Insufficient Temporal Bone Window Research Articles

Increased pulsatility index of the basilar artery is a risk factor for neurological deterioration after stroke: a case control study

BackgroundHigher pulsatility of the middle cerebral artery (MCA) is known to be associated with stroke progression. We investigated whether pulsatility index (PI) of the basilar artery (BA) can predict neurological deterioration (ND) after acute cerebral infarction.MethodsA total of 708 consecutive patients with acute ischemic stroke who had undergone transcranial Doppler (TCD) ultrasonography were included. ND was defined as an increase in the National Institutes of Health Stroke Scale scores by two or more points after admission. The patients were categorized into quartiles according to BA PI. Multivariable logistic regression analysis was performed to examine whether BA PI is independently associated with ND.ResultsBA PI was well correlated with the right (n = 474, r2 = 0.573, P < 0.001) by Pearson correlation analysis although MCA PI could not be measured from right MCA (n = 234, 33.05%) and left MCA (n = 252, 35.59%) by TCD owing to insufficient temporal bone window. Multivariable logistic regression analysis including age, sex, cerebral atherosclerosis burden, National Institutes of Health Stroke Scale at admission, and the proportion of patients with current smoking status, hypertension, diabetes mellitus, atrial fibrillation revealed that the higher BA PI (odds ratio, 3.28; confidence interval, 1.07–10.17; P = 0.038) was independently associated with ND.ConclusionsBA PI, which would be identified regardless of temporal window, could predict ND among acute stroke patients.

Right‐to‐left shunt detection using transforaminal insonation of the basilar artery

Investigation for patent foramen ovale (PFO) is warranted in patients with cryptogenic stroke (CS), as PFO closure is recommended in select CS patients for secondary stroke prevention. Transcranial Doppler (TCD) is noninvasive and has high sensitivity for PFO screening. However, 10% of the population has insufficient temporal bone windows to perform standard TCD monitoring of the middle cerebral arteries (MCAs). Prior reports showed similar diagnostic accuracy between the basilar artery and MCAs insonation. Our objective was to assess the accuracy of transforaminal insonation of the basilar artery (TIBA) in diagnosis of right-to-left shunt (RLS) in patients with inadequate temporal windows. We performed a retrospective, single-center, observational study of TIBA in patients with CS and inadequate temporal windows. We compared the PFO screening accuracy using TIBA versus echocardiogram, either transthoracic (TTE) or transesophageal echocardiogram (TEE). Sixteen females and four males were included (mean age 63.2). All patients underwent TTE, 10 (50%) underwent gold-standard TEE. Nine patients had positive PFO with both TCD and echocardiogram. Two patients with negative echocardiogram had TCD-positive shunt. Three patients had PFO present on echocardiogram, whereas TCD was negative. Six patients had absent shunt with both TCD and echocardiogram. The sensitivity and specificity of TIBA for RLS detection were 75%, positive predictive value 82%, and negative predictive value 67%. PFO screening accuracy using TIBA was 75%. Prospective evaluation of CS patients with TIBA and comparison to the gold-standard TEE should be performed to further guide clinical practice.

Accelerated sonothrombolysis with Definity in a xenographic porcine cerebral thromboembolism model

Adjuvant ultrasound at 2 MHz with or without an ultrasound contrast agent improves the rate of thrombus resolution by recombinant tissue plasminogen activator (rt-PA) in laboratory and clinical studies. A sub-megahertz approach can further expand this therapy to a subset of patients with an insufficient temporal bone window, improving efficacy in unselected patient populations. The aim of this study was to determine if a clinical ultrasound contrast agent (UCA), Definity, and 220 kHz pulsed ultrasound accelerated rt-PA thrombolysis in a preclinical animal model of vascular occlusion. The effect of Definity and ultrasound on thrombus clearance was first investigated in vitro and subsequently tested in a xenographic porcine cerebral thromboembolism model in vivo. Two different microcatheter designs (end-hole, multi-side-hole) were used to infuse rt-PA and Definity at the proximal edge or directly into clots, respectively. Sonothrombolysis with Definity increased clot mass loss relative to saline or rt-PA alone in vitro, only when rt-PA was administered directly into clots via a multi-side-hole microcatheter. Combined treatment with rt-PA, Definity, and ultrasound in vivo increased the rate of reperfusion up to 45 min faster than clots treated with rt-PA or saline. In this porcine cerebral thromboembolism model employing retracted human clots, 220 kHz ultrasound, in conjunction with Definity increased the probability of early successful reperfusion with rt-PA.

Transcranial B-Mode Sonography in Movement Disorders.

Applying a 2-4MHz probe at the temporal bone window transcranial B-mode sonography (TCS) enables the depiction of the brain parenchyma through the intact skull. Meanwhile it has been applied for the diagnosis and the differential diagnosis of movement disorders for decades. In the first part of this chapter, we summarize the technical requirements and describe the ultrasound method for optimal TCS examination. Imaging planes and the relevant structures are explained in detail. In the second part of the chapter, we focus on the role of substantia nigra hyperechogenicity for the diagnosis of Parkinson's disease (PD) and prodromal PD. In this part, we also mention the role of TCS in atypical and secondary Parkinsonian syndromes and other movement disorders. Summarizing all these information we explain how TCS can be helpful for the differential diagnosis of movement disorders. The current data show that TCS is an easily applicable and economic imaging method which can be used as an additional tool for the diagnosis of PD with a high sensitivity (>85%), specificity (>80%) and inter-rater reliability (>84%) as well as for the differential diagnosis of movement disorders. Lately, TCS has also been utilized in further areas such as the detection of individuals at risk for PD or the determination of electrode localization in patients with deep brain stimulation. An insufficient temporal bone window especially in the elderly and the necessity of an experienced investigator are limitations of this method.

Abstract WP237: Novel Probe Attached to the Cervix Can Evaluate Right-to-left Shunt More Precisely Than Transcranial Doppler

Introduction: While the examination for the evaluation of right-to-left shunt (RLS) using contrast transcranial Doppler (TCD) is useful, insufficient temporal bone window interrupts the adequate TCD examination for precise diagnosis of RLS. Thus, we developed a novel probe (paste-able soft ultrasound probe; PSUP) attached to the cervix for RLS diagnosis. Hypothesis: Monitoring at carotid artery using PSUP can detect greater number of contrast microembolic signals (cMES) than that of TCD. Methods: Subjects were patients with ischemic stroke or transient ischemic attack who had one and more cMES in middle cerebral artery detected by screening test of TCD on admission. PSUP was a 2.0-MHz center frequency and had an equal property with TCD transducer. The shape was thin, soft, and square modified for adequate attachment to the neck. We monitored blood flow of unilateral middle cerebral artery by TCD and ipsilateral common carotid artery by PSUP simultaneously. After injection of saline agitated with air in the right antecubital vein, we performed single test without Valsalva maneuver (VM) and triple tests with VM. And then, we compared the number of cMES between PSUP and TCD among each patient. Results: We performed 48 simultaneous PSUP and TCD examination (12 studies without VM, and 36 studies with VM) on 12 patients (11 male, median age of 49 years) without any complication. The number of cMES on PSUP was significantly larger than that of TCD in all of 48 examination (345 vs. 206, p&lt;0.001), in 12 studies without VM (72 vs. 37, p=0.017), and in 36 studies with VM (273 vs. 169, p&lt;0.001). Conclusions: In order to evaluate the RLS, PSUP examination at common carotid artery is a powerful approach in comparison with TCD. For patients without sufficient temporal bone window, PSUP should play an important role of RLS diagnosis.

Erratum: Structural Ultrasound of the Medial Temporal Lobe inAlzheimer's Disease.

Purpose One of the anatomical hallmarks of Alzheimer’s disease (AD) is the atrophy of the medial temporal lobe (MTL), yet cost-effective and broadly available methodological alternatives to the current imaging tools for screening of this brain area are not currently available. Materials and Methods Using structural transcranial ultrasound (TCS), we attempted to visualize and measure the MTL, and compared the results of 32 AD patients and 84 healthy controls (HC). The MTL and the surrounding space were defined in the coronal plane on TCS. A ratio of the height of the MTL/height of the choroidal fissure (M/F) was calculated in order to obtain a regional proportion. Results An insufficient temporal bone window was identified in 22 % of the AD patients and 12 % of the HCs. The results showed that the ratio of M/F was significantly smaller in the AD group on both sides (p = 0.004 right, p = 0.007 left side). Furthermore, the M/F ratio made it possible to discriminate AD patients from HCs with a sensitivity of 83 % (right)/73 % (left) and a specificity of 76 % (right)/72 % (left) which is basically comparable to results published for magnetic resonance imaging. The measurements showed substantial intra/interrater reliability (ICC:0.79/0.69). Conclusion These results suggest that utilization of structural TCS may possibly constitute a cheap and easy-to-use supplement to other techniques for the diagnosis of AD. It may be especially useful as a screening tool in the large population of individuals with cognitive decline. Further studies are needed to validate this novel method.

Structural Ultrasound of the Medial Temporal Lobe inAlzheimer's Disease.

Purpose One of the anatomical hallmarks of Alzheimer's disease (AD) is the atrophy of the medial temporal lobe (MTL), yet cost-effective and broadly available methodological alternatives to the current imaging tools for screening of this brain area are not currently available. Materials and Methods Using structural transcranial ultrasound (TCS), we attempted to visualize and measure the MTL, and compared the results of 32 AD patients and 84 healthy controls (HC). The MTL and the surrounding space were defined in the coronal plane on TCS. A ratio of the height of the MTL/height of the choroidal fissure (M/F) was calculated in order to obtain a regional proportion. Results An insufficient temporal bone window was identified in 22 % of the AD patients and 12 % of the HCs. The results showed that the ratio of M/F was significantly smaller in the AD group on both sides (p = 0.004 right, p = 0.007 left side). Furthermore, the M/F ratio made it possible to discriminate AD patients from HCs with a sensitivity of 83 % (right)/73 % (left) and a specificity of 76 % (right)/72 % (left) which is basically comparable to results published for magnetic resonance imaging. The measurements showed substantial intra/interrater reliability (ICC:0.79/0.69). Conclusion These results suggest that utilization of structural TCS may possibly constitute a cheap and easy-to-use supplement to other techniques for the diagnosis of AD. It may be especially useful as a screening tool in the large population of individuals with cognitive decline. Further studies are needed to validate this novel method.

Comparison of Vertebral Artery and Middle Cerebral Artery Monitoring for Right-to-left Shunt Detection by Contrast-enhanced Transcranial Doppler.

Contrast-enhanced transcranial Doppler (c-TCD) is a reliable and reproducible method for right-to-left shunt (RLS) detection, with high sensitivity. Monitoring the middle cerebral artery (MCA) is an optimal choice, yet for patients with insufficient temporal bone windows or severe stenosis of carotid arteries, an alternative should be established. The aim of the present study was to further establish whether c-TCD with vertebral artery (VA) monitoring is as effective as MCA monitoring for RLS detection. We evaluated 194 subjects for RLS detection with VA and MCA monitoring simultaneously. There was no significant difference between the positive rates of VA and MCA monitoring for RLS detection. c-TCD with VA monitoring could be an alternative for RLS detection, with high sensitivity and specificity both at rest and during the Valsalva manoeuvre.

Abstract TP221: A Novel Ultrasound Probe Attached to the Cervix Can Precisely Detect Large Patent Foramen Ovale

Introduction: We developed a novel probe (paste-able soft ultrasound probe; PSUP) attached to the cervix for detection of right-to-left shunt (RLS), because insufficient temporal bone window interrupts the precise examination for diagnosis of RLS. Hypothesis: We assessed the hypothesis that diagnostic ability of PSUP for RLS detection is equal to those of transesophageal echocardiography (TEE). Methods: Subjects were patients with ischemic stroke and transient ischemic attack who underwent TEE. PSUP was a 2.0-MHz center frequency, which had an equal property with TCD, and the shape was thin, soft, and square modified for attachment to the neck. At first, we performed TEE with the echoscope at the level of the fossa ovalis after injection of saline agitated with air in the right antecubital vein. The procedure was performed with and without Valsalva maneuver. Visualization of microembolic signals (MES) induced contrast agent within the right atrium and crossing the interatrial septum was considered as positive patent foramen ovale (PFO). We divided PFO into two groups according to number of MES, such as small PFO (1-29 of MES) and large PFO (≥30 of MES). Then, monitoring using PSUP was performed at unilateral common carotid artery (CCA) using similar preparation and procedure to TEE. RLS by PSUP diagnosed when we found 1and more MES in CCA. We compared detectable rate by size of PFO between TEE and PSUP, and calculated accuracy of PSUP against TEE. Results: From May 2014 to July 2015, 62 patients (46 male, mean age of 61 years) were included in this study. We diagnosed 26 of 62 patients (42%) as PFO by TEE, whereas PSUP detected in 17 of them (27%). As a reference of TEE findings, diagnostic ability of PSUP was 58% of sensitivity, 94% of specificity, and 79% of accuracy. In TEE examination, large PFO was 11 patients and small was 15 patients. PSUP could evaluate large PFO (9 of 11 patients) more accurately than small one (6 of 15, 82% vs. 40%, p=0.05). Conclusion: PSUP should have a considerable accuracy of large PFO diagnosis. For patients with insufficient temporal bone window, PSUP may play an important role of detecting large PFO.

Factors Associated with No or Insufficient Temporal Bone Window Using Transcranial Color-coded Sonography

PurposeTranscranial color-coded sonography (TCCS) noninvasively assesses physiologic and pathologic intracranial blood flow especially in non-Caucasians who have high prevalence of intracranial steno-occlusive arterial disease. However, a higher temporal bone window failure (WF) rate is found in non-Caucasians and thus limits the utilization of TCCS. This study was performed to explore the associated factors of temporal bone WF in Taiwanese patients. MethodsBetween January 2014 and June 2014, 355 consecutive patients who received TCCS examination during their hospitalization at neurological ward were enrolled in this study, including 218 men and 137 women. Patients were classified into two groups, one with no or insufficient temporal bone window and the other with good temporal bone window for identification of middle, anterior, and posterior cerebral arteries via transtemporal approach. Age, sex, and conventional vascular risk factors in each group were compared. ResultsIt was found that 28.8% of the patients had no or insufficient temporal bone window. Among them, 20.3% had complete bilateral temporal bone WF. For all factors studied, older age and female sex were significantly associated with no or insufficient temporal bone window. ConclusionThe failure rate of temporal bone window was considered high as compared to Western countries but, not surprisingly, age and sex remained the significant factors. Introducing echo contrast agents during the TCCS examination might help to increase the success rate of TCCS examination and provide useful information to clinicians.

Abstract W P204: Diagnostic Ability of a Novel Probe Attached to the Cervix for the Detection of Right-to-left Shunt Is Similar to Transesophageal Echocardiography

Introduction: Although transcranial Doppler (TCD) plays an important role of detecting right-to-left shunt (RLS) in order to diagnose patients as a paradoxical brain embolism, insufficient temporal bone window interrupts the precise examination. So, we developed the novel probe (PSUP) attached to the cervix for the detection of RLS. Our hypothesis is that diagnostic accuracy of RLS by PSUP is comparable to those of transesophageal echocardiography (TEE) as a gold standard. . Methods: Subjects were patients with ischemic stroke and transient ischemic attack who underwent TEE. PSUP was a 2.0-MHz center frequency and had an equal property with TCD transducer. The shape was thin, soft, and square modified for adequate attachment to the neck. At first, we performed TEE with the echoscope at the level of the fossa ovalis after injection of saline agitated with air in the right antecubital vein. The procedure was performed with and without Valsalva maneuver. Visualization of microembolic signals (MES) induced contrast agent within the right atrium and crossing the interatrial septum was considered positive for RLS. Then, monitoring using PSUP was performed at unilateral common carotid artery (CCA) using similar preparation and procedure to TEE. RLS by PSUP was diagnosed as having 1and more MES in CCA. After compared RLS detectable rate between TEE and PSUP, accuracy parameters for RLS detection of PSUP against TEE were calculated. Results: From May to August 2014, 21 patients were included in this study. RLS was 5 (24%) of 21 on TEE, and 5 (24%) on PSUP, respectively (table). As a reference of TEE findings, diagnostic power of PSUP was 84% of sensitivity, 94% of specificity, 84% of positive predictive value, 94% of negative predictive value, and 91% of accuracy. Conclusion: RLS detection by PSUP is substantially correct. PSUP may be useful for patients with insufficient temporal bone window, such as elder Asian women.

Abstract WMP56: Utility of Bubble Test with Cervical Internal Carotid Artery Triplex Ultrasound in Detection of Right-to-left Shunts

BACKGROUND: Transcranial Doppler (TCD) ultrasound with bubble test is a dependable method to detect cardiac right-to-left shunts (RLS). In patients with insufficient temporal bone windows, cervical internal carotid artery (ICA) recording can be used as an alternative method for detection of RLS. However, bubble tests performed via insonation of cervical ICA have issues with probe fixation, signal differentiation and breathing/swallowing artifacts. To overcome these problems, we developed a new technique for bubble test with cervical ICA and compared its utility with traditional middle cerebral artery (MCA) TCD studies. METHODS: MCA and ICA recordings were compared in 156 bubble studies obtained from 78 patients. ICA bubble study was performed by hand-held 1-3 MHz phase-arrayed sector transducer and triplex ultrasound technology. RLS volume was graded according to the International Consensus Criteria (ICC) [grade-0: no micro bubble (MB), grade-1: 1-20 MB, grade-2: &gt;20 MB or shower, and grade-3: curtaining]. RESULTS: In 133 studies there was concordance of MCA and ICA studies. In 11 patients ICC grade was higher with MCA monitoring, while in 12 patients, ICA method showed higher RLS grade. Overall MB number was higher in ICA than MCA (33 vs. 20 MB). Bubble test with triplex ICA was reliable (Cronbach’s alpha: 0.87) and well correlated (weighted quadratic kappa: 0.874) with traditional MCA method. There was no signal loss during Valsalva’s maneuver with ICA recording, where triplex technique provided timely relocation of the signal with real-time color imaging. CONCLUSION: The bubble test performed with triplex ICA recording is a sensitive and specific alternative of traditional bubble studies performed by MCA recording. This method is feasible not only in patients with poor ultrasonic bone windows but also for all cases evaluated for RLS presence and grading.

Near-Infrared Spectroscopy Can Predict the Onset of Cerebral Hyperperfusion Syndrome after Carotid Endarterectomy

Background: Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA) is a potential life-threatening complication. Therefore, early identification and treatment of patients at risk is essential. CHS can be predicted by a doubling of postoperative transcranial Doppler (TCD)-derived mean middle cerebral artery blood velocity (V_mean) compared to preoperative values. However, in approximately 15% of CEA patients, an adequate TCD signal cannot be obtained due to an insufficient temporal bone window. Moreover, the use of TCD requires specifically skilled personnel. An alternative and promising technique of noninvasive cerebral monitoring is relative frontal lobe oxygenation (rSO₂) measured by near-infrared spectroscopy (NIRS), which offers on-line information about cerebral oxygenation without the need for specialized personnel. In this study, we assess whether NIRS and perioperative TCD are related to the onset CHS following CEA. Methods: Patients who underwent CEA under general anesthesia and had a sufficient TCD window were prospectively included. The V_mean and rSO₂ measured before induction of anesthesia were compared to measurements performed in the first postoperative hour (ΔV_mean, ΔrSO₂, respectively). Logistic regression analysis was performed to determine the relationship between ΔV and ΔrSO₂ and the occurrence of CHS. Subsequently, receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values. Diagnostic values were shown as positive and negative predictive values (PPV and NPV). Results: In total, 151 patients were included, of which 7 patients developed CHS. The ΔV_mean and ΔrSO₂ differed between CHS and non-CHS patients (median, interquartile range), i.e. 74% (67–103) versus 16% (–2 to 41), p = 0.001, and 7% (4–15) versus 1% (–6 to 7), p = 0.009, respectively. The mean arterial blood pressure did not change. Postoperative ΔV_mean and ΔrSO₂ were significantly related to the occurrence of CHS [odds ratio (OR) 1.40 (95% CI 1.02–1.93) per 30% increase in V_mean and OR 1.82 (95% CI 1.11–2.99) per 5% increase in rSO₂]. ROC curve analysis showed an area under the curve of 0.88 (p = 0.001) for ΔV_mean and an optimal cutoff value of 67% increase (PPV 38% and NPV 99%), and an area under the curve of 0.79 (p = 0.009) for ΔrSO₂ and an optimal cutoff value of 3% rSO₂ increase (PPV 11% and NPV 100%). The combination of both monitoring techniques provided a PPV of 58% and an NPV of 99%. Conclusions: Both TCD and NIRS measurements can be used to safely identify patients not at risk of developing CHS. It appears that NIRS is a good alternative when a TCD signal cannot be obtained.

Transcranial sonography: Brazilian experience

entitled “Transcranial sonography as a diagnostic tool for Parkinson’s disease”. These authors aimed to establish the per-centage of subjects with adequated temporal bone windows for transcranial sonography (TCS) studies and also to revisit in a Brazilian sample the hypothesis that increased echogenic size of substantia nigra (SN) might distinguish Parkinson’s disease (PD) patients from healthy individuals. We would like to congratu -late the authors for the original idea to assess the Brazilian sub -jects with a case-control study. The authors found that 10.8% of the subjects had insufficient temporal acoustic bone windows, which is in line with previous data. Also, they identified hyper -echogenicity of the SN in 88.2% of PD patients, against 14.2% of control group individuals. In addition, the authors pointed out that “in Brazil there is no systematic study on transcranial sonography”. Actually, this is an appropriate opportunity to report that our group has sys -tematically studied TCS findings in some neurological dis -eases, such as spinocerebellar ataxias (SCA) and restless legs syndrome (RLS) (Figure). We have recently published a study entitled “Transcranial sonography findings in spinocerebellar ataxia type 3 (Machado-Joseph disease): a cross sectional study”, in which we conducted TCS studies in 30 patients with clinical and molecular proven Machado-Joseph disease (MJD), and used 44 healthy subjects as control group, and found that hiperecho -genicity of the SN was more frequent in MJD patients (75%) than in the control group subjects (18%), and that brain atrophy and lenticular nucleus hyperechogenicity occurred more frequently in MJD group. Two out of 30 MJD patients were excluded from the study due to limitation of acoustic temporal bone windows

Abstract 2959: Diagnosis of Right-to-Left Shunt in Intracranial Vertebral Artery by Transcranial Color Flow Imaging

Objective: Right-to-Left shunt (RLS) detection by Transcranial Doppler is useful for diagnosis of paradoxical embolism. However, we sometimes could not monitor MCA due to insufficient temporal bone window, especially in old patients. Other insonation windows such as transorbital and suboccipital window (basilar artery) are using recently, whereas the ability to detect of intracranial arteries from these windows was not so high. We evaluated usefulness of RLS detection in intracranial vertebral artery (VA) from suboccipital approach that could be measured in almost patients. Methods: We evaluated RLS using transcranial color flow imaging (TC-CFI) in patients with ischemic stroke or transient ischemic attack who could be detected middle cerebral artery (MCA) from temporal bone window and intracranial VA from suboccipital window by TC-CFI. We monitored microembolic signal (MES) at ipsilateral MCA and VA (not hypoplastic side) for 90seconds after injection of 9ml saline agitated with 1ml of air in the right antecubital vein. The procedure was performed three times in each artery with and without Valsalva maneuver. The presence of MES was classified according to Spencer Logarithmic Scale (SLS) criteria. Results: Fifty two patients (46 male, mean age of 64.1±14.3) were included. Twelve patients were positive of MES (23.1%). VA comparison to MCA showed 10 true positive, 40 true negative, 0 false positive and 2 false negative cases (sensitivity 83.3%, specificity 100%, positive predictive value 100%, negative predictive value 95.2% and accuracy 96.2%). In 12 patients with MES, 22 of 36 examinations in MCA were positive of MES (SLS grade I was 20 examinations and grade II was 2 examinations), on the other hand, 20 of 36 examinations in VA were positive (SLS grade I was 20 examinations). The positive ratio of 36 examinations in 12 patients did not show significant difference statistically between MCA and VA. Conclusion: The evaluation of RLS in intracranial VA using TC-CFI from suboccipital window has equal diagnostic ability to MCA, and is useful for the patients with insufficient temporal bone window.

Visibility of the Lesser Sphenoid Wing Is an Important Indicator for Detecting the Middle Cerebral Artery on Transcranial Color-Coded Sonography

Background: Failure to detect the sphenoidal segment of the middle cerebral artery (M1) on transcranial color-coded sonography (TCCS) results from either M1 occlusion or an insufficient temporal bone window (TBW). We sought to identify a simple indicator on B mode images for M1 evaluation. Methods: Consecutive acute ischemic stroke patients with an intact M1 segment underwent prospective TCCS evaluation. Visibilities of the contralateral temporal bone (CTB), midbrain (MB) and lesser sphenoid wing (LSW) on B mode images were defined as follows: ‘invisible’, ‘poor’ if the contour was less than 50% visible, ‘fair’ if more than 50% visible and ‘good’ if totally visible. M1 detectability on color Doppler images was defined as follows: ‘INVISIBLE’, ‘POOR’ if the M1 was detected as color dots, ‘FAIR’ if linearly but discontinuously detectable, and ‘GOOD’ if linearly and continuously detectable. The relationship between each structure’s visibility and M1 detectability was assessed. Results: Seventy-six patients with 152 TBWs were evaluated. The CTB was ‘invisible’ in 2%, ‘poor’ in 22%, ‘fair’ in 36% and ‘good’ in 40%. Visibility of the MB was 36, 24, 26 and 14%, respectively. Visibility of the LSW was 16, 22, 29 and 32%, respectively. The M1 was ‘INVISIBLE’ in 51%, ‘POOR’ in 7%, ‘FAIR’ in 7% and ‘GOOD’ in 35%. Spearman’s rank correlation coefficient between each structure’s visibility and M1 detectability was 0.68 for the CTB, 0.66 for the MB and 0.80 for the LSW, respectively (p < 0.001 for all). Conclusion: Visibility of the LSW on B mode appears to be a better indicator than other structures for M1 evaluation.

Transcranial Ultrasound from Diagnosis to Early Stroke Treatment – Part 2: Prehospital Neurosonography in Patients with Acute Stroke – The Regensburg Stroke Mobile Project

Background and Purpose: The primary aim of this study was to investigate the diagnostic accuracy and time frames for neurological and transcranial color-coded sonography (TCCS) assessments in a prehospital ‘911’ emergency stroke situation by using portable duplex ultrasound devices to visualize the bilateral middle cerebral arteries (MCAs). Methods: This study was conducted between May 2010 and January 2011. Patients who had sustained strokes in the city of Regensburg and the surrounding area in Bavaria, Germany, were enrolled in the study. After a ‘911 stroke code’ call had been dispatched, stroke neurologists with expertise in ultrasonography rendezvoused with the paramedic team at the site of the emergency. After a brief neurological assessment had been completed, the patients underwent TCCS with optional administration of an ultrasound contrast agent in cases of insufficient temporal bone windows or if the agent had acute therapeutic relevance. The ultrasound studies were performed at the site of the emergency or in the ambulance during patient transport to the admitting hospital. Relevant timelines, such as the time from the stroke alarm to patient arrival at the hospital and the duration of the TCCS, were documented, and positive and negative predictive values for the diagnosis of major MCA occlusion were assessed. Results: A total of 113 patients were enrolled in the study. MCA occlusion was diagnosed in 10 patients. In 9 of these 10 patients, MCA occlusion could be visualized using contrast-enhanced or non-contrast-enhanced TCCS during patient transport and was later confirmed using computed tomography or magnetic resonance angiography. One MCA occlusion was missed by TCCS and 1 atypical hemorrhage was misdiagnosed. Overall, the sensitivity of a ‘field diagnosis’ of MCA occlusion was 90% [95% confidence interval (CI) 55.5–99.75%] and the specificity was 98% (95% CI 92.89–99.97%). The positive predictive value was 90% (95% CI 55.5–99.75%) and the negative predictive value was 98% (95% CI 92.89–99.97%). The mean time (standard deviation) from ambulance dispatch to arrival at the patient was 12.3 min (7.09); the mean time for the TCCS examination was 5.6 min (2.2); and the overall mean transport time to the hospital was 53 min (18). Conclusion: Prehospital diagnosis of MCA occlusion in stroke patients is feasible using portable duplex ultrasonography with or without administration of a microbubble contrast agent. Prehospital neurological as well as transcranial vascular assessments during patient transport can be performed by a trained neurologist with high sensitivity and specificity, perhaps opening an additional therapeutic window for sonothrombolysis or neuroprotective strategies.

Transcranial sonography as a diagnostic tool for Parkinson's disease: a pilot study in the city of Rio de Janeiro, Brazil

In Brazil there is no systematic study on Transcranial Sonography (TCS), a neuroimaging method that depicts echogenic deep brain structures using ultrasound. To establish the percentage of subjects with permissive temporal windows and to address the ability of TCS of the substantia nigra (SN) to distinguish parkinsonian patients in a Brazilian sample. We performed TCS using the Acuson X300 (Siemens, Germany) in 37 individuals: 23 with Parkinson's disease (PD) and 14 healthy controls. 10.8% of subjects had insufficient temporal acoustic bone windows. SN echogenic areas were larger in patients (mean ± SD, 0.31 ± 0.08 cm(2)) compared to controls (mean ± SD, 0.17 ± 0.02 cm(2)). TCS accurately identified 88.2% of PD patients. A large proportion of Brazilians seem to be eligible for TCS. An expressive number of PD patients could be diagnosed by TCS based on an expanded SN echogenic area. However, the current data is preliminary and must be corroborated by larger studies.

Combination of transcranial sonography, olfactory testing, and MIBG myocardial scintigraphy as a diagnostic indicator for Parkinson’s disease

Appropriate diagnostic biomarkers are useful for improving speed and accuracy of a diagnosis. Substantia nigra (SN) hyperechogenicity visualized by transcranial sonography (TCS), olfactory dysfunction, and the reduced uptake of (123) I-metaiodobenzylguanidine (MIBG) in myocardial scintigraphy have been suggested as potential biomarkers for the identification of Parkinson's disease (PD). To evaluate the diagnostic potential of these tests and to determine whether combining them increases their diagnostic power. Subjects were 44 patients with clinically diagnosed PD and 36 healthy controls. TCS of the SN, the odor stick identification test for Japanese (OSIT-J), and MIBG myocardial scintigraphy were conducted. Eleven patients with PD (25%) and four controls (11%) were excluded because of an insufficient acoustic temporal bone window in the TCS. Thus, 33 patients with PD and 32 healthy controls were finally included. The diagnostic sensitivity of TCS, OSIT-J, and MIBG myocardial scintigraphy was 78.8%, 84.8%, and 60.6%, respectively. The specificity of TCS and OSIT-J was 93.8% and 78.1%, respectively. The combination of TCS of the SN and OSIT-J substantially increased the sensitivity to a sufficient level for discriminating patients with PD from controls. TCS of the SN and olfactory testing play complementary roles in increasing diagnostic power in PD. As both tests are easy to perform, noninvasive, and inexpensive, the combination of TCS of the SN and olfactory testing may contribute to early and accurate diagnosis of PD.

Presurgical functional transcranial Doppler sonography (fTCD) with intravenous echo enhancing agent SonoVue enables determination of language lateralization in epilepsy patients with poor temporal bone windows

Presurgical determination of language lateralization is important for planning and outcome estimation of neurosurgical interventions in patients with drug-refractory epilepsy. Functional transcranial Doppler sonography (fTCD) provides an established measure for language lateralization using the temporal bone windows for continuous recording of the cerebral blood flow velocity (CBFV) in both middle cerebral arteries (MCAs). However, because of insufficient temporal bone windows, fTCD cannot be applied properly in every patient. Here, we established stable and sufficient CBFV signals in both MCAs using continuous intravenous application of echo-enhancing agent SonoVue in 7 of 10 patients with poor temporal bone windows and were thus able to determine language lateralization. We conclude that the application of SonoVue can solve one principal disadvantage of fTCD and improves the applicability of the technique as a presurgical functional language lateralization procedure.