Transcranial Doppler sonography for detecting stenosis or occlusion of intracranial arteries in people with acute ischaemic stroke.

BACKGROUND: An occlusion or stenosis of intracranial large arteries can be detected in the acute phase of ischaemic stroke in about 42% of patients. The approved therapies for acute ischaemic stroke are thrombolysis with intravenous recombinant tissue plasminogen activator (rt-PA), and mechanical thrombectomy; both aim to recanalise an occluded intracranial artery. The reference standard for the diagnosis of intracranial stenosis and occlusion is intra-arterial angiography (IA) and, recently, computed tomography angiography (CTA) and magnetic resonance angiography (MRA), or contrast-enhanced MRA. Transcranial Doppler (TCD) and transcranial colour Doppler (TCCD) are useful, rapid, noninvasive tools for the assessment of intracranial large arteries pathology. Due to the current lack of consensus regarding the use of TCD and TCCD in clinical practice, we systematically reviewed the literature for studies assessing the diagnostic accuracy of these techniques compared with intra-arterial IA, CTA, and MRA for the detection of intracranial stenosis and occlusion in people presenting with symptoms of ischaemic stroke. OBJECTIVES: To assess the diagnostic accuracy of TCD and TCCD for detecting stenosis and occlusion of intracranial large arteries in people with acute ischaemic stroke. SEARCH METHODS: We limited our searches from January 1982 onwards as the transcranial Doppler technique was only introduced into clinical practice in the 1980s. We searched MEDLINE (Ovid) (from 1982 to 2018); Embase (Ovid) (from 1982 to 2018); Database of Abstracts of Reviews of Effects (DARE); and Health Technology Assessment Database (HTA) (from 1982 to 2018). Moreover, we perused the reference lists of all retrieved articles and of previously published relevant review articles, handsearched relevant conference proceedings, searched relevant websites, and contacted experts in the field. SELECTION CRITERIA: We included all studies comparing TCD or TCCD (index tests) with IA, CTA, MRA, or contrast-enhanced MRA (reference standards) in people with acute ischaemic stroke, where all participants underwent both the index test and the reference standard within 24 hours of symptom onset. We included prospective cohort studies and randomised studies of test comparisons. We also considered retrospective studies eligible for inclusion where the original population sample was recruited prospectively but the results were analysed retrospectively. DATA COLLECTION AND ANALYSIS: At least two review authors independently screened the titles and abstracts identified by the search strategies, applied the inclusion criteria, extracted data, assessed methodological quality (using QUADAS-2), and investigated heterogeneity. We contacted study authors for missing data. MAIN RESULTS: A comprehensive search of major relevant electronic databases (MEDLINE and Embase) from 1982 to 13 March 2018 yielded 13,534 articles, of which nine were deemed eligible for inclusion. The studies included a total of 493 participants. The mean age of included participants was 64.2 years (range 55.8 to 69.9 years). The proportion of men and women was similar across studies. Six studies recruited participants in Europe, one in south America, one in China, and one in Egypt. Risk of bias was high for participant selection but low for flow, timing, index and reference standard. The summary sensitivity and specificity estimates for TCD and TCCD were 95% (95% CI = 0.83 to 0.99) and 95% (95% CI = 0.90 to 0.98), respectively. Considering a prevalence of stenosis or occlusion of 42% (as reported in the literature), for every 1000 people who receive a TCD or TCCD test, stenosis or occlusion will be missed in 21 people (95% CI = 4 to 71) and 29 (95% CI = 12 to 58) will be wrongly diagnosed as harbouring an intracranial occlusion. However, there was substantial heterogeneity between studies, which was no longer evident when only occlusion of the MCA was considered, or when the analysis was limited to participants investigated within six hours. The performance of either TCD or TCCD in ruling in and ruling out a MCA occlusion was good. Limitations of this review were the small number of identified studies and the lack of data on the use of ultrasound contrast medium. AUTHORS' CONCLUSIONS: This review provides evidence that TCD or TCCD, administered by professionals with adequate experience and skills, can provide useful diagnostic information for detecting stenosis or occlusion of intracranial vessels in people with acute ischaemic stroke, or guide the request for more invasive vascular neuroimaging, especially where CT or MR-based vascular imaging are not immediately available. More studies are needed to confirm or refute the results of this review in a larger sample of stroke patients, to verify the role of contrast medium and to evaluate the clinical advantage of the use of ultrasound.

Amplitude Instability of Somatosensory Evoked Potentials as an Indicator of Delayed Cerebral Ischemia in a Case of Subarachnoid Hemorrhage.

We describe a 55-year-old male patient with a subarachnoid hemorrhage (SAH) as a result of left middle cerebral artery (MCA) aneurysm rupture, who underwent continuous electroencephalogram (EEG) and somatosensory evoked potential (cEEG-SEP) monitoring that showed an unusual SEP trend pattern. EEG was continuously recorded, and SEPs following stimulation of median nerves were recorded every 50 minutes, with the amplitude and latency of the cortical components automatically trended. An increase in intracranial pressure required a left decompressive craniectomy. cEEG-SEP monitoring was started on day 7, which showed a prolonged (24 hours) instability of SEPs in the left hemisphere. During this phase, left MCA vasospasm was demonstrated by transcranial Doppler (TCD), and computed tomography perfusion (CTP) showed a temporo-parieto-occipital ischemic penumbra. Following intravascular treatment, hypoperfusion and the amplitude of cortical SEPs improved. In our case, a prolonged phase of SEP amplitude instability during vasospasm in SAH correlated with a phase of ischemic penumbra, as demonstrated by CTP. In SAH, SEP instability during continuous monitoring is a pattern of alert that can allow treatments capable of avoiding irreversible neurological deterioration.

Muscle-ultrasound evaluation in healthy pediatric subjects: Age-related normative data.

INTRODUCTION: The muscle ultrasound examination (MUS) is a noninvasive and inexpensive technique for evaluating neuromyopathies. Standardized MUS normative data are incomplete in pediatric subjects. METHODS: We performed a MUS study with 120 healthy children (59 males; mean age, 10.44 years; age range, 2-16 years). We measured the width and the echogenicity bilaterally in the following muscles: biceps brachii and brachialis, brachioradialis, forearm-flexors, rectus femoris and vastus intermedius, tibialis anterior, extensor hallucis longus, lateral and medial gastrocnemius. RESULTS: The muscle thickness increased with age for all muscles. Confidence limits were set for each age group muscle width. Echogenicity increased with age only in some muscles. DISCUSSIONS: Our MUS study provides new data on physiological muscle structural changes in healthy children to address the limited available references in this age group. Muscle Nerve 58: 245-250, 2018.

Retrospective Analysis of Transcranial Doppler Patterns in Veno-Arterial Extracorporeal Membrane Oxygenation Patients: Feasibility of Cerebral Circulatory Arrest Diagnosis.

Transcranial Doppler (TCD) is able to detect cerebral hemodynamic changes in real-time. Impairment of cerebral blood flow during veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) treatment is referred to in the literature. Several cerebrovascular complications can affect VA ECMO patients, eventually leading to brain death (BD). Transcranial Doppler is a worldwide accepted technique for cerebral circulatory arrest (CCA) diagnosis for BD confirmation, and in Italy, it is mandatory in certain clinical conditions. Nowadays, no data have been published on the use of TCD as a confirmation test in VA ECMO patients evolved to BD. The aim of our study was to investigate the feasibility of TCD in CCA diagnosis during VA ECMO treatment. Thirty-two TCD examinations, performed in 25 patients on VA ECMO, were retrospectively analyzed, and factors that could be responsible for TCD waveforms abnormalities were reviewed. Differences in TCD patterns were detected depending on values of left ventricular ejection fraction and the absence or presence of intraaortic balloon pump (IABP). Four categories of different TCD patterns were then identified. In five BD patients, diagnostic CCA patterns in all cerebral arteries were identified by TCD. Our data suggest that cerebral hemodynamic changes due to both residual cardiac function and the effects of IABP can be detected by TCD in VA ECMO patients. In the case of BD, TCD seems to be a reliable instrumental test for CCA diagnosis in patients on VA ECMO when a pulsatile flow is maintained (native or IABP support).

Brain Circulation during Panic Attack: A Transcranial Doppler Study with Clomipramine Challenge.

Introduction. Cerebral blood flow has been well studied in patients with panic disorder, but only few studies analyzed the mechanisms underlying the onset of a panic attack. The aim of the present study was to monitor the cerebral hemodynamics modifications during a panic attack. Materials and Methods. 10 panic disorder patients with recent onset, fully drug naïve, were compared to 13 patients with panic disorder with a previous history of treatment and to 14 controls. A continuous bilateral monitoring of mean flow velocities in right and left middle cerebral arteries was performed by transcranial Doppler. Clomipramine was chosen as challenge. Results. Eight out of 10 patients drug naïve and 6 control subjects out of 13 had a full blown panic attack during the test, whereas none of the patients with a history of treatment panicked. The occurrence of a panic attack was accompanied by a rapid decrease of flow velocities in both right and left middle cerebral arteries. Discussion. The bilateral acute decrease of mean flow velocity during a panic attack suggests the vasoconstriction of the microcirculation of deep brain structures perfused by middle cerebral arteries and involved in the so-called "fear circuitry," thus suggesting that cerebral homeostatic dysfunctions seem to have a key role in the onset of a panic attack.

The relevance of early TCD monitoring in the intensive care units for the confirming of brain death diagnosis.

Brain death (BD) diagnosis is the clinical assessment of the irreversible loss of function of the entire brain, including the brainstem. Transcranial Doppler (TCD) examination is used in several countries as a confirmatory test to assess cerebral circulatory arrest (CCA). A total of 1,400 TCD examinations were performed in 623 patients (pts) admitted to intensive care units (ICUs) of our hospital during the last 6 years. Oscillating flow, systolic spikes and the absence of any TCD signal were considered as diagnostic patterns of irreversible CCA. TCD patterns of CCA were detected in 56 pts. In 25 pts, deeply sedated with barbiturate therapy, TCD was employed as confirmatory test for BD diagnosis and 14 of them could become organ and/or tissue donors. TCD is a safe and inexpensive tool that can be performed at the bedside, and it allows to shorten the diagnostic process of BD, which is the prerequisite for organ donation.

Cerebral hemodynamic lateralization during memory tasks as assessed by functional transcranial Doppler (fTCD) sonography: effects of gender and healthy aging.

INTRODUCTION: Previous neuropsychological, lesional and functional imaging studies deal with the lateralization of memory processes, suggesting that they could be determined by the stage of processing (encoding vs retrieval) or by content (verbal vs non-verbal stimuli). The aims of the present study were: 1) to investigate if tasks that can be carried out using different strategies depending on the verbalizability of the material induce a lateralization of the mean cerebral blood flow velocity (mCBFV) in the middle cerebral arteries (MCAs), as monitored by a functional transcranial Doppler (fTCD); 2) to evaluate if these patterns of cerebral activation differ in relation to age, gender and task performance. METHOD: Using TCD bilateral monitoring, we recorded mCBFV variations in 35 male and 35 female healthy, right-handed volunteers, classified as "young" (age range 21-40 years, n=35) or "old"(age range 41-60 years, n=35), performing four different cognitive tasks: encoding and recognition of Geometric Figures (GF), encoding and recall of Object Localization (OL) on a picture, encoding of a verbal Room Description (RD) and Arithmetic Skill (AS). RESULTS: We found a significant right lateralization for the OL recall phase, and a significant left lateralization for RD and AS. When we took into consideration gender, age and performance, there was a strong effect of age on both OL encoding and recall phase, with significant right lateralization in young volunteers not seen in the older ones. No difference in gender was detected. We found a gender×performance interaction for RD, with poor performance females showing significant left lateralization. CONCLUSIONS: According to our findings, hemispheric lateralization during memory encoding is material specific in both men and women, depending on the verbalizability of the material. mCBFV right lateralization during scene encoding and recall appears lost in older people, suggesting that healthy elderly could take advantage of mixed verbal and non-verbal strategies.

Negative influence of HIV infection on day-night blood pressure variability.

OBJECTIVE: An attenuation of the physiological day-night blood pressure (BP) reduction is an important predictor of cardiovascular (CV) events and death. We compared circadian BP profile in treatment-naive HIV-infected patients and in healthy control subjects. METHODS: Fifty-two antiretroviral therapy-naive HIV-infected patients (85% men, age 39 ± 11 years, BP 125/78 ± 11/9 mm Hg) and 156 age- and BP-matched HIV-negative controls (85% men, age 39 ± 10 years, BP 125/78 ± 9/7 mm Hg) underwent 24-hour BP monitoring. Subjects with a nocturnal reduction of systolic BP <10% were defined as "nondippers." RESULTS: Nighttime BP was higher in HIV-infected subjects (113/69 ± 11/9 vs 109/67 ± 8/6 mm Hg, P = 0.008/0.005). Nocturnal systolic/diastolic BP reduction was 8.8/13.2% in HIV-positive patients and 11.7/17.2% in HIV negative (P = 0.002/0.001). The prevalence of "nondippers" was 35% and 15%, respectively (P = 0.003). In multivariate analysis, nocturnal systolic BP fall was negatively associated to HIV infection (ß = -0.22, P = 0.001). HIV viral load, low CD4 cell count, and AIDS progression risk were all related with a flattened day-night BP profile (P < 0.01). CONCLUSIONS: HIV infection per se negatively affects circadian BP rhythm. These findings, obtained in subjects without major CV risk factors and antiretroviral naive, suggest that day-night BP changes may play a role in the HIV-related increase in CV risk.