Guidelines for the assessment of the intracranial circulation

TCD and TCDS are non-invasive ultrasound-based methods for studying the cerebral circulation. The accuracy on which the recommendations are based is provided in tables 3 (TCD) and 4 (TCDS). Transcranial ultrasound techniques are indicated: — to assess the stroke risk of children and adolescent with sickle-cell disease Recommendation 1 - 1 Level A — for the diagnosis and prognostic assessment of spon- taneous cerebral vasospasm; Recommendation 1 – 2 Level A — for the diagnosis and prognostic assessment of post- trauma cerebral vasospasm; Recommendation 3 Level B — as a test for diagnostic confirmation of brain death Recommendation 2 Level A Transcranial ultrasoun techniques are mainly used to as- sess patients with symptomatic or asymptomatic cerebrov- ascular disease to show: — stenosis of intracranial arteries; Recommendation 2 – 1 Level B — cerebral vasoreactivity; Recommendation 2 – 2 Level B — effects on the cerebral hemodynamics of plaques and/or stenosis of carotid, vertebral arteries and or subcla- vian arteries (subclavian steal syndrome); Recommendation 2 – 3 Level C — the risk of embolic stroke in patients with potentially embolic sources on the level of supraortic trunks, heart or the peripheral veins (combined with a right-to-left shunt); Recommendation 2 – 4 Level B — the presence of aneurysms and/or intracranial arte- ro-venous malformations (AVM) Recommendation 2 – 5 Level C In patients undergoing carotid open surgery or carotid stenting TCD is used to: — assess tolerance to clamping and/or hemodynamic changes due to the PTA-carotid stenting procedure; Recommendation 2 – 6 Level B — monitor the efficacy of the shunt (during surgery) or of the cerebral protection devices (during stenting); Recommendation 2 – 7 Level C — detecting pre-, intra- and/or post-procedural embolic events; Recommendation 2 – 8 Level A — monitoring the cerebral hyperperfusion syndrome that may follow carotid artery repair. Recommendation 2 – 9 Level C — the data gathered with those methos in the diagnos- tic stage are presently still correlated with those of other imaging studies (MR or AngioCT) and or with the DSA Recommendation 2 – 10 Level B angioCT or angioMRI should be indicated to: — completing the diagnosis of the intracranial vessels where it is advisable for planning treatment — when the TCD or TCDS are insufficient with suspect- ed significant injury of the extracranial vessels — investigating the brain prior to and after invasive pro- cedures to assess the hemodynamic modifications induced by arterial repair, ischaemic modifications after embolism and bleeding that might possibly follow hyperperfusion. Recommendation 2 – 11 Level B DSA should be restricted to: — cases of endovascular treatment — cases where non-invasive ultrasound techniques and AngioCT or AngioMRI did not provide sufficient and reli- able findings or could not be correlated with the clinical data. Recommendation 2 – 12 Level B Near infrared spectroscopy can be used in assessing oxygen saturation during carotid surgery or neurosurgery. Like TCD it detects brain ischemia during operation. It still needs validation. Recommendation 2 – 13 Level C The radionuclide techniques (flow measurement, PET and SPECT) assess the efficacy of the cerebral circulation only indirectly, measuring the perfusion of the brain and are restricted to functional and still experimental studies. Recommendation 2 – 14 Level C The SEP can be indicated for an intraoperative assess- ment as a carotid cross-clamping tolerance test to use the shunt selectively. Recommendation 2 – 15 Level C REPORTING PROPOSAL FOR TCD AND TCDS EXAMINATION IN DIAGNOSTIC PHASE Last name, name .................................... age date .... / .... / .... The examination is carried out with – Device .......................................................... – Probe type ...................................................... SIDE: RH ....... LH ........ Windows: Temporal ........................... Occipital ........................... Transorbitary ........................... Submandibular ........................... Depth Features Velocity direction – MCA .......... ............ ............ – PCA. .......... ............ ............ – Vertebral .......... ............ ............ – Basilar trunk .......... ............ ............ – Ophthalmic .......... ............ ............ – Syphon .......... ............ ............ – Anterior communicating artery not activated activated can be activated not assessable – Posterior communicating artery not activated activated can be activated not assessable – Asymmetry *: RH < LH RH > LH – asymmetry is the expression of intracranial hemodynamic changes due to unilateral injury of the arteries district up- stream and/or downstream of the insonated vessels – C.C. compression ipsilateral contralateral – Microembolic events in the basal examination (Yes / No and number) During compression