bluuebunny/crossref_metadata_2025 huggingface dataset:
Human Brain Temperature In Vivo: Lack of Heating During Color Transcranial Doppler Ultrasonography
Authors: Mariak Z. , Krejza J. , Swiercz M. , Lyson T. , Lewko J.
Published: November 2009

This study was undertaken to assess the effect of ultrasound on human brain temperature in vivo. The investigation consisted of direct recording of intracranial temperature during color transcranial Doppler (TCD) sonography in a neurosurgical patient. The temperature was recorded from 3 thermocouples. One was implanted together with an intracranial pressure sensor into a surgically reduced intraparenchymal hematoma, the second was placed within the subdural space close to the temporal acoustic window, and the third was located extracranially at the outer surface of the temporal bone. Tympanic temperatures were also measured to give an approximation of global brain temperature. A 2.5‐MHz transducer was used, and the system settings were as follows: spatial peak temporal average intensity = 234 mW/cm2in B‐mode at a maximum power of 32.3 mW and 2132 mW/cm2in Doppler mode at a maximum power of 149.3 mW. Neither increase in the intraparenchymal brain temperature nor increase in the temperature at the bone/soft tissue interface was observed during 30 minutes of insonation. The ipsilateral tympanic temperature increased by only 0.06°C, and this value may be regarded as a measure of the overall increase in brain temperature. Passive cooling effect produced by the transducer, which was at ambient temperature, was found to reach the brain surface and to surpass any possible heating caused by the ultrasound. The results indicate that no noticeable increases in human brain temperature occur in response to ultrasound emitted by a color TCD device at high transmitter power settings within the diagnostic range.
High‐Resolution Magnetic Resonance Imaging Reveals Symmetric Bitemporal Cortical Necrosis After Carbon Monoxide Intoxication
Authors: Müller Notger G. , Gruber Oliver
Published: November 2009

High‐resolution magnetic resonance images obtained in a patient several months after carbon monoxide (CO) intoxication revealed nearly symmetric regional atrophy of both lateral temporal lobes. This pattern of cortical lesions after CO exposure has not been reported before. The patient suffered from severe cognitive deficits including a transient Klüver‐Bucy–like behavior. This report underlines the value of high‐resolution magnetic resonance imaging in chronic stages of CO intoxication in the attempt to understand the neuroanatomical bases of the observed behavior.
Discordance Between Cerebral Oxygen and Glucose Metabolism, and Hemodynamics in a Mitochondrial Encephalomyopathy, Lactic Acidosis, and Strokelike Episode Patient
Authors: Nariai Tadashi , Ohno Kikuo , Ohta Yoshihisa , Hirakawa Kimiyoshi , Ishii Kenji , Senda Michio
Published: November 2009

A patient with mitochondrial encephalomyopathy, lactic acidosis, and strokelike episode (MELAS) syndrome underwent serial measurement of cerebral blood flow with xenon computed tomography (Xe‐CBF) while presenting with strokelike episodes accompanied by a cerebral lesion. He underwent positron emission tomography (PET) measurement of the regional cerebral blood flow (PET‐CBF), metabolic rate of oxygen (CMRO2), and glucose (CMRGlu) after his symptoms and lesion disappeared. During the symptomatic period, Xe‐CBF and the Xe‐CBF response to acetazolamide loading were well preserved both in and outside the low‐density lesion. In the PET study, decreased CMRO2and increased PET‐CBF and CMRGlu were noted in the entire brain. The strokelike episodes of patients with MELAS are more likely attributed to the failure of oxygen metabolism than to a vascular accident.
Intraosseous Sacral Myxopapillary Ependymoma and the Differential Diagnosis of Sacral Tumors
Authors: Cihangiroglu Mutlu , Hartker Frederick W. , Lee Max , Sehgal Vivek , Ramsey Ruth G.
Published: November 2009

Although involvement of other regions of the spinal cord and brain stem is seen, myxopapillary ependymoma is most commonly found at the filum terminale or cauda equina. Less commonly, myxopapillary ependymoma may occur outside the central nervous system from direct metastatic extension of an intrathecal tumor, and rarely it may present as a primary tumor outside the thecal sac. The authors present a case of primary sacral myxopapillary ependymoma, which was first diagnosed as a chordoma. They then discuss the magnetic resonance imaging findings of this and other sacral tumors. Myxopapillary ependymoma should be considered in the differential diagnosis for a primary expansile sacral mass along with other lesions such as chordoma, aneurysmal bone cyst, and giant cell tumor.
Clinical and Magnetic Resonance Imaging Regression of Progressive Multifocal Leukoencephalopathy in an AIDS Patient After Intensive Antiretroviral Therapy
Authors: Shapiro Rita A. , Mullane Kathleen M. , Camras Lawrence , Flowers Calvin , Sutton Sarah
Published: November 2009

A 36‐year‐old homosexual man with 6 months of visual symptoms and headaches had right homonymous hemianopia, mild new learning impairment, and alexia with agraphia. The initial brain magnetic resonance imaging (MRI) scan was reported consistent with left occipital infarction. Subsequent MRI demonstrated abnormal demyelination in the subcortical white matter and deep parieto‐occipital white matter bilaterally, but primarily left. Human immunodeficiency virus testing and cerebrospinal fluid polymerase chain reaction for JC virus DNA were both positive, consistent with progressive multifocal leukoencephalopathy (PML) with AIDS. His clinical status steadily deteriorated, and MRI white matter abnormalities worsened despite high‐dose antiretroviral therapy. After the antiretroviral regimen was intensified by the addition of a protease inhibitor, rapid clinical and radiographic improvement occurred with subsequent MRI studies revealing only residual left parieto‐occipital encephalomalacia. PML in AIDS patients has been associated with a nearly uniformly poor prognosis until recent reports of improved outcomes after highly active antiretroviral therapy. This patient with PML and AIDS similarly showed a robust clinical and MRI response to intensive antiretroviral combination therapy, which has been maintained for more than 3 years.
Stroke Prevention in Sickle Cell Disease (STOP) Study Guidelines for Transcranial Doppler Testing
Authors: Nichols Fenwick T. , Jones Anne M. , Adams Robert J.
Published: November 2009

The Stroke Prevention in Sickle Cell Disease (STOP) trial used transcranial Doppler (TCD) to screen children with sickle cell disease with no history of stroke. Children (who consented) who had time‐averaged mean of the maximum (TAMM) velocities in the middle cerebral artery and/or distal internal carotid artery were randomized to transfusion or standard. Over a slightly more than 20‐month average follow‐up, there were 11 strokes in the standard care arm and 1 stroke in the transfusion arm. This study has caused a great deal of interest in using TCD to screen children with sickle cell disease. For the STOP TCD data to be applied appropriately, it is necessary for users of TCD to understand how the STOP TCD examinations were performed, how the TCD velocities were measured, and which velocities were used. This article will review the STOP TCD scanning protocol and the reading protocol and review the TAMM velocity and how it differs from other velocity measurements.
Comparison of Transcranial Color‐Coded Sonography and Magnetic Resonance Angiography in Acute Ischemic Stroke
Authors: Lien Li‐Ming , Chen Wei‐Hung , Chen Jiunn‐Rong , Chiu Hou‐Chang , Tsai Yuh‐Feng , Choi Wai‐Man , Reynolds Patrick S. , Tegeler Charles H.
Published: November 2009

Background and Purpose. This study was designed to assess the accuracy of transcranial color‐coded sonography (TCCS) as compared to magnetic resonance angiography (MRA) for detecting intracranial arterial stenosis in patients with acute cerebral ischemia. Methods. The authors prospectively identified 120 consecutive patients admitted with acute ischemic stroke and performed both TCCS and MRA with a mean interval of 1 day. TCCS data (sampling depth, peak systolic and end diastolic angle‐corrected velocity, mean angle‐corrected velocity, and pulsatility index) for middle cerebral arteries (MCAs) were compared to MRA data and classified into 4 grades: normal (grade 1): normal caliber and signal; mild stenosis (grade 2): irregular lumen with reduced signal; severe stenosis (grade 3): absent signal in the stenotic segment (flow gap) and reconstituted distal signal; and possible occlusion (grade 4): absent signal. The cutoffs were chosen to maximize diagnostic accuracy. Results. Interobserver agreement for MRA grading resulted in a weighted‐kappa value of 0.776. The rate of poor temporal window was 37% (89/240). Doppler signals were obtained in 135 vessels, and the angle‐corrected velocities (peak systolic, end diastolic, mean) were significantly different (P= .001, P= .006, P < .001) among the MRA grades: grade 1 (100, 47, 68 cm/s), grade 2 (171, 72, 110 cm/s), grade 3 (226, 79, 134 cm/s), grade 4 (61, 26, 39 cm/s). Additionally, an angle‐corrected MCA peak systolic velocity ≥120 cm/s correlates with intracranial stenosis on MRA (grade 2 or worse) with high specificity (90.5%; 95% confidence interval = 78.5%∼96.8%) and positive predictive value (93.9%) but relatively low sensitivity (66.7%; 95% confidence interval = 61.2%∼69.5%) and negative predictive value (55.1%). Conclusion. Elevated MCA velocities on TCCS correlate with intracranial stenosis detected on MRA. An angle‐corrected peak systolic velocity ≥120 cm/s is highly specific for detecting intracranial stenosis as defined by significant MRA abnormality.
Diagnostic Value of Apparent Diffusion Coefficient Hyperintensity in Selected Patients With Acute Neurologic Deficits
Authors: Schaefer Pamela W. , Gonzalez R. Gilberto , Hunter George , Wang Bing , Koroshetz Walter J. , Schwamm Lee H.
Published: November 2009

Background and Purpose. A pattern of decreased intensity on apparent diffusion coefficient (ADC) maps is useful in the early detection of ischemic brain injury. Less information exists with regard to patients with acute neurologic deficits in whom there is abnormal conventional magnetic resonance imaging (MRI) and increased ADC intensity. Methods. The authors identified 13 patients with acute neurologic deficits who underwent diffusion MRI and had calculated ADC maps demonstrating hyperintensity in regions characterized by computed tomography hypodensity and MRI T2 hyperintensity. The initial and follow‐up imaging characteristics and clinical syndromes were recorded. Results. Clinical syndromes included hypertensive encephalopathy, posterior leukoencephalopathy, hyperperfusion following carotid endarterectomy, venous sinus thrombosis, HIV encephalopathy, and brain tumor. Diffusion‐weighted imaging (DWI) was hyperintense in 3 of 13 patients, isointense in 4 of 13 patients, heterogeneous in 3 of 13 patients, and hypointense in 3 of 13 patients. The ADC values in these regions were significantly higher than those in control regions (P < .0001). At early follow‐up, MRI abnormalities resolved completely in 3 of 13 patients and partially in 9 of 13 patients. MRI abnormalities were unchanged in 1 patient. Conclusions. In the evaluation of patients with acute neurologic deficits, ADC hyperintensity may identify a subset of patients with vasogenic edema of nonischemic etiology. Frequently, these conditions are potentially reversible if appropriately managed. DWI and conventional images alone are not sufficient to identify these neurologic conditions.
Interobserver and Intraobserver Reliability of Venous Transcranial Color‐Coded Flow Velocity Measurements
Authors: Stolz E. , Babacan S. S. , Bödeker R.‐H. , Gerriets T. , Kaps M.
Published: November 2009

Background and Purpose. Venous transcranial color‐coded duplex sonography is a new technique for noninvasive evaluation of the intracranial venous system. However, the interobserver and intraobserver reliability of this method is unclear. Methods. In 23 healthy volunteers (30 ± 7.3 years of age), the deep middle cerebral vein (dMCV), basal vein (BV), vein of Galen (VG), and straight (SRS), transverse (TS), and superior sagittal (SSS) sinuses in addition to the arterial segments of the circle of Willis were insonated through the temporal bone window on 2 consecutive days by 2 experienced examiners. The examiners were blinded to each other's results. The interobserver and intraobserver reliability was calculated using a method described by Bland and Altman, resulting in 2‐SD confidence intervals. Results. Non‐angle‐corrected and angle‐corrected systolic and end diastolic venous flow velocities (FV) were in good accordance with published normal values, ranging between 8.6 and 19.2 cm/s. The interobserver reliabilities for non‐angle‐corrected systolic FVs in the dMCV, BV, VG, SRS, and TS were ±1.8, 2.4, 2.6, 3.3, and 4.6 cm/s; for angle‐corrected systolic FVs, the interobserver reliabilities were ±2.5, 3.1, 13.9, 11.6, and 7.7 cm/s. The intraobserver reliabilities for non‐angle‐corrected systolic FVs in the dMCV, BV, VG, SRS, and TS were ±2.9, 3.2, 2.6, 3.2, and 6.1 cm/s; for angle‐corrected systolic FVs, the intraobserver reliabilities were 3.2, 3.7, 13.9, 11.6, and 7.5 cm/s. Angle correction was not attempted for the SSS. The interobserver and intraobserver reliabilities for systolic FVs in the SSS were ±3.3 and ±3.3 cm/s, respectively. Conclusions. Intracranial venous FV can be measured with a high interobserver and intraobserver reliability in healthy human subjects. Intraobserver reliability was higher for cerebral veins than for dural sinuses, predisposing them for follow‐up examinations; however, angle correction for venous FV in the VG and the SRS is not advisable.
Increased Incidence of a Midline Brain Anomaly in Patients With Nonsyndromic Clefts of the Lip and/or Palate
Authors: Nopoulos Peg , Berg Stephanie , VanDemark Duane , Richman Lynn , Canady John , Andreasen Nancy C.
Published: November 2009

Background and Purpose. Nonsyndromic clefts of the lip and palate (CLP) are developmental craniofacial abnormalities that are often associated with cognitive dysfunction. This study was designed to evaluate, in patients with CLP, the presence of a specific midline brain anomaly (enlarged cavum septi pellucidi [CSP]) that has been shown in other developmental syndromes to be related to poor cognitive function. Methods. Brain images were obtained using magnetic resonance imaging on 49 adult men with CLP and 75 healthy controls. Size of CSP was measured using consecutive coronal images. Results. The incidence of large CSP in the CLP group was 8% (4 of 49), significantly higher than that found in the control group. In 2 of these 4 subjects, the anomaly was complete nonfusion of the septal leaflets, known as a combined CSP and cavum vergae. Furthermore, there was a significant inverse relationship of IQ and CSP in CLP patients that was not present in controls. That is, in individuals with CLP, the larger the CSP, the lower the IQ. Conclusions. Adult men with CLP have an increased prevalence of enlarged CSP. Moreover, this anomaly is directly related to cognitive deficits. This study provides further evidence that the development of the face and the development of the brain are intimately related and that defects in craniofacial development are most likely associated with defects in brain development.
Venous Infarction of Brainstem and Cerebellum
Authors: Krespi Yakup , Gurol Mahmut Edip , Coban Oguzhan , Tuncay Rezzan , Bahar Sara
Published: November 2009

The authors describe 2 cases of posterior fossa venous infarction. A 56‐year‐old woman with essential thrombocytemia presented with fluctuating complaints of headache, nausea, vomiting, left‐sided numbness‐weakness, and dizziness and became progressively stuporous. Cranial magnetic resonance imaging (MRI) showed bilateral parasagittal frontoparietal and left cerebellar contrast‐enhancing hemorrhagic lesions. On magnetic resonance venography, the left transverse and sigmoid sinuses were occluded. The second patient, a 39‐year‐old woman, presented with acute onset of diplopia, numbness of the tongue, vertigo, and right‐sided weakness following a gestational age stillbirth. MRI revealed lesions in the right half of midbrain and pons and in the superior part of the right cerebellar hemisphere. Digital subtraction angiography showed right transverse and sigmoid sinus occlusion. The authors suggest that one should investigate the possibility of venous infarction in the presence of posterior fossa lesions that are often hemorrhagic and are not within any arterial territory distribution but respect a known venous drainage pattern. Recognition of the observed clinical and neuroimaging features can lead to earlier diagnosis and, potentially, more effective management.
Transient Crossed Cerebellar Diaschisis Following Thalamic Hemorrhage
Authors: Takasawa Masashi , Hashikawa Kazuo , Ohtsuki Toshiho , Imaizumi Masao , Oku Naohiko , Kitagawa Kazuo , Hori Masatsugu , Matsumoto Masayasu
Published: November 2009

This report concerns a 65‐year‐old right‐handed woman with cerebral hemorrhage who presented with mild right‐sided hemiparesis. Computed tomography (CT) revealed hematoma in the left thalamus and compression of the posterior limb of the internal capsule by a brain edema surrounding the lesion. 99mTc‐hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) images obtained 4 days after onset showed hypoperfusion in the left thalamus containing a hematoma as well as contralateral cerebellar hypoperfusion to the supratentorial lesion, which is well recognized as crossed cerebellar diaschisis (CCD) after stroke. CT 14 days after the onset revealed reduction of the brain edema of the posterior limb of the internal capsule accompanied by gradual neurological improvement. SPECT obtained 14 and 28 days later showed that CCD had disappeared. In this case report, the authors discuss the disappearance of CCD due to transient edematous compression of the internal capsule following thalamic hemorrhage on serial 99mTc‐HMPAO SPECT scans. CCD was possibly caused by the lesion confined to the posterior limb of the internal capsule, which anatomically constitutes the cerebropontocerebellar pathway.
Continuous Arterial Spin Labeling Perfusion Magnetic Resonance Imaging Findings in Postpartum Vasculopathy
Authors: Chalela Julio A. , Kasner Scott E. , McGarvey Michael , Alsop David C. , Detre John A.
Published: November 2009

Postpartum vasculopathy (PPV) is a rare heterogeneous nonatherosclerotic vasculopathy that occurs in the puerperium. It occurs spontaneously but may be triggered by vasoconstrictor substances. The angiographic findings vary and include narrowing of the intracranial arteries and vasospasm. The angiographic findings and the occurrence of ischemic infarcts suggest that cerebral blood flow (CBF) is impaired in PPV. The purpose of this study is to determine CBF in patients with PPV. The authors conducted a case study of 3 patients with clinical and laboratory criteria for PPV examined during a 2‐year period. Clinical examination, computed tomography imaging, structural magnetic resonance imaging (MRI), cerebral angiography, and continuous arterial spin labeling perfusion (CASL‐PI) MRI were performed in all patients. Mean global CBF was determined, and perfusion maps were visually inspected. The CBF values and perfusion maps were correlated with the clinical symptoms and the neuroimaging findings. Three women were studied (22, 34, and 36 years old). The median time of presentation was 4 days postpartum. One presented with intracranial hemorrhage and diffuse arterial narrowing, the other 2 with stroke‐like lesions, encephalopathy, and segmental narrowing mainly in the posterior circulation. CASL‐PI was performed within 1 week of symptom onset in all 3 patients. Global mean CBF values were 51.8, 39.3, and 41.8 cc/100 g/min. Although global CBF was mildly diminished, it was above ischemic levels. Visual inspection of the CASL‐PI perfusion maps did not reveal areas of focal hypoperfusion or hyperperfusion. In this series of patients with PPV, CBF was close to normal. Although angiography often reveals diffuse arterial narrowing, the CBF values encountered in this study do not support a state of generalized or focal oligoemia. Vasomotor tone may change intermittently in patients with PPV.
Massive Cerebral Edema After Recanalization Post‐Thrombolysis
Authors: Cruz‐Flores Salvador , Thompson Daryl W. , Boiser Joey R.
Published: November 2009

Background. Intravenous thrombolysis with tissue plasminogen activator is an approved and effective therapy for acute ischemic stroke within the first 3 hours from onset. In addition to the risk of hemorrhage, there is a risk of postrecanalization cerebral edema. The authors present the case of a patient with an ischemic stroke treated successfully with intra‐arterial thrombolysis who subsequently developed massive brain edema in the face of clinical improvement. Case. An 81‐year‐old man presented within 1 hour of developing a full right middle cerebral artery (MCA) syndrome. Computed tomography (CT) was normal. A cerebral angiogram demonstrated an occlusion of the M1 segment of the right MCA. The patient was treated with intra‐arterial urokinase 750,000 units. He recovered during the procedure. Serial CT scans demonstrated progressive edema with mass effect in the right MCA distribution. The patient remained asymptomatic except for a mild sensory deficit. Discussion. Postrecanalization cerebral edema is an uncommon but potentially lethal complication of thrombolysis. It is postulated that the edema is due to ischemic injury aggravated by reperfusion with vasogenic edema. The presence of this massive edema is usually associated with clinical worsening. The present case illustrates that this disorder can be associated with good outcome.
The Nature of Microemboli in Patients With Artificial Heart Valves
Authors: Telman G. , Kouperberg E. , Sprecher E. , Yarnitsky D.
Published: November 2009

Cognitive decline has recently been found to be associated with microemboli in cerebral vessels in patients with artificial heart valves. The authors sought to determine the nature of such microemboli, that is, whether they are gaseous or solid, by comparing their characteristics to those of artificially generated air emboli in patients with patent foramen ovale (PFO). Three hundred and forty‐eight microemboli were recorded in 11 patients with artificial valves (all taking coumadin), and 86 microemboli were recorded in response to intravenous injection of saline agitated with air in 8 PFO patients. No difference in intensity, duration, or relative velocity of microemboli was found between groups. The authors conclude that microemboli generated from artificial heart valves are generally gaseous and not solid.
The Role of Neuroimaging in Headache
Authors: Jamieson Dara G. , Hargreaves Richard
Published: November 2009

Headaches are a universal experience and one of the most common causes for physician consultation. The physician must determine whether a neuroimaging study is warranted to aid in the diagnosis of primary or secondary headaches. Guidelines on neuroimaging of headache patients have been developed based on review of the literature; however, their applicability must be adapted to specific clinical situations. In general, neuroimaging is most likely to be useful if the history is not typical of a primary headache type (eg, tension type, migraine, cluster headaches) or the neurological examination is abnormal. Neuroimaging has been crucial in the investigation of the pathogenesis of migraine and cluster headaches. Secondary headaches, which may be diagnosed by neuroimaging studies, include subarachnoid hemorrhage, cerebral venous thrombosis, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, aqueductal stenosis, and arterial dissection.
Acute Disseminated Encephalomyelitis Confined to Brainstem
Authors: Tateishi K. , Takeda K. , Mannen T.
Published: November 2009

A 21‐year‐old man was troubled with a subacute history of brainstem involvement and a leukocyte pleocytosis in the cerebrospinal fluid. Magnetic resonance imaging (MRI) demonstrated a massive lesion with Gd enhancement in the pons. Steroid therapy, not antiviral drugs, was dramatically effective for the mass reduction and symptom improvement. Over 4 years no recurrence has been recognized, so this case was diagnosed to be an unusual case of acute disseminated encephalomyelitis (ADEM). ADEM must be included in the differential diagnosis for a brainstem mass in MRI.
Paradoxical Brain Embolism From Thrombus Associated With Vena Caval Filter in a Patient With Cancer
Authors: Ionita Catalina , Giglio Pierre , Isayev Eugene , Alberico Ronald , Pullicino Patrick
Published: November 2009

A 71‐year‐old man experienced sudden onset of hemiparesis and aphasia. He had a 4‐month history of gallbladder cholangiocarcinoma, complicated with a postoperative deep‐vein thrombosis (DVT) that necessitated a vena caval filter placement. Diffusion‐weighted magnetic resonance imaging of the brain showed multiple hyperintense foci. Magnetic resonance spectroscopy was compatible with cerebral infarction. Abdominal computed tomography showed a thrombus in the inferior vena cava extending through the filters. A transcranial Doppler bubble study revealed the presence of a right‐to‐left shunt. Paradoxical cerebral embolism must be considered in patients with DVT who have new onset neurologic deficits even in the presence of a caval filter.
Intravenous Tissue Plasminogen Activator and Flow Improvement in Acute Ischemic Stroke Patients with Internal Carotid Artery Occlusion
Authors: Christou Ioannis , Felberg Robert A. , Demchuk Andrew M. , Burgin W. Scott , Malkoff Marc , Grotta James C. , Alexandrov Andrei V.
Published: November 2009

Background and Purpose. It has been suggested that intravenous tissue plasminogen activator (TPA) would not lyse the large thrombus associated with internal carotid artery (ICA) occlusion and, therefore, would be ineffective in this setting. Vascular imaging, safety, and outcome of TPA therapy for ICA occlusion is not well described. Our goal was to determine the site of occlusion, early recanalization after TPA infusion, and its relationship to outcome. Methods. We reviewed our database of all stroke patients treated with IV TPA between July 1997 and July 1999. We identified all cases with carotid occlusion suggested by transcranial Doppler (TCD) and angiography. Occlusion and recanalization were assessed by site including proximal ICA (prICA), terminal ICA (tICA), and middle cerebral artery (MCA). Baseline National Institutes of Health Stroke Scale (NIHSS) scores and follow‐up Rankin scores were obtained. Results. We treated 20 patients with carotid occlusion (age 63.9 ± 10.8 years, 11 males, 9 females). Time to TPA infusion after stroke onset was 128 ± 66 minutes. Baseline NIHSS scores were 16.4 ± 5.4. Time to follow‐up was 3.5 ± 4.9 months (2 patients were lost to follow‐up). Occlusion sites were prICA 40%, tICA 70%, and concurrent MCA 45%. Multiple sites were involved in 10/20 patients (50%). Among patients with pretreatment and posttreatment vascular imaging studies (n= 18), recanalization in the prICA and tICA was complete in 10%, partial in 16%, and none in 74%. MCA recanalization was complete in 35%, partial in 24%, and none in 41%. At follow‐up, Rankin 0–1 was found in 8 patients (44%), Rankin 2–3 in 3 (17%), and Rankin 4–5 in 3 (17%). Mortality was 22% (n= 4) including 1 fatal intracerebral hemorrhage. Improvement was closely related to resumption of MCA flow (P < .01). Conclusions. Most patients did not recanalize their ICA occlusion after intravenous TPA therapy. However, recanalization of associated proximal MCA clot, found in 45% of our patients, or improved MCA collateral flow was strongly associated with good outcome.
Doppler Velocity Criteria Based on Receiver Operating Characteristic Analysis for the Detection of Threshold Carotid Stenoses
Authors: Hwang Chi‐Shin , Shau Wen‐Yi , Tegeler Charles H.
Published: November 2009

Background and Purpose. Duplex scanning is an accepted method for noninvasive evaluation of carotid stenosis. However, the ultrasound criteria used for the detection of threshold stenoses vary widely between laboratories, and quality assurance measures to allow adjustment of criteria are often lacking. This study was completed using receiver operating characteristic (ROC) analysis to determine Doppler velocity criteria for threshold carotid stenoses, compared to an accepted standard, and to demonstrate methods to allow adjustment of criteria. Methods. The study cohort included 134 patients who had carotid endarterectomy. Ultrasound and arteriographic data were collected for both the operated and nonoperated sides. Each carotid artery was treated as an independent case in the final analysis. Angiograms were used as the gold standard in ROC analysis to determine the Doppler velocity criteria for the detection of different threshold stenoses. Results. The ROC analysis results showed that for the detection of 70% stenosis, the best Doppler systolic criterion was 200 cm/s (sensitivity 93.6%, specificity 71.7%, area under the curve [AUC] 87.6%), the best diastolic criterion was 65 cm/s (sensitivity 85.1%, specificity 74.6%, AUC 84.3%), and the best criterion of carotid ratio (CR) (internal carotid artery systolic velocity/common carotid artery systolic velocity) was 3.0 (sensitivity 78.7%, specificity 75.4%, AUC 81.3%). For 50% stenosis, the best systolic criterion was 140 cm/s (sensitivity 90.3%, specificity 95.2%, AUC 97.0%), the best diastolic criterion was 60 cm/s (sensitivity 98.6%, specificity 77.8%, AUC 92.1%), and the best criterion of CR was 2.5 (sensitivity 93.1%, specificity 72.0%, AUC 89.0%). Conclusions. This study showed that duplex scanning is able to detect threshold carotid stenoses. For the best performance, each laboratory should have its own criteria; however, the criteria provided here could be a helpful reference to those laboratories that have not yet established their own criteria. Most important, this study provides an example of how to evaluate the performance criteria, how to modify them, how such changes can affect performance, and how performance can be modified depending on the goals of the laboratory.
Subclavian Steal Syndrome: Can the Blood Pressure Difference Between Arms Predict the Severity of Steal
Authors: Tan Teng‐Yeow , Scsminke ULF , Lien Li‐Ming , Tegeler Charles H.
Published: November 2009

Background and Purpose. A side‐to‐side difference in systolic brachial arterial blood pressure is a common finding in subclavian artery stenosis and is frequently used as a screening tool for subclavian steal syndrome (SSS). It was the goal of this retrospective study to investigate the relationship between different vertebral artery waveform types and the side‐to‐side difference in systolic blood pressure in patients with sonographically proven SSS. Methods. The records of 1860 patients from the Neuroultrasound Laboratory between January 2000 and December 2000 were screened for the diagnosis of SSS in the final ultrasound report. In all patients, bilateral brachial arterial blood pressure was measured in a sitting position prior to the ultrasound examination. Vertebral artery waveforms were classified as (1) systolic deceleration, (2) alternating flow, and (3) complete reversal at rest. Blood pressure difference as calculated by normal‐side blood pressure minus lesion‐side blood pressure was compared with the 3 Doppler waveform types. Results. SSS was found in 51 of 1860 (2.7%) ultrasonography studies of 49 patients (17 men, 32 women; mean age 65.3 ± 10.5 years). Two patients (4%) had bilateral SSS. In 3 patients (6%), SSS was related to an innominate artery stenosis. Waveform analysis showed a completely reversed flow in 16 (31%), an alternating flow in 24 (47%), and a systolic deceleration in 11 (22%) cases. Systolic blood pressure difference was significantly higher in the complete reversal and alternating groups than in the systolic deceleration group (P < .001). Conclusion. Brachial systolic blood pressure difference is related to the severity of SSS and can be used as a screening tool for SSS. However, it performed better in severe steal than milder steal phenomena.
Integration and Added Value of the Modern Noninvasive Vascular Laboratory in Vascular Diseases Management
Authors: Boyajian Robert A. , Otis Shirley M.
Published: November 2009

Background and Purpose. Today's vascular laboratory technology offers broad applications throughout vascular medicine. We explore the diagnostic work‐up and management of selected peripheral vascular diseases by benchmarking the institutional mix of invasive and noninvasive technology utilization and associated cost burdens. Methods. Specialized diagnostic studies for prevention of stroke and pulmonary embolism, and diagnosis and management of femoral pseudoaneurysm were reviewed for our 355‐physician clinic and hospital practice. The proportions and costs for invasive and noninvasive diagnostic procedures were tabulated for carotid stenosis, deep venous thrombosis (DVT), and iatrogenic femoral pseudoaneurysm. Current technology utilization mix cost burdens were compared to projected cost burdens for hypothetical equivalent medical value (ie, the same total test volume) in the theoretical absence of noninvasive laboratory services. Results. The technology utilization mix was dominated by noninvasive duplex ultra‐sonography for all 3 vascular disease workups. The technology utilization mix benchmarks were 92% noninvasive for carotid stenosis, 98% noninvasive for DVT, and 100% noninvasive for pseudoaneurysm. Under hypothetical constant test volume normalized to utilization level for the 2‐year period, the maximal range in cost burdens between current reliance on noninvasive diagnoses versus projected 100% reliance on invasive procedures for the 3 vascular applications is approximately $6 million. Conclusion. Benchmark indices reveal near total adoption of noninvasive technology for vascular diagnostic workups at our center. The benefits to institutions of benchmarking their technology utilization mix and costs are discussed in relation to identifying potential for cost‐containment from modifying technology utilization practices.
Transcranial Doppler Ultrasound: A New Method of Monitoring Hemispheric Anesthetization During the Intracarotid Amobarbital Procedure
Authors: Acharya Vinita J. , Acharya Jayant N. , Tegeler Charles H. , Morris Pearse , Meads Dana , O'Donovan Cormac A.
Published: November 2009

Background. Electroencephalography (EEG) is traditionally used to assess the duration of hemispheric anesthetization and to monitor return of function in the anesthetized hemisphere during the intracarotid amobarbital procedure (IAP), but EEG changes are not consistently seen. The authors evaluated the role of continuous transcranial Doppler (TCD) monitoring as an alternative to EEG. Methods. The authors performed both continuous TCD monitoring and EEG during the IAP in 10 patients with medically intractable partial epilepsy. Mean velocities were monitored continuously in both middle cerebral arteries (MCAs), and changes in MCA velocities on continuous TCD monitoring were time locked with the EEG changes. Results. The average mean MCA velocities were within normal limits bilaterally (50–85 cm/s) in all patients at baseline. Mean MCA velocities increased in all patients to 95–115 cm/s at the start of the test when the patients were asked to raise their hands and start counting. After injection of sodium amobarbital, mean MCA velocities in all patients dropped dramatically on the ipsilateral side to values of 12–39 cm/s and returned to the baseline average value when the hemiparesis recovered. In 8 patients, the duration of delta activity on EEG coincided with the time interval during which the mean MCA velocities were low on TCD monitoring. In 2 patients, despite the presence of hemiparesis clinically and a drop in mean MCA velocities on the ipsilateral side on continuous TCD monitoring, EEG remained normal on the ipsilateral side. Conclusions. Continuous TCD monitoring may be a more sensitive method than EEG in determining the duration of hemispheric anesthetization during IAP. Because the items for assessment of memory are presented during the period of hemispheric anesthetization, TCD may be useful in more precisely defining the time window for memory testing.
Vertebral Artery Dissection Presenting With Isolated Neck Pain
Authors: Krespi Yakup , Gurol Mahmut Edip , Coban Oguzhan , Tuncay Rezzan , Bahar Sara
Published: November 2009

Unilateral pain in the cervical region and limitation of neck movements are nonspecific symptoms frequently encountered in daily medical practice. Vertebral artery dissection is rarely considered as a diagnostic possibility unless brainstem or cerebellar ischemia follows the acute pain. Three cases of vertebral artery dissection (VAD) having the sole complaint of pain of acute onset in the posterior neck region are presented. None of the patients had ever reported a similar pain, and the neurological examination was unremarkable in all of them. Doppler ultrasonography suggested VAD in 2 cases, and the diagnosis was confirmed with T1 fat‐suppressed magnetic resonance imaging technique in all patients. Severe neck pain and/or occipital headache frequently accompanies ischemic symptoms in cases with VAD. The cases in this report emphasize that spontaneous and often unilateral posterior cervical pain of acute onset can be the only manifestation of a VAD. A high degree of suspicion especially in young patients with no past history of a similar pain can help to establish the diagnosis, thereby preventing erroneous and potentially hazardous therapeutic interventions such as physiotherapy or neck manipulation.
Magnetic Resonance Imaging of Primary Spinal Intramedullary Lymphoma
Authors: Nakamizo Tomoki , Inoue Haruhisa , Udaka Fukashi , Oda Masaya , Kawai Makoto , Uemura Kengo , Takahashi Makio , Nishinaka Kazuto , Sawada Hideyuki , Kameyama Masakuni , Koyama Tsunemaro
Published: November 2009

The authors report 2 cases of primary spinal intramedullary lymphoma and review all previously reported magnetic resonance imaging findings on this disease. The most common finding was a solid and homogeneously enhanced mass that was hyperintense on T2‐weighted images, without associated syringomyelia. In a few cases, swelling of the spinal cord was minimal.
Optimal Values of Flow Velocity on Transcranial Doppler in Grading Middle Cerebral Artery Stenosis in Comparison With Magnetic Resonance Angiography
Authors: Gao Shan , Lam Wynnie W. M. , Chan Yu Leung , Yan Liu Jun , Wong Ka Sing
Published: November 2009

Background and purpose. To investigate the optimal values of flow velocity on transcranial Doppler (TCD) in grading the severity of middle cerebral artery (MCA) stenosis in comparison with magnetic resonance angiography (MRA). Methods. Both TCD and MRA examinations were performed on 148 asymptomatic patients. The peak flow velocities of each MCA were recorded. Severity of MCA stenosis on MRA was classified as normal‐mild (< 50% lumen diameter reduction), moderate (50%‐75%), and severe‐void (> 75% and void of flow signal). Results. Among 296 MCAs evaluated, normal‐mild stenosis was found in 75 (25%), moderate stenosis in 112 (38%), and severe stenosis in 109 (37%). The mean of systolic velocity (Vs) of MCA differed significantly among these three groups: mean Vs = 121.83 ± 22.52 cm/s in the normal‐mild group; 155.96 ± 21.62 cm/s for the moderate group; and 199.39 ± 43.86 cm/s for the severe group (P < .001). The optimal cutoff velocity for detection of MCA (> 50%) stenosis was found at Vs > 140 cm/s on TCD (area under the ROC curve is 0.87, P < 0.001). The best cutoff points for grading severity of on TCD were 140 cm/s and 180 cm/s. Conclusion. TCD enables grading of the severity of MCA stenosis according to the flow velocity. This method provides a noninvasive and reliable method for grading MCA stenosis and allows longitudinal monitoring of the relationship between clinical outcome and hemodynamic change.
Criteria for Normalcy of Cavities Observed Within the Adult Hippocampus: High‐Resolution Magnetic Resonance Imaging Study on a 3.0‐T System
Authors: Yoneoka Yuichiro , Kwee Ingrid L. , Fujii Yukihiko , Nakada Tsutomu
Published: November 2009

Background and Purpose. Cavities occasionally found within the hippocampus during routine clinical magnetic resonance imaging (MRI) studies are believed to be a normal variant reflecting fluid collection within the vestigial hippocampal sulcus. However, the lack of systematic studies defining objective criteria for such cavities has hampered further assessment of potential abnormalities within the hippocampus. This study assessed the detailed characteristics of hippocampal cavities in normal subjects using a new high‐resolution MRI technique in an attempt to define objective criteria of normalcy. Methods. A new high‐resolution imaging technique, T2‐reversed MRI on a high‐field (3.0‐T) system was used to image the hippocampus in 74 normal volunteers in 3 age groups (28 young, 24 middle, and 22 senior). Results. Residual cavities in the vestigial hippocampal sulcus were resolved as single, crescent‐shaped structures along the deep aspect of the vestigial hippocampal sulcus. The size of the cavities did not vary with age and never exceeded 1 mm in width and 3 mm in length. The frequency of detection, however, increased with age (21.4% [5/28] in the young, 25.0% [6/24] in the middle, and 36.4 [8/22] in the senior age group). Conclusion. The study established clear objective criteria for normal cavities within the hippocampus. These cavities likely represent physiological fluid collection within the vestigial hippocampal sulcus. Any cavity that does not meet these defined criteria should be considered potentially abnormal.
Volumetric Assessment of Plaque Progression With 3‐Dimensional Ultrasonography Under Statin Therapy
Authors: Schminke U. , Hilker L. , Motsch L. , Griewing B. , Kessler C.
Published: November 2009

Background and Purpose. Lowering of serum cholesterol levels with HMG‐CoA reductase inhibitors (statins) slowed the progression of atherosclerosis in the carotid arteries in several clinical trials using carotid artery intima media thickness as primary outcome measure. Whereas conventional ultrasonography is limited to thin 2‐dimensional image planes, 3‐dimensional (3D) ultrasonography provides quantitative measurement of the entire carotid artery plaque volume. This study aims to assess the feasibility of 3D ultrasonography to monitor plaque progression in hypercholesterolemic patients. Methods. The authors prospectively assessed the progression of 31 carotid artery plaques over 15.1 ±4.5 months in a study of 23 patients (6 women, 17 men; mean age = 61.7 ±7.5 years) with hypercholesterolemia under therapy with HMG‐CoA reductase inhibitors. All patients were maintained on a lipid‐lowering diet. Sixteen patients were additionally treated with statins. Quantitative measurements of carotid artery plaque volumes were performed after 3D reconstruction of exactly parallel transverse duplex ultrasound scans (slice distance = 0.1 mm) into volumetric 3D data sets and segmentation of voxels representing the carotid artery plaque. Results. Within the treatment group, plaques were significantly less frequently progressive if they had a hypoechoic echogenicity (11%, n= 9 vs 64%, n= 14; P= .016) or if baseline serum cholesterol levels were above 8.0 mmol/L (9%, n= 11 vs 75%, n= 12; P= .002). Conclusion. Three‐dimensional ultrasonography extends the measurement of the arterial wall thickness to the 3D volume of an entire atherosclerotic plaque including analysis of its morphology and configuration. However, further clinical trials with an adequate sample size to achieve sufficient statistical power are necessary to assess the effect of statin therapy on plaque progression.
Transcranial Doppler Study of the Cerebral Hemodynamic Changes During Breath‐Holding and Hyperventilation Tests
Authors: Settakis Georgios , Lengyel András , Molnár Csilla , Bereczki Dániel , Csiba László , Fülesdi Béla
Published: November 2009

Background and purpose. The aim of the present study was to assess the time course of hyperventilation (HV) and breath‐holding (BH) tests in healthy volunteers. Subjects and Methods. Young healthy volunteers (n= 29) underwent continuous registration of the middle cerebral artery mean blood flow velocity (MCAV) during and after 30 seconds of BH and 60 seconds of HV. Absolute values as well as percentage changes of the MCAV are reported. In 13 subjects, determination of capillary blood gas parameters (pH, pCO2, pO2, and O2 saturation) was performed before tests, after BH and after HV. Results. MCAV during 30 seconds of breath‐holding starts to increase after 10 seconds and reaches its highest level at 30 seconds. After breathing normally, MCAV normalizes within 30 seconds. Hyper‐ ventilation results in a decrease in MCAV, which reaches a plateau at 20 to 30 seconds after starting to hyperventilate, and blood flow velocity did not change significantly any further until the end of the procedure. The normalization of the MCAV is incomplete at 30 seconds after finishing hyperventilation. None of the capillary blood gases changed significantly after breathholding, whereas capillary pH, pO2, and oxygen saturation increased and pCO2 decreased after hyperventilation. No relationship was found between capillary blood gas parameters and MCAV values. Conclusions. The authors concluded that breathholding and hyperventilation tests seem to be a practical alternative to acetazolamide and the CO2 inhalation method in the assessment of cerebral hemodynamics.
Magnetic Resonance Imaging of Multiple Sclerosis
Authors: Filippi Massimo , Tortorella Carla , Rovaris Marco
Published: November 2009

Although conventional magnetic resonance imaging (cMRI) is widely used for diagnosing multiple sclerosis (MS) and monitoring disease activity and evolution, the correlation between cMRI and clinical findings is far from strict. Among the reasons for this “clinical‐MRI paradox,” a major role has been attributed to the limited specificity of cMRI to the heterogeneous pathological substrates of MS and to its inability to quantify the extent of damage in the normal‐appearing tissue. Modern quantitative MRI techniques have the potential to overcome some of the limitations of cMRI. Metrics derived from magnetization transfer and diffusion‐weighted MRI enable one to quantify the extent of structural changes occurring within and outside macroscopic MS lesions with increased pathological specificity over cMRI. Magnetic resonance spectroscopy can add information on the biochemical nature of such changes, with the potential to improve significantly our ability to monitor inflammatory demyelination and axonal injury. Finally, functional MRI might provide new insights into the role of cortical adaptive changes in limiting the clinical consequences of white‐matter structural damage. This review outlines the major contributions given by MRI‐based techniques to the diagnostic work‐up of MS patients, to the understanding of the pathobiology of the disease, and to the assessment of the effects of new experimental treatments.