UNEXPECTED CAUSE(S) OF CEREBRAL MICROEMBOLISATION INVESTIGATED BY

TRANSCRANIAL DOPPLER DUPLEX COLOUR SONOGRAPHY

Muriel SPRYNGERCardiology-AngiologyCHU 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 20’’ after 1st MB – at rest, more sensitive than at rest, more sensitive than

cTEEcTEE– sensitivity 97%, specificity sensitivity 97%, specificity

78%78%– Semi-quantitative Semi-quantitative

(« curtain »)(« curtain »)– Intrapulmonary shuntIntrapulmonary 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.