Ultrasound assessment of brain supplying arteries (extracranial). / Die Ultraschalluntersuchung der hirnversorgenden Arterien (extrakraniell).

Ultrasonography of the brain-supplying arteries is a non-invasive and highly efficient technique for the assessment of a stenosis or a vessel occlusion in patients with cerebrovascular diseases. This article reviews the examination technique for a standardized ultrasound assessment of the extracranial carotid and vertebral arteries. It further describes the multiparametric grading criteria of internal carotid artery stenosis and it gives recommendations for a standardised documentation of findings. Additionally, it proposes recommendations for intima-media thickness measurement and for classifying atherosclerotic plaques with B-mode ultrasonography. Moreover, criteria for the diagnosis of in-stent stenoses, vertebral artery dissections and subclavian steal syndrome are provided.

Ultrasound assessment of brain supplying arteries (transcranial). / Die Ultraschalluntersuchung der hirnversorgenden Arterien (transkraniell).

Ultrasonography of intracranial arteries is a non-invasive and highly efficient method for the diagnosis and follow-up of patients with cerebrovascular diseases, also in the bedside setting of the critically ill. For reliable assessment and interpretation of sonographic findings, the technique requires - apart from dedicated anatomic and pathophysiological knowledge of cerebral arteries and their hemodynamics - the comprehension of alternative imaging modalities such as CT or MR angiography. This article reviews the transcranial color-coded duplex sonographic (TCCS) examination technique including the transcranial Doppler sonography (TCD) for a standardized ultrasound assessment of the intracranial arteries and typical pathological cases. As a complementary tool, transorbital ultrasound for the assessment of the optic nerve sheath diameter and adjacent structures is also described in this article.

Neuropathic pain in two-generation twins carrying the sodium channel Nav1.7 functional variant R1150W.

We present clinical, neuropathological, and molecular genetic findings of a family with a new pain phenotype of the sodium channel gene SCN9A polymorphism R1150W. A 46-year-old woman presented with a 5-year history of episodic temperature- and exercise-dependent burning pain of the feet and lower legs associated with numbness of the distal upper and lower limbs. Her monozygotic twin sister and their mother and her twin presented similar symptoms. Clinical evaluation was normal except for a mild distal sensory deficit in fingers and feet. Electrophysiological testing was unremarkable, as were serum and cerebrospinal fluid laboratory findings. Skin biopsies of the distal lower limbs revealed an epidermal nerve fiber density at the lower limit of normal. Myelinated dermal nerve fibers showed elongated nodes of Ranvier, but normal distribution of nodal and paranodal proteins. Genetic testing for ion channel-associated pain disorders revealed an amino acid R1150W substitution of the Nav1.7 sodium channel. The combination of a Nav1.7 polymorphism with dysmyelinating features in small-caliber peripheral nerves has not been described before and may suggest an explanation for the clinical syndrome in our patients. Treatment with the sodium channel blocker lamotrigine provided some relief, consistent with a role of sodium channel dysfunction in the pain syndrome of this family.

High rate of restenosis after carotid artery stenting in patients with high-grade internal carotid artery stenosis. Medium-term follow-up.

OBJECTIVE: Carotid endarterectomy (CEA) is the gold-standard procedure for the majority of patients with high-grade symptomatic internal carotid artery stenosis and also for specified high-grade asymptomatic stenoses; however, a proportion of patients are treated with carotid endovascular therapy. We aimed to document medium-term clinical and neurosonographical outcome after carotid artery stenting (CAS). METHODS: 53 patients (mean age: 65 +/- 8 years) with high-grade (> or = 70 % by means of duplex sonography) carotid artery stenosis were enrolled into the study. Nineteen patients had asymptomatic, 34 patients had symptomatic stenoses. All patients had a pre-interventional CT, Doppler and duplex sonography, and digital subtraction angiography (DSA) or magnetic resonance angiography (MRA) prior to the procedural DSA. All patients were offered CEA as the gold-standard procedure and as an alternative to CAS. Both clinical and Duplex sonographical follow-up was obtained at day 1 and 7, month 1, month 3, month 6, month 12, and every subsequent 6 months after the procedure. Mean follow-up time was 22 +/- 1.6 months (+/- SEM). RESULTS: 2/53 patients suffered from stroke. A further 2 patients suffered from carotid artery occlusion shortly after CAS. The cumulative rate of restenosis during follow-up was 24.5 % (13/53). Four of these (7.5 %) were of high-grade and led to further interventional or surgical therapy. CONCLUSIONS: A high rate of restenosis was found during follow-up after CAS. Our analysis of non-selected patients emphasizes that CEA remains the gold-standard procedure for the treatment of symptomatic internal carotid artery stenosis. The frequently performed endovascular treatment of carotid stenosis outside the setting of a randomized controlled trial is not supported by our data.

Extracranial and intracranial vertebral artery dissection: long-term clinical and duplex sonographic follow-up.

PURPOSE: To determine the value of color Doppler sonography (CDUS) in the diagnosis and follow-up of patients with extracranial and intracranial vertebral artery (VA) dissection. METHOD: Thirty-three patients aged 42 +/- 12 years with 40 VADS confirmed via digital subtraction angiography (DSA) (n = 37) and magnetic resonance angiography (MRA) (n = 3) were included in the study. All patients were investigated with extracranial CDUS and transcranial CDUS (TCCDUS) over a mean +/- SD follow-up period of 42 +/- 24 months and occurrence of new ischemic symptoms was assessed. Sonographic results were compared with initial and follow-up angiographic results. RESULTS: At presentation, 24/33 (73%) patients had suffered an ischemic stroke, 5/33 (15%) had a transient ischemic attack (TIA), and 4/33 (12%) were asymptomatic. Two patients had a recurrent vertebrobasilar TIA; there was no recurrent stroke. The initial DSA findings consisted of 14 stenoses, 20 tapered occlusions, and 6 pseudoaneurysms. During follow-up, 63% of the vessels recanalized. Sonographic findings were consistent with angiographic findings in 80% at the initial examination and in 86% during follow-up. The main reason for discordant results was the failure of CDUS to detect pseudoaneurysms. No recurrence occurred in the vertebral arteries (VA), but 1 patient had an asymptomatic carotid artery dissection during follow-up. CONCLUSION: Recurrent TIA or stroke after VAD appears to be extremely rare, independent of recanalization or persistent occlusion of the affected artery. CDUS and TCCDUS provide reliable follow-up of VAD in all patients presenting with stenosis or occlusion, but do not allow for detection of pseudoaneurysms of the VA.

The prognostic value of early transcranial Doppler ultrasound following cardiopulmonary resuscitation.

The aim of the presented study was to estimate the prognostic value of transcranial Doppler sonography (TCD) for the prediction of clinical outcome of patients after cardiopulmonary resuscitation (CPR) on the basis of the measured flow velocity changes in the basal cerebral arteries. Thirty-nine patients (27 men, 12 women) aged 66 +/- 15 y (+/-SD) who had undergone CPR were involved. Serial TCD examinations of the intracranial arteries were performed 1.5, 4, 8, 16, 24 and 72 h after CPR. Plasma neuron specific enolase (NSE), ventilation parameters (pH, paO(2), paCO(2)) and hemodynamic parameters were registered. Seventeen patients (group 1) survived with moderate or without neurologic deficits. Twenty-two patients (group 2) either died (n = 21) within 9 +/- 14 days or remained in vegetative state (n = 1). NSE levels ranged from 9 to 29 microg/L in group 1 and from 22 to 1242 microg/L in group 2 (p < 0.05). Four and 72 h after CPR, peak systolic flow velocities in the middle cerebral artery (MCA) were significantly higher in group 1 than in group 2 (p < 0.05). Twenty-four h after CPR, peak systolic and diastolic flow velocities in the ACA and PCA were also significantly higher in group 1 than in group 2 (p < 0.05). At this time, patients of group 2 showed significantly higher resistance index-values (RI = (sys-dia)/sys) in the anterior cerebral artery (ACA) and the posterior cerebral artery (PCA) (p < 0.05). A high correlation between peak systolic blood flow velocity in the MCA and systemic systolic blood pressure was observed in group 2 early 4 to 16 h after CPR (r = +0.52 to + 0.81, p < 0.05), while there was no such correlation in group 1. Using serial TCD examinations, patients with severely disabling or fatal outcome could be identified within the first 24 h. Besides established clinical and laboratory parameters, postanoxic myoclonus and NSE, serial TCD examinations following CPR may be helpful to predict the clinical outcome, but further studies with a larger number of patients are necessary to approve this hypothesis.

Cerebral aneurysms and arteriovenous malformations.

Cerebral aneurysms and arteriovenous malformations (AVMs), including arteriovenous fistulae, are rather seldom investigated by means of transcranial color-coded duplex sonography (TCCS). Nevertheless, the continuous improvements in high-quality scanners, ultrasound contrast enhancers, and special software, such as three-dimensional reconstruction tools, make these lesions assessable in a high number of patients. In particular, the possibility of investigating hemodynamics and hemodynamic changes in a noninvasive manner is a unique feature of TCCS, which is therefore particularly valuable for monitoring stepwise transcatheter treatment of these lesions. Limitations of the technique, mainly caused by restrictions of the insonated bone windows, render this method inadequate as a screening tool. However, TCCS has proven to be a highly useful technique for follow-up investigations of treated and untreated cerebral aneurysms and AVMs. This chapter explains the investigation of these lesions and gives an insight into the most important up-to-date literature.

Sonographic detection and follow up of an atypical pineal cyst: a comparison with magnetic resonance imaging. Case report.

The incidental ultrasonographic detection of an asymptomatic cystic pineal lesion in a young woman is described and compared with findings on magnetic resonance (MR) images. Follow-up studies obtained using both imaging modalities are presented. The results indicate that transcranial ultrasonography may represent an easy and cost-effective imaging technique for follow up of cystic lesions of the pineal gland, especially in patients unable to undergo MR imaging.

Assessment of dural arteriovenous fistulae by transcranial color-coded duplex sonography.

BACKGROUND AND PURPOSE: To study hemodynamic changes and to determine the value of contrast-enhanced transcranial color-coded sonography (TCCS) for the evaluation of dural arteriovenous fistulae (DAVF) before and after transcatheter embolization. METHODS: Twenty-four patients (mean age 61+/-11 years) with occipitally located DAVF were studied with contrast-enhanced TCCS using the transtemporal bone window in transverse-axial and coronal insonation planes. Blood flow velocity measurements of all depictable basal cerebral veins and sinuses were obtained before and after transcatheter embolization. Pretreatment and post-treatment flow velocity values were compared. RESULTS: Four of the 24 patients (17%) could not be studied because of an insufficient temporal bone window. In all remaining patients (n=20), draining veins/sinuses could be identified because of pathologically increased blood flow velocities with peak systolic flow velocities of >50 cm/s. Of the 27 draining vessels depicted by DSA, TCCS correctly identified 25 (93%): the basal vein (3 of 3), the straight sinus (3 of 3), the superior sagittal sinus (1 of 3), the transverse sinus (9), the sigmoid sinus (4), and the superior petrosal sinus (5/5). However, TCCS failed to depict supplementary drainage via cortical veins. After transcatheter embolization, mean reduction of blood flow velocity was 44+/-18% (P<0.01) compared with pretreatment values. CONCLUSIONS: Contrast-enhanced TCCS is a promising technique for monitoring embolization of DAVF, follow-up after complete fistula occlusion, and may even be useful as a screening tool in patients with pulsatile tinnitus.

MR-imaging of thrombus in extra- and intracranial arteries employing balanced fast-field echo MRI.

Causes of stroke in young adults include a variety of disorders that are less frequently seen in older patients. We report the case of a young patient, who suffered recurrent mild embolic infarctions from a free-floating thrombus formation of the internal carotid artery bulb. During preoperative preparation, the thrombus dislodged and led to middle cerebral artery occlusion and major stroke. Both during preoperative work-up and after thrombus displacement balanced fast field echo sequences were able to demonstrate thrombus with a high signal-to-noise ratio and a superior delineation of thrombus and flowing blood. The high contrast between blood and thrombus helped to establish the diagnosis, to plan subsequent treatment strategies and to follow closely the clinical course. Further studies have to show whether this technique might help in thrombus characterization.

Comparative study of methods for determining vascular permeability and blood volume in human gliomas.

PURPOSE: To characterize human gliomas using T1-weighted dynamic contrast-enhanced MRI (DCE-MRI), and directly compare three pharmacokinetic analysis techniques: a conventional established technique and two novel techniques that aim to reduce erroneous overestimation of the volume transfer constant between plasma and the extravascular extracellular space (EES) (Ktrans) in areas of high blood volume. MATERIALS AND METHODS: Eighteen patients with high-grade gliomas underwent DCE-MRI. Three kinetic models were applied to estimate Ktrans and fractional blood plasma volume (vp). We applied the Tofts and Kermode (TK) model without arterial input function (AIF) estimation, the TK model modified to include vp and AIF estimation (mTK), and a "first pass" variant of the TK model (FP). RESULTS: KTK values were considerably higher than KmTK and KFP values (P <0.001). KmTK and KFP were more comparable and closely correlated (rho=0.744), with KmTK generally higher than KFP (P <0.001). Estimates of vp(mTK) and vp(FP) also showed a significant difference (P <0.001); however, these values were very closely correlated (rho=0.901). KTK parameter maps showed "pseudopermeability" effects displaying numerous vessels. These were not visualized on KmTK and KFP maps but appeared on the corresponding vp maps, indicating a failure of the TK model in commonly occurring vascular regions. CONCLUSION: Both of the methods that incorporate a measured AIF and an estimate of vp provide similar pathophysiological information and avoid erroneous overestimation of Ktrans in areas of significant vessel density, and thus allow a more accurate estimation of endothelial permeability.