bluuebunny/crossref_metadata_2025 huggingface dataset:
Giant Axonal Neuropathy: MRS Findings
Authors: Alkan Alpay , Kutlu Ramazan , Sigirci Ahmet , Baysal Tamer , Altinok Tayfun , Yakinci Cengiz
Published: November 2009

Giant axonal neuropathy (GAN) is a rare genetic disease of childhood involving the central and peripheral nervous systems. Axonal loss with several giant axons filled with neurofilaments is the main histopathological feature of peripheral nerve biopsies in this disease. Routine neuroimaging studies reveal diffuse hyperintensities in cerebral and cerebellar white matter. In this case report, the authors present the brain magnetic resonance spectroscopic features (normal N‐acetylaspartate/creatine and increased choline/creatine and myoinositol/creatine ratios), which might indicate the absence of neuroaxonal loss and the presence of significant demyelination and glial proliferation in white matter, of an 11‐year‐old boy diagnosed with GAN.
Asymmetric Neuroimaging in Creutzfeldt‐Jakob Disease: A Ruse
Authors: Bavis James , Reynolds Patrick , Tegeler Charles , Clark Paige
Published: November 2009

Creutzfeldt‐Jakob disease (CJD) causes diffuse neurological symptoms, but asymmetric lesions have been found on conventional magnetic resonance imaging (MRI) and diffusion‐weighted imaging (DWI).Less often, positron emission tomography (PET) scanning can also reveal asymmetric lesions in patients with CJD. Such imaging may mislead clinicians. The authors present a case of a woman with CJD who was diagnosed as having suffered a stroke because she had asymmetric T2‐weighted imaging (T2WI) MRI abnormalities that were interpreted as a stroke. It was noted that the patient had clinical features consistent with CJD, including rapidly progressive dementia, myoclonus, cerebellar dysfunction, and pyramidal and extrapyramidal signs. This diagnosis was supported by periodic epileptiform discharges on the electroencephalogram (EEG) and by elevated 14‐3‐3 protein in the cerebrospinal fluid. MRI T2WI and DWI showed dramatically asymmetric abnormalities involving the left cortex. A PET study found decreased metabolism in the left cerebral and right cerebellar hemispheres. The patient's clinical, EEG, and laboratory data were all consistent with CJD, not other diseases, but the MRI and PET had atypical, asymmetric findings. This case demonstrates that CJD should be considered in the differential diagnosis of patients with rapidly progressive neurological decline, even if they have asymmetric imaging findings.
Characteristics and Predictors of Aortic Plaques in Patients with Transient Ischemic Attacks and Strokes
Authors: Yahia Abutaher M. , Kirmani Jawad F. , Xavier Andrew R. , Shaukat Aasma , Qureshi Adnan I.
Published: November 2009

Objective. To identify the prevalence and characteristics of aortic atherosclerotic plaque disease and its association with cerebrovascular risk factors in patients with cerebral ischemic events. Background. Aortic atheroma is associated with ischemic stroke. Its characteristics, including morphology and distribution among different stroke subtypes, are not well described. Method. From July 2000 to August 2001, all patients evaluated by transesophageal echocardiography (TEE) with diagnoses of transient ischemic attacks (TIAs) and strokes were prospectively studied. Demographics, including age, gender, ethnicity, cerebrovascular risk factors, and stroke subtypes, were collected. Results. Thoracic aortic atheromas (TAAs) were present in 141 of 237 patients (59%) (mean age = 59 ± 14, 119 [50%] male). Mild plaque (<2mm) was present in 13 of 237 (5%), moderate plaque (2–4 mm) in 49 (21%), severe plaque (≥4 mm) in 79 (33%), and complex plaque in 64 (27%). Patients’ ages (odds ratio [OR] = 1.05, confidence interval [CI] 1.03–1.08, P < .001), coronary artery disease (OR = 2.2, CI 1.02–4.8, P < .042), and patent foramen ovale (PFO) (OR = 0.39, CI 0.22–0.70, P < .002) were associated with the severity and complexity of aortic plaque. In multivariate analysis, age (OR = 1.06, CI 1.03–1.08, P < .001) and the presence of PFO (OR = 0.35, CI 0.18–0.65, P < .001) continued to be significant to the severity and complexity of aortic atheroma. Gender, history of stroke, hypertension, diabetes mellitus, hyperlipidemia, and history of smoking were not associated with TAA. Conclusion. One third of TAA plaques are severe and complex in nature and more frequently present in the descending aorta and the arch of the aorta than in the ascending aorta. TEE should be considered for the early detection and treatment of TAA in patients without identified causes of stroke.
Multiple Cerebral Microbleeds: Mri Marker of a Diffuse Hemorrhage–Prone State
Authors: Chalela Julio A. , Kang Dong‐Wha , Warach Steven
Published: November 2009

Background. Recent reports have indicated that cerebral microbleeds (CMBs) detected on gradient‐echo (GRE) magnetic resonance imaging may be a risk factor for therapy‐related intracranial hemorrhages (ICHs). Case Description. The authors describe 3 patients with multiple CMBs in whom ICHs occurred either after tissue plasminogen activator administration or after the initiation of antiplatelet therapy. Hemorrhages occurred in brain areas with normal appearances on GRE imaging and remote from the CMBs. Conclusion. Multiple CMBs may signal a diffuse hemorrhage–prone vasculopathy.
Neuroimaging in Posterior Reversible Encephalopathy Syndrome
Authors: Lamy C. , Oppenheim C. , Méder J. F. , Mas J. L.
Published: November 2009

The terms posterior reversible leukoencephalopathy, reversibleposterior cerebral edema syndrome, and posterior reversibleencephalopathy syndrome(PRES) all refer to a clinicoradiologic entity characterized by headaches, confusion, visual disturbances, seizures, and posterior transient changes on neuroimaging. Clinical findings are not sufficiently specific to readily establish the diagnosis; in contrast, magnetic resonance imaging pattern is often characteristic and represents an essential component of the diagnosis of PRES. Typical lesions predominate in the posterior white matter, with some involvement of the overlying cortex; are hyperintense on T2‐weighted images; and are usually hypointense or isointense on diffusion‐weighted images, with an increase of the apparent diffusion coefficient, indicating vasogenic edema. The pathogenesis is incompletely understood, although it seems to be related to the breakthrough of autoregulation and endothelial dysfunction. Since its initial description, this syndrome has been subsequently described in an increasing number of medical conditions, including hypertensive encephalopathy, eclampsia, and the use of cytotoxic and immunosuppressive drugs. The diagnosis has important therapeutic and prognostic implications because the reversibility of the clinical and radiologic abnormalities is contingent on the prompt control of blood pressure and/or discontinuing the offending drug. On the contrary, when unrecognized, conversion to irreversible cytotoxic edema may occur.
Differentiating Vascular Pathophysiological States by Objective Analysis of Flow Dynamics
Authors: Crutchfield Kevin E. , Razumovsky Alexander Y. , Tegeler Charles H. , Mozayeni B. Robert
Published: November 2009

Background and Purpose. There is an unmet need to classify cerebrovascular conditions physiologically and to assess cerebrovascular system performance. The authors hypothesized that by simultaneously considering the dynamic parameters of flow velocity, acceleration, and pulsatility index (PI) (impedance) in individual Doppler spectrum waveforms, they could develop an objective method to elucidate the pathophysiology of vascular conditions and classify cerebrovascular disorders. This method, dynamic vascular analysis (DVA), is described. Methods. First, a theoretical model was developed to determine how any vascular segment and the ensemble of intracranial vascular segments could be defined according to its dynamic physiological characteristics. Next, the DVA method was applied to 847 anonymous serial complete clinical transcranial Doppler (TCD) studies of patients without regard for their diagnosis to ascertain actual reference ranges and the normality of the distribution curves for each dimension of the 3‐parameter nomogram. The authors applied DVA to 2 clinicalcases to see if they could track the changes in vascular performance of 2 known progressive diseases. Results. The theoretical analysis identified 295,245 possible vascular states for the ensemble of vascular segments in the cerebral circulation. When applied to clinical TCD data, DVA revealed continuous, normally distributed data for the velocity, PI, and logarithm of the acceleration. Conclusions. DVA is proposed as a method for monitoring the physiological state of each cerebral artery segment individually and in ensemble. DVA evaluates the relationship among acceleration (force or pressure), velocity, and PI and provides an objective means to evaluate intracranial vascular segments using the paradigm of the well‐described pressure‐perfusion autoregulation relationship. DVA may be used to study cerebrovascular pathophysiology and to classify, evaluate, and monitor cerebrovascular disorders or systemic disorders with cerebrovascular effects.
CLOTBUST: Design of a Randomized Trial of Ultrasound‐Enhanced Thrombolysis for Acute Ischemic Stroke
Authors: Alexandrov Andrei V. , Wojner Anne W. , Grotta James C.
Published: November 2009

Background: Intravenous tissue plasminogen activator (TPA) therapy can be monitored with 2 MHz transcranial Doppler (TCD). This article describes the design of CLOTBUST (combined lysis of thrombus in brain ischemia using transcranial ultrasound and systemic TPA), the first prospective international multicenter randomized clinical trial of noninvasive externally applied ultrasound to enhance systemic thrombolysis in human stroke. Subjects: Patients with acute ischemic stroke eligible for intravenous TPA therapy within 3 hours of symptom onset who have detectable middle cerebral artery occlusion on a prebolus TCD are included in this trial. All patients receive standard 0.9 mg/kg TPA therapy. Patients are randomized (1:1) to either 2 hours of continuous monitoring with TCD or placebo monitoring. FDA‐approved portable diagnostic TCD equipment and standard headframes (Marc series, Spencer Technologies, Seattle, WA) are used. Output of TCD units is set at 100% power achievable at depths of insonation that display the worst TIBI flow grade signals. Methods and End‐Points: Acute MCA occlusion on prebolus TCD is defined as thrombolysis in brain ischemia (TIBI) flow grades 0–3. Treating physicians are blinded to randomization assignment, and certified scorers measure stroke severity using the National Institute of Health Stroke Scale (NIHSS). Safety of continuous TCD monitoring is determined by rates of symptomatic (NIHSS score increase by 4+ points) intracerebral hemorrhage within 72 hours after initial symptom onset. Potential enhancement of TPA therapy will be determined using combined primary end‐point of early complete recanalization on TCD (TIBI flow grades 4‐5), dramatic recovery (NIHSS ≤ 3 points), or decline in the NIHSS ≤ 10 pointsepeatedly measured every 30 minutes within 2 hours after TPA bolus. Other end‐points include recovery at 24 hours and 3 months. modified Rankin scores (mRS) are obtained at 90 days, and favorable outcome is determined as NIHSS or mRS scores 0–1. Conclusions: The aim of phase II CLOTBUST trial is to determine the rates of early complete recanalization and dramatic/early clinical recovery in TPA+TCD and TPA groups. The sample size is set at 126 patients since a medium effect size (.50) is anticipated for TPA+TCD group vs TPA alone to achieve combined primary end‐point.
Continuous Arterial Spin Labeled Perfusion Magnetic Resonance Imaging in Patients before and after Carotid Endarterectomy
Authors: Ances Beau M. , McGarvey Michael L. , Abrahams John M. , Maldjian Joseph A. , Alsop David C. , Zager Eric L. , Detre John A.
Published: November 2009

Continuous arterial spin labeling perfusion magnetic resonance imaging (CASL‐pMRI)uses magnetically labeled arterial blood water as a tracer to obtain quantifiable measurements of cerebral blood flow (CBF)(mL/100 g−1/min−1).CASL‐pMRI was used to assess CBF changes in major vascular distributions in patients (n = 10)prior to and 3 months after carotid endarterectomy (CEA). No significant change in the global baseline CBF before and after CEA was observed in the group as a whole (P =.81). In patients with reduced CBF prior to CEA (<50 ml/100g/min), a significant increase in global CBF following CEA was observed. An inverse relationship existed between percent change in CBF after CEA versus baseline CBF within the anterior circulation (r =−.78, P <.05) but not in the posterior distribution (r =.25, P =.63). CASL‐pMRI may provide a convenient, inexpensive, noninvasive method for identifying CEA patients at risk for hyperperfusion following carotid revascularization.
Examining the Effect of Cerebral Perfusion Abnormality Magnitude on Cognitive Performance in Recently Abstinent Chronic Cocaine Abusers
Authors: Browndyke Jeffrey N. , Tucker Karen A. , Woods Steven P. , Beauvais John , Cohen Ronald A. , Gottschalk P. C. H. , Kosten Thomas R.
Published: November 2009

Background and Purpose. Cerebral perfusion abnormalities and neuropsychological impairment are common sequelae of chronic cocaine abuse. While perfusion abnormalities have been shown to relate to cognitive deficits in this substance abuse population, the relationship between cognitive performance and the magnitude of perfusion abnormality has yet to be fully determined. Methods. Thirty‐seven abstinent cocaine abusers and 13 normal controls were administered resting 99m‐Tc‐HMPAO single photon emission computed tomography (SPECT) scans followed by a neuropsychological assessment battery tapping executive skills, attention, memory, and motor performance. Statistical parametric mapping (SPM99) techniques were used to analyze the SPECT data to detect significant regional perfusion abnormalities in the cocaine group relative to normal controls, and resulting abnormal SPECT counts were employed for comparison with the assessment measures to examine the relationship between cocaineinduced perfusion abnormalities and cognitive performance. Results. SPECT data analysis revealed significant regional perfusion abnormalities in the cocaine abuse sample relative to controls and significant differences in neuropsychological functioning on measures of executive functioning, complex attention, memory, and manual dexterity. For chronic cocaine abusers, however, within‐group comparisons of the magnitude of abnormal perfusion and neuropsychological performance were largely nonsignificant, with the exception of complex attention and motor speed. Conclusions. Perfusion abnormalities and neuropsychological impairments readily distinguished cocaine abusers from normal controls. However, when the magnitude of cocaine‐induced perfusion abnormalities is examined in relation to cognitive performance, motor speed and complex attention appear to be the best behavioral indicants of the severity of perfusion dysfunction within this substance abuse population.
Serial Positron Emission Tomography Findings in a Patient with Hydrocephalic Dementia and Alzheimer's Disease
Authors: Jeong Yong , Chin Juhee , Tae Woo Suk , Hong Seung Bong , Kim Sang Eun , Suh Yeon‐Lim , Na Duk L.
Published: November 2009

Comorbidity of normal pressure hydrocephalus (NPH) and Alzheimer's disease (AD) is not uncommon. However, few studies have reported the clinical courses of these patients in depth. A 73‐year‐old woman was confirmed to have AD by a biopsy performed during a shunt operation for NPH after a head trauma. She was followed for 4 years using serial neuropsychological tests and positron emission tomography (PET). Her clinical symptoms remained improved for 2.5 years and then declined. The 1‐year minus the presurgical PET scan highlighted the bilateral frontal area, basal ganglia, and thalamus, which may reflect brain regions associated with the improvement of hydrocephalic dementia. On the other hand, the 1‐year minus the 4‐year scan highlighted the bilateral temporoparietal area and the posterior cingulate gyrus, which may reflect brain regions associated with the aggravation of AD. This subtraction method may be useful for monitoring the clinical course in patients with NPH and AD.
Rapidly Progressive Dementia Due to Bilateral Internal Carotid Artery Occlusion with Infarction of the Total Length of the Corpus Callosum
Authors: Rabinstein Alejandro A. , Romano Jose G. , Forteza Alejandro M. , Koch Sebastian
Published: November 2009

The authors report a patient with rapidly progressive cognitive declinedue to bilateral internal carotid artery occlusion (ICAO) resulting inmultiple pathologically proven cerebral infarctions including the entire length of the corpus callosum. The gradual evolution of the deficits wassuggestive of hemodynamic ischemia. Bilateral ICAO should be consideredin the differential diagnosis of patients with rapidly cognitive decline.Although ICAO commonly spares the splenium, complete callosalinfarction is possible in the presence of bilateral ICAO.
Acquired Cerebral Hemiatrophy: Idiopathic?
Authors: Kumar Neeraj , Lindell Edward P. , Port John D.
Published: November 2009

The authors report the case of a young man with acquired cerebral hemiatrophy that was progressive initially but stabilized after a few months. He did not have any seizure throughout the course of his illness. No definite cause was evident despite extensive investigations. He did have a slight increase in white cell count on a cerebrospinal fluid study done during the progressive phase of his illness suggesting that an unidentified infective or inflammatory illness may have resulted in the cerebral hemiatrophy. The authors suggest that Rassmusen's encephalitis may in fact be a spectrum with the typical descriptions representing one end. The importance of multimodality imaging in evaluating patients with cerebral hemiatrophy is discussed.
Clinical Applications of Transcranial Color‐Coded Duplex Sonography
Authors: Krejza Jaroslaw , Baumgartner Ralf W.
Published: November 2009

Transcranial color‐coded duplex sonography (TCCS), in contrast to “blind” conventional transcranial Doppler sonography (TCD), enables a sonographer to outline the intracranial bony and parenchymal structures, visualize the basal cerebral arteries in color, and measure angle‐corrected blood flow velocities in a specific site of the artery in question. This makes measurements of flow velocity more valid than those obtained with conventional TCD. TCCS is becoming a reliable tool for detecting the occlusion and narrowing of major intracranial arterial trunks. TCCS can image the collateral flow through the anterior and posterior communicating arteries in patients with unilateral, high‐grade stenosis or occlusion of the extracranial internal carotid artery, without using potentially dangerous compression tests. Large and medium‐sized arteriovenous malformations can also be detected with TCCS. The rapid sonographic assessment of cerebral hemodynamics in a neurosurgical patient with increased intracranial pressure can guide further management. The use of sonographic contrast agents can increase the number of conclusive TCCS studies in patients with insufficient acoustic windows.
A Method for the Automated Assessment of Temporal Characteristics of Functional Hemispheric Lateralization by Transcranial Doppler Sonography
Authors: Deppe M. , Knecht S. , Lohmann H. , Ringelstein E. B.
Published: November 2009

Background and Purpose. Transcranial Doppler sonography (TCD) can guide and complement investigations based on functional magnetic resonance and positron emission tomography imaging by providing continuous information on cerebral perfusion changes correlated to cerebral activation. So far, however, the role of functional TCD has been limited by a lack of sensitivity.Methods. Here, the authors present an outline of a method that increases the potential of TCD to detect perfusion changes within a vascular territory. Sensitivity on the order of 1% can be achieved by transformation of Doppler envelope curves, which accounts for systemic quasi‐periodic and irregular spontaneous blood flow modulations and artificial disturbances related to the recording. A statistical technique is introduced that allows the automatic detection of time periods of significant hemispheric lateralization in evoked flow studies. Furthermore, an index of laterality is defined quantifying the extent of hemispheric dominance during stimulus processing.Results and Discussion. The analysis technique described in this article has been successfully employed in recent examinations on vision, motor activation, language, language recovery, and other cognitive tasks. Conclusion. The novel functional TCD technique permits valid and reproducible assessments of the temporal characteristics of functional hemispheric lateralization.
Improving Cerebral Cortical Magnetic Resonance Imaging Using a Readily Available Surface Coil
Authors: Gomez‐Hassan Diana M. , Blaesing Cathy , Shattock Steven , Chenevert Thomas L.
Published: November 2009

Subtle structural deformities of the cerebral cortex have been shown to be the cause of seizures in patients with refractory epilepsy. Brain imaging using high‐resolution focused protocols with standard head coils may not provide sufficient image quality needed for evaluating subtle cortical abnormalities. The authors describe the use of a readily available shoulder coil placed over a specific area of the brain that has been clinically determined to enhance the signal to noise and resolution of the cortical surface. Delineating the cortical surface using a shoulder coil can help to detect subtle areas of cortical thickening, blurring of the gray‐white matter junction, or focally abnormal gyral and sulcal patterns.
Computed Tomography Angiographic Correlates of Early Computed Tomography Signs in Acute Ischemic Stroke
Authors: Garg Neeta , Eshkar Noam , Tanenbaum Lawrence , Cohen Barry , Sen Souvik
Published: November 2009

Background and Purpose. Early computed tomography (CT) signs of stroke signify major arterial occlusion. CT angiogram (CTA) is useful in detecting major arterial occlusion and may help triaging patients for intra‐arterial thrombolysis. The correlation between the early signs of stroke and arterial occlusion on CTA was studied.Methods. Consecutive patients with suspected acute anterior circulation ischemic stroke presenting within 6 hours of symptom onset underwent noncontrast CT of the head followed by CTA. The scans were later reviewed for evidence of early signs of stroke on CT scan and intracranial arterial occlu‐sion on CTA.Results. Sixteen of 65 patients had arterial occlu‐sion on CTA; 12 (75%) of these showed the early CT signs of stroke. All the early signs except M2 “dot” sign significantly cor related with middle cerebral artery (MCA) occlusion on CTA. Hyperdense MCA sign was the only independent predictor of a MCA occlusion.Conclusion. In a small sample, early CT signs of stroke strongly correlated with arterial occlusion, with hyperdense MCA sign being the most predictive of a MCA occlusion.
Common Carotid Artery Remodeling Studied by Sonomorphological Criteria
Authors: Kazmierski Radoslaw , Watala Cezary , Lukasik Maria , Kozubski Wojciech
Published: November 2009

Background and Purpose. Only a few attempts have been made to establish the impact of critical intima‐media thickness (IMT) on narrowing of the lumen of the common carotid artery (CCA). In the present study, sonomorphological criteria have been used to assess how intima‐media thickening in the CCA may influence the artery geometry.Methods. High‐resolution ultrasonography was employed in 233 patients (466 arteries) to quantify the selected parameters of CCA biometry: IMT, arterial lumen diameter (LD), interadventitial diameter (IAD), and outer artery diameter (OAD).Results. With an increase of CCA IMT up to the critical point of 1.2 mm, the LD showed parallel compensatory increases. Above the inflection point of 1.3 mm, the lumen became progressively narrower proportionally to the increasing IMT.Conclusion. There are limits to the compensa‐tory enlargement of the CCA lumen. Above the inflection point of CCA IMT of 1.3 mm, the artery lumen becomes progressively narrower with increasing IMT.
Combined Surgical and Endovascular Management of a Complex Posttraumatic Dural Arteriovenous Fistula of the Tentorium and Straight Sinus
Authors: Zink Walter E. , Meyers Philip M. , Connolly E. Sander , Lavine Sean D.
Published: November 2009

Diagnosis and management of a complex tentorial dural arteriovenous fistula (DAVF) of the straight sinus with vein of Galen aneurysmal dilatation is presented. A 65‐year‐old woman with remote history of cranial gunshot lapsed into coma after months of progressive neurological decline. Computed tomography brain scan showed cerebellar hemorrhage while arteriography demonstrated a complex arteriovenous fistula of an isolated straight sinus and tentorium with extensive arterial supply. First extracranial then intracranial arterial feeders to the fistula were occluded in separate procedures following initial presentation. Eleven days after presentation, an occipital burr‐hole craniotomy was performed, the isolated straight sinus was cannulated under fluoroscopic guidance, and the fistula eradicated with multiple thrombogenic fibered platinum and Gugliemi detachable coils. Staged embolization now represents the standard of care for many complex DAVFs. A multi‐disciplinary surgical and endovascular approach is a valuable combination to cure deep lesions with limited surgical or transvascular access.
“Whippets”‐Induced Cobalamin Deficiency Manifesting as Cervical Myelopathy
Authors: Diamond Alan L. , Diamond René , Freedman S. Mitchell , Thomas Florian P.
Published: November 2009

Background. Nitrous oxide (N O) is inhaled in anesthesia and as a recreational drug from whipped cream dispensers. Its abuse reaches −10% in some age groups. By inactivating cobalamin (Cbl) (vitamin B12), N O can cause neurologic and hematologic manifestations. We present a case of N O‐induced Cbl deficiency presenting as cervical myelopathy. Case History. After regularly inhaling N O for many months, a 31‐year‐old man developed limb paresthesiae and ataxia over 3 months. Examination revealed finger pseudoathetosis, hyporeflexia, decreased sensation, and gait ataxia. Brain magnetic resonance imaging (MRI) was normal, but the posterior columns of the cervical and upper thoracic cord revealed patchy nonenhancing hyperintense lesions. Serum Cbl was 98 pg/mL (normal = 170–900 pg/mL). Cbl replacement led to recovery within 3 months.Discussion. This patient presented with the symptoms and signs of Cbl deficiency. The MRI lesions in the posterior columns aided the diagnosis. Physicians need to have a high level of suspicion in cases of unexplained Cbl deficiency and myelopathy.
Parasellar Solitary Fibrous Tumor of Meninges: Magnetic Resonance Imaging Features With Pathologic Correlation
Authors: Lo Chung‐Ping , Chen Cheng‐Yu , Lin Chih‐Kung , Chin Shy‐Chyi , Juan Chun‐Jung , Hsueh Chun‐Jen
Published: November 2009

Solitary fibrous tumor (SFT) is a benign mensenchymal neoplasm of spindle‐cell origin. The authors report the case of a 50‐year‐old man with SFT arising from the meninges of the left parasellar region with cavernous sinus involvement. The tumor was demonstrated isointense on T1‐weighted and heterogeneously hypointense on T2‐weighted magnetic resonance imaging (MRI) with strong contrast enhancement. The preoperative MRI diagnosis was meningioma or hemangiopericytoma. Pathological study revealed an SFT that stained positive immuno‐histochemically for CD34 and vimentin.
Neuroimaging of Hypoxia and Cocaine‐Induced Hippocampal Stroke
Authors: Bolouri Mohammad Reza , Small George A.
Published: November 2009

The hippocampus has been a subject of numerous studies of behavior and memory in patients who demonstrate atrophy, sclerosis, or injury by autopsy or imaging. It has also been studied in patients who undergo surgical treatment for intractable epilepsy. The effects of hypoxia and ischemia on the hippocampus have been studied in animals; however, human cases of hippocampal stroke are rarely reported. The authors report a case of bilateral hippocampal stroke in a patient with severe ischemia secondary to cardiac arrest and cocaine exposure. These findings likely resulted from the combination of hypoxia and cocaine‐related excitotoxicity.
Magnetization Transfer Magnetic Resonance Imaging in the Assessment of Neurological Diseases
Authors: Filippi Massimo , Rocca Maria A.
Published: November 2009

In several white matter diseases of the central nervous system (CNS), and in particular in multiple sclerosis, conventional magnetic resonance imaging (MRI) has proved to be sensitive for detecting lesions and their changes over time. However, con ventional MRI is not able to characterize and quantify the tissue damage within and outside such lesions. Magnetization transfer MRI (MT‐MRI) is a quantitative MRI technique with the potential to overcome this limitation and, as a consequence, to provide additional information about the nature and the extent of tissue damage. Metrics derived from MT‐MRI can quantify the structural changes occurring within and outside lesions visible on conventional MRI scans. The present review summarizes the major contributions given by MT‐MRI to provide an accurate in vivo picture of the heterogeneity of CNS pathology and, ultimately, to improve our ability to monitor the evolution of various neurological conditions.
The Accuracy of Transcranial Doppler in the Diagnosis of Stenosis or Occlusion of the Terminal Internal Carotid Artery
Authors: Navarro Jose C. , Mikulik Robert , Garami Zsolt , Alexandrov Andrei V.
Published: November 2009

Background and Purpose. Transcranial Doppler (TCD) can detect intracranial stenoses and occlusions that can help in the diagnosis and management of ischemic stroke. The accuracy parameters for lesions located in the terminal internal carotid artery (TICA) are less known, unlike other basal cerebral vessels. Patients and Methods. The authors studied consecutive patients referred for TCD who underwent contrast angiography or magnetic resonance angiography. They calculated the sensi tivity, specificity, positive and negative predictive values (PPV and NPV), and likelihood ratios. Results. Forty‐three patients had TCD and angiography: mean age was 57 ± 20 years, and 65% were men. Twenty‐two patients were diagnosed with TICA stenosis or occlusion on TCD underwent angiography. Four patients had abnormal TCD findings that were not confirmed by angiography. Two of 21 patients with normal TCD showed mod erate (< 50%) stenosis of the TICA and cavernous segment of the internal carotid artery at angiography. Accuracy parameters for TCD were as follows: sensitivity = 90% (confidence interval [CI], 63%‐96%), specificity = 83% (CI, 61%‐94%), PPV = 82%, NPV = 86%, positive likelihood ratio = 5, and negative likelihood ratio = 0.17. Conclusions. TCD is a sensitive screening tool for the lesions in the TICA. Specificity is likely affected by a wide spectrum of the stenosis severity shown at angiography and time lags between the studies.
Ictal Single‐Photon Emission Computed Tomography Imaging in Extra Temporal Lobe Epilepsy Using Statistical Parametric Mapping
Authors: Knowlton Robert C. , Lawn Nicholas D. , Mountz James M. , Buddhiwardhan Ojha , Miller Suzanne , Burneo Jorge G. , Kuzniecky Ruben I.
Published: November 2009

Purpose. To examine the application of statistical parametric mapping (SPM) to analyze ictal single‐photon emission computed tomography (SPECT) scans in surgical candidates with extratemporal lobe epilepsy. Methods. The authors selected patients who underwent successful ictal SPECT acquisition in the process of surgical treatment of intractable partial epilepsy. Thirteen patients were identified who met inclusion criteria for confident seizure localization from either intracranial electroencephalogram recordings or epilepsy surgery outcome. In these cases, ictal scans were registered to an in‐house‐developed normal SPECT atlas composed of 14 spatially normalized brains of normal subjects. SPM96 was used to test on a voxel‐by‐voxel basis for statistically significant increases in blood flow associated with each patient's ictal scan. The results were then mapped back onto the patient's magnetic resonance image (MRI) for final interpretation. Statistical parametric mapping (SPM) analysis of ictal SPECT scans was compared to both conventional visual interpretation and the analysis of subtraction ictal SPECT co‐registered to MRI (SISCOM). Results. Ten of 13 patient scans showed localizing focal ictal increases in regional cerebral blood flow, all of which were concordant with ultimate epilepsy localization. Of the 3 cases not localized with SPM, 1 was localized by conventional visual interpretation and another, not localized by visual interpretation, was correctly localized with SISCOM. Two cases not localized by SISCOM were localized by both visual and SPM analysis. Conclusions. This work provides supportive evidence for proof of principle that SPM can be used to provide objective, accurate analysis of ictal SPECT scans in patients with extratemporal lobe epilepsy.
Transcranial Doppler in Asymptomatic Carotid Stenosis Representing Hemodynamic Impairment: Correlation Study with Magnetic Resonance Imaging
Authors: Kim Dong Wook , Min Ju‐Hong , Lee Yong‐Seok
Published: November 2009

Background and Purpose. Since the benefit of an endarter ectomy in an asymptomatic carotid stenosis is not as clear as that in symptomatic stenosis, identifying patients with a high risk of stroke will allow the improved selection of surgical candidates. To evaluate the role of transcranial Doppler (TCD) in assessing an asymptomatic stenosis, this study examined the association of a TCD‐detected hemodynamic change with a stenosis‐related abnormality on magnetic resonance imaging (MRI). Methods. Asymptomatic patients with a more than 60% internal carotid artery stenosis were enrolled in this study. The hemodynamic change in the TCD was analyzed in terms of the demographic characteristics, the stroke risk factors, and the stenosis‐related MRI abnormalities that are a proven risk factor of a further stroke. Results. Fifty‐three patients were retrospectively recruited. While there were no differences in the demo graphic characteristics or frequency of the stroke risk factors, the proportion of patients with stenosis‐related MRI abnormality was significantly higher in patients with a hemodynamic change on TCD (13/19 vs 6/34, P < .01; odds ratio = 10.11; 95% confidence interval = 2.73–37.4). Conclusions. The TCD‐detected hemodynamic changes may provide useful information for assessing the frequency of silent stroke in patients with an asymptomatic carotid stenosis.
Three‐Dimensional Contrast‐Enhanced Magnetic Resonance Angiography of Carotid Artery after Stenting
Authors: Teng Michael M. H. , Tsai Fong , Liou Adrian Jy‐Kang , Lirng Jiing‐Feng , Chang Feng‐Chi , Luo Chao‐Bao , Cheng Hui‐Cheng
Published: November 2009

Purpose. This study presents 3‐dimensional, contrast‐enhanced, magnetic resonance (MR) angiographic appearances of the carotid artery after stenting. Methods. The authors reviewed contrast‐enhanced MR angiograms of 18 carotid arteries in 13 patients. These arteries were not stenotic or occluded in the stented segment, as shown on carotid angio‐grams (11 patients) or carotid Doppler images (2 patients) obtained later. Results. Five patients had 1 stent in each of their bilateral carotid arteries. One patient with 1 stent in 1 artery underwent the examination twice with different MR coils. Different artifact patterns were found in 19 carotid‐stent examinations. Type 1a involved short segments of false narrowing or false focal occlusion at both ends of the stent (n = 12); the carotid artery in the stented segment between the ends was normal. Types 2a and 2b occurred along the stented segment of the artery between the 2 ends of the stent. Type 2a was milder, with segmental faint signal intensity or luminal stenosis in the entire length of the stented segment (n = 5). Type 2b was total loss of luminal signal intensity over the whole length of the stented segment (n = 2). Last, type 1b was a band of hyperintensity at the ends of type 2a or 2b artifacts. Types 1a and 1b were due to susceptibility effect, and types 2a and 2b were from radio‐frequency shielding effect. Both of these effects were identified in MR angiogram of nitinol stents and stainless steel stents. Conclusion. Awareness of these artifacts is essential to prevent misdiagnosis.
Power M‐Mode Transcranial Doppler for Diagnosis of Patent Foramen Ovale and Assessing Transcatheter Closure
Authors: Spencer Merrill P. , Moehring Mark A. , Jesurum Jill , Gray William A. , Olsen John V. , Reisman Mark
Published: November 2009

Background and Purpose. Transcatheter closure of patent fora men ovale (PFO) can benefit from a less invasive diagnostic method than transesophageal echocardiography (TEE). Thirty‐three gate power m‐mode transcranial Doppler (pmTCD) was evaluated for its accuracy in diagnosis of PFO and utility in evalu ating residual intracardiac right‐to‐left shunt (RLS) following transcatheter closure. Methods. The sensitivity of pmTCD and single‐gate TCD (sgTCD) to detect contrast bubble emboli through RLS was compared during transcatheter PFO closure. During 100 preclosure diagnostic evaluations and in 81 postclosure assessments, embolic tracks on pmTCD were counted following intravenous contrast injections and were graded using a 6‐level logarithmic scale. The accuracy of TEE and pmTCD was separately compared to PFO anatomical find ings during transcatheter closures. Results. There were signifi cantly more microemboli detectable on pmTCD (322 ± 166; 95% confidence interval [CI], 388–257) than on sgTCD (186 ± 109; 95% CI, 229‐143; P < .001). McNemar change tests sug gest that the diagnostic capabilities of pmTCD and TEE for detecting PFO are comparable and correspond to the anatomi cal findings determined during cardiac catheterization (P= .69 and .45, respectively). During 6‐month postclosure evaluation (mean = 185 days), 66% of the patients demonstrated success ful closure without significant RLS (ie, grades 0, I, or II), and 34% were found to have incomplete closure with significant RLS (ie, grades III, IV, or V). Conclusions. pmTCD provides greater sensitivity to contrast bubble emboli than does sgTCD. Among candidates for transcatheter closure, pmTCD provides an improved noninvasive method for diagnosing PFO and evaluating transcatheter closure.
Contralateral Cerebral Blood Flow Velocity Changes after Intracarotid Amobarbital Injection
Authors: Pfefferkorn T. , Hundt C. , Arnold S. , Missler U. , Noachtar S. , Hamann G. F.
Published: November 2009

Background and Purpose. The intracarotid amobarbital procedure (IAP) leads to a prompt decrease in ipsilateral middle cere bral artery (MCA) mean blood flow velocity (MFV). Little is known about contralateral MFV changes. Methods. The authors investigated bilateral MCA MFV using transcranial Doppler sonography (TCD) in 8 patients with epilepsy undergoing IAP. Measurements were excluded from analysis if angiography revealed any signs of interhemispheric cross‐flow. Results. With in 64 seconds after amobarbital injection, ipsilateral MFV decreased to a mean of 44.4%± 7.5% of baseline value (P < .01). In the absence of interhemispheric cross‐flow and within 68 seconds, contralateral MFV decreased to 83.1%± 7.9% (P < .01). Conclusions. The observed decrease of contralateral MFV was not caused by amobarbital cross‐perfusion. A possible underlying mechanism may be interhemispheric deafferentation.
Reversible Cerebellar Lesions Induced by Metronidazole Therapy for Helicobacter Pylori
Authors: Ito Hirono , Maruyama Michiyuki , Ogura Naoko , Fujioka Toshiki , Iwasaki Yasuo , Aikawa Atsushi , Hasegawa Akira
Published: November 2009

Metronidazole is widely used for chronic or refractory infection and has recently also been used for the treatment of Helicobacter pylori. The authors report the case of a Japanese patient presenting with reversible cerebellar lesions induced by prolonged administration of metronidazole for treatment of H pylori with magnetic resonance imaging findings. Although rare, prolonged and high‐dose administration of metronidazole may induce cerebellar lesions. Increased awareness of this phenomenon is important, as these lesions are reversible with discontinuation of this drug.
Novel Neuroimaging Findings in a Patient with Cerebral Whipple's Disease: A Magnetic Resonance Imaging and Positron Emission Tomography Study
Authors: Galldiks N. , Burghaus L. , Vollmar S. , Cizek J. , Impekoven P. , Thomas A. , Jacobs A. H. , Herholz K.
Published: November 2009

The authors report a 43‐year‐old patient with histopathologically proven cerebral Whipple's disease. Magnetic resonance imaging (MRI) revealed a multilayered left frontal lesion without mass effect, no perifocal brain edema, no contrast enhancement, and a thin shell of fluid signal that presented as an incomplete, open ring. An [C]methionine positron emission tomography (PET) study showed low uptake below the threshold that is characteristic for brain tumors. In precise co‐registration to the MR images, the PET data showed that increased uptake was mainly located in the direct adjacent part of the MRI lesion. The fluid signal on MRI corresponded to the extensive outflow of fluid from the lesion, which was observed during neurosurgical resection, and also to the neuropathological findings. The authors conclude that this cerebral manifestation of Whipple's disease made a unique and hitherto undescribed appearance on MRI; uptake pattern of PET amino acid tracer may help in the preoperative distinction of inflammatory from neoplastic lesions.
Anatomical Functional Changes in a Patient Presenting a Complex Malformation of Cortical Development
Authors: Calistri Valentina , Lenzi Delia , Gilio Francesca , Di Bonaventura Carlo , Inghilleri Maurizio , Mainero Caterina , Pantano Patrizia
Published: November 2009

The authors describe a case of right fronto‐parietal micropoligyria associated with small schizencephaly clefts and the presence of a frontal open‐lip schizencephaly with corpus callosum agenesis. A functional magnetic resonance imaging (fMRI) study was performed to evaluate the possible reorganization of cortical functions in a patient presentinga complex malformation pattern and to investigate which cortical areas were activated during left finger movements. An fMRI study was performed during the execution of a repetitive index finger‐to‐thumb opposition movement with the right hand and the left hand in 2 separate sessions. Movement of the right hand induced a normal motor activation pattern involving the contralateral left sensory‐motor cortex. Movement of the left hand produced significant activation of brain cortex. This fMRI study highlights the compensatory role of the ipsilateral cortical pathways in hand movements in the case of a complex brain malformation that involves the main motor activation areas.
Atrophy of the Brain and Spinal Cord in Multiple Sclerosis
Authors: Bakshi Rohit
Published: November 2009

The destructive nature of the multiple sclerosis disease process is of growing clinical and neuroscientific interest. Axonal transection, neuronal loss, Wallerian degeneration, and chronic demyelination likely contribute to macroscopic atrophy of the brain and spinal cord in patients with the disease. This neurodegenerative process belies the traditional view of multiple sclerosis as an inflammatory demyelinating disease. Magnetic resonance imaging is a key tool in the diagnosis and longitudinal monitoring of central nervous system atrophy. This supplement to theJournal of Neuroimaging is devoted to brain and spinal cord atrophy in MS, with a focus on the role of magnetic resonance imaging. The authors and topics of the articles have been chosen by the Guest Editor to provide a state‐of‐the‐art review of this important field. An emphasis is placed on several key issues pertaining to central nervous system atrophy in multiple sclerosis: pathogenesis, magnetic resonance imaging techniques for quantification, clinical relevance, and effects of disease‐modifying therapies.
Magnetic Resonance Imaging Surrogates of Multiple Sclerosis Pathology and Their Relationship to Central Nervous System Atrophy
Authors: Meier Dominik S. , Weiner Howard L. , Khoury Samia J. , Guttmann Charles R. G.
Published: November 2009

This article focuses on the various magnetic resonance imaging metrics currently used in multiple sclerosis and discusses how they relate to central nervous system atrophy. The authors discuss the significance of T2 lesion burden, gray matter damage, T1 hypointense lesions (black holes), contrast‐enhanced lesions, magnetization transfer imaging, diffusion imaging, and magnetic resonance spectroscopy. These magnetic resonance imaging surrogates exhibit different sensitivities for each of the underlying pathogenic processes of multiple sclerosis. By exploiting the complementary nature and varying sensitivities of these magnetic resonance imaging surrogates, it is possible to create a more comprehensive picture of the degenerative process of multiple sclerosis.
Ultrasound Contrast Agents for Brain Perfusion Imaging and Ischemic Stroke Therapy
Authors: Martina Alberto Della , Meyer‐Wiethe Karsten , Allémann Eric , Seidel Günter
Published: November 2009

Stroke is one of the major causes of death and disabilities in industrialized countries. Ultrasound imaging is a largely wide spread bedside technique that is easily accessible and valuable in case of emergency but suffers from the fact that the ultrasound wave has to cross the skull for brain imaging. However, ultrasound contrast agents and new contrast‐specific imaging modalities have helped to improve the diagnostic quality of transcranial ultrasonography. This review article surveys and discusses the current state of microbubbles technology and the use of contrast‐enhanced transcranial ultrasound for the assessment of brain perfusion. Future aspects and expecta tions in contrast agent functionality, such as targeting and drug or gene delivery, acceleration of thrombolysis, and imaging technology, are also discussed.
Isotropic Component Trace Analysis
Authors: Matsuzawa Hitoshi , Nakayama Naoki , Kwee Ingrid L. , Nakada Tsutomu
Published: November 2009

A new method for analyzing diffusion tensor imaging (DTI) of the brain, based on a recently introduced algorithm, lambda chart analysis (LCA), is presented. Pretreatment of a given DTI data set with LCA, which effectively segregates isotropic and aniso tropic components, allows for total removal of the anisotropic component from the DTI data set. The remaining pure isotropic component can therefore be subjected to further analysis simi lar to that applied in the trace histogram method. Deconvolution of the trace function yielded 3 Gaussian elements. Remapping of these 3 deconvoluted isotropic elements back onto the 2‐dimensional image plane provided anatomical correlates of each element. The algorithm, referred to here as isotropic com ponent trace analysis, can be used as a pictorial analytic tool, as well as a numerical analytical tool, for the noninvasive assess ment of isotropic parenchymal components. The presented method provides quantitative indices of certain parenchymal parameters with better clarity than currently available methods. A ready‐to‐use program, EZ‐LCA, for this powerful method is provided (available at http://coe.bri.niigata‐u.ac.jp).