Giant Cell Arteritis (GCA)
Conditions
Keywords
Giant Cell Arteritis, Optic nerve sheath, Ultrasound
Brief summary
The purpose of this study is to evaluate whether the measure of the optic nerve sheath is a reliable diagnostic marker for giant cell arteritis
Detailed description
Giant Cell Arteritis (GCA) is a vasculitis affecting large and medium-sized vessels. It predominantly occurs in women, with a sex ratio of 3:1, and mainly affects individuals around 70 years of age. GCA is a rare condition, with an incidence of approximately 10 cases per 100,000 people in France. Current recommendations suggest using imaging techniques and/or temporal artery biopsy (TAB) based on the clinical resources available. The key challenge in suspected cases of GCA is to establish a rapid diagnosis. It is important to note that false-negative imaging results may occur if corticosteroid treatment is initiated prior to imaging: after 3 days for PET-CT, 5 to 7 days for Doppler ultrasound, and up to 14 days for TAB. Diagnosing GCA is not always easy and depends on depends on the prompt performance of complementary examinations. Studies have shown that the optic nerve sheath is thickened on ultrasound in patients with GCA. In this context, the investigator aims to evaluate the measurement of the optic nerve sheath via ultrasound for diagnosing GCA. Ultrasound offers a faster, non-invasive, widely available, and cost-effective diagnostic tool.
Interventions
DIAGNOSTIC_TESTorbital ultrasound
orbital ultrasound at the beginning of the participation, and at 6 months after the inclusion.
Sponsors
Hôpital NOVO
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patient with suspected GCA * Patient over 50 years
Exclusion criteria
* Patient with history of GCA * Patient with a history of polymyalgia rheumatic (PMR) without initial PET scan * Patient with a history of retinal disease, demyelinating disease, or intracranial hypertension * Use of corticosteroids \> 0.5mg/kg in the last 2 weeks
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Assess whether the Optic Nerve Sheath Diameter (ONSD) measured by orbital ultrasound serves as an effective diagnostic marker for Giant Cell Arteritis (GCA) | At the patient enrollment visit and at 6 months | Area under the ROC curve (AUC) of the optic nerve sheath measurements obtained by ultrasound during the enrollment phase, using the final clinical expert diagnosis at 6 months as the reference standard. The clinical expert's evaluation will be blinded to the optic nerve sheath measurements. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Evaluate the diagnostic performance of ONSD in GCA. | At the patient enrollment visit and at 6 months | Sensitivity, specificity, ROC curve inflection point (pathological threshold value), positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio. |
| Study the evolution of ONSD under treatment between M0 and M6 in patients with GCA. | At the patient enrollment visit and at 6 months | Measurement of the optic nerve sheath diameter (ONSD) by ultrasound at baseline (within 3 days of corticosteroid initiation) in all patients, and at 6 months in patients with GCA. |
| Assess the reproducibility of the optic nerve sheath diameter (ONSD) measurements by ultrasound. | At the patient enrollment visit and at 6 months | Mean bias according to Bland-Altman analysis, limits of agreement with their confidence intervals, maximum acceptable difference (clinical and statistical difference calculated using the root sum of squares of the coefficients of variation), inter-rater ICC. |
| Exploratory evaluation of ONSD based on the presence or absence of GCA with visual involvement. | At the patient enrollment visit and at 6 months | Comparison of mean ONSD between subgroups: GCA with visual involvement, GCA without visual involvement, and GCA-negative patients |
| Assess the feasibility of ultrasound as a diagnostic tool for GCA. | At the patient enrollment visit and at 6 months | Description of the patient flow : average duration of the exam |
| Exploratory evaluation of ONSD according to the presence or absence of extracranial GCA. | At the patient enrollment visit and at 6 months | Comparison of mean ONSD between subgroups: cranial GCA, extracranial GCA, and GCA-negative patients. |
Countries
France
Contacts
Primary ContactMaryline DELATTRE
Backup ContactMathilde WLODARCZYK
Outcome results
None listed