UNEXPECTED SOURCE OF CEREBRAL MICROEMBOLISATION INVESTIGATED BY TRANSCRANIAL DOPPLER DUPLEX COLOUR SONOGRAPHY

UNEXPECTED CAUSE(S) OF CEREBRAL MICROEMBOLISATION INVESTIGATED BY TRANSCRANIAL DOPPLER DUPLEX COLOUR

SONOGRAPHY

Muriel SPRYNGER

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

CAROTID ULTRASOUND

– Right internal carotid occlusion

– Moderate narrowing at the distal part of the left internal carotid stent

CEREBRAL MRI

TEE + CONTRAST

• _{multiple irregular aortic} plaques

• interatrial septal aneurysm + right-to-left interatrial shunt through a patent foramen ovale (PFO)

CONTRAST TCD

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

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

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?

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}

cTEE

cTEE

– sensitivity 97%, specificity _{sensitivity 97%, specificity}

78%

78%

– Semi-quantitative _{Semi-quantitative}

(« curtain »)

(« curtain »)

Bilateral MES

• despite or because of

right internal carotid

occlusion

• Origins ?

– Venous – Aortic

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

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%