ICTUS CEREBRI, STENOSI CEREBROVASCOLARI
E ULTRASUONI: DIAGNOSI E TERAPIA CON IL
DOPPLER TRANSCRANICO
Dr A. Costa
U.O. Neurologia Vascolare
A.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 cardiochirurgici
 Visualizzazione 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
 NEW
 Brain perfusion imaging
 Trombolisi con ultrasuoni
 Stratificazione del richio
Diagnostic Criteria – Stenosis
 Increased flow velocity – generally focal
 Disturbed flow
 Turbulence; spectral broadening
 Covibration phenomena
 Vibration of the vessel wall & surrounding soft tissue
 Drop in post-stenotic velocity
 Changes in post-stenotic waveform morphology
 Prolonged systolic upstroke
 Decreased pulsatility
Diagnostic Criteria – Occlusion
 Absence 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
anteriore
o 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 omolaterale
La 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
Sensibilità 70-90%
Specificità 90-95%
Occlusione segmento distale M1 o di multipli rami di M2Criteri 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
Sensibilità 70-90%
Specificità 90-95%
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 Accuracy
 Lack of flow signal due to an inadequate temporal window
 Misinterpretation of hyperdynamic collateral channels or




AVM feeders as stenosis
Displacement of arteries because of a space-occupying
lesion
Misinterpretation of physiologic variables in the circle of
Willis
Misdiagnosis of vasospasm as stenosis
Misinterpretation of reactive hyperemia following
spontaneous recanalization as stenosis
Pitfalls & Diagnostic Accuracy
Vertebral-Basilar System
 Normal flow and size of vessels are highly variable
 Location and course of the arteries are unpredictable
 Difficulty in reliably identifying the junction of the
vertebral arteries
 Absence of the vertebral artery flow signal on one side may
not represent disease
 Lack 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 findings
Intracranial Steno-Occlusive Disease
INDICATION
SENSITIVITY
(%)
SPECIFICITY
(%)
Intracranial
Steno-Occlusive
Disease:
REFERENCE
STANDARD
Conventional
angiography
Anterior
Circulation
70-90
90-95
Posterior
Circulation
Occlusion
50-80
80-96
Copyright 2004 American Academy of Neurology
Summary of findings
Intracranial Steno-Occlusive Disease
(Continued )
INDICATION
SENSITIVITY
(%)
SPECIFICITY
(%)
MCA
85-95
90-98
ICA, VA, BA
55-81
96
REFERENCE
STANDARD
Recommendation: Data are insufficient to establish TCD
criteria for greater than 50% stenosis or for progression of
stenosis in intracranial arteries (Type U).
19
Copyright 2004 American Academy of Neurology
Summary of findings
Acute cerebral infarction
INDICATION
Acute cerebral
infarction
SENSITIVITY
(%)
SPECIFICITY
(%)
85-95
90-98
REFERENCE
STANDARD
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 findings
Extracranial ICA Stenosis
INDICATION
SENSITIVITY
(%)
SPECIFICITY
(%)
Extracranial ICA
Stenosis:
REFERENCE
STANDARD
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 IIIII evidence).
Transcranial Color-Coded
Sonography (TCCS) or Imaging
TCD
Summary of findings
Ischemic Cerebrovascular Disease
INDICATION
SENSITIVITY SPECIFICITY
(%)
(%)
ACoA
Collateral
Flow
100
100
PCoA
Collateral
Flow
85
98
REFERENCE
STANDARD
Summary of findings
Ischemic Cerebrovascular Disease
(Continued)
INDICATION
SENSITIVITY SPECIFICITY
(%)
(%)
Intracranial
StenoOcclusive
Lesions
Any
Up to 100
Up to 83
REFERENCE
STANDARD
Summary of findings
Ischemic Cerebrovascular Disease
(Continued)
INDICATION
SENSITIVITY SPECIFICITY
(%)
(%)
/= 50%
Stenosis
MCA
100
100
ACA
100
100
VA
100
100
BA
100
100
PCA
100
100
REFERENCE
STANDARD
Summary of findings
Ischemic Cerebrovascular Disease
(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 findings
Hemorrhagic Cerebrovascular Disease
INDICATION
Parenchymal
Hypoechogenicity
in MCA
Distribution
SENSITIVITY SPECIFICITY
(%)
(%)
69
83
REFERENCE
STANDARD
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 findings
Cerebral Thrombolysis
INDICATION
SENSITIVIT
Y (%)
SPECIFICITY
(%)
Cerebral
Thrombolysis
Conventional
angiography,
magnetic resonance
angiography, clinical
outcome
Complete
Occlusion
50
100
Partial
Occlusion
100
76
91
93
Recanalization
REFERENCE
STANDARD
Summary of findings
Cerebral 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 findings
Carotid Endarterectomy (CEA)
INDICATION
Carotid
Endarterectomy
(CEA):
SENSITIVITY SPECIFICITY
(%)
(%)
REFERENCE
STANDARD
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 findings
Vasomotor 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 findings
Detection of Cerebral Microemboli
INDICATION
Cerebral
Microembolization
SENSITIVITY SPECIFICITY
(%)
(%)
REFERENCE
STANDARD
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 acuta
Conclusioni
 Utile nell’approccio diagnostico in fase acuta
 Consente il monitoraggio dei vasi intracranici sia in
fase acuta che a lungo termine
 Migliora la trombolisi sia farmacologica che spontanea
 Consente il monitoraggio dell’interventistica cardiocerebrovascolare
 Ha valore prognostico in fase acuta del TIA (stenosi e
microemboli) e dell’ictus acuto (stenosi)