bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuroimaging of Focal Cortical Dysplasia
Authors: Widdess‐Walsh Peter , Diehl Beate , Najm Imad 
Published: October 2009

ABSTRACTFocal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy that is amenable to surgical resective treatment. The identification of structural FCD by magnetic resonance imaging (MRI) can contribute to the detection of the epileptogenic zone and improve the outcome of epilepsy surgery. MR epilepsy protocols that include specific T1 and T2 weighted, and fluid‐attenuated inversion recovery (FLAIR) sequences give complementary information about the characteristic imaging features of FCD; focal cortical thickening, blurring of the gray‐white junction, high FLAIR signal, and gyral anatomical abnormalities. Novel imaging techniques such as magnetic resonance spectroscopy (MRS), magnetization transfer imaging (MTI), and diffusion tensor imaging (DTI) can improve the sensitivity of MR to localize the anatomical lesion. Functional/metabolic techniques such as positron emission tomography (PET), ictal subtraction single photon emission computed tomography (SPECT), functional MRI (fMRI), and magnetic source imaging (MSI) have the potential to visualize the metabolic, vascular, and epileptogenic properties of the FCD lesion, respectively. Identification of eloquent areas of cortex, to assist in the surgical resection plan, can be obtained non‐invasively through the use of fMRI and MSI. Although a significant number of FCD lesions remain unidentified using current neuroimaging techniques, future advances should result in the identification of an increasing number of these cortical malformations.
Topographic Patterns of Small Subcortical Infarcts Associated with MCA Stenosis: A Diffusion‐Weighted MRI Study
Authors: Wang Xin , Lam Wynnie W. M. , Fan Yu Hua , Graham Colin A. , Rainer Timothy H. , Wong Ka Sing 
Published: October 2009

ABSTRACT Background and Purpose. Small subcortical infarcts (SSI, maximum lesion diameter ≤2.0 cm) are usually considered as infarcts caused by small vessel disease. However, SSI can also be associated with large artery occlusive disease such as middle cerebral artery (MCA) stenosis. We performed a prospective study to investigate the relationship between MCA stenosis and SSI distribution and further to investigate the mechanism of SSI caused by MCA stenosis. Methods. Magnetic resonance angiography (MRA) and diffusion‐weighed MRI (DWI) of consecutive acute ischemic stroke patients with recent SSI were studied. The distribution of acute infarcts on DWI was categorized as cortical infarct (CI), border zone infarct (BI), or perforating artery infarct (PAI). Results. Totally, 93 cases were recruited, among which 12 had single SSI with MCA stenosis (group 1) and 26 patients had multiple SSI with MCA stenosis (group 2), while 55 patients without MCA stenosis had single SSI (group 3). For patients with single SSI and MCA stenosis, 6 had BI and 6 had PAI; for patients with multiple SSI and MCA stenosis, 25 had BI, 4 had PAI and 9 had CI (compared with group1: P= .001); for patients with single SSI but without MCA stenosis, 20 had BI and 35 had PAI (compared with group1: P= .58). Conclusion. Multiple acute infarcts along the border zone are the commonest pattern in small infarcts with MCA stenosis, especially among those with multiple acute infarcts. Our data suggest that hemodynamic compromise and artery‐to‐artery embolism may be both important factors for infarcts in patients with MCA stenosis.
Functional Brain Reorganization in Multiple Sclerosis: Evidence from fMRI Studies
Authors: Pantano Patrizia , Mainero Caterina , Caramia Francesca 
Published: October 2009

ABSTRACTIn patients with multiple sclerosis (MS), the severity of clinical signs is not closely related to indices of structural brain damage provided by conventional magnetic resonance MR. Accordingly, patients with MS may show symptom recovery while progressively accumulating tissue damage.Changes in functional organization of the cerebral cortex have been reported in functional magnetic resonance (fMRI) studies that have compared the activation patterns during motor, visual, and cognitive tasks of patients with MS with those of healthy controls.fMRI studies on MS have provided the results that are difficult to compare and may be discrepant because of differences in the criteria used for patient selection, the activation paradigm, the experimental design, and the MR acquisition parameters. Nevertheless, they do provide a new, interesting tool that sheds light on how the brain changes its functional organization in response to MS.In patients with MS, functional brain reorganization mainly consists of an increase in the extent of activation of the brain areas used by healthy subjects, as well as the recruitment of additional brain areas. These findings have been interpreted as adaptive or compensatory mechanisms that allow normal performance despite neural damage or loss. However, brain functional activity may also change in response to clinical disability, though the precise role of brain functional changes in MS has yet to fully undersand. Longitudinal studies designed to explore the effects of both rehabilitation and pharmacological agents on brain plasticity might shed light on this issue.
Relationship Between Cerebral Vasomotor Reactivity and White Matter Lesions in Elderly Subjects Without Large Artery Occlusive Disease
Authors: Fu Jian Hui , Lu Chuan Zhen , Hong Zhen , Dong Qiang , Ding Ding , Wong Ka Sing 
Published: October 2009

ABSTRACT Background and Purpose. The relationships between cerebral vasomotor reactivity (CVR) and white matter lesions (WMLs) were investigated mainly in patients with carotid stenosis. We aimed to study the relationship in asymptomatic elderly subjects without large artery occlusive disease. Methods. A total of 33 elderly individuals (mean age was 76.2 years) who were free from neurological deficit or cognitive impairment were studied. Bilateral mean blood flow velocity was measured in the middle cerebral artery using a 2‐MHz pulsed transcranial Doppler (TCD) system together with intravenous administration of acetazolamide as vasodilatory stimuli. WMLs on a fluid‐attenuated inversion recovery (FLAIR) sequence of MRI were classified into two categories: subcortical deep white matter hyperintensity (SDWMH) and periventricular hyperintensity (PVH). The lesions in each category were then divided into three grades (grade 0‐I, grade II, grade III) according to the Fazekas scale. Results. CVR was inversely associated with the extent of SDWMH and PVH. The differences in CVR were statistically significant among different severity of WMLs: for SDWMH (70%± 10% in grade 0‐I, 60%± 10% in grade II, and 40%± 10% in grade III, P < .001); for PVH (80%± 10% in grade 0‐I, 60%± 10% in grade II, and 40%± 10% in grade III, P < .001). Conclusions. Impaired CVR is related to the extent of WMLs in asymptomatic elderly individuals without large artery stenosis. The findings in our study suggest that dysfunction of cerebral vascular autoregulation might be an important factor in the development of WMLs in the asymptomatic elderly without large artery occlusive disease.
CT and CT‐Perfusion Findings of Reversible Leukoencephalopathy During Triple‐H Therapy for Symptomatic Subarachnoid Hemorrhage‐Related Vasospasm
Authors: Wartenberg Katja E. , Parra Augusto 
Published: October 2009

ABSTRACT Background: Reversible leukoencephalopathy syndrome (RLS) is an acute neurological syndrome associated with altered mental status and visual disturbances described in patients with sudden elevations in systemic blood pressure and other medical conditions. In this process, neuroimaging studies usually demonstrate diffuse edema involving the subcortical structures of the posterior regions of the brain. Triple H (HHH) therapy is an established treatment for symptomatic vasospasm following subarachnoid hemorrhage (SAH). RLS has not been reported in the scientific literature as a complication of HHH therapy with perfusion computed tomography (CTP) imaging documentation. Case: A 73‐year‐old woman developed iatrogenic RLS during HHH therapy for SAH‐related vasospasm. The computed tomography (CT) revealed bilateral parieto‐occipital hypodensities. The CTP study showed increased cerebral blood volume and blood flow as well as decreased mean transit time in both parietal‐occipital regions, which is compatible with vasogenic edema. Conclusion: The induction of hypertension as part of HHH therapy for SAH‐related cerebral vasospasm may result in RLS. Therefore, it should be considered as a potentially reversible cause in the differential diagnosis of neurological deterioration in SAH patients while on HHH therapy. CTP study can offer an alternative for the assessment of this cerebrovascular syndrome.
Neuroimaging of Tuberculous Myelitis: Analysis of Ten Cases and Review of Literature
Authors: Wasay Mohammad , Arif Hiba , Khealani Bhojo , Ahsan Humera 
Published: October 2009

ABSTRACTWe retrospectively reviewed the clinical and neuroimaging features of 10 patients with tuberculous myelitis. The most common presenting symptoms were fever (70%) and paraplegia (60%). Bladder and bowel symptoms were present in 90% patients. On MRI, the involvement of the cervical/thoracic segment of the spinal cord was most commonly seen (90%). The most consistent finding was hyperintense signals on T2‐weighted MRI. T1‐weighted images showed isointense (n= 5) and hypointense (n= 4) signals in the spinal cord lesions. Post‐contrast enhancement was present in 6 patients, epidural enhancement in 4 patients, and cord swelling in 2 patients.We reviewed more than 250 published cases with the diagnosis of tuberculous myelitis and radiculomyelitis with special attention to MRI findings. It is predominantly a disease of the thoracic spinal cord. Most spinal cord lesions appear as hyperintense on T2 and iso‐ or hypointense on T1‐weighted images. MRI findings in patients with spinal cord tuberculosis have both diagnostic and prognostic significance. Cord atrophy or cavitation and the presence of syrinx on MRI may be associated with poor outcome.
Imaging Cerebral Activity in Recovery from Chronic Traumatic Brain Injury: A Preliminary Report
Authors: Lewis David H. , Bluestone Judith P. , Savina Maryann , Zoller William H. , Meshberg Emily B. , Minoshima Satoshi 
Published: October 2009

ABSTRACTPeople in chronic phase of traumatic brain injury (TBI) are often told that there will be no further recovery in brain function that they are in a “static phase.” Holistic Approach to NeuroDevelopment and Learning Efficiency (HANDLE®), an alternative therapy, aims to improve function by teaching a series of physical and mental activities that clients perform and encouraging changes in lifestyle. Five subjects (3 males) with chronic TBI (at least 3 years since ictus) completed the HANDLE Institute's program and were prospectively evaluated. Each had six regional cerebral blood flow (rCBF) single‐photon emission computed tomography (SPECT) scans over 7 months (scans n= 30). Paired scans were performed with injection of Tc‐99m ECD to image rCBF at rest and during the HANDLE “Crossed Arm Bounce” (CAB) exercise before the program, at 3‐4 months into the program, and at 6‐7 months, after the program had ended. SPECT images were analyzed statistically using Neurostat in which image sets were coregistered and warped into Talaraich atlas for pairwise subtraction between conditions. Group analysis of SPECT showed that CAB activated (increased rCBF) vermis and cerebellar hemispheres in first two paired scans and anterior cingulate and vermis on the final pair. Increased rCBF at rest occurred in cerebellar hemispheres, vermis, and right dorsomedial frontal cortex. These preliminary observations suggest that there may be a role of the hindbrain (vermis and cerebellum) with HANDLE treatment of chronic TBI.
Transcranial Doppler and Carotid Duplex Ultrasonography Findings in Bow Hunter's Syndrome
Authors: Iguchi Yasuyuki , Kimura Kazumi , Shibazaki Kensaku , Iwanaga Takeshi , Ueno Yuji , Inoue Takeshi 
Published: October 2009

ABSTRACTBow hunter's syndrome (BHS) is caused by transient vertebro‐basilar ischemia on head rotation. We report a patient with BHS who was identified from dynamic changes to blood flow velocities in the posterior cerebral, basilar and vertebral arteries using carotid duplex ultrasonography and transcranial Doppler, simultaneously. Neurosonology appears to be useful for diagnosing and evaluating BHS.
Hematoma Size in Deep Intracerebral Hemorrhage and its Correlation with Dot‐Like Hemosiderin Spots on Gradient Echo T2*‐Weighted MRI
Authors: Imaizumi Toshio , Honma Toshimi , Horita Yoshifumi , Kohama Ikuhide , Miyata Kei , Kawamura Maiko , Niwa Jun 
Published: October 2009

ABSTRACT Background and Purpose. Dot‐like low intensity spots (dot‐like hemosiderin spots: dotHSs) on gradient echo T2*‐weighted MRI have been histologically diagnosed to represent old cerebral microbleeds associated with microangiopathies. They have also been correlated to the fragility of small vessels and the tendency to bleed. Therefore, a substantial number of dotHSs might be associated with a large‐sized, deep intracerebral hematoma (ICH). On the other hand, dotHSs may reflect old microbleeds that did not enlarge to symptomatic size. Methods. To investigate how dotHSs are related to the size (maximal diameter) of primary deep ICH, we analyzed the diameter and the number of dotHSs in 151 patients with deep ICH not associated with subarachnoid hemorrhage or intraventricular hemorrhage (75 males and 76 females, age ranged from 37 to 90 [65.7 ± 11.3 years old] who were consecutively admitted to Hakodate Municipal Hospital. The hazard ratio (HR) for a maximal diameter of deep ICH ≤2 cm was estimated, using the number of dotHSs and risk factors for stroke. Results. The number of dotHSs associated with the diameter ≤2 cm was 9.2 ± 11.5, significantly larger than that with the diameter ≥2 cm (4.7 ± 7.0, P= .012). Multivariate analysis revealed that a maximal diameter of deep ICH of ≤2 cm was found in patients with dotHS (HR, 3.7; 95% confidence interval [CI], 1.4‐10.1; P= .009). Conclusion. Though small sample size limited the power of our analyses, these findings suggest that the number of dotHSs may be associated with a small diameter of deep ICH.
Intracranial Angioplasty and Stenting in the Awake Patient
Authors: Abou‐Chebl Alex , Krieger Derk W. , Bajzer Christopher T. , Yadav Jay S. 
Published: October 2009

ABSTRACT Background and Purpose. Endovascular treatment for intracranial atherosclerosis is evolving, but complications remain an issue. Most interventions are performed under general anesthesia, preventing intraprocedural clinical evaluations. We describe our approach to intracranial angioplasty and stenting, using local rather than general anesthesia, and intraprocedural neurological assessment. Methods. We prospectively collected procedural and outcome information on all patients undergoing intracranial angioplasty and stenting. Patients underwent interventions under local anesthesia with mild intravenous sedation or analgesia only if needed. Intraoperative neurological evaluations were performed, and symptomatology was used to guide the interventional technique. Results. Forty‐eight arteries in 40 patients with a mean age of 65.2 years were treated. Thirty‐two anterior and 16 posterior circulation segments were treated. Technical success was achieved in 100% of patients with reduction of the mean pretreatment stenosis from 85 ± 8.6% to 7 ± 10.1%. Stents were deployed in 40 segments; five patients were treated with drug‐eluting stents. The cobalt‐chromium coronary stents were the easiest to deliver. Thirty‐seven patients were treated under local anesthesia and, of those, 61.4% experienced intraprocedural symptoms that led to some alteration of the interventional technique. Headache was the most common symptom, and, when persistent, it heralded the occurrence of subarachnoid hemorrhage. There were seven total neurological complications, but only five (10.5%) led to permanent morbidity (4 strokes) or mortality (1 death). Conclusions. Intracranial angioplasty and stenting can be successfully performed using coronary techniques and equipment including drug‐eluting stents. Local anesthesia permits neurological evaluations and often leads to the adjustment of the interventional technique, potentially making the procedure safer.
Screening for High‐grade Carotid Stenosis Using a Portable Ultrasonography Instrument
Authors: Schminke Ulf , Motsch Lillian , Lien Li‐Ming , Tan Teng‐Yeow , Bond M. Gene , Toole James F. , Tegeler Charles H. 
Published: October 2009

ABSTRACT Background and Purpose. We investigated the diagnostic performance of a brief Power Doppler Imaging (PDI) screening examination for carotid artery stenoses using a newly developed portable instrument. Methods. A highly experienced sonographer screened in total 152 carotid arteries by either continuous wave (cw) Doppler (n= 50) or a lightweight (2.4 kg) portable duplex device (n= 102) in a prospective study of 76 high‐risk patients. The screening protocols included either spectrum analysis and frequency shift measurement in both internal carotid arteries with cw‐Doppler or determination of area and diameter ratios in transverse and longitudinal views of both carotid arteries in B‐mode and with PDI, but without velocity measurement. Both protocols were evaluated against a complete routine duplex ultrasonography examination. Results. According to the complete examination, stenoses were <50% in 73 of 102 (71.6%), 50–75% in 19 of 102 (18.6%), 75–95% in 7 of 102 (6.9%), and occluded in 3 of 102 (2.9%) arteries (PDI cohort), and <50% in 39 of 50 (78%), 50–75% in 8 of 50 (16%), 75–95% in 2 of 50 (4%), and occluded in 1 of 50 (2%) artery (cw‐Doppler cohort). Mean screening time was 8.8 ± 2.5 minute (PDI) and 9.4 ± 2.6 minute (cw‐Doppler). For stenoses >75%, Az values (area under the receiver operating characteristics curve) were 0.897 for area ratios, 0.843 for diameter ratios (PDI protocol) and 1.0 for the cw‐Doppler protocol. Conclusions. The diagnostic performance of the cw‐Doppler protocol was superior to the PDI protocol. Nevertheless, both protocols appear suitable as inexpensive screening strategies to identify subjects with >75% stenosis measured by carotid Doppler ultrasound. However, these preliminary data need further verification.
Functional Imaging of Carotid Atheromatous Plaques
Authors: Warburton Liz , Gillard Jonathan 
Published: October 2009

ABSTRACTAtherosclerotic plaque rupture within the internal carotid artery is an important cause of transient ischemic attack (TIA) and stroke. Conventional imaging techniques such as ultrasound and angiography provide information about the structural consequences of such plaques in terms of luminal stenosis. Most clinical trials of carotid surgery and stenting and based on these imaging methods. Techniques aimed at imaging the biological ‘functional’ status of the plaque are now emerging. Most of these are based on the premise that inflammatory activity is an index of plaque stability. In this article we review potential imaging targets from the known molecular biological pathways of atherosclerosis. Both conventional imaging techniques and the newer methods are discussed. Recent data from position emission tomography (PET) imaging and from the use of superparamagnetic iron oxide particles with magnetic resonance (MR) imaging are shown.
Neuroimaging Findings in Neurosyphilis
Authors: Fadil Halim , Gonzalez‐Toledo Eduardo , Kelley Bradford J. , Kelley Roger E. 
Published: October 2009

ABSTRACTWe report two cases of neurosyphilis with atypical clinical presentations that were compounded by atypical neuroimaging findings. In the first case, MRI brain scan findings were felt to be compatible with mesial temporal sclerosis or herpes simplex encephalitis. The second patient presented with a clinical picture compatible with normal pressure hydrocephalus as well as some degree of ventricular enlargement and prominent periventricular white matter changes by MRI brain scan. He actually underwent ventriculo‐peritoneal shunting prior to determination that he had active syphilitic involvement of the central nervous system. Neurosyphilis, “the great imitator,” is not only capable of mimicking various other neurological disease clinical presentations, it can also mimic neuroimaging features of various other disease processes as well.
Dynamic Vascular Analysis Shows a Hyperemic Flow Pattern in Sickle Cell Disease
Authors: Ausavarungnirun Pornpatr , Sabio Hernan , Kim Jongyeol , Tegeler Charles H. 
Published: October 2009

ABSTRACT Background. By the age of 20 years, 10% of sickle cell disease (SCD) patients have experienced a stroke. It is unclear if SCD stroke is due primarily to hemodynamic effects of intracranial stenosis, or metabolic failure from anemia. Transcranial Doppler ultrasound (TCD) identifies a SCD subgroup with high stroke risk, but high mean flow velocity (MFV) can be due to stenosis or high flow rate, as with metabolic hyperemia of severe anemia. Dynamic Vascular Analysis (DVA; New Health Sciences, Inc., Bethesda, MD) is a new way to analyze TCD data, with potential to separate structural from metabolic causes of high MFV. Methods. Eighty SCD patients, regardless of hemoglobin genotypes, aged 2 to 22 years, without clinical stroke or transient ischemic attack (TIA), who had TCD (1/1/02 to 1/1/04) as part of routine outpatient clinical follow‐up, with both the TCD report and study videotape available, were included. Waveforms were reviewed and marked by protocol, and DVA indices calculated including MFV, pulsatility index (PI), systolic acceleration (SA), dynamic flow index (DFI), dynamic pressure index (DPI), and dynamic compliance index (DCI). Mean and standard deviation were defined for the whole group, and for four subgroups, by age. Results. MFV, DFI, and DPI were highest at 6‐ to 9‐year‐olds, declining thereafter. The 14‐ to 22‐year‐old group was also compared to a group of healthy young athletes (15‐ to 22 years old). SCD patients had higher MFV, lnSA, DFI, DPI, and lower PI and DCI in most segments, suggesting global hyperemia. Conclusion. This is the first report of cross‐sectional results of DVA in a cohort of SCD outpatients without prior clinical stroke (TIA). These results suggest hyperemia without significant focal intracranial stenosis. There were also differences between asymptomatic SCD and young athletes, and the MFV, DFI, and DPI were highest at the age of 6 to 9 years, decreasing as age increased.