Phenotypic and Etiological Characterization of Susac Syndrome (CARESS Cohorte)

SUSAC's Syndrome (SS) is characterized by the clinical triad of encephalopathy, hearing loss, and retinal artery branch occlusions. Since the first description of SS in 1979, hundreds of patients with SS, mostly young women, have been reported. However, comprehensive epidemiological, clinical and etiological features of SS have never been specifically addressed so far.

Study Overview

• Status: Recruiting
• Conditions: Susac Syndrome

Detailed Description

Susac's Syndrome (SS) is characterized by the clinical triad of encephalopathy, hearing loss, and retinal artery branch occlusions. Since the first description of SS in 1979, hundreds of patients with SS, mostly young women, have been reported. However, comprehensive epidemiological, clinical and etiological features of SS have never been specifically addressed so far.

The diagnosis of SS is difficult because its characteristic signs often do not occur simultaneously or may be too subtle for the patient to notice. Neurological features of SS may occur several months prior to other symptoms. The retinal artery branch occlusion, by occurring in the peripheral portion of the retina, may remain asymptomatic. Sensorineural hearing loss may also be asymptomatic and disclosed only by audiogram. Besides mild pleocytosis in cerebro-spinal fluid, all performed biological tests are virtually negative. No infectious agent, consistent autoimmune marker, or coagulopathy has been disclosed. Changes seen on brain MRI are well characterized although not specific. The only site from which biopsy material is available for pathological analysis is the brain. The most common finding in brain biopsies is the presence of microinfarcts but brain biopsy is not currently performed.

Although the treatment of SS has not been studied in controlled trials, most patients have a good response to treatment with glucocorticoids, with the addition of antithrobomtic therapy and, for cases in which the disease is refractory to steroids, intravenous immune globulin or cyclophosphamide. The clinical course is characterized by recurrent attacks involving 1 or more components of the triad that characterize the active phase of the disease. Remission usually occurs after the active phase but some patients show residual mild to moderate dementia or gait disturbance, and impaired hearing and vision.

Susac's Syndrome is a vasculopathy causing small infarcts in the cochlea, retina and brain. Proposed explanations include a hypercoagulable state, vasospasm, and vasculitis, none of which are supported by laboratory results or findings on brain biopsies. The unique distribution of arteriolar disease affecting the brain, the retina, and the cochlea suggests selective vulnerability of these three structures. The brain, retina, and cochlea all have a blood-tissue barrier, and the endothelium in these sites shares a common embryologic origin and unique structural and antigenic characteristics. It has therefore been proposed that SS is an autoimmune disease in which the endothelium is the primary target, and damage to the endothelium triggers arteriolar occlusion and microinfarcts. However, the pathogenesis remains unknown.

The objective of this study is to characterize the epidemiological, clinical, and etiological features of Susac's Syndrome. In this aim, we will constitute a national clinical-based cohort including all SS new cases prospectively observed. French Society of Neurology, Ophtalmology and Internal Medicine will be asked to collaborate.The exhaustive and systematic analysis of each case will help to better define different aspects of the disease such as the incidence and prevalence, the clinical presentation, the diagnostic modalities and the impact of treatments.

Because Susac's syndrome is a rare disease, we expect to include 180 patients in this cohort. The constitution of the cohort will last for 19 years (9 years of inclusion and 10 years of follow-up.

The conclusion of the study, based on statistical analysis done once all patients will be included in the cohort, should allow new recommendations in the diagnosis strategy and give new understandings of the therapeutic management of the disease. The result of this study may also give rise to hypothesis for an interventional study.

• Study Type: Observational
• Enrollment (Estimated): 180

Contacts and Locations

• Study Contact: Name: Karim Sacre, MD, PHD; Phone Number: +33140258705; Email: karim.sacre@aphp.fr
• Study Contact Backup: Name: Thomas Papo, MD, PHD; Email: thomas.papo@aphp.fr

Study Locations

• France
  • Paris, France, 75018
    • Recruiting
    • Hôpital Bichat
    • Contact: Karim Sacre, MD, PHD; Phone Number: +33140258705; Email: karim.sacre@aphp.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The population to be studied will be patients with defined Susac syndrome, presenting with at least two of the signs of the clinical triad, having compatible complementary examinations and after elimination of differential diagnoses (see inclusion and non-inclusion criteria below). Patients will be included prospectively.

The existence of an associated pathology (autoimmune, tumour, metabolic, etc.) is not a criterion for exclusion.

Description

Inclusion Criteria:

• Patient over 18 years of age
• Patient presenting with at least two of the signs of the clinical triad: encephalopathy, cochlear damage authenticated by an audiogram (uni- or bilateral, predominantly in the middle or low frequencies), retinal artery occlusion assessed by fundoscopy or fluorescein retinal angiography.

Exclusion Criteria:

• Patient having been individually informed and objecting to the use of his/her data
• Patient under legal protection (guardianship or curatorship)
• Differential diagnosis established: multiple sclerosis, mitochondriopathy, CADASIL, primary tumour of the central nervous system, Lyme disease.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To characterize the epidemiological Susac's Syndrome	Variables collected at inclusion: Date of birth	10 years
1. To characterize the epidemiological of Susac's Syndrome	Variables collected at inclusion: • Place of birth	10 years
1. To characterize the epidemiological of Susac's Syndrome	• Variables collected at inclusion: Sex	10 years
1. To characterize the epidemiological of Susac's Syndrome	• Variables collected at inclusion : Date of first symptom	10 years
1. To characterize the epidemiological of Susac's Syndrome	• Variables collected at inclusion: Date of diagnosis	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at inclusion : • Personal medical history	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at inclusion : • Gynaecological history	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at inclusion : • Surgical history	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at inclusion : • Family history	10 years
2. To characterize the etiological of Susac's Syndrome	• Variables collected at inclusion : Previous travel and vaccination status	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at inclusion : • Any symptoms (flu-like illness, fever)	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at each visit : • - Weight in kilograms	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at each visit : • - Tobacco consumption	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at each visit : • - Use of oestroprogestogenic contraception	10 years
2. To characterize the etiological of Susac's Syndrome	Variables collected at each visit : • - Alcohol consumption	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : Headache	10 years
3. To characterize the clinical of Susac's Syndrome	Neurology: Neurological symptoms: present / absent / date of onset : • Sensory disturbance	10 years
3. To characterize the clinical of Susac's Syndrome	Neurology: Neurological symptoms: present / absent / date of onset : • Motor deficit	10 years
3. To characterize the clinical of Susac's Syndrome	Neurology: Neurological symptoms: present / absent / date of onset : • Osteotendinous pyramidal reflexes	10 years
3. To characterize the clinical of Susac's Syndrome	Neurology: Neurological symptoms: present / absent / date of onset : • Babinski sign	10 years
3. To characterize the clinical of Susac's Syndrome	Neurology: Neurological symptoms: present / absent / date of onset : • Hoffman's sign	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Tact sensitivity disorder	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Thermoal sensitivity deficit	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : Proprioceptive disorder : • If yes, specify : Ataxia	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : Proprioceptive disorder : • If yes, specify : Anomaly of the sense of position of the big toe	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Paresthesias	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Encephalopathy, If yes, specify the signs present: Confusion	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Encephalopathy, If yes, specify the signs present: Obnubilation	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Encephalopathy, If yes, specify the signs present: Coma	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Encephalopathy, If yes, specify the signs present: Agitation	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Encephalopathy, If yes, specify the signs present: Temporo-spatial disorientation	10 years
3. To characterize the clinical of Susac's Syndrome	1) Neurology: Neurological symptoms: present / absent / date of onset : • Encephalopathy, If yes, specify the signs present: Fluctuating memory disorders	10 years
3. To characterize the clinical of Susac's Syndrome	• Any sequelae : Results of neurocognitive assessment : BREF	10 years
3. To characterize the clinical of Susac's Syndrome	Any sequelae : • Results of neurocognitive assessment: MMS	10 years
3. To characterize the clinical of Susac's Syndrome	Any sequelae : For mood disorders and quality of life: DSMIV criteria for depression	10 years
3. To characterize the clinical of Susac's Syndrome	Any sequelae : For mood disorders and quality of life: SF36	10 years
3. To characterize the clinical of Susac's Syndrome	Any sequelae : • For disability : Barthel Index	10 years
3. To characterize the clinical of Susac's Syndrome	• Any sequelae : For disability : Rankin score	10 years
3. To characterize the clinical of Susac's Syndrome	Ophthalmology • Ophthalmological examination results : Fundus	10 years
3. To characterize the clinical of Susac's Syndrome	Ophthalmology • Ophthalmological examination results : Visual field	10 years
3. To characterize the clinical of Susac's Syndrome	Ophthalmology • Ophthalmological examination results : o Angiography	10 years
3. To characterize the clinical of Susac's Syndrome	• Ophthalmology Ophthalmological symptoms: scotoma	10 years
3. To characterize the clinical of Susac's Syndrome	Ophthalmology : Ophthalmological symptoms: decrease in visual acuity	10 years
3. To characterize the clinical of Susac's Syndrome	Ophtalmology : Evolution of retinal arterial occlusions: improvement	10 years
3. To characterize the clinical of Susac's Syndrome	Ophthalmology : Evolution of retinal arterial occlusions: stability	10 years
3. To characterize the clinical of Susac's Syndrome	Ophthalmology : Evolution of retinal arterial occlusions: worsening	10 years
3. To characterize the clinical of Susac's Syndrome	• Ophthalmology : Sequelae	10 years
3. To characterize the clinical of Susac's Syndrome	ENT : Cochlear symptoms: vertigo, tinnitus, ataxia, hearing loss	10 years
3. To characterize the clinical of Susac's Syndrome	ENT: • Audiogram results	10 years
3. To characterize the clinical of Susac's Syndrome	ENT • Results of vestibular examinations	10 years
3. To characterize the clinical of Susac's Syndrome	ENT • Course of deafness: improvement, stability, worsening	10 years
3. To characterize the clinical of Susac's Syndrome	ENT : • Possible sequelae (functional discomfort, psycho-social repercussions, follow-up audiograms)	10 years

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Investigators: Principal Investigator: Karim Sacre, MD, PHD, Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2025
• Primary Completion (Estimated): November 30, 2044
• Study Completion (Estimated): February 15, 2045

Study Registration Dates

• First Submitted: January 29, 2025
• First Submitted That Met QC Criteria: March 11, 2025
• First Posted (Actual): March 18, 2025

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Eye Diseases; Otorhinolaryngologic Diseases; Vision Disorders; Ear Diseases; Arterial Occlusive Diseases; Retinal Diseases; Eye Manifestations; Retinal Artery Occlusion; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Susac Syndrome
• Other Study ID Numbers: APHP241173; 2025-A00214-45 (Other Identifier: ANSM ID-RCB)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No