bluuebunny/crossref_metadata_2025 huggingface dataset:
T1‐ and T2‐Based MRI Measures of Diffuse Gray Matter and White Matter Damage in Patients with Multiple Sclerosis
Authors: Neema Mohit , Stankiewicz James , Arora Ashish , Dandamudi Venkata S.R. , Batt Courtney E. , Guss Zachary D. , Al‐Sabbagh Ali , Bakshi Rohit
Published: October 2009

Magnetic resonance imaging (MRI) has emerged as a powerful noninvasive tool to assist in the diagnosis and monitoring of multiple sclerosis (MS). In addition, investigators have used MRI metrics as supportive outcome measures to explore drug efficacy in clinical trials. Conventional MRI surrogates provide information at the macroscopic level but lack sensitivity and specificity in identifying the full extent of underlying MS pathology. They also show relatively weak relationships to clinical status such as predictive strength for clinical change. Advanced MRI techniques involving quantitative measures of diffuse damage in normal appearing (NA) white matter (WM) and gray matter (GM) may help in resolving this apparent clinical MRI paradox. T2 hypointensity has been described in the GM of patients with MS and has been linked to physical disability, cognitive dysfunction, and brain atrophy. While this T2 hypointensity is thought to represent iron deposition, this awaits pathologic confirmation. Advanced MRI measures of iron deposition such as R2, R2*, R2' relaxometry, 3T imaging and other new approaches are beginning to be applied to studies of MS and should yield interesting information. Both T1 and T2 relaxometry have a role in detecting damage in NA brain tissue that escapes detection by conventional MRI lesion measures. For example, T2 mapping may allow an assessment of myelin content in NAWM. In this review, we will focus on MRI advances in the last 10 years pertaining to T1 and T2 measures of diffuse GM and WM damage.
Functional MRI in Multiple Sclerosis
Authors: Rocca Maria A. , Filippi Massimo
Published: October 2009

There is increasing evidence that the severity of the clinical manifestations of multiple sclerosis (MS) does not simply depend on the extent of tissue destruction, but rather represents a complex balance among tissue damage, tissue repair, and cortical reorganization. Functional magnetic resonance imaging (fMRI) provides information about the extent and nature of brain plasticity, which follows MS structural injury and might have the potential to limit the clinical manifestations of the disease. An altered recruitment of regions normally devoted to the performance of a given task and/or the recruitment of additional areas, which are not typically activated by healthy people for performing that given task, have been described in patients with MS, independent of their clinical phenotype when investigating the visual, cognitive, and motor systems. These functional changes have been related to the extent and severity of brain damage within and outside T2‐visible lesions and to the involvement of specific central nervous system (CNS) structures, including the spinal cord and the optic nerve. Brain functional changes have been shown to be dynamic over time, not only after an acute relapse, but also in clinically stable patients. An increased recruitment of the cerebral networks might represent a first step of cortical reorganization with the potential to maintain a normal level of function in the course of MS. The progressive failure of these mechanisms might, on the one hand, result in the activation of previously silent “second‐order” compensatory areas, and, on the other, contribute to the clinical manifestations of the disease.
Optic Nerve Imaging in Multiple Sclerosis
Authors: Hickman Simon J.
Published: October 2009

In this article I review the last 10 years of progress in the imaging of the optic nerve with a particular focus on applications to multiple sclerosis (MS). Development of magnetic resonance imaging (MRI) of the optic nerve has lagged behind imaging of other parts of the CNS. These limitations are due to technical challenges related to the small size and mobility of the optic nerves and artefacts caused by surrounding cerebrospinal fluid, orbital fat, and air‐bone interfaces. Nonetheless the last 10 years has seen significant progress with regard to detecting optic nerve atrophy following optic neuritis, the use of fat‐ and CSF‐suppressed high resolution imaging, the ability to measure magnetization transfer ratio and diffusivity in the optic nerve, and the emergence of SPIR‐FLAIR for increasing sensitivity to inflammatory demyelination. Remaining challenges include further reduction of movement artifacts, testing ultra‐high field MRI systems and dedicated surface coils, and developing automated segmentation techniques to improve the reproducibility of quantitative measurements. Finally the role of optic coherence tomography as a marker of retinal damage needs to be clarified further through correlations with MRI, clinical, and electrophysiologic data.
Diffusion Tensor and Functional Magnetic Resonance Imaging of Diffuse Axonal Injury and Resulting Language Impairment
Authors: Mao Hui , Polensek Sharon H. , Goldstein Felicia C. , Holder Chad A. , Ni Chunchun
Published: October 2009

Diffuse axonal injury (DAI) is a common aftermath of brain trauma. The diagnosis of DAI is often difficult using conventional magnetic resonance imaging (MRI). We report a diffusion tensor imaging (DTI) study of a patient who sustained DAI presenting with language impairment. Fractional anisotropy (FA) and DTI tractography revealed a reduction of white matter integrity in the left frontal and medial temporal areas. White matter damage identified by DTI was correlated with the patient's language impairment as assessed by functional MRI (fMRI) and a neuropsychological exam. The findings demonstrate the utility of DTI for identifying white matter changes secondary to traumatic brain injury (TBI).
When Touch Elicits Cold: Functional Imaging of an Abnormal Sensation
Authors: Maihöfner Christian , Seifert Frank
Published: October 2009

The authors report a 58‐year‐old man who presented with touch‐induced cold sensations and loss of pain and normal temperature sensation in the left leg and trunk. He was found to have syringomyelia at the level of the third thoracic vertebrae. A functional magnetic resonance imaging (fMRI) study was performed to evaluate the underlying cortical processing of the touch‐induced cold sensations. Blood oxygen level‐dependent(BOLD) responses were measured in response to light tonic pressure stimuli and to cold stimuli applied to both the symptomatic area on the left leg and to the unaffected contralateral side. Tonic pressure applied on the unaffected right thigh and the left hand resulted in activations of contralateral primary (S1) and bilateral secondary somatosensory cortices (S2). In contrast, application of tonic pressure to the affected left thigh, ie, where touch stimuli elicited cold sensations, induced robust activations not only in contralateral S1 and bilateral S2, but also in bilateral insular cortices, which are cortical areas known to be pivotally involved in the central processing of cold. The fMRI data argue in favor of supraspinal cross‐submodal plastic changes within the somatosensory system.
Prospective Evaluation of the Role of Atherosclerosis on Cerebral Atrophy: Pilot Study
Authors: Erbay Sami H. , O'Callaghan Mark. , Shah Paraq , Kini Jonathan , Bassett Midle Jennifer , Polak Joseph F.
Published: October 2009

PURPOSE

Our purpose was to study the association between atherosclerosis measured by arterial calcium on computed tomography (CT) and cerebral atrophy demonstrated by brain magnetic resonance imaging (MRI).

MATERIALS AND METHODS

IRB approved this prospective study. Twenty‐one consecutive patients with acute stroke‐like symptoms who are scheduled to have brain MRI were recruited on a voluntary basis. electrocardiogram (ECG)‐gated helical CT scans were used to determine the arterial calcium as a reliable index of underlying atherosclerosis. Extracranial arterial calcium content was measured quantitatively by special software available in our CT scanner. Intracranial calcium was graded qualitatively. Brain MRI was independently evaluated to identify cortical, central atrophy, and ischemic changes. Relationship between CT demonstrated atherosclerosis and cerebral ischemic changes, brain atrophy patterns were evaluated both without and with adjustment for age and hypertension.

RESULTS

Out of 21 patients 20 were included in final study group. There was no correlation between atherosclerotic calcium measures and cortical atrophy, ischemic findings. Both intracranial and extracranial atherosclerosis had partial correlation with central atrophy (R= 0.43 and 0.52, respectively). After adjustment for age, only intracranial atherosclerosis maintained a partial correlation with central atrophy (R= 0.41). However, this correlation did not reach a statistically significant level (P= .10).

CONCLUSIONS

Intracranial atherosclerosis demonstrated a possible correlation with central atrophy.
Diagnosis of Lacunar Infarcts within 6 Hours of Onset by Clinical and CT Criteria Versus MRI
Authors: Rajajee Venkatakrishna , Kidwell Chelsea , Starkman Sidney , Ovbiagele Bruce , Alger Jeffrey , Villablanca Pablo , Saver Jeffrey L. ,   for the UCLA MRI Acute Stroke Investigators
Published: October 2009

BACKGROUND

The diagnosis of small deep infarcts (SDIs) based on clinical and noncontrast CT findings is often employed to triage stroke patients for emergent endovascular interventions. Few studies have evaluated the accuracy of <6 hours presentation with lacunar clinical syndromes in predicting the presence of a SDI and the absence of large vessel occlusion.

METHODS

Consecutive patients were identified with symptoms suggestive of acute stroke, diffusion‐weighted magnetic resonance imaging (DW‐MRI) and CT performed within 6 hours of onset, and absence of hemorrhage on imaging. Patients were given a diagnosis of SDI if they met the defined clinical and CT criteria. Diagnoses of large vessel occlusion absent (LVOA) and final diagnoses of SDI versus non‐SDI incorporated hyperacute multimodal MRI data.

RESULTS

Of 64 patients, 15 were diagnosed as SDI at <6 hours based on clinical/CT criteria. Fourteen of 15 patients (93%) had a final diagnosis of LVOA. Ten of 15 (67%) had a final MR‐DWI‐confirmed diagnosis of SDI. Clinical/CT diagnosis of SDI showed sensitivity of 44%, specificity 97%, positive predictive value (PPV) 93%, and negative predictive value (NPV) of 61% in predicting LVOA and sensitivity 83%, specificity 90%, PPV 67%, and NPV 96% compared to the final diagnosis of SDI. Most patients incorrectly diagnosed with SDIs harbored small cortical branch infarcts.

CONCLUSIONS

Diagnoses of SDI <6 hours from symptom onset based on a classic lacunar syndrome and CT criteria show only modest predictive value in predicting the presence of a small‐vessel territory infarct but perform fairly well in identifying patients without large‐vessel occlusions amenable to endovascular therapy.
Functional Imaging of Working Memory in Parkinson's Disease: Compensations and Deficits
Authors: Marié Rose‐Marie , Lozza Catherine , Chavoix Chantal , Louis Defer Gilles , Baron Jean‐Claude
Published: October 2009

BACKGROUND AND PURPOSE

Over and above typical motor alterations, executive and working memory (WM) impairment can also occur in early idiopathic Parkinson's disease (PD). We aimed to investigate the compensatory neural processes involved in WM performance, as well as the networks involved in the long‐term memory transfer from short‐term stores in PD.

METHODS

Relative cerebral blood flow (rCBF) was mapped with H2O15‐PET in eight treated nondemented PD patients while performing a WM verbal double‐task (Brown‐Peterson paradigm) using both short (6‐second) and long (18‐second) delays.

RESULTS

As compared to nine age‐matched healthy subjects, performance of the PD group was only slightly reduced on the short‐delay but markedly impaired on the long‐delay task. Underlying the relatively preserved short‐delay performance, the PD group exhibited overactivation of prefrontal and parietal areas involved in attention‐demanding processes, suggestive of efficient compensatory processes. Further supporting this, significant positive correlations were found between short‐delay performance and rCBF in the bilateral inferior parietal cortex. In contrast, the lack of overactivation with the long‐delay task together with posterior cingulate hypoactivation would support the idea of functional disconnection impairing transfer of information from prefrontal onto (para)limbic areas. These findings suggest novel areas of investigation into early cognitive impairments in PD.
Diffusion Tensor Tractography‐based Analysis of the Pyramidal Tract in Patients with Amyotrophic Lateral Sclerosis
Authors: Hong Yoon‐Ho , Sung Jung‐Joon , Kim Sung‐Min , Park Kyung‐Seok , Lee Kwang‐Woo , Chang Kee‐Hyun , Song In Chan
Published: October 2009

BACKGROUND AND PURPOSE

We attempted to measure DTI parameters of the brainstem pyramidal tract using two approaches, ie, simple ROI and tract‐specific analyses. Results obtained for healthy subjects and ALS patients were compared.

METHODS

DTI was performed using a single shot SE‐EPI with 25 noncollinear diffusion gradient directions (b= 1000 second/mm2) and with no diffusion gradient on a 3.0‐T MR system in 10 ALS patients and in 8 age‐ and sex‐matched normal controls. To delineate the brainstem pyramidal tract, tractography was performed using two ROIs, ie, a seed ROI at the cerebral peduncle (ROI‐1) and a target ROI at the lower pons (ROI‐2). ROI‐1 was subsequently restricted to voxels that contained streamlines in the tract reconstruction, thus creating a sub‐ROI.

RESULTS

Mean fractional anisotropy (FA) and mean diffusivity values were highly reproducible by tract specific analysis, whereas simple ROI analysis yielded larger variabilities between operators. FA values were significantly lower in ALS patients than in normal controls in the tractography‐derived sub‐ROI (P= .01), but not in the seed or target ROIs.

CONCLUSIONS

These results suggest, compared with simple ROI analysis, that tract‐specific analysis using DTI fiber‐tracking is more reliable and sensitive for detecting upper motor neuron pathology in ALS.
Assessment of Metabolism and Microcirculation of Healthy Skeletal Muscles by Magnetic Resonance and Ultrasound Techniques
Authors: Weber Marc‐André , Krakowski‐Roosen Holger , Hildebrandt Wulf , Schröder Leif , Ionescu Ingrid , Krix Martin , Kinscherf Ralf , Bachert Peter , Kauczor Hans‐Ulrich , Essig Marco
Published: October 2009

PURPOSE

To assess metabolism and microcirculation of healthy skeletal muscle by magnetic resonance (MR) and ultrasound techniques and to compare these data with muscle histology, and anthropometric and blood parameters.

METHODS

Thirty‐four healthy volunteers were selected such that their measured aerobic capacity (VO2max) per body weight ranged between 23 and 66 mL/minute/kg to render a large variability of skeletal muscle capillarization as a result of their different physical activity. We analyzed body composition, blood parameters, and skeletal muscle fiber size and capillarization in biopsies of the vastus lateralis muscle. These data were compared with knee extensor cross‐sectional area (CSA) obtained by MR imaging, microcirculation of the vastus lateralis muscle by contrast‐enhanced ultrasound (CEUS), and its energy and lipid metabolism measured with 31P and 1H MR spectroscopy. Statistical analysis was performed using Pearson's correlation coefficient and significance was tested at a level of .5%.

RESULTS

The variable physical activity was reflected in a large variability of vastus lateralis muscle perfusion and metabolism at rest with highest histologic capillarization and CEUS‐perfusion values observed in the best‐trained volunteers. Levels of high‐energy phosphates, such as phosphocreatine, were positively correlated with CSA (r= .5) and histologic fiber size (r= .6 for type IIA and IIX fibers), while phosphocreatine concentration was significantly negatively correlated to myocellular lipids (r=−.6) and trimethyl ammonium containing compounds (r=−.8). Local blood volume measured in vivo with CEUS was positively correlated with several histologic capillarization parameters.

CONCLUSIONS

Dedicated MR‐ and CEUS‐methods deliver (patho‐)physiologic information about capillarization and fiber characteristics of skeletal muscles in vivo and hence establish a useful diagnostic tool for muscular diseases.
MR Imaging after Hip and Knee Replacement
Authors: Koch Sebastian , Forteza Alejandro , Lavernia Carlos , Romano Jose G. , Campo Nelly , Bhatia Rita , Campo‐Bustillo Iszet
Published: October 2009

BACKGROUND

Diffusion‐weighted (DW) imaging abnormalities often develop in patients after invasive procedures associated with cerebral microembolism. Cerebral microembolism has recently been shown during orthopedic surgery. We here examine the effects of intraoperative microembolism on acute magnetic resonance(MR) imaging in patients undergoing hip and knee replacement.

METHODS

We enrolled 24 patients, at least 65 years old, requiring elective knee or hip replacement surgery. MR with DW and axial fluid‐attenuated inversion recovery (FLAIR) imaging was performed pre‐ and postoperatively. All patients were monitored intraoperatively for microemboli.

RESULTS

The mean age of patients was 74 years. All patients had intraoperative microemboli. The mean number of emboli detected was 9.9 ± 18 per surgery. MR imaging was obtained a mean of 3.5 days postoperatively. No DW imaging abnormalities were found after surgery. One patient had new findings on postoperative FLAIR imaging.

CONCLUSION

Intraoperative microembolism occurred universally, but did not lead to acute DW imaging abnormalities following knee and hip replacement. Acute imaging abnormalities on FLAIR imaging are rare but may occasionally occur after joint surgery.
Intracranial Artery Calcification: A Newly Identified Risk Factor of Ischemic Stroke
Authors: Chen Xiang‐yan , Lam Wynnie Wai Man , Ng Ho Keung , Fan Yu‐hua , Wong Ka Sing
Published: October 2009

BACKGROUND AND PURPOSE

Calcification in cerebral arteries is understudied, although frequently observed on computed tomography of the brain (CT brain). We aimed to assess the incidence of intracranial artery calcification in ischemic stroke patients and to evaluate its correlation with ischemic stroke.

METHODS

Our study included ischemic stroke patients and age‐gender‐matched nonischemic stroke patients referred for CT brain.

RESULTS

One hundred and seventy‐five ischemic stroke patients and 182 controls were enrolled. The highest prevalence of calcification was seen in intracranial internal carotid artery (IICA) (80.4%), and less commonly in the vertebral artery (35.6%). There was a higher prevalence of intracranial artery calcification in ischemic stroke patients than controls (92.6% vs. 76.4%, P < .001). Hypertension (OR = 2.056, 95% CI: 1.129 ∼ 3.745), diabetes (OR = 2.483, 95% CI: 1.233 ∼ 5.001), smoking (OR = 2.844, 95% CI: 1.542 ∼ 5.243), intracranial artery calcification (OR = 3.172, 95% CI: 1.252 ∼ 8.036), hyperlipidemia (OR = 6.714, 95% CI: 3.302 ∼ 13.650), and atrial fibrillation (OR = 7.941, 95% CI: 2.790 ∼ 22.599) were found to be independently associated with ischemic stroke.

CONCLUSIONS

We demonstrated a higher incidence of intracranial artery calcification in ischemic stroke patients. Besides traditional risk factors, intracranial artery calcification was found to be an independent risk factor of ischemic stroke.
Computed Tomographic Angiography as the Primary Diagnostic Study in Spontaneous Subarachnoid Hemorrhage
Authors: Nijjar Satnam , Patel Bijal , McGinn Greg , West Michael
Published: October 2009

PURPOSE

To evaluate the utility of computed tomographic angiography (CTA) as the primary diagnostic investigation in patients with spontaneous subarachnoid hemorrhage (SAH), and to correlate the results with intraoperative findings in those with ruptured aneurysms.

MATERIALS AND METHODS

A retrospective review of 243 patients with spontaneous SAH was performed. The patients selected were those with acute SAH confirmed by noncontrast head computed tomography or by cerebrospinal fluid findings from a lumbar puncture. Patients subsequently underwent preoperative three‐dimensional CTA as the sole or primary diagnostic study. The results of the CTA were correlated with the intraoperative findings in those patients undergoing emergent surgical clipping of acutely ruptured intracranial aneurysms.

RESULTS

CTA correctly detected the ruptured aneurysm in 170 of the 171 cases, which required surgical clipping. Our data demonstrates that CTA has a 99.4% detection rate in acutely ruptured aneurysms as compared to intraoperative findings [confidence interval 97.8‐99.9%].

CONCLUSION

CTA can provide prompt and accurate diagnostic and anatomic information in the setting of SAH with an excellent detection rate in acute ruptured aneurysms. These findings suggest an increased role for CTA in the evaluation of cerebral aneurysms.
Neuroimaging in Stroke and Seizure As Neurological Emergencies (NISSAN) Study
Authors: Rodriguez Gustavo J. , Nasar Abu , Suri M. Fareed K. , Ezzeddine Mustapha A. , Qureshi Adnan I.
Published: October 2009

OBJECTIVE

To report the current national utilization of neuroimaging in the emergency department for the two most common neurological emergencies; stroke and seizure.

METHODS

Patients were identified using primary International Classification of Diseases (ICD)‐9‐CM codes from the 2004 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is designed to collect data on the utilization and provision of care in emergency departments of hospitals in the United States. We analyzed the use of neuroimaging in patients presenting to the emergency department with seizure or stroke.

RESULTS

About 60% of 1,190,219 patients with the diagnosis of stroke or seizure had neuroimaging performed emergently. Patients with any type of stroke were more likely to undergo neuroimaging compared to patients with seizure (78% vs. 37%, P < .05). When stroke subtypes were analyzed separately, neuroimaging was performed in the emergency department among 100% of patients with subarachnoid hemorrhage, 79% with ischemic stroke, and 69% with intracerebral hemorrhage.

CONCLUSIONS

In a nationally representative study, emergent neuroimaging appeared to be underutilized among patients with ischemic stroke and intracerebral hemorrhage. There is a need to increase the utilization of neuroimaging in the emergency department in anticipation of new acute stroke treatments.
Intracranial Atherosclerotic Disease: Medical, Biomechanical, Imaging, and Flow Dynamics Perspective
Authors: Suri M. Fareed K. , Divani Afshin A. , Hoffmann Kenneth R. , Qureshi Adnan I.
Published: October 2009

INTRODUCTION

Intracranial stenosis is one of the most common disease entities encountered by neurointerventionists. The physical and hemodynamic properties of the lesion are determined by the experience of the clinician. Computerized analysis may provide more accurate values of these parameters which can be used during the procedure for improving patient care.

MATERIALS AND METHODS

We present a case of a 55‐year‐old man who was having ischemic symptoms related to severe middle cerebral artery stenosis. Intralesional stent placement normalized the diameter of the vessel leading to cessation of the episodes of neurological events.

DISCUSSION

Discussants include a neurointerventionist, a neurovascular image analyst, and a neurovascular flow and hemodynamic analyst. Questions discussed included qualitative and quantitative analysis of stenosis; comparison of angiographic perfusion studies including analysis of delay in opacification, transit times and time density curves; role of automation in analysis of “emboli tolerance” and “no re‐flow” phenomenon; and relationship of compliance and recoil in normal and diseased segments of a vessel during angioplasty or stent placement.
Functional MRI in Malformations of Cortical Development: Activation of Dysplastic Tissue and Functional Reorganization
Authors: Vitali Paolo , Minati Ludovico , D'Incerti Ludovico , Maccagnano Elio , Mavilio Nicola , Capello Dario , Dylgjeri Suela , Rodriguez Guido , Franceschetti Silvana , Spreafico Roberto , Villani Flavio
Published: October 2009

BACKGROUND AND PURPOSE

Functional neuroimaging and electrophysiological studies suggest that dysplastic neural tissue in malformations of cortical development may participate in task performance, and that functional organization can be altered beyond visible lesion boundaries. The aim of this work was to investigate cortical function in a heterogeneous group of patients with malformations of cortical development.

METHODS

Twelve patients participated in the study, 2 for each of the following categories: subcortical, periventricular, and band heterotopia, unilateral and bilateral polymicrogyria, and focal cortical dysplasia. Functional magnetic resonance imaging was performed with finger tapping, somatosensory and visual stimulation, and language‐related tasks.

RESULTS

We found activations within the dysplastic tissue in subcortical heterotopia, band heterotopia, and polymicrogyria, but not in periventricular heterotopic nodules. In one of the patients with focal cortical dysplasia, language‐related activation involved part of the lesion. Functional reorganization beyond visible lesion boundaries was seen, with different patterns, in 4 patients.

CONCLUSIONS

In accordance with previous reports, our findings indicate that dysplastic neural tissue can be activated during task performance, and that in some patients, extensive functional reorganization occurs, highlighting the importance of functional magnetic resonance imaging in presurgical planning in those patients for whom epilepsy surgery is considered as an option.
Retrieval of a Displaced Detachable Coil and Intracranial Stent with an L5 Merci Retriever During Endovascular Embolization of an Intracranial Aneurysm
Authors: Vora Nirav , Thomas Ajith , Germanwala Anand , Jovin Tudor , Horowitz Michael
Published: October 2009

Coil displacement during endovascular embolization of an intracranial aneurysm can result in significant thromboembolic complications. To avoid this problem, microsnares and other techniques have been developed to retrieve a lost foreign body in the cerebral circulation. The Merci Retriever (Concentric Medical, Inc., Mountain View, CA) is an FDA‐approved device for clot removal in the intracranial vessels. Modifications to its original design have enhanced this device not only for embolectomy but also for intravascular foreign body retrieval. To our review, we report the first use of an L5 Merci Retriever to evacuate a displaced detachable endovascular coil and intracranial stent during aneurysm treatment.
Prenatal Thrombosis of Torcular Herophili with Spontaneous Resolution and Normal Outcome
Authors: Grigoriadis Savvas , Cohen Jose E. , Gomori John Moshe
Published: October 2009

BACKGROUND

Prenatal thrombosis of torcular Herophili is a rare condition. It may be suspected during the routine ultrasonographic follow‐up of the fetus, but MRI is necessary to establish the diagnosis. There are 7 reported cases with various results.

METHODS

We report a case of prenatal torcular Herophili thrombosis. We present 2 series of fetal MRIs. The first one was performed at 21 and the second at 37 weeks' gestation.

RESULTS

The second MRI revealed a total resolution of the thrombus. The product was a neurologically intact infant with normal development.

CONCLUSIONS

This is the fourth reported case of fetal torcular Herophili thrombosis with normal outcome. There are no sufficient data regarding the best management of this rare condition; however, following up with fetal MRIs seems to be the most rational choice.
Neurogenic Bladder Due to Hypoxic‐Ischemic Demyelination
Authors: Ramchandren Sindhu , Liebeskind David S.
Published: October 2009

BACKGROUND AND PURPOSE

Hypoxia is commonly known to target neuronal cell bodies. Although myelin is a non‐infrequent target, posthypoxic demyelination is a rarely described entity. We describe the case of a man who developed neurogenic bladder following a motor vehicle accident.

CASE REPORT

Following a severe motor‐vehicle accident involving massive blood loss, a 46‐year‐old man developed urinary urgency requiring catheterization, with hyperactive reflexes and bilateral Babinski signs on exam.

RESULTS

Magnetic resonance imaging of the brain and cervical cord revealed diffuse, isolated white matter signal abnormality in a symmetric, confluent distribution, extending inferiorly into the spinal cord, with changes consistent with bilateral Wallerian degeneration. Serologic and CSF evaluations were normal.

CONCLUSIONS

Unlike previous reports of hypoxic‐ischemic demyelination, our patient lacked any cortical abnormalities, presumably due to isolated white matter changes. This report alerts physicians to the possibility of hypoxic‐ischemic demyelination due to global hypoxia‐ischemia as an etiologic factor for neurogenic bladder.
Association of Pretreatment ASPECTS Scores with tPA‐Induced Arterial Recanalization in Acute Middle Cerebral Artery Occlusion
Authors: Tsivgoulis Georgios , Saqqur Maher , Sharma Vijay K. , Lao Annabelle Y. , Hoover Steven L. , Alexandrov Andrei V. ,   for the CLOTBUST Investigators
Published: October 2009

BACKGROUND AND PURPOSE

The Alberta Stroke Program Early CT‐Score (ASPECTS) assesses early ischemic changes within the middle cerebral artery (MCA) and predicts poor outcome and increased risk for thrombolysis‐related symptomatic ICH. We evaluated the potential relationship between pretreatment ASPECTS and tPA‐induced recanalization in patients with MCA occlusions.

SUBJECTS & METHODS

Consecutive patients with acute ischemic stroke due to MCA occlusion were treated with standard IV‐tPA and assessed with transcranial Doppler (TCD) for arterial recanalization. Early recanalization was determined with previously validated Thrombolysis in Brain Ischemia (TIBI) flow‐grading system at 120 minutes after tPA‐bolus. All pretreatment CT‐scans were prospectively scored by trained investigators blinded to TCD findings. Functional outcome at 3 months was evaluated using the modified Rankin Scale (mRS).

RESULTS

IV‐tPA was administered in 192 patients (mean age 68 ± 14 years, median NIHSS‐score 17). Patients with complete recanalization (n= 51) had higher median pretreatment ASPECTS (10, interquartile range 2) than patients with incomplete or absent recanalization (n= 141; median ASPECTS 9, interquartile range 3, P= .034 Mann‐Whitney U‐test). An ASPECTS ≤6 was documented in 4% and 17% of patients with present and absent recanalization, respectively (P= .019). Pretreatment ASPECTS was associated with complete recanalization (OR per 1‐point increase: 1.54; 95% CI 1.06–2.22, P= .023) after adjustment for baseline characteristics, risk factors, NIHSS‐score, pretreatment TIBI grades and site of arterial occlusion on baseline TCD. Complete recanalization (OR: 33.97, 95% CI 5.95–185.99, P < .001) and higher ASPECTS (OR per 1‐point increase: 1.91; 95% CI 1.17–3.14, P= .010) were independent predictors of good functional outcome (mRS 0–2).

CONCLUSIONS

Higher pretreatment ASPECT‐scores are associated with a greater chance of complete recanalization and favorable long‐term outcome in tPA‐treated patients with acute MCA occlusion.
Quantitative Magnetic Resonance Angiography of the Cerebrovasculature in Physiologic and Pathologic States
Authors: Conway Stafford A. , Bowling Susana M. , Geyer James D. , Potts Daniel C. , Clemons Brett L. , Gomez Camilo R.
Published: October 2009

BACKGROUND

In the past, clinical decisions regarding treatment of neurovascular disorders leading to ischemia have been guided by the percentage of stenosis of the vessel in question. However, such an approach assumes a predictable and stable relationship between the percentage of stenosis and the degree of flow reduction it causes. Historically, this type of relationship has been difficult to document. Thus, a method for noninvasively measuring the absolute flow of specific cerebral arteries is of potential practical value.

METHODS

We set to quantify the mean blood flow (Qm, in mL/min) in the cerebral arteries using quantitative magnetic resonance angiography (QMRA), and to compare the findings in normal vessels with those found in vessels considered pathologically narrowed. Specific vascular segments were identified, studied, and the results entered into a database. Statistical analyses of the measurements were carried out using StatPlus for Microsoft Excel. It involved comparing of the Qm found in specific vessels, as well as those found in normal and abnormal vessels, using analysis of variance (ANOVA). The abnormal vessels were selected from specifically identified magnetic resonance angiography (MRA) studies.

RESULTS

A total of 57 patients, 26 men and 31 women, with ages ranging from 19 to 86 years (mean = 64.5), underwent MRA with subsequent QMRA of 157 arteries. The latter included 72 internal carotid (ICA), 45 vertebral (VA), 18 common carotid (CCA), 13 middle cerebral (MCA), and nine basilar (BA) arteries. The mean Qm obtained were CCA = 313.9 (±115.4), ICA = 231.1 (±83.7), VA = 90.5 (±45.8), MCA = 92.5 (±62.3) and BA = 120.1 (±64.5). ANOVA showed significant differences between individual vessels (P < .00001). The values obtained were consistent with those predicted mathematically, as derivatives of their proportional contributions to overall cerebral arterial flow (Qbrain) as a product of the normal cardiac output (CO) [ie, Qbrain = CO*.2]. Further ANOVA of the normal and abnormal vessels showed statistically significant differences between the two groups (186.5 ± 108.6 vs. 117.9 ± 76.1, respectively; P= .000514).

CONCLUSIONS

The use of QMRA provides the mean for direct measurement of absolute blood flow within the cerebral arteries in physiologic and pathologic states. This technique may be of future importance in characterizing absolute flow compromise in the cerebral arteries under a variety of clinically relevant circumstances.
Ultrasonic Radio‐Frequency Spectrum Analysis Differentiates Normal and Edematous Brain Tissue from Meningioma Intraoperatively
Authors: Strowitzki Martin , Brand Sebastian , Ketter Ralf , Steudel Wolf Ingo , Jenderka Klaus‐Vitold
Published: October 2009

Intraoperative ultrasound imaging of the brain is used for tumor localization and resection control. The aim of the present study was to prove whether spectral analysis of radio‐frequency (rf) signals is able to improve its diagnostic capabilities by adding quantitative acoustical parameters to pure visual analysis. Meningioma was chosen as a first model because of its distinct borders during surgery as well as in ultrasound imaging. Rf signals were captured intraoperatively. Spectral analysis of rf signals was performed off‐line in areas of normal brain, edematous tissue, and meningioma within the bandwidth of the transducer. At 5.0 MHz, attenuation allowed significant differentiation for normal brain versus edema (P= .00002), normal brain versus meningioma (P= .000004), and edema versus meningioma (P= .002). The slope of attenuation reached significant levels among the three groups, too. Backscatter analysis consisted of determination of the power spectral density with a significant difference for edema versus meningioma at 5 MHz (P= .02). The same was true for a relative integrated backscatter coefficient (P= .01). Frequency‐dependent backscatter coefficients were estimated using a standard phantom with edema showing the highest values followed by parenchyma and meningioma. Spectral analysis of rf signals has the potential of differentiating intracranial tissues as could be shown exemplarily with meningioma in this study. If this is also true for infiltrating tumors, the method might serve as a tool to better define tumor borders, thus improving the extent of resection.
Identification of the Sensorimotor Cortex with Functional MRI: Frequency and Actual Contribution in a Neurosurgical Context
Authors: Pujol Jesus , Deus Joan , Acebes Juan J. , Villanueva Alicia , Aparicio Alberto , Soriano‐Mas Carles , Ortiz Hector , Conesa Gerardo
Published: October 2009

BACKGROUND AND PURPOSE

We assessed the actual frequency of motor functional MRI (fMRI) in a neurosurgical environment and estimated the extent to which it aided surgeons' identifications of the sensorimotor cortex.

METHODS

During five consecutive years, an fMRI protocol aimed at generating a selective activation of the hand cortical area was prescribed to 147 patients showing a centrally located space‐occupying lesion, which represents 6.7% of all assisted surgical candidates showing an intracranial mass. Three senior neurosurgeons indicated the position of the sensorimotor cortex on two different anatomical displays, reporting confidence ratings for each decision.

RESULTS

The sensorimotor cortex could not be identified in 16.5% of cases using conventional anatomical MRI, and in 15% of cases using 3‐dimensional reconstructions. In an additional 12.5% of cases, the neurosurgeons were not confident when they correctly identified the sensorimotor cortex. The tumor distorting effect on central region anatomy significantly contributed to sensorimotor cortex misidentification. fMRI, by contrast, showed a selective activation indicating the position of the sensorimotor cortex in all but 4% of cases.

CONCLUSIONS

In our neurosurgical environment, fMRI was prescribed to a selected group of surgical candidates showing a centrally located brain lesion. Compared to conventional anatomical imaging, fMRI does appear to improve the identification of sensorimotor cortex.
Rotational Vertebrobasilar Insufficiency Due to Dynamic Compression of the Dominant Vertebral Artery by the Thyroid Cartilage and Occlusion of the Contralateral Vertebral Artery at C1–2 Level
Authors: Dabus Guilherme , Gerstle Ronald J. , Parsons Matthew , Cross DeWitte T. , Moran Christopher J. , Thompson Robert , Derdeyn Colin P.
Published: October 2009

BACKGROUND

Vertebrobasilar insufficiency caused by head rotation is an uncommon event. The mechanism is obstruction of the vertebral artery resulting in flow limitation or, less frequently, thromboembolism.

CASE DESCRIPTION

A 41‐year‐old male developed dizziness and light‐headedness during chiropractic manipulation when his head was turned to the extreme right position. Computed tomography angiography (CTA) of the neck and selective digital subtraction angiography (DSA) of the vertebral arteries revealed that when the patient turned his head to the extreme right position the dominant right vertebral artery was compressed between the posterior aspect of the thyroid cartilage and anterior aspect of the right transverse process of C6 resulting in focal stenosis, while the left vertebral artery is severely compressed with significant flow limitation at the level of C1–2. Because the patient was healthy and asymptomatic, conservative management was adopted. At the 9‐month follow‐up visit the patient was asymptomatic and able to compensate for his problem avoiding turning his head to the extreme right position.

CONCLUSIONS

We present an uncommon case of rotational vertebrobasilar insufficiency (VBI) where the dominant vertebral artery has an anomalous course compressed by the thyroid cartilage at C6 level, associated with contralateral vertebral artery rotational stenosis at C1–2. The patient was successfully managed conservatively.
Early Spontaneous Recanalization Following Acute Carotid Occlusion
Authors: Szabo Kristina , Kern Rolf , Gass Achim , Griebe Martin , Lanczik Oliver , Daffertshofer Michael , Hennerici Michael G.
Published: October 2009

BACKGROUND AND PURPOSE

Occlusion of the internal carotid artery (ICA) and stroke may be the consequence of either local thrombosis due to atherosclerosis or massive embolism. Up to date, there are only few reports of subsequent recanalization.

METHODS

We report 12/76 cases of acute ICA occlusion leading to ischemic stroke, in which early recanalization was identified. Ultrasound and stroke MRI findings, therapeutic options, and outcome are described.

RESULTS

10/12 patients showed an‐ or hypoechogenic morphology of occlusion. While in 7/12 cases complete recanalization was seen, in 5/12 patients partial recanalization with filiform flow (4) or residual high‐grade stenosis (1) was detected. 10/12 patients had territorial or subcortical infarction, while two showed small cortical lesions only. In 7/12 cases, a potential cardiac source of embolism was found. Five patients received tPA; four patients underwent early carotid endarterectomy of the partially recanalized ICA within 48 hours. In the 10‐day follow‐up examination 10/12 patients showed clinical improvement as measured by the NIHSS.

CONCLUSIONS

Spontaneous recanalization after occlusion of the ICA may occur and might be more frequent than hitherto assumed. Echogenicity analysis and serial examinations of symptomatic ICA occlusion is useful for identifying a patient subgroup that might benefit from further therapy.
Functional Imaging of Stroke Recovery: An Ecological Review from a Neural Network Perspective with an Emphasis on Motor Systems
Authors: Erik Ween Jon
Published: October 2009

Functional imaging is beginning to outline the brain's functional architecture and mechanisms of recovery from injury. I will review primarily the motor‐function literature from normal populations, learning trials, stroke recovery, and rehabilitation with a neural network approach that may prove fruitful in further advancing our understanding of brain plasticity in response to focal lesions. A key consideration in this review will be how the development of distributed motor networks might constrain recovery as a function of the altered connectivity between damaged and nondamaged areas. It will be argued that this connectivity is central to both recovery from injury and response to treatment.
Clinical‐Sonographic Index (CSI): A Novel Transcranial Doppler Diagnostic Model for Middle Cerebral Artery Stenosis
Authors: Jung Keun‐Hwa , Lee Yong‐Seok
Published: October 2009

BACKGROUND

Transcranial Doppler sonography is useful for the diagnosis of middle cerebral artery (MCA) stenosis. Although the previous studies have focused on the elevated mean flow velocity (MFV) or asymmetry of MFV, the lack of clinical correlation might limit diagnostic accuracy. We try to develop and validate a new diagnostic model including more comprehensive clinical and sonographic parameters.

METHODS

Consecutive patients with magnetic resonance angiography (MRA)‐verified MCA stenosis were included, and compared with control subjects with normal MCA. The age, sex, corresponding symptoms (CS) to sonographic side, diabetes mellitus (DM), and hypertension were included for analysis. As sonographic parameters, MFV (cm/sec), asymmetry index (AI,%), and difference of pulsatility index (ΔPI) were analyzed. Clinical‐sonographic index (CSI) model was built with significant parameters by multivariate logistic regression analysis.

RESULTS

One hundred and seven patients (

M:F = 53:54
, age: 61.6 ± 11.6 years), and 100 control subjects (M:F = 49:51, age: 54.9 ± 14.5 years) were included. In logistic regression, MFV (odds ratio [OR], 1.057; 95% confidence interval [95% CI], 1.030–1.084), AI (OR, 1.067; 95% CI, 1.031–1.104), ΔPI (OR, 41.754; 95% CI, 2.771–626.999), CS (OR, 15.904; 95% CI, 5.055–50.042), and DM (OR, 3.949; 95% CI, 1.132–13.783) were independent predictors of MCA stenosis. CSI was simplified for clinical use, CSI = MFV(cm/sec) + 3 * AI (%) + 180 *ΔPI + 90 * CS(presence = 1, absence = 0) + 30 * DM (presence = 1, absence = 0). The area under the receiver operator characteristic (ROC) curve of MCA stenosis versus MFV, ΔPI, AI, and CSI was .641, .668, .865 and .953. According to ROC curve, cut‐off point for MCA stenosis was suggested as CSI > 180 (sensitivity: 87%, specificity: 92%).

CONCLUSION

CSI might be useful to enhance diagnostic accuracy.
Dual Origin Extracranial Vertebral Artery: Case Report and Embryology
Authors: Thomas Ajith J. , Germanwala Anand V. , Vora Nirav , Prevedello Daniel M. , Jovin Tudor , Kassam Amin , Horowitz Michael
Published: October 2009

Duplication of the vertebral artery origin is a rare vascular anomaly. The authors describe this finding in a patient who underwent neurointerventional treatment for a midbasilar aneurysm. The embryology and clinical significance is also presented.
Cerebral Changes in SLE With or Without Antiphospholipid Syndrome. A Case‐Control MRI Study
Authors: Valdés‐Ferrer Sergio I. , Vega Felipe , Cantú‐Brito Carlos , Ceballos‐Ceballos Joel , Estañol Bruno , García‐Ramos Gullermo , Cabral Antonio R.
Published: October 2009

BACKGROUND

To determine and characterize the prevalence of cerebral changes on MRI in patients with antiphospholipid syndrome (APLS) within systemic lupus erythematosus (SLE).

METHODS

Seventy‐one patients with SLE were prospectively studied with brain MRI: 32 with definite APLS and 39 without. Atrophy, ventricular enlargement, leukoaraiosis, interuncal distance, Evans' index, infarcts, and white matter hyperintensities (WMH) were analyzed. Demographic data, treatment, and SLE activity were analyzed.

RESULTS

Groups were similar in age (32.4 vs. 32.8 years old; P= non‐significant [NS]), and gender. Duration of disease was longer in patients with APLS (87.3 vs. 55.4 months; P= .064). Cortical atrophy was common in both groups (68.7% vs. 89.7%; P= NS). Leukoaraiosis was present in only 3 patients (9.4%; P= .08), all in the APLS group. WMH were found in more than 40% of the patients from both groups. Infarcts (21.9% vs. 2.6%; P= .019) and infarcts plus WHM (12.5% vs. 0; P= .037) were more common in patients with APLS.

CONCLUSIONS

Although a higher prevalence of neurological involvement in SLE has been reported in APLS patients, we found gross brain changes to be similar between groups. Strokes and leukoaraiosis were more common in the APLS group, consistent with the idea of an APLS‐induced prothrombotic state.
Postprocedure Intravenous Eptifibatide Following Intra‐Arterial Reteplase in Patients with Acute Ischemic Stroke
Authors: Qureshi Adnan I. , Hussein Haitham M. , Janjua Nazli , Harris‐Lane Pansy , Ezzeddine Mustapha A.
Published: October 2009

BACKGROUND AND PURPOSE

Early use of intravenous platelet glycoprotein IIB/IIIA antagonists after intra‐arterial (IA) thrombolysis may reduce the risk of reocclusion and microvascular compromise.

METHODS

We performed a retrospective study to determine the in‐hospital outcomes using serial neurological evaluations and imaging among patients treated with intravenous eptifibatide administered as a 135 microg/kg single‐dose bolus, followed by 0.5 microg/kg/min infusions for 20 to 24 hours following treatment with IA reteplase.

RESULTS

Twenty patients were treated (mean age ± standard deviation, 68.4 ± 14.5 years; median National Institutes of Health Stroke Scale [NIHSS] score was 17). The dose of reteplase ranged from 0.5 to 4 units. Eleven patients demonstrated early neurological improvement, defined as a decline of ≥4 points on the 24 hours NIHSS score compared with initial NIHSS score; neurological deterioration, defined as an increase of ≥4 points on the 24 hours NIHSS score as compared with initial NIHSS score, was observed in one patient. Two asymptomatic intracerebral hemorrhages were observed while no symptomatic hemorrhages were observed on serial computed tomographic scans.

CONCLUSIONS

The use of intravenous eptifibatide within 24 hours in selected patients after IA thrombolysis is feasible and safe. Further studies are required to determine the benefit of early use of intravenous eptifibatide following thrombolysis.