bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional Cerebral Blood Flow Abnormalities in Nondemented Patients With Memory Impairment
Authors: Tanaka Makoto , Fukuyama Hidenao , Yamauchi Hiroshi , Narita Minoru , Nabatame Hidehiko , Yokode Masayuki , Fujimoto Naoki , Kita Toru , Murakami Motonobu
Published: November 2009

Background. Patients with objective evidence of memory impairment have been considered to be at risk for developing Alzheimer's disease (AD). However, little is known about patterns of regional cerebral blood flow abnormalities and their prognostic significance in these patients. Methods. The authors retrospectively studied 28 nondemented subjects with memory loss and investigated patterns of blood flow abnormalities on single photon emission computed tomography (SPECT). Results. The patients were followed up for more than 2 years; during follow‐up, 14 patients (50%) developed AD. The onset of memory impairment in patients who progressed to AD was significantly earlier than in those who remained in a nondemented condition. SPECT data from the initial evaluation were analyzed by region of interest analysis and statistical parametric mapping. Interestingly, both groups of patients shared hypoperfusion in the medial temporal regions and the posterior cingulate. In addition to these regions, significant blood flow reduction in the parietal and anterior cingulate cortices was detected in patients who progressed to AD. Conclusions. These results demonstrate that (1) subjects with an earlier onset of memory loss have an increased risk for developing AD, (2) SPECT can be useful for distinguishing subjects with memory loss who will rapidly progress to AD from those who will not, and (3) perfusion impairment typical of AD was evident even in subjects with memory impairment who remained nondemented.
Noninvasive Ultrasound Evaluation of the Vertebral Artery in Hypertension
Authors: Ratanakorn Disya , Yunis Carla , Ferrario Carlos M. , McKinney William M.
Published: November 2009

Background and Purpose. Surgical decompression of the vascular loop of the vertebral artery (VA) at the left lateral medulla can reduce blood pressure (BP) in hypertension, and a larger diameter of the left VA has been found in hypertensive patients. Noninvasive evaluation of the VA in hypertension may assist selecting patients for more appropriate diagnosis and treatment. Duplex ultrasonography is used to study the relationship between VA diameter and BP. Methods. A retrospective review of VA duplex ultrasonography was performed in 112 consecutive patients who were sent to the neurovascular laboratory at the Wake Forest University School of Medicine during a 2‐month period. All measurements (BP, pulse rate, peak systolic velocity [PSV], end diastolic velocity [EDV], and diameters of both VAs) were determined according to standardized protocols. Left‐right comparisons of VA diameters, PSV, and EDV between hypertensives and normotensives were performed by the matched‐pairs analysis techniques. Results. Fifty‐five women and 57 men with a mean age of 64.8 years were studied. Hypertension was present in 65.2% of all patients. The age‐adjusted mean left VA diameter was significantly higher than that of the right VA with an age‐adjusted average differences of 0.2 mm (P= .03) for hypertensives compared to 0.04 mm (P= .75) for normotensives. No significant differences were observed in either PSV or EDV. Conclusions. Differences in left‐right VA diameter in hypertensive subjects may be a previously unrecognized component of the vascular disturbances associated with the disease and represent an additional criterion for identifying those who may benefit from surgical and medical management.
Magnetic Resonance Imaging in Patients Diagnosed With Papilledema: A Comparison of 6 Different High‐Resolution T1‐ and T2(*)‐Weighted 3‐Dimensional and 2‐Dimensional Sequences
Authors: Seitz Johannes , Held Paul , Strotzer Michael , Müller Michael , Völk Markus , Lenhart Markus , Djavidani Behrus , Feuerbach Stefan
Published: November 2009

Purpose. To evaluate visualization and signal characteristics of macroscopic changes in patients with ophthalmologically stated papilledema and to find a suitable high‐resolution magnetic resonance imaging (MRI) protocol. Method. Nine consecutive patients with 12 ophthalmologically stated papilledemas underwent MRI of the head and orbits, which consisted of the following high‐resolution sequences: 3‐dimensional (3D), T2*‐weighted (T2*w) constructive interference in steady‐state sequence (CISS); 3D, T1‐weighted (T1w) magnetization prepared‐rapid gradient echo sequence (MP‐RAGE) (with and without intravenous contrast medium); transverse 3D and 2‐dimensional (2D) (2mm), T2‐weighted (T2w) turbo spin echo (TSE); transverse 2D (2mm), contrast‐enhanced T1w TSE with fat‐suppression technique; and transverse 2D (5mm), T2w TSE. A quantitative and qualitative evaluation of the papilla, optic nerve, optic nerve sheath, optic chiasm, and the brain was performed. The 6 high‐resolution sequences were compared. Results. The elevation of the optic disc into the optic globe in ophthalmologically stated papilledema was best visualized in T2w, 3D CISS sequence. The pathological contrast enhancement was best seen in T1w contrast‐enhanced 2D TSE sequence with fat‐suppression technique. The mean width of the optic nerve sheath directly behind the globe was 7.54 mm (± 1.05 mm) in the pathological eyes, compared to 5.52 mm (± 1.11 mm) in the normal eyes. In all patients, the cerebral indices calculated showed no signs of increased intracranial pressure or other abnormalities changing the volume of the brain or ventricles. The contrast of the orbital fat versus the optic nerve sheath, the optic nerve sheath versus the surrounding cerebrospinal fluid (CSF), the surrounding CSF versus the optic nerve, the optic chiasm versus the CSF, and the optic papilla versus the optic globe were best visualized in the 3D, T2*w CISS sequence. An enhancement of the swollen optic nerve head was best seen in all 12 cases in the T1w contrast‐enhanced 2D TSE sequence with fat‐suppression technique. Conclusion. An MRI protocol consisting of a 5‐mm transverse T2w TSE sequence; a T2*w, 3D CISS sequence; a T1w, 3D MP‐RAGE sequence with and without contrast medium; and a transverse T1w, (2‐mm) 2D TSE sequence with fat‐suppression technique with intravenous contrast medium is suitable to visualize the macroscopic changes in papilledema. In addition, this combination is an excellent technique for the examination of the orbits and the brain.
Activation of Pre–Supplementary Motor Area (SMA) and SMA Proper During Unimanual and Bimanual Complex Sequences: An Analysis Using Functional Magnetic Resonance Imaging
Authors: Toyokura Minoru , Muro Isao , Komiya Taizo , Obara Makoto
Published: November 2009

Several functional imaging studies have shown that the extent of activation and percentage change in cerebral blood flow in the supplementary motor area (SMA) during a bimanual mirror performance of a simple repetitive movement are almost identical to those during a unimanual movement. The aim of this study was to investigate whether this finding was also applicable to a more complex movement. Eight right‐handed, healthy volunteers performed unimanually (with their right and left hands) and bimanually (in a mirror fashion) thumb‐finger opposition in a nonconsecutive order (index‐middle‐index‐ring‐index‐little‐index‐middle… fingers). The SMA proper was more activated during the bimanual movement than the unimanual movement with either hand. This is in accordance with the hypothesis that bimanual movement, even in a mirror fashion, is more difficult than unimanual movement when the task is complex but not when the task is simple. Pre‐SMA was inconsistently activated. The results suggest that the SMA proper plays an active role in executive processing during bimanual mirror performance of complex movements.
Subclavian Steal and a Persistent Trigeminal Artery
Authors: Koch Sebastian , Romano Jose G. , Forteza Alejandro
Published: November 2009

A persistent trigeminal artery (PTA) has been found in a number of cerebrovascular diseases. A 73‐year‐old asymptomatic woman was noted to have a left PTA and left subclavian steal by catheter angiography. Carotid duplex revealed a peak systolic flow velocity of 294 cm/s in the internal carotid artery (ICA) and an ICA to common carotid artery ratio >4, suggestive of a high‐grade stenosis. Only a low‐grade stenosis was identified by catheter angiography. The elevated flow velocities in the left ICA were attributed to increased collateral blood flow across the stenosis to the left PTA, which compensated for the subclavian steal. Transcranial Doppler found an alternating flow pattern in the basilar artery (mean flow velocity [MFV] = 18 cm/s) and left vertebral artery (MFV = 43 cm/s). During brachial hyperemia, the MFV increased by 178% in the basilar artery and 102% in the left vertebral artery. The data suggest that a PTA may compensate for subclavian steal and may have a protective hemodynamic role in this setting.
Focal Cortical Dysplasia: Improving Diagnosis and Localization With Magnetic Resonance Imaging Multiplanar and Curvilinear Reconstruction
Authors: Montenegro Maria Augusta , Min Li Li , Guerreiro Marilisa M. , Guerreiro Carlos A. M. , Cendes Fernando
Published: November 2009

Objective. To establish the contribution of multiplanar reconstruction (MPR) and curvilinear reformatting (CR) to the MRI investigation of focal cortical dysplasia (FCD). Methods. From a group of patients with intractable frontal lobe epilepsy, we selected patients with neuroimaging diagnosis of FCD. The diagnosis of FCD was based on the neuroimaging findings after a three step evaluation, always in the same order: (a) plain MRI films, (b) MPR, and (c) CR. After the selection of patients, the process of reviewing all the images in the three stages described above was performed by one of us, who did not take part on the selection of patients nor on the initial evaluation, and who was blind to the clinical and EEG findings of the patients. For data analysis, we first assessed the contribution of the additional findings of MPR analysis compared to the results of the evaluation using only plain MRI films, as is usually done in routine practice. Second, we assessed the contribution of CR to the findings of plain MRI films plus MPR. After completing the multistep evaluation, we all went back to review the plain MRI films with knowledge of lesion topography, in order to identify possible subtle features associated with FCD. Results. Seventeen patients met the inclusion criteria. Twelve had imaging diagnosis of FCD and were included in the second step of this project. Plain films of high resolution MRI showed the lesion in 6 (50%) of the 12 patients. By adding MPR to the plain MRI films, we identified lesions in all 12 patients. Furthermore, we found that MPR provided a better lesion localization and ascertainment of its relationship to other cerebral structures in 5 of 6 (83%) patients who had a lesion identified on plain films. By adding CR to the plain MRI films plus MPR analysis, we observed that (a) CR also allowed the identification of the dysplastic lesion in all patients, (b) CR improved lesion localization in one patient, and (c) CR provided a better visualization of the lesion extent in 4 patients (33%), showed a larger lesion in 3, and demonstrated that part of the area suspected as abnormal was more likely volume averaging in 2. Conclusion. MPR and CR analysis add to the neuroimaging evaluation of FCD by improving the lesion diagnosis and localization. CR helps to establish the extent of the lesion more precisely, allowing the visualization of some areas not shown on high resolution MRI and MPR. These techniques are complementary and do not replace the conventional wisdom of MRI analysis.
Transcranial Doppler Characteristics of Different Embolic Materials During In Vivo Testing
Authors: Rodriguez Rosendo A. , Giachino Allan , Hosking Martin , Nathan Howard J.
Published: November 2009

Purpose. The authors investigated whether ultrasonic characteristics of embolic signals could be used to differentiate embolic composition. Materials and Methods. The authors analyzed high‐intensity transient signals (HITS) from 3 patients with patent foramen ovale during the bubble contrast test and during total joint replacement surgery. In 3 anesthetized dogs, latex microspheres, fat particles, and air bubbles were injected into the internal carotid artery and HITS were identified in the cerebral circulation. The area under the receiver operating characteristic curve quantified the usefulness of each measure to distinguish embolic composition. Results. In humans, HITS intensity (area: 0.80) and frequency (area: 0.73) but not duration (area: 0.32) were useful to distinguish air bubbles from presumed solid emboli. In animals, intensity distinguished micro‐spheres from air (area: 0.94) and microspheres from fat (area: 0.94) but was less useful for fat and air (area: 0.64). The duration (area: 0.54–0.76) and frequency (area: 0.54–0.63) were poor discriminators. Conclusion. The HITS intensity best distinguished embolic composition. Particle size should be taken into account in future research.
Diffusion‐Weighted Magnetic Resonance Imaging in Superior Sagittal Sinus Thrombosis
Authors: Wasay Mohammad , Bakshi Rohit , Bobustuc George , Dubey Neeraj , Cheema Zahid , Dai Alper
Published: November 2009

Background and Purpose. Diffusion‐weighted imaging (DWI) has shown high sensitivity in the diagnosis of acute arterial strokes. The pathophysiology of cerebral venous thrombosis with associated venous stroke appears to differ from that of arterial strokes. The purpose of this study was to describe DWI findings in venous strokes. Methods. The authors reviewed 3 adults with superior sagittal sinus thrombosis who underwent DWI and magnetic resonance imaging within 24 hours of symptom onset. DWI was obtained at 1.5 T using the multishot echo planar technique (TR = 8000, TE = 97, field of view = 30 ?19 cm, slice thickness = 6.0 mm, interslice gap = 0.5 mm, matrix 128 ?128, NEX = 1). The diffusion gradients were applied in 3 orthogonal directions with 3 increasing b values (0–1000 s/mm2) to create average (trace) DWI images. Apparent diffusion coefficient (ADC) values were calculated on a pixel‐by‐pixel basis and displayed as ADC maps. Results. DWI showed hyperintensities in patients 1 and 2 and hypointensity in patient 3 in corresponding to parenchymal lesions on conventional images. As compared to the homologous uninvolved location in the contralateral hemisphere, ADC values were decreased (0.53 ?10−3 mm2/s [patient 1] and 0.68 −3 mm2/s [patient 2]) and increased (1.1 ?10−3 mm2/s [patient 3]). The ADC ratio of the lesion in the involved to uninvolved side was 88% (patient 1), 81% (patient 2), and 120% (patient 3). Conclusion. Acute cerebral venous strokes may contain cytotoxic edema and/or vasogenic edema on DWI scans. DWI may be helpful in diagnosing cerebral venous thrombosis in cases with cryptic presentations.
Transient Focal Leptomeningeal Enhancement in Sturge‐Weber Syndrome
Authors: Shin Robert K. , Moonis Gul , Imbesi Steven G.
Published: November 2009

The authors describe a 36‐year‐old man with Sturge‐Weber syndrome who presented with focal seizures and subsequently developed a temporary post‐ictal hemianopia. Magnetic resonance imaging of the brain demonstrated focal leptomeningeal enhancement, which subsequently resolved.
A Case of Adult Influenza A Virus–Associated Encephalitis: Magnetic Resonance Imaging Findings
Authors: Iijima Hiroyuki , Wakasugi Kyoko , Ayabe Mitsuyoshi , Shoji Hiroshi , Abe Toshi
Published: November 2009

A 27‐year‐old man presented with fever, convulsive seizure, and sudden impairment of consciousness. Magnetic resonance imaging (MRI) abnormalities were found in the bilateral thalami, including the brain stem and white matter. The possibility of a previous influenza A virus infection was considered, and cerebrospinal fluid cells and interleukin‐6 were elevated. The MRI findings closely resembled those found in cases of childhood acute necrotizing encephalopathy (ANE). The present case suggests that adult influenza A virus‐associated encephalitis/encephalopathy or ANE can occur during winter influenza epidemics.
Is Cerebral Microembolism in Mechanical Prosthetic Heart Valves Clinically Relevant?
Authors: Nadareishvili Zurab G. , Beletsky Vadim , Black Sandra E. , Fremes Stephen E. , Freedman Morris , Kurzman David , Leach Larry , Norris John W.
Published: November 2009

Background and Purpose. High‐intensity transient signals (HITS) are frequently detected by transcranial Doppler (TCD) ultra‐sound in patients with mechanical prosthetic heart valves (PHVs), but published data about their clinical relevance are controversial. This study was undertaken to determine the clinical relevance of HITS in patients with mechanical PHVs. Methods. The authors prospectively studied patients with mechanical PHVs using TCD monitoring for microemboli detection with and without O2 inhalation. The cognitive testing of patients included the Mini‐Mental State Examination, the Dementia Rating Scale, and MicroCog. Results. The authors studied 36 patients (20 women, aged 58 ±13 years). HITS were detected in 72% of patients, with a nonsignificant increase of HITS rate in the aortic valve group (P= .07). There was no significant difference in HITS rate between asymptomatic and symptomatic patients. In a multiple linear regression model, HITS rate was predicted only by younger age (P= .024). No correlation was found between HITS rate and the cognitive performance of patients. There was a significant decrease in HITS rate after 100%O2 inhalation compared to baseline levels (32.8 ±40.2 vs 6.1 ±11.3, P= .011). Subgroup analysis in asymptomatic patients confirmed this finding (P= .017), but in symptomatic patients, decreased HITS rate was not statistically significant (P= .18). Conclusion. Only age was a significant predictor of HITS in patients with mechanical PHVs. The lack of association between HITS, clinical symptoms, and cognitive functioning suggests that most of these signals represent harmless epiphenomena, and only HITS detected after O2 inhalation have any clinical relevance.
Comparison of Striatal Dopamine D2 Receptors in Parkinson's Disease and Progressive Supranuclear Palsy Patients Using [123I] Iodobenzofuran Single‐Photon Emission Computed Tomography
Authors: Oyanagi Chisako , Katsumi Yukinori , Hanakawa Takashi , Hayashi Takuya , Thuy Din ha Duy , Hashikawa Kazuo , Nagahama Yasuhiro , Fukuyama Hidenao , Shibasaki Hiroshi
Published: November 2009

Background and Purpose. To investigate the clinical applicability and validity of [123I] iodobenzofuran (IBF) single‐photon emission computed tomography (SPECT), the authors analyzed the changes in striatal dopamine D2 receptor binding among 7 patients with Parkinson's disease (PD), 6 patients with progressive supranuclear palsy (PSP) (Hoehn and Yahr stage II to IV), and 8 normal controls. Methods. SPECT data were acquired every 1 minute for 60 minutes postinjection of 167 MBq [123I] IBF. The binding potential (BP) of the striatum was evaluated by 2 methods: region‐of‐interest (ROI) analysis by the nonlinear least squares method using blood sampling and time‐series brain radioactivities in normal controls and a voxel‐by‐voxel method based on a region model that provided parametric images of BP without blood sampling. Results. Statistical parametric mapping indicated that BP in the striatum of PSP patients was significantly lower than that of PD patients and normal controls (P <.005, uncorrected), and there was no significant difference between PD patients and normal controls, even in patients with PD at an advanced stage. Data derived from the ROI method and a simplified reference region model showed good correlations in normal controls, indicating the validity of the latter model. Conclusions. The results predict that [123I] IBF SPECT, especially voxel‐by‐voxel BP parametric imaging, can discriminate among extrapyramidal diseases such as PD and PSP and may be applicable for clinical use.
The Radial Width of the Temporal Horn in Mild Cognitive Impairment
Authors: Frisoni Giovanni B. , Rossi Roberta , Beltramello Alberto
Published: November 2009

Background and purpose. The diagnosis of preclinical Alzheimer's disease (AD) (or mild cognitive impairment [MCI]) is loaded with a high degree of uncertainty. The aim was to test the accuracy of a computed tomography‐based (CT‐based) marker of medial temporal lobe atrophy, the radial width of the temporal horn (rWTH), in MCI. Methods. Ten MCI and 42 AD patients and 29 nondemented controls underwent brain CT on the temporal lobe plane (slice thickness = 2 mm). The rWTH was taken on CT films with a precision caliper placed at the tip of the temporal horn radial to the curvature of the hippocampal head region. Results. When specificity was fixed at 95%, the sensitivity for the detection of AD was 39/42 (93%) and that for the detection of MCI was 8/10 (80%). Conclusion. The rWTH is a measure sensitive to the regional brain atrophy common in early AD.
Decreased Cerebral Blood Flow in Neuro‐Behcet's Syndrome Patients With Neuropsychiatric Manifestations and Normal Magnetic Resonance Imaging—A Preliminary Report
Authors: Huang Wei‐Shih , Chiu Pai‐Yi , Kao Albert , Tsai Chon‐Haw , Lee Cheng‐Chun
Published: November 2009

Involvement of the brain is one of the most important complications of Behcet's disease, but its diagnosis is difficult because of the lack of effective imaging tools. Therefore, technetium‐99m ethyl cysteinate dimer (Tc‐99m ECD) single‐photon emission computed tomography (SPECT) of the brain was used to detect abnormal regional cerebral blood flow in patients with neuro‐Behcet's syndrome (NBS). Tc‐99m ECD brain SPECT was per‐formed to detect hypoperfusion areas of the brain in 10 NBS patients with definite neuropsychiatric symptoms or signs and normal brain magnetic resonance imaging (MRI) findings. Tc‐99m ECD brain SPECT demonstrated hypoperfusion areas of the brain in all of the 10 NBS patients. The parietal lobes were the most common areas with hypoperfusion lesions. Tc‐99m ECD brain SPECT is a more sensitive and useful tool than brain MRI for detecting hypoperfusion areas of the brain in NBS patients.
Diffusion Magnetic Resonance Imaging in Intermediate Form of Maple Syrup Urine Disease
Authors: Sener R. N.
Published: November 2009

An 8‐year‐old boy with the intermediate variant of maple syrup urine disease is reported. On b= 1000 s/mm2 (heavily diffusion weighted) images of diffusion magnetic resonance imaging, there was symmetric high signal in the globus pallidus, mesencephalon, dorsal pons, and nucleus dentatus, consistent with restriction of the mobility of water molecules. Apparent diffusion coefficient (ADC) maps revealed low ADC values ranging from 0.42 to 0.56 ?10−3mm2/s in these regions, compared to those of apparently unaffected regions in the brain parenchyma ranging from 0.63 to 0.97 ?10−3 mm 2/s. It is suggested that the areas of increased signal (and low ADC values) are the result of dysmyelination as a reflection of disorganized tissue integrity.
Cerebral and Systemic Hemodynamics Changes During Upright Tilt in Chronic Fatigue Syndrome
Authors: Razumovsky Alexander Y. , DeBusk Karen , Calkins Hugh , Snader Sally , Lucas Katherine E. , Vyas Pranav , Hanley Daniel F. , Rowe Peter C.
Published: November 2009

Background and Purpose. During head‐up tilt (HUT), patients with chronic fatigue syndrome (CFS) have higher rates of neurally mediated hypotension (NMH) and postural tachycardia syndrome (POTS) than healthy controls. The authors studied whether patients with CFS were also more likely to have abnormal cerebral blood flow velocity (CBFV) compared with controls in response to orthostatic stress. Methods. Transcranial Doppler monitoring of middle cerebral artery (MCA) CBFV was performed during 3‐stage HUT prospectively in 26 patients with CFS and 23 healthy controls. At the same time, continuous monitoring of arterial blood pressure (BP), heart rate (HR), end‐tidal CO2 (ET‐CO2) were performed. Results are reported as mean ± SD. Results. NMH developed in 21 patients with CFS and in 14 controls (P = .22). POTS was present in 9 CFS patients and 7 controls (P = .76). Supine HR was higher in CFS patients, but all other hemodynamics and CBFV measures were similar at baseline. The median time to hypotension did not differ, but the median time to onset of orthostatic symptoms was shorter in those with CFS (P < .001). The CBFV did not differ between groups in the supine posture, at 1 or 5 minutes after upright tilt, at 5 or 1 minute before the end of the test, or at termination of the test. Mean CBFV fell at termination of tilt testing in those with CFS and controls. ET‐CO2 was lower at termination of the test in those with CFS versus controls (P = .002). Conclusions. The results of this study are not consistent with the hypothesis that patients with CFS have a distinctive pattern of MCA CBFV changes in response to orthostatic stress.
Residual Hippocampal Atrophy in Asphyxiated Term Neonates
Authors: Mañ;eru Cristina , Serra‐Grabulosa Josep M. , Junqué Carme , Salgado‐Pineda Pilar , Bargalló Núria , Olondo Miren , Botet‐Mussons Francesc , Tallada Mercé , Mercader Josep Maria
Published: November 2009

Background and Purpose. Previous studies have shown the hippocampus and basal ganglia to be highly sensitive to hypoxic‐ischemic insult. The authors' aim was to evaluate the long‐term effects of perinatal asphyxia (PA) on the hippocampus and caudate nucleus in a group of participants born at term and who met the criteria for hypoxic‐ischemic encephalopathy (HIE). Additionally, the authors looked for damage in other brain regions using voxel‐based morphometry (VBM). Methods. The sample consisted of 13 participants (8 boys and 5 girls) with a mean age at study of 16.23 years (± 2.89) with antecedents of perinatal asphyxia, diagnosed as moderate hypoxic‐ischemic encephalopathy. A group of 13 healthy adolescents matched for age, sex, educational level, and social background were recruited as a comparison group. MR scans were acquired on a 1.5T Signa (General Electric, Milwaukee, WI) to evaluate hippocampal and caudate volumes and to perform VBM analysis. Finally, Rey's Auditory Verbal Learning Test was administered to evaluate verbal long‐term memory. Results. HIE participants were found to have bilateral hippocampal atrophy (P = .015) and gray matter damage in temporal and frontal lobes. The caudate nucleus showed no atrophic changes in PA participants, and VBM analysis did not reveal other consistent brain abnormalities. Verbal long‐term memory was slightly worse in HIE participants. Conclusions. These findings indicate that PA produces hippocampal and other nonspecific long‐term damage, which cannot be compensated for by plasticity mechanisms. However, this damage does not preclude normal development and scholarship.
Diffusion‐Weighted Magnetic Resonance Imaging Abnormalities in Bartonella Encephalopathy
Authors: Singhal Aneesh B. , Newstein Michael C. , Budzik Ronald , Cha Jang‐Ho , Rordorf Guy , Buonanno Ferdinando S. , Panzara Michael A.
Published: November 2009

The authors describe 2 patients with new‐onset, refractory status epilepticus and serological evidence for Bartonella infection. Brain magnetic resonance imaging (MRI) in patient 1 showed transient diffusion abnormalities in the posterior (pulvinar) thalami. In patient 2, brain MRI showed several enhancing cortical lesions, of which one lesion was bright on diffusion‐weighted imaging (DWI). In patients with unexplained, refractory seizures, the presence of DWI abnormalities warrants a search for unusual infectious or inflammatory disorders, like Bartonella encephalitis.
Cerebrovascular Reactivity in Hypertensive and Healthy Adolescents: TCD With Vasodilatory Challenge
Authors: Settakis Georgios , Páll Dénes , Molnár Csilla , Bereczki Dániel , Csiba László , Fülesdi Béla
Published: November 2009

Background. Adolescent hypertension predicts hypertension and increased cardiovascular morbidity in adulthood. The aim of the present work was to test whether cerebrovascular reactivity to CO2is altered among hypertensive adolescents.Methods. From the population‐based cohort of the Debrecen Hypertension Study, 113 hypertensive and 58 normotensive adolescents underwent transcranial Doppler measurements at rest and after 30 seconds of breath holding.Results. Systolic, mean, and diastolic blood flow velocities were higher among hypertensive individuals at rest. Taking the absolute blood flow velocity parameters into account, after breath holding, only the pulsatility index was significantly higher in the hypertensive group. The percentage change of the different blood flow parameters showed less intensive change in hypertensive teenagers.Conclusion. Cerebral vasoreactivity is decreased among hypertensive individuals as compared to healthy controls.
Apolipoprotein E Genotype and Early Alzheimer's Disease: A Longitudinal SPECT Study
Authors: Sakamoto Shigeki , Matsuda Hiroshi , Asada Takashi , Ohnishi Takashi , Nakano Seigo , Kanetaka Hidekazu , Takasaki Masaru
Published: November 2009

Background and Purpose. To determine the association of the apolipoprotein E (APOE) genotype and longitudinal changes of regional cerebral blood flow (rCBF) in Alzheimer's disease (AD). Previous reports have yielded conflicting results concerning this association. Methods. A retrospective cohort study was performed. rCBF was noninvasively measured using 99mTc‐ethyl cysteinate dimer single‐photon emission computed tomography in 23 patients with probable AD at the very early stage and at a mean interval of 24 months, as well as in 55 age‐matched healthy volunteers. Patients were classified into 2 groups according to the presence of the ɛ4 allele: 11 ɛ4 carriers and 12 noncarriers. Correction for partial volume effects (PVEs) was performed in all patients using gray matter volume measured by magnetic resonance imaging. Statistical parametric mapping was used for the analysis of absolute rCBF data and the adjusted rCBF images of relative flow distribution. Results. In the baseline study, both carriers and noncarriers showed significant decreases of absolute and adjusted rCBF in the posterior cingulate gyri and precunei. After PVE correction, carriers showed a greater spread of areas with significant rCBF reduction from the parietotemporal to the frontal areas than noncarriers during the follow‐up period compared to healthy volunteers. Moreover, carriers showed a significant decline of absolute rCBF in the frontal cortex from the baseline to the follow‐up study. Conclusions. The authors' study suggests that the APOE ɛ4 allele is associated with the faster progression of AD, and PVE correction may be necessary for accurate assessments of SPECT studies of AD.
Imaging of Alzheimer's Disease
Authors: Lee Benjamin C.P. , Mintun Mark , Buckner Randy L. , Morris John C.
Published: November 2009

Imaging is widely used in the evaluation of Alzheimer's disease (AD). In addition to imaging's traditional role of aiding in the exclusion of diseases that may be confused with AD, structural and functional imaging are being explored for potential use in the early detection of AD and as surrogate markers of treatment outcome. Volumetric measurements of the hippocampal and entorhinal regions using modern magnetic resonance imaging (MRI) and computed tomography are most widely studied in the discrimination of AD from nondemented aging and other dementias. Other imaging modalities include positron emission tomography and single‐photon‐emission computed tomography, which evaluate global and regional disturbances of blood flow and metabolism, and proton spectroscopy, which assesses neuronal degeneration and loss as marked by the presence of abnormal metabolites. Diffusion tensor and functional MRI, which examine whiter matter changes and brainbehavior relationships, are more recent techniques that contribute to the burgeoning application of imaging techniques to dementing illnesses and are notably improving our understanding of the pathophysiology of AD.
Neuroimaging Curriculum for Neurology Trainees: Report from the Neuroimaging Section of the AAN
Authors: Bakshi Rohit , Alexandrov Andrei V. , Gomez Camilo R. , Masdeu Joseph C.
Published: November 2009

Neuroimaging plays a major role in the evaluation of patients with neurological disorders. Surveys of neurologists have revealed that most rely on their own readings of images for patient management, and a majority believe that neurologists should be allowed to officially interpret and bill for scan reviews. The importance of neuroimaging training for neurology residents has been stressed by the Association of University Professors of Neurology. Although there is a desire to promote the neuroimaging education of neurologists, no curricula have existed previously. The Neuroimaging Section of the American Academy of Neurology (AAN) developed a task force of practicing neuroimagers to provide a neuroimaging curriculum for neurological trainees and training directors. The resulting curriculum is available on the Web sites of the AAN (http://www.aan.com) and the American Society of Neuroimaging (http://www.asnweb.org/education/curriculum.shtml) and will be updated as the need arises through evolving technology or breadth of applications. This curriculum should help in the design of neurology residency and fellowship programs and subspecialty path‐ways in which adequate neuroimaging education and training are desired for various reasons, including certification and the demonstration of competency and proficiency.
Quantification of Hippocampal Signal Intensity in Patients with Mesial Temporal Lobe Epilepsy
Authors: Coan Ana Carolina , Kobayashi Eliane , Li Li Min , Cendes Fernando
Published: November 2009

Background. Refractory mesial temporal lobe epilepsy (MTLE) is frequently associated with hippocampal atrophy (HA) and an abnormal hippocampal signal (Hsig) on magnetic resonance imaging (MRI). Objective. To quantify Hsig on MRI using a simplified technique. Methods. The authors included 15 patients with refractory MTLE who underwent surgery and had preoperative MRI with hippocampal volumetry. Hsig was quantified on preoperative coronal T1‐weighted and T2‐weighted MRI using the NIH‐Image program. Hsig was determined for the head, tail, and entire hippocampal extension. Abnormal Hsig was defined when values were above (for T2) or below (for T1) 2 standard deviations from the mean of normal control group. Results. The lateralization of abnormal Hsig values was concordant with electroencephalograms and HA in all patients. There was a significant difference in ipsilateral T2 Hsig between patients and controls (P < .0001), but not for contralateral T2 Hsig. T1 Hsig showed bilateral abnormalities more frequently, whereas T2 Hsig could lateralize better hippocampal abnormalities. Overall, there were no differences when comparing T2 Hsig for the entire hippocampus, head, or tail only. However, there were some individual differences. T2 Hsig abnormalities involved the entire hippocampus in most patients but were restricted to the head in one patient and to the tail in another. Conclusions. This simplified method for the quantification of Hsig using NHI‐Image is an efficient method for the identification and quantification of hippocampal abnormalities in patients with MTLE. The assessment of the entire extension of the hippocampal formation may provide important additional data, compared to T2 relaxometry maps limited to one segment of the hippocampus.
MRI Brain T1 Relaxation Time Changes in MS Patients Increase Over Time in Both the White Matter and the Cortex
Authors: Parry A. , Clare S. , Jenkinson M. , Smith S. , Palace J. , Matthews P. M.
Published: November 2009

Objective. To test the sensitivity of whole‐brain T1 relaxometry to the evolution of pathological changes in multiple sclerosis (MS). Background. T1‐weighted hypointense lesion load in the brains of patients with MS is associated with axonal loss. Other work has shown that T1 measurements may provide information complementary to existing imaging techniques, such as magnetization transfer imaging. Methods. The authors studied 14 MS patients twice over a median time interval of 19.5 months (range, 14–22 months). Structural images and whole‐brain T1 maps using a novel rapid‐scanning technique (3 min/study) were performed at 3 T. Analysis focused on defining changes separately in the lesional and normal‐appearing white matter (NAWM) and in the cortical gray matter. Results. At baseline, there was an inverse relationship between disease duration and the NAWM T1 histogram peak height (r=−0.75, P= .03). The total white matter T1 histogram peak height decreased over time (P < .001). This could be accounted for by changes in the NAWM (P < .03). there also was a decrease (6%) in the mean (11 of 14 patients, P= .004) and in the median (7%) (13 of 14 patients, P < .001) neocortical gray matter T1 over the follow‐up period. Conclusions. Brain T1 maps can be generated quickly and are sensitive to pathological changes over time. T1 values in both the gray and the white matter at the baseline visit were related to disease duration, suggesting that the T1 changes are clinically relevant. Although the absolute values will be different, it is likely that similar changes will be able to be detected at 1.5 T. The role of T1 measurement as a magnetic resonance imaging outcome measure in clinical trials now should be explored.
Monitoring the Effect of Chemotherapy in a Mixed Glioma by C‐11‐Methionine PET
Authors: Herholz K. , Kracht L. W. , Heiss W. D.
Published: November 2009

The effect of chemotherapy with procarbazine, CCNU, and vincristine in an anaplastic oligoastrocytoma was monitored by repeated positron emission tomography (PET) with C‐11‐methionine (C‐11‐MET). Chemotherapy caused a continuous decline of active tumor volume at a rate of approximately 2.4% per day, resulting in complete remission that persisted until the end of follow‐up at 3 years. Thus, the authors conclude that C‐11‐MET PET may be useful for monitoring chemotherapy in gliomas and deserves further study.
Importance of Jugular Valve Incompetence in Contrast Transcranial Doppler Ultrasonography for the Diagnosis of Patent Foramen Ovale
Authors: Topçuoglu M. Akif , Buonanno Ferdinando S.
Published: November 2009

Transcranial Doppler (TCD) ultrasound with the intravenous injection of agitated saline as contrast (cTCD) is an effective method for detecting right‐to‐left intracardiac and extracardiac shunt (RLS); however, the sensitivity of cTCD in the diagnosis of RLS remains slightly less than that of transesophageal echocardiography, even in patients with adequate transtemporal ultrasonic bone windows. The authors present a case with cTCD underestimating RLS because of jugular valve incompetence in a 42‐year‐old man presenting with an episode of transient aphasia. Three weeks after transcatheter closure of a patent foramen ovale associated with an atrial septal aneurysm, he experienced 2 episodes of amaurosis fugax. Following a negative 45‐minute embolus detection study with power M‐mode TCD, the patient underwent a cTCD study with monitoring of the left middle cerebral artery (MCA), the anterior cerebral artery, and the submandibular extracranial internal carotid artery. A single microbubble (MB) was detected in the left MCA in only 1 of 5 studies; the remaining runs all failed to detect an RLS. Significant MB reflux was noted in the left internal jugular vein because of jugular valve incompetence. The authors conclude that incompetence of the jugular vein valve can result in a false negative cTCD study for RLS detection.
Brain Perfusion Imaging of a Craniopharyngioma by Transcranial Duplex Sonography
Authors: MD Thilo Hölscher , Draganski Bogdan , Postert Thomas , Bogdahn Ulrich , Wilkening Wilko
Published: November 2009

Background and Purpose. The aim of this study was to test a new ultrasound software tool to assess pathological perfusion in a brain tumor patient. Methods. Tissue harmonic imaging (THI) enables an improved depiction of brain morphology, employing nonlinear parenchyma and ultrasound contrast agent (UCA) backscatter information. With specialized software, morphological information can be separated from perfusion information. Both can be superimposed at a preferred mixing ratio in a single image. Results. Using THI and a perfluoropropane‐based UCA, a pathologic perfusion pattern described by abnormal perfused areas in the tumor region could be demonstrated. After super‐imposing morphologic and perfusion information, subtle structural tumor inhomogeneities were depicted. Craniopharyngioma structure and perfusion defect were confirmed by T2‐weighted and perfusion‐weighted magnetic resonance imaging. Conclusion. Transcranial duplex sonography in combination with contrast specific imaging methods might be helpful to visualize perfusion defects without loss of morphological information.
A Multiple Regression Model of Combined Duplex Criteria for Detecting Threshold Carotid Stenosis and Predicting the Exact Degree of Carotid Stenosis
Authors: Hwang Chi‐Shin , Liao Kuo‐Meng , Tegeler Charles H.
Published: November 2009

Background and Purpose. Combined duplex criteria are commonly used in vascular laboratories for evaluating carotid stenosis. However, most of these combinations are empirical, and systemic validation is lacking. This study was completed using a multiple regression method to evaluate the accuracy of different combined duplex criteria for detecting threshold carotid stenosis and predicting the exact degree of carotid stenosis on angiography. Methods. Two hundred sixty‐six sets of unilateral carotid duplex and angiographic data were randomly divided into 2 sets: a derivation set and a validation set. The derivation set was used to develop a multiple logistic regression model for detecting 70% threshold carotid stenosis. Age, sex, systolic blood pressure, diastolic blood pressure, Doppler peak systolic velocity (PSV), Doppler end diastolic velocity (EDV), the systolic carotid ratio (SCR), and ophthalmic artery flow direction were tested as independent variables. A multiple linear regression model was also developed for predicting the exact degree of carotid stenosis on angiogram. The validation set was then used to evaluate the accuracy of these models. Results. According to the logistic regression strategy, the best multiple logistic regression model was as follows: probability of threshold carotid stenosis = exp(2.6 PSV ‐ 6.2)[H20907][1 + exp(2.6 PSV ‐ 6.2)]. The best linear regression model was as follows: degree of carotid stenosis = 20.2 PSV ‐7.4 EDV + 0.4 SCR + 8.5. Both models proved to be valid following an evaluation of the validation set. Conclusions. This study illustrates that Doppler parameters may be of use in predicting the exact degree of carotid stenosis and the probability of threshold carotid stenosis. This is important if duplex criteria are going to replace angiography as the only tool for selecting endarterectomy candidates.
Comparative Evaluation of Concomitant Structural and Functional Neuroimages in Rasmussen's Encephalitis
Authors: Fogarasi András , Hegyi Márta , Neuwirth Magdolna , Halász Péter , Barsi Péter , Farkas Viktor , Bognár László
Published: November 2009

Background and Purpose. Rasmussen's encephalitis (RE) is a rare condition of unknown cause characterized by intractable seizures, progressive hemiparesis, mental impairment, and inflammatory histological findings in the cortex. The primary diagnosis is based on biopsy to confirm the typical clinical, electroencephalography, and brain imaging findings. The main objective of this study was to compare simultaneous structural and functional neuroimages in RE. Methods. Concomitant magnetic resonance imaging and 2‐deoxy‐2‐[18F]‐fluoro‐D‐glucose positron emission tomography data from the authors'series of 5 children and 8 patients described in the literature were analyzed and compared. Results. Typical early findings of RE include metabolic abnormalities (hypermetabolism and hypometabolism) starting in the frontal or temporal regions or, occasionally, involving the whole hemisphere. Focal abnormalities of cerebral glucose metabolism indicate lesions sooner and depict their extent better than concomitant magnetic resonance images. The major structural abnormality remains unilateral; however, contralateral frontal lobe hypometabolism or crossed cerebellar diaschisis can be a finding of this disease. Basal ganglia involvement and whole hemispheric metabolic abnormality appear typically only after several months of disease onset. Conclusion. Concomitant structural and functional neuroimaging provide possibly complementary information in the early noninvasive workup of RE and may facilitate the early diagnosis of this rare disorder.
MRI Features of Intramedullary Spinal Cord Ependymomas
Authors: Sun Bo , Wang Chungcheng , Wang James , Liu Ali
Published: November 2009

Background and Purpose. To assess the magnetic resonance (MR) imaging characteristics of spinal intramedullary ependymomas. Methods. MR images were obtained from 60 patients with spinal intramedullary ependymomas. All patients were treated surgically, and pathological diagnoses were con‐firmed. MR images of ependymomas and associated cysts were correlated with surgical findings. Results. Among 60 cases of intramedullary ependymomas, 39 were cervical and 11 thoracic, and 10 were located at the conus medullaris and filum terminale. The lesions measured 1 to 10 vertebral segments in length along the neuraxis, with a mean length of 3.7 segments. All tumors had slightly hyperintense signals on T2‐weighted MR images. Clear tumor margins were seen in 77% of patients; 75% had uniform contrast enhancement. Rostral and caudal cysts were seen in 90% of all patients; all cysts were hypointense on T1‐weighted images and hyperintense on T2‐weighted images. The rostral cysts were 1 to 5 segments in length and caudal cysts 2 to 10 segments in length. Conclusion. Ependymomas occur most often at the upper cord rather than in the conus medullaris and filum terminale. Of the cervical and thoracic ependymomas, most were cellular or epithelial types. Papillary ependymomas occurred exclusively in the conus medullaris and filum terminale. Rostral and caudal cysts are frequently associated with intramedullary ependymomas. Clear tumor margins, more uniform enhancement, and central locations can help differentiate ependymomas from other intramedullary spinal cord tumors.
The Positions of the Patients in the Diagnosis of Patent Foramen Ovale by Transcranial Doppler
Authors: Telman Gregory , Kouperberg Efim , Sprecher Eliott , Yarnitsky David
Published: November 2009

Background and Purpose. There is no information about the optimal position of a patient for the performance of a transcranial Doppler (TCD) examination to detect patent foramen ovale (PFO). Such information is important to improving the sensitivity of the test in comparison to the gold standard of transesophageal echocardiography (TEE). Methods. Thirty‐four patients with TEE‐proved PFO were examined by contrast TCD. Examinations were done in both the sitting and supine positions in random order. Results. Eight hundred ninety‐two microemboli were recorded. Patients'positions and the sequence of testing did not affect the number of microemboli detected. Yet for each individual, 1 of the 2 positions was more sensitive. Conclusions. To improve the sensitivity of TCD in the detection of PFO, it is recommended, in the case of a first negative test, to change the patient's position for a repeated TCD examination.
Neuroimaging in Autistic Spectrum Disorder (ASD)
Authors: Sokol Deborah K. , Edwards‐Brown Mary
Published: November 2009

Autistic spectrum disorder (ASD) is a lifelong developmental disorder characterized by impairment in socialization and communication. Neuroimaging research has shown abnormalities in the frontal lobes, limbic systems, and cerebella of individuals with ASD. Recently, abnormal developmental trajectories of brain growth have been reported, with increases in brain volume (in both gray and white matter) seen in younger rather than older individuals with this disorder. Despite 30 years of research, a reliable marker for ASD has not been identified. Therefore, routine neuroimaging for individuals with ASD is not recommended.