ICTUS CEREBRI, STENOSI CEREBROVASCOLARI E ULTRASUONI: DIAGNOSI E TERAPIA CON IL DOPPLER TRANSCRANICO Dr A. Costa U.O. Neurologia Vascolare A.O. Spedali

ICTUS CEREBRI, STENOSI CEREBROVASCOLARI E ULTRASUONI: DIAGNOSI E TERAPIA CON IL DOPPLER TRANSCRANICO

Dr A. CostaU.O. Neurologia VascolareA.O. Spedali Civili di Brescia

Indicazioni

Visualizzare le occlusioni e le stenosi intracraniche nelle principali arterie

Valutare gli effetti emodinamici intracranici in presenza di stenosi o occlusioni extracraniche

Monitorare la ricanalizzazione dei vasi intracranici nella fase acuta dell’ictus

Monitorare l’emodinamica cerebrale intracranica Dopo emorragia subaracnoidea InIn pazienti con aumentata ICP Durante/dopo procedure di rivascolarizzazione extracranica

Endarterectomia carotidea Angioplastica

Durante/dopo interventi neuroradiologici Balloon occlusion Coiling of AVM

Durante interventi cardiochirurgiciVisualizzazione e quantificazione dello shunt destro-sinistro

Patent foramen ovale

Indicazioni (2)Test funzionali

Stimulazione delle arteriole intra craniche con CO2 o altri farmaci vasoattivi

Lateralizzazione del linguaggio prima della neurochirurgia

NEWBrain perfusion imagingTrombolisi con ultrasuoniStratificazione del richio

Diagnostic Criteria – Stenosis

Increased flow velocity – generally focalDisturbed flow

Turbulence; spectral broadeningCovibration phenomena

Vibration of the vessel wall & surrounding soft tissue

Drop in post-stenotic velocityChanges in post-stenotic waveform

morphologyProlonged systolic upstrokeDecreased pulsatility

Diagnostic Criteria – OcclusionAbsence of arterial signal at expected depth

Presence of signals in vessels which communicate with the occluded artery

Altered flow in communicating vessels, indicating collateralization

Occlusione Arteria Cerebrale Media M1 - Criteri diagnostici

NAIS TCCS Consensus

Il segnale di flusso dell’MCA è assente in contemporanea alla visualizzazione delle restanti arterie del circolo anteriore

Il segnale di flusso dell’MCA è assente in contemporanea alla visualizzazione delle restanti arterie del circolo anterioreo delle vene profonde cerebrali o del circolo controlaterale

Sensibilità 85-100% Specificità 90-98%

Occlusione ICA a T - Criteri diagnostici

NAIS TCCS Consensus

Il segnale di flusso dell’MCA, ICA distale e A1 è assente in contemporanea alla visualizzazione dalla finestra omolaterale di A1 del circolo controlaterale o omolaterale

Il segnale di flusso dell’MCA, ICA distale e A1 è assente in contemporanea alla visualizzazione dalla finestra omolaterale di A1 del circolo controlaterale o omolateraleLa visualizzazione delle vene profonde cerebrali, di A2 o del circolo controlaterale aumenta la credibilità della diagnosi.Meglio se confermata dalla riduzione della velocità di flusso diastolico sull’ICA cervicale o sulla CCA o dalla presenza di flusso oscillante


Occlusione segmento distale M1 o di multipli rami di M2- Criteri diagnostici

NAIS TCCS Consensus

Differenze del 30% nella velocità di picco sistolico nel segmento prossimale di M1

Velocità di fine diastole inferiore a 26 cm/s e indice di fine diastole inferiore a 2.5 (se >2.5 indice di occlusione M1)(?).Calcolare l’indice di asimmetria se non vi sono alterazioni del flusso lungo l’ICA o M1 bilateralmente.Basse velocità di flusso vanno comunque tenute in considerazione in relazione al beneficio derivante dalla trombolisi


Stenosi M1 (o del segmento distale dell’ICA) – Criteri diagnostici

NAIS TCCS Consensus

Significativa (cioè superiore al 50%) se la velocità di picco sistolico dell’MCA o ICA distale è superiore a 220 cm/s.

Non vi sono dati validati per definire una diagnosi.

Sensibilità 70-90%? Specificità 90-95%?

MCA Stenosis

Pitfalls & Diagnostic AccuracyLack of flow signal due to an inadequate temporal

windowMisinterpretation of hyperdynamic collateral

channels or AVM feeders as stenosisDisplacement of arteries because of a space-

occupying lesionMisinterpretation of physiologic variables in the

circle of WillisMisdiagnosis of vasospasm as stenosisMisinterpretation of reactive hyperemia following

spontaneous recanalization as stenosis

Pitfalls & Diagnostic AccuracyVertebral-Basilar SystemNormal flow and size of vessels are highly

variableLocation and course of the arteries are

unpredictableDifficulty in reliably identifying the junction of

the vertebral arteries Absence of the vertebral artery flow signal on one

side may not represent diseaseLack of flow in one vertebral artery distally, above the

origin of the PICA due to vertebral artery hypoplasia Occlusion of one vertebral artery or a “top of the

basilar” occlusion does not necessarily lead to relevant flow abnormalities

Summary of findingsIntracranial Steno-Occlusive Disease

INDICATION SENSITIVITY (%)

SPECIFICITY (%)

REFERENCE STANDARD

Intracranial Steno-Occlusive Disease:

Conventional angiography

Anterior Circulation

70-90 90-95

Posterior CirculationOcclusion

50-80 80-96

Copyright 2004 American Academy of Neurology

19

Summary of findingsIntracranial Steno-Occlusive Disease (Continued )


SPECIFICITY (%)

REFERENCE STANDARD

MCA 85-95 90-98

ICA, VA, BA 55-81 96

Recommendation: Data are insufficient to establish TCD criteria for greater than 50% stenosis or for progression of stenosis in intracranial arteries (Type U).

Copyright 2004 American Academy of Neurology

Summary of findingsAcute cerebral infarction


SPECIFICITY (%)

REFERENCE STANDARD

Acute cerebral infarction

85-95 90-98

Recommendation: TCD is probably useful for the evaluation of patients with suspected intracranial steno-occlusive disease, particularly in the ICA siphon and MCA (Type B, Class II evidence). The relative value of TCD compared with MRA or CTA remains to be determined (Type U). Data are insufficient to give a recommendation regarding replacing conventional angiography with TCD (Type U).

Summary of findingsExtracranial ICA Stenosis


SPECIFICITY (%)

REFERENCE STANDARD

Extracranial ICA Stenosis:

Conventional angiography

Single TCD variable

3-78 60-100

TCD Battery 49-95 42-100

TCD Battery & Carotid Duplex

89 100

Recommendation:TCD is possibly useful for the evaluation of severe extracranial ICA stenosis or occlusion (Type C, Class II-III evidence).

Transcranial Color-Coded Sonography (TCCS) or Imaging

TCD

Summary of findingsIschemic Cerebrovascular Disease


SPECIFICITY (%)

REFERENCE STANDARD

ACoA Collateral Flow

100 100

PCoA Collateral Flow

85 98


SPECIFICITY (%)

REFERENCE STANDARD

Intracranial Steno-Occlusive Lesions

Any Up to 100 Up to 83


(Continued)


SPECIFICITY (%)

REFERENCE STANDARD

/= 50% Stenosis

MCA 100 100

ACA 100 100

VA 100 100

BA 100 100

PCA 100 100


(Continued)


(Continued)

Recommendation: (CE)-TCCS is probably useful in the evaluation and monitoring of patients with ischemic cerebrovascular disease (Type B, Class II-IV evidence).

Summary of findingsHemorrhagic Cerebrovascular DiseaseINDICATION SENSITIVITY

(%) SPECIFICITY

(%) REFERENCE STANDARD

Parenchymal Hypoechogenicity in MCA Distribution

69 83 Computed tomographic

scan

Recommendation: (CE-) TCCS is probably useful in the evaluation and monitoring of patients with aneurysmal SAH or intracranial ICA/MCA VSP following SAH (Type B, Class II-III evidence). Data are insufficient regarding the use of TCCS to replace CT for diagnosis of ICH (Type U).

Summary of findingsCerebral Thrombolysis


SPECIFICITY (%)

REFERENCE STANDARD

Cerebral Thrombolysis

Conventional angiography, magnetic resonance angiography, clinical outcome

Complete Occlusion

50 100

Partial Occlusion

100 76

Recanalization 91 93

Summary of findingsCerebral Thrombolysis (continued)

Recommendation: TCD is probably useful for monitoring thrombolysis of acute MCA occlusions (Type B, Class II-III evidence). Present data are insufficient to either define the optimal frequency of TCD monitoring for clot dissolution and enhanced recanalization or to influence therapy (Type U).

Summary of findingsCarotid Endarterectomy (CEA)


SPECIFICITY (%)

REFERENCE STANDARD

Carotid Endarterectomy

(CEA):

EEG, magnetic resonance imaging, clinical outcomes

Recommendation: CEA monitoring with TCD can provide important feedback pertaining to hemodynamic and embolic events during and after surgery that may help the surgeon take appropriate measures at all stages of the operation to reduce the risk of perioperative stroke. TCD monitoring is probably useful during and after CEA in circumstances where monitoring is felt to be necessary (Type B, Class II-III evidence).

Summary of findingsVasomotor Reactivity (VMR) Testing

Recommendation: TCD vasomotor reactivity testing is considered probably useful for

–the detection of impaired cerebral hemodynamics in patients with asymptomatic severe (>70%) stenosis of the extracranial ICA–patients with symptomatic or asymptomatic extracranial ICA occlusion and patients with cerebral small artery disease (Type B, Class II-III evidence).

How the results from these techniques should be used to influence therapy and affect patient outcomes remains to be determined (Type U).

Summary of findingsDetection of Cerebral Microemboli


SPECIFICITY (%)

REFERENCE STANDARD

Cerebral Microembolization

Experimental model, pathology, magnetic resonance imaging, neuropsychological tests

Recommendation: TCD is probably useful to detect cerebral microembolic signals in a wide variety of cardiovascular/ cerebrovascular disorders/procedures (Type B, Class II-IV evidence). However, data at present do not support the use of TCD for diagnosis or for monitoring response to antithrombotic therapy in ischemic cerebrovascular disease in these settings(Type U).

TCD in fase acutaConclusioni

Utile nell’approccio diagnostico in fase acutaConsente il monitoraggio dei vasi intracranici

sia in fase acuta che a lungo termineMigliora la trombolisi sia farmacologica che

spontaneaConsente il monitoraggio dell’interventistica

cardio-cerebrovascolareHa valore prognostico in fase acuta del TIA

(stenosi e microemboli) e dell’ictus acuto (stenosi)

Documents

ICTUS CEREBRI, STENOSI CEREBROVASCOLARI E ULTRASUONI: DIAGNOSI E TERAPIA CON IL DOPPLER TRANSCRANICO Dr A. Costa U.O. Neurologia Vascolare A.O. Spedali