UNEXPECTED CAUSE(S) OF CEREBRAL MICROEMBOLISATION INVESTIGATED BY TRANSCRANIAL DOPPLER DUPLEX COLOUR SONOGRAPHY Muriel SPRYNGER Cardiology-Angiology CHU Sart Tilman, Liège BSTH, November the 27th, 2009

CASE REPORT 72-year old hypertensive man december 2008 : right internal carotid thrombotic occlusion with left hemispheral stroke + 80% left internal carotid stenosis january 2009 : stenting of the left internal carotid october 2009 : admitted for suspected worsening left hemiparesia and cerebral confusion Medication : clopidogrel + simvastatine

CAROTID ULTRASOUND –Right internal carotid occlusion –Moderate narrowing at the distal part of the left internal carotid stent

CEREBRAL MRI bilateral ischemic parietal sequellae

TEE + CONTRAST multiple irregular aortic plaques interatrial septal aneurysm + right-to-left interatrial shunt through a patent foramen ovale (PFO)

CONTRAST TCD Saline contrast TCD with injection of 10 cc of 9°/°° saline infusion in the right forearm Bilateral middle cerebral artery recording

CONTRAST TCD : middle cerebral artery Microembolic signals (MES) were recorded on both sides

DISCUSSION

CARDIOEMBOLIC STROKE approximately 20% of strokes are cardioembolic (40% in younger populations) atrial fibrillation valvular heart disease endocarditis mitral valve prolapse prosthetic heart valves, recent myocardial infarction (0,8% strokes, 1-2%/y), intracardiac thrombus, dilated cardiomyopathy sick sinus syndrome, patent foramen ovale, hypokinetic/akinetic left ventricular segment calcification of the mitral valve cardiac surgical procedures : 1-7% perioperative stroke

TEE « gold standard » for the detection of : –PFO : < 20 bubbles : small shunt > 20 bubbles : large shunt –Atrial septal aneurysm PFO is found in 25% of the healthy population PFO + aneurysm : dangerous association? 15% of patients who underwent PFO closure had AF detected 3 to 6 months afterwards. PFO closure patients warrant antiplatelet medication at a minimum

CLINICAL RELEVANCE OF TCD AND TEE IN PFO DETECTION cTEE = gold standard ? Semi-invasive 90% concordance cTCD :cTCD : –20’’ after 1st MB –at rest, more sensitive than cTEE –sensitivity 97%, specificity 78% –Semi-quantitative (« curtain ») –Intrapulmonary shunt

Bilateral MES despite or because of right internal carotid occlusion Origins ? –Venous –Aortic –Supra-aortic (heterolateral carotid) –Cardiac (AF)

CONCLUSION In case of right-to-left shunts, cTCD can complete cTEE : –better sensitivity –Semi-quantitative method cTCD can also detect potential ME in unexpected cerebral areas and/or explain unexpected strokes.

CONCLUSION Contrast-TCD can diagnose large PFO

PFO - CLOSING DEVICE ? The data supporting risk factors (ie, atrial septal aneurysm or large PFO) are weak. Right-to-left shunting may not be the only possible mechanism for stroke ? More AF. High-level evidence for PFO management is desperately needed.

TCD and PFO Contrast Transcranial Doppler Can Diagnose Large Patent Foramen Ovale Small PFO : 19 MES/78 (24%) Large PFO : 27 MES/27 (100%) No PFO : 3 MES/216 2 MES is the cutoff to predict large PFO : –Sensitivity : 96,3% –Specificity : 96.8% –Accuracy : 96.9% When two or more MES were determined by c-TCD, large PFO could be accurately diagnosed.