A more recent report evaluated a multimodal approach to ICH prognostication including TCD­derived parameters in combination with electro­encephalography (EEG) as predictors of outcome. In this prospective study of 49 patients with ICH from China, quantitative EEG was assessed using different combinations of power, amplitude, and frequency analyses while TCD evaluated BFV and PIs. Results revealed that the relationship between slow and fast EEG frequencies (delta/ alpha ratio—DAR) and TCD-derived PI were independent predictors of 6-month mortality and that the combination of both parameters demon­strated excellent discrimination of long-term sur­vival with an area under the ROC curve of 0.95 [14]. As suggested by these ndings, the multi­modal noninvasive evaluation of patients with ICH may prove useful to determine those at high risk of death or long-term dependency, as early as during their ICU stay. More data is still needed to improve our knowledge of the temporal changes that individual patients present, potentially linked to worse outcomes.

CA can be estimated in a variety of ways using TCD, both in its static and dynamic components. Static autoregulation is assessed by evaluating a baseline blood ow velocity on TCD and exam­ining its response to induced changes in blood pressure. Dynamic CA (dCA) responds to instan­taneous (over seconds) and spontaneous blood pressure uctuations and associated cerebral per­fusion pressure changes, as measured by TCD velocities. Dynamic CA has been estimated in clinical studies of ICH patients either through the correlation coefcient index Mx, which measures the correlation of blood pressure (BP) and MCA

mean ow velocities, or by transfer function analysis parameters such as phase and gain. In summary, Mx is calculated as the moving aver­age of 1-min Pearson correlation coefcients of BP and MCA mean BFV.Phase and gain, on the other hand, reect the speed of the autoregulatory response and damping characteristics of dynamic regulation, respectively.

More than 20years ago, authors have shown that TCCD is capable of reliably detecting intra­cerebral hematomas and differentiating hemor­rhagic from ischemic stroke in patients that present with acute neurological signs [20, 21]. In this early report of 151 patients, despite the absence of a viable acoustic window in 12%, TCCD correctly diagnosed the etiology in 95% of acute strokes compared to CT scan results. Moreover, ultrasound was able to identify stroke­related complications such as midline shift and hemorrhagic transformation of ischemic stroke in 85% of patients. Although these results were interesting, the widespread availability of urgent CT scans probably prevented this specic indica­tion of TCCD to be further studied and applied in clinical practice [20].

As evidenced by the studies described above, the experience with TCCD for assessing patients with intracerebral hemorrhage is still limited to specialized centers and research groups. However, available data support the clinical application of TCCD as a reliable method of detecting intracerebral hemorrhage and possibly HT after ischemic stroke. Most of the available studies, although small, also conrm that volume estimation of hematomas is comparable to the one obtained by CT scans. Hence, we suggest that TCCD should be integrated into the multi­modal clinical and imaging monitoring approach to patients with stroke. After the initial CT scan conrming an ICH, a baseline TCCD should be performed with analysis of hematoma volume and follow-up TCCD exams should be repeated in regular intervals during the acute phase of ICH. Although to date the time course of early expansion has remained poorly described, dynamic assessments can capture early hema­toma expansion (EHE) in patients with intracere­bral hematoma. In a small study, authors demonstrated that TCCD had good volume esti­mation for EHE as compared to the follow-up CT scan with a maximum absolute volume deviation within 7 mL [27]. Therefore, the authors con­cluded that sequential TCCD reliably detected

hematoma expansion occurring in the rst 8 h after symptom onset.

Finally, baseline and follow-up TCCD exams will not substitute CT scans but instead dynamic changes in the sonographic assessments should prompt an urgent neuroimaging assessment to evaluate hematoma expansion.

tion of CT imaging and TCCD for assessment of MLS was found in patients with acute ischemic stroke with malignant cerebral edema [33, 34].

As well as for hematoma volume estimation and follow-up, we recommend that MLS should be monitored in patients with signicant mass effect secondary to acute intracranial pathologies at high risk for neurological deterioration, cere­bral edema, and intracranial hypertension. Repeated TCCD examinations can be a valuable noninvasive tool in patients with unchanged clin­ical exam. Dynamic changes in MLS should prompt an urgent CT scan that will guide deci­sion on further clinical or surgical treatment, as well as more intensive and invasive monitoring.

study of 64 patients with various primary brain injuries requiring invasive ICP monitoring that underwent 445 ultrasound examinations. After extensive ultrasound assessment, the parameters that showed the best correlation with ICP were the optic nerve sheath diameter (ONSD) and the straight sinus systolic ow velocity (FVsv). The accuracy of these parameters was better as com­pared to the pulsatility index (PI) and the arterial diastolic ow velocity (FVd). In combination, ONSD and FVsv showed the best correlation with invasive ICP (P = 0.80) and an excellent ability to discriminate episodes of intracranial hypertension above 20 mmHg (area under the ROC curve 0.93, 95% CI 0.90–0.97, P = 0.0) [42]. Although data is still limited on venous drainage assessment by TCCD, measurements appear to be feasible and reproducible. More studies are needed to explore the clinical use of temporal changes of venous outow monitoring as part of the noninvasive assessment of intracra­nial pressure.