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
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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
190
orbital ultrasound at the beginning of the participation, and at 6 months after the inclusion.
Rhumatology departement - Centre Hospitalier Aix en Provence
Aix-en-Provence, France
NOT_YET_RECRUITINGRhumatology department - Centre Hospitalier Universitaire de Brest
Brest, France
NOT_YET_RECRUITINGAssess whether the Optic Nerve Sheath Diameter (ONSD) measured by orbital ultrasound serves as an effective diagnostic marker for Giant Cell Arteritis (GCA)
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.
Time frame: At the patient enrollment visit and at 6 months
Assess the reproducibility of the optic nerve sheath diameter (ONSD) measurements by ultrasound.
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.
Time frame: At the patient enrollment visit and at 6 months
Evaluate the diagnostic performance of ONSD in GCA.
Sensitivity, specificity, ROC curve inflection point (pathological threshold value), positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio.
Time frame: At the patient enrollment visit and at 6 months
Study the evolution of ONSD under treatment between M0 and M6 in patients with GCA.
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.
Time frame: At the patient enrollment visit and at 6 months
Exploratory evaluation of ONSD according to the presence or absence of extracranial GCA.
Comparison of mean ONSD between subgroups: cranial GCA, extracranial GCA, and GCA-negative patients.
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Internal Medecine Department- CHU Caen
Caen, France
Internal Medicine and Clinical Immulogy department - Centre Hospitalier Universitaire de Dijon
Dijon, France
NOT_YET_RECRUITINGInternal Medicine and VascularMedecine Department - Centre Hospitalier Universitaire de Nantes
Nantes, France
NOT_YET_RECRUITINGInternal Medicine department - Hôpital Saint-Antoine
Paris, France
NOT_YET_RECRUITINGRhumatology department - Hôpital Bichat
Paris, France
NOT_YET_RECRUITINGRhumatology department - Hôpital NOVO - Pontoise site
Pontoise, France
NOT_YET_RECRUITINGRhumatology department - Centre Hospitalier Universitaire de Tours
Tours, France
NOT_YET_RECRUITINGTime frame: At the patient enrollment visit and at 6 months
Exploratory evaluation of ONSD based on the presence or absence of GCA with visual involvement.
Comparison of mean ONSD between subgroups: GCA with visual involvement, GCA without visual involvement, and GCA-negative patients
Time frame: At the patient enrollment visit and at 6 months
Assess the feasibility of ultrasound as a diagnostic tool for GCA.
Description of the patient flow : average duration of the exam
Time frame: At the patient enrollment visit and at 6 months
Assess the feasibility of ultrasound as a diagnostic tool for GCA.
Description of the patient flow : percentage of exams performed, and percentage of interpretable exams.
Time frame: At the patient enrollment visit and at 6 months
Assess the feasibility of ultrasound as a diagnostic tool for GCA.
Description of the patient flow : number of exams performed, and number of interpretable exams.
Time frame: At the patient enrollment visit and at 6 months