meas-ured in 210 healthy adults received in the medical imaging department of the Borgou and Alibori University Hospital Center in Benin. The ONSD corre-sponded to the average of 12 measurements (03 horizontal and 03 vertical for each eye) taken 3 mm behind the papilla. The transverse ETD corresponded to the average of 03 measurements. Results: The mean ONSD was 4.20 ± 0.28 mm (95% CI = [4.17;4.24] mm and 95th percentile = 4.70 mm). The mean ETD was 24.25 ± 1.10 mm. The ONSD/ETD ratio was 0.17 ± 0.01 (95% CI = [0.17;0.17] and 95th percentile = 0.19). There was no difference between ver-tical and horizontal ONSD and between right and left ONSD. The ONSD and the ONSD/ETD ratio were not correlated with any of the socio-demographic and anthropometric characteristics studied (sex, age, ethnicity, weight, height, body mass index, head circumference and waist circumference). The ONSD was associated with ETD (p < 0.001 and r = 0.55). Conclusion: An ONSD and an ONSD/ETD ratio respectively greater than 4.70 mm and 0.19 should sus-pect intracranial hypertension. The ONSD/ETD ratio may be a better indicator of HICT because of its small variation.

Shunting,optic nerve sheath fenestration and dural venous stenting for medically refractory idiopathic intracranial hypertension:systematic review and meta-analysis

Background:Cerebrospinal fluid(CSF)-diversion procedures have traditionally been the standard of treatment for patients with medically refractive idiopathic intracranial hypertension(IIH).However,dural venous sinus stent(VSS)placement has been described as a safe and effective procedure for the management of medically refractive IIH.We performed a meta-analysis comparing outcomes and complications of CSF-diversion procedures,VSS and optic nerve sheath fenestration(ONSF)for the treatment of medically refractive IIH.Methods:Electronic searches were performed using six databases from 1988 to January 2017.Data was extracted and meta-analysed from the identified studies.Results:From 55 pooled studies,there were 538 CSF-diversion cases,224 dural venous stent placements,and 872 ONSF procedures.Similar improvements were found in terms of postoperative headaches(CSF vs.VSS vs.ONSF:84%vs.78%vs.62%,P=0.223),papilledema(CSF vs.VSS vs.ONSF:71%vs.86%vs.77%,P=0.192),whilst visual acuity changes favored venous stenting(CSF vs.VSS vs.ONSF:55%vs.69%vs.44%,P=0.037).There was a significantly lower rate of subsequent procedures with venous stent placement(CSF vs.VSS vs.ONSF:37%vs.13%vs.18%,P<0.001),but other complication rates were similar(CSF vs.VSS vs.ONSF:13%vs.8%vs.14%,P=0.28).Subgroup analysis of lumbar-peritoneal vs.ventriculoperitoneal shunts found no differences in symptom improvements,complications and subsequent procedure rates.Conclusions:Our findings suggest that dural venous sinus stenting may be a viable alternative to traditional surgical interventions in patients who are refractory to medical treatment.

Increase in optic nerve sheath diameter predicts early cerebral involvement in fat embolism syndrome

Early diagnosis of cerebral fat embolism in a patient with contradiction to MRI is challenging.Here we report an interesting case,where the raised optic nerve sheath diameter helped us to predict the early cerebral involvement with fat emboli in a left femoral shaft fracture patient.MRI scan could not be performed due to the presence of a metallic implant in the patient from a previous surgery.He was later diagnosed as an atypical presentation of fat embolism syndrome.Optic nerve sheath monitoring also helped us to guide further management of the patient.

The effect of increased intra-abdominal pressure on orbital subarachnoid space width and intraocular pressure

In accordance with the trans-lamina cribrosa pressure difference theory, decreasing the trans-lamina cribrosa pressure difference can re- lieve glaucomatous optic neuropathy. Increased intracranial pressure can also reduce optic nerve damage in glaucoma patients, and a safe, effective and noninvasive way to achieve this is by increasing the intra-abdominal pressure. The purpose of this study was to observe the changes in orbital subarachnoid space width and intraocular pressure at elevated intra-abdominal pressure. An inflatable abdominal belt was tied to each of 15 healthy volunteers, aged 22-30 years （12 females and 3 males）, at the navel level, without applying pressure to the abdomen, before they laid in the magnetic resonance imaging machine. The baseline orbital subarachnoid space width around the optic nerve was measured by magnetic resonance imaging at 1, 3, 9, and 15 mm behind the globe. The abdominal belt was inflated to increase the pressure to 40 mmHg （1 mmHg = 0.133 kPa）, then the orbital subarachnoid space width was measured every 10 minutes for 2 hours. After removal of the pressure, the measurement was repeated 10 and 20 minutes later. In a separate trial, the intraocular pressure was measured for all the subjects at the same time points, before, during and after elevated intra-abdominal pressure. Results showed that the baseline mean orbital subarachnoid space width was 0.88 ＋ 0.1 mm （range： 0.77-1.05 mm）, 0.77 ＋ 0.11 mm （range： 0.60-0.94 mm）, 0.70 ＋ 0.08 mm （range： 0.62-0.80 ram）, and 0.68 _＋ 0.08 mm （range： 0.57-0.77 mm） at 1, 3, 9, and 15 mm behind the globe, respectively. During the elevated intra-abdominal pressure, the orbital subarachnoid space width increased from the baseline and dilation of the optic nerve sheath was significant at 1, 3 and 9 mm behind the globe. After decompression of the abdominal pressure, the orbital subarachnoid space width normalized and returned to the baseline value. There was no significant difference in the intraocular pressure before, during and after the intra-abdominal pressure elevation. These results verified that the increased intra-abdominal pressure widens the orbital subarachnoid space in this acute trial, but does not alter the intraocular pressure, indicating that intraocular pressure is not affected by rapid increased in- tra-abdominal pressure. This study was registered in the Chinese Clinical Trial Registry （registration number： ChiCTR-ONRC-14004947）.

Using point-of-care ultrasound in ocular emergencies: A mini review

As a diagnostic aid in emergency services,ultrasound has expanded considerably in recent years.Among its applications,ocular ultrasonography allows for a better evaluation of patients with ophthalmological emergencies.In addition,it provides a simple and easy technique to obtain clinical information that may not be easily accessible either through the clinical examination or by using the ophthalmoscope.Ocular ultrasonography can help to diagnose hemorrhage and retinal detachment and/or vitreous,eye infections,foreign bodies,retrobulbar hematomas,papilledema,and eye trauma.By measuring the diameter of the optic nerve sheath,intracranial hypertension could be screened.This article reviewed the approach to eye exam by ultrasound and common ophthalmic pathologies diagnosed with ultrasound in the emergency department.