Susac syndrome
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(RED M syndrome, SICRET syndrome, retino-cochleo-cerebral vasculopathy)
Rare but probably non-diagnosed in the majority of cases. Non-inflammatory and non-necrotizing vasculopathy (probably an autoimmune endotheliopathy associated with endothelial cell antibodies) which causes microinfarctus at the level of the terminal branches of brain, retinal and vestibulo-cochlear arteries. It affects primarily women (F/M = 3 to 5: 1) between the age of 18 and 40 years and evolves by outbreaks separated by free intervals of a few weeks to a few months. Its clinical presentation can therefore be confused with multiple sclerosis or a vascular pathology causing multiple stroke (CADASIL, MELAS etc).
The typical but rarely complete clinical picture consists in a triad of:
- encephalopathy: headaches, short-term memory, behavioral disorders, ataxia, sometimes involvement of cranial nerves
- retinopathy following the occlusion of distal branches of the retinal artery: blurred vision
- perception hypoacusis of brutal onset, often bilateral and sometimes poorly symptomatic (audiogram); low frequencies are preferentially affected.
Some authors distinguish a hot phase which lasts approximately 2 years followed by a cold phase where hearing sequelae and paucisymptomatic retinal lesions persist...
Myalgia and skin lesions were observed in some cases.
Diagnosis: retinal angiography, audiogram, MRI with lesions mainly at the level of the central part of the corpus callosum (typical image of 'snowball') but there is no correlation between the severity of brain injury and imaging.
Treatment: corticosteroids, IV gammaglobulin, immunosuppressants, platelet antiaggregants .
There is a risk of relapse in case of pregnancy or during the postpartum .
Anesthetic implications:
maintain the cerebral pressure perfusion within normal values for the patient: avoid hypo- and hypercapnia as well as systemic hypo- or hypertension. It is probably useful to use the NIRS to assess cerebral oxygenation (cortical !) and quickly detect hypoperfusion in the monitored area (obtain the basal values while awake).
References :
- PapoT, Klein I, Sacré K, Doan S, Bodaghi B, Aubart-Cohen F.
Syndrome de Susac.
Revue Médecine Interne 2012; 33:94-8.
- Kleffner I, Duning T, Lohmann H, Deppe M et al.
A brief review of Susac syndrome.
J Neurol Sciences 2012; 322: 35-40.
Updated: September 2018