bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parkinson's Disease and Segmental Coordination during Turning: II. Walking Turns
Authors: Akram Sakineh , Frank James S. , Jog Mandar 
Published: December 2014

Abstract:Objective:Individuals with Parkinson's disease (PD) show poorer balance and greater incidence of falls while turning. We investigated whether a disturbance in timing and sequence of reorientation of body segments is a potential cause of turning difficulty in PD and is altered by levodopa.Methods:The sequence and timing of segmental reorientation during 45° and 90° walking turns were recorded in nineteen healthy controls and fourteen individuals with PD “off” and “on” medication.Results:Both healthy elderly and PD patients “off” medication displayed a top-down sequence of segment reorientation, but differed with respect to the delay time between segments: PD “off” medication displayed a shorter delay between the onset of head and shoulder reorientation and longer delays for pelvis and foot reorientation. Furthermore, for all segments the peak angular velocities were lower for PD patients than healthy controls, with greater difference between the two groups during larger turns. While for both groups the velocity and magnitude of rotation of all segments were greater during larger turns, the relative timing of reorientation of segments remained the same during small and large turns. Medication had no significant effect on the timing and sequence of reorientation of segments and caused only a small and non-significant increase to segment velocities.Conclusion:This study further characterized the turning performance of individuals with PD. Our findings have clinical applications and therapeutic value for PD patients with difficulty turning. Understanding the specific deficiencies of turning performance of PD patients allows the therapists to opt for the most effective rehabilitation techniques.
Mechanisms Underlying Taurine Protection Against Glutamate-Induced Neurotoxicity
Authors: Ye Hai-Bo , Shi Hai-Bo , Yin Shan-Kai 
Published: December 2014

Abstract:Taurine appears to exert potent protections against glutamate (Glu)-induced injury to neurons, but the underlying molecular mechanisms are not fully understood. The possibly protected targets consist of the plasma membrane and the mitochondrial as well as endoplasmic reticulum (ER) membranes. Protection may be provided through a variety of effects, including the prevention of membrane depolarization, neuronal excitotoxicity and mitochondrial energy failure, increases in intracellular free calcium ([Ca2+]i), activation of calpain, and reduction of Bcl-2 levels. These activities are likely to be linked spatially and temporally in the neuroprotective functions of taurine. In addition, events that occur downstream of Glu stimulation, including altered enzymatic activities, apoptotic pathways, and necrosis triggered by the increased [Ca2+]i, can be inhibited by taurine. This review discusses the possible molecular mechanisms of taurine against Glu-induced neuronal injury, providing a better understanding of the protective processes, which might be helpful in the development of novel interventional strategies.
Mitochondrial Depletion Syndromes in Children and Adults
Authors: Finsterer Josef , Ahting Uwe 
Published: December 2014

Abstract:To highlight differences between early-onset and adult mitochondrial depletion syndromes (MDS) concerning etiology and genetic background, pathogenesis, phenotype, clinical presentation and their outcome. MDSs most frequently occur in neonates, infants, or juveniles and more rarely in adolescents or adults. Mutated genes phenotypically presenting with adult-onset MDS include POLG1, TK2, TyMP, RRM2B, or PEO1/twinkle. Adult MDS manifest similarly to early-onset MDS, as myopathy, encephalo-myopathy, hepato-cerebral syndrome, or with chronic progressive external ophthalmoplegia (CPEO), fatigue, or only minimal muscular manifestations. Diagnostic work-up or treatment is not at variance from early-onset cases. Histological examination of muscle may be normal but biochemical investigations may reveal multiple respiratory chain defects. The outcome appears to be more favorable in adult than in early-onset forms. Mitochondrial depletion syndromes is not only a condition of neonates, infants, or juveniles but rarely also occurs in adults, presenting with minimal manifestations or manifestations like in the early-onset forms. Outcome of adult-onset MDS appears more favorable than early-onset MDS.
Visual Hallucinations and Cognitive Impairment in Parkinson's Disease
Authors: Park Hee Kyung , Kim Jae Seung , Im Ki Chun , Kim Mi Jung , Lee Jae-Hong , Lee Myoung C. , Kim Juhan , Chung Sun Ju 
Published: December 2014

Abstract:Background:Visual hallucination (VH) is a common psychotic symptom in patients with Parkinson's disease (PD) and may be a significant predictor of cognitive impairment (CI) in such patients.Objective:This study aimed to investigate the pattern of glucose metabolism of VH and the relationship between VH and CI in PD.Methods:We studied 28 PD patients, including 15 with VH (PD-VH) and 13 without VH (PD-NVH). Of the 15 PD-VH patients, 8 patients had cognitive impairment (PD-VHCI) whereas 7 did not (PD-VHNCI). All patients underwent [18F] fluorodeoxyglucose positron emission tomography ([18F] FDG PET) followed by statistical parametric mapping (SPM) analyses.Results:Compared to the patients with PDNVH, PD-VHNCI patients showed glucose hypometabolism in the inferior and middle temporal cortices, fusiform gyri, and frontal areas, suggesting the involvement of the ventral visual pathway. Compared to the patients with PDNVH, PD-VHCI patients showed glucose hypometabolism in the temporoparietal association cortices with scattered frontal areas.Conclusion:Dysfunction of ventral visual pathway involving the temporal lobe may play a key role in VH development in PD patients. The evolving distribution from the ventral visual pathway to more extensive posterior cortices in PD-VHCI patients suggests that VH may be a prodromal symptom occurring prior to CI in PD patients.
Spontaneous Blink Rates in Children During Different Types of Eye Movements
Authors: Salman Michael S. , Liu Liumei 
Published: December 2014

Abstract:Introduction:The spontaneous blink rate (SBR) is variable in humans. It increases rapidly during childhood before reaching a plateau in adulthood at 10-20 blinks/minute. Our aim was to compare the SBR during different visual tasks in children.Methods:Thirty-nine healthy participants (mean age(SD):13.6(3.5)years, M=21), made horizontal and vertical visually-guided saccades, tracked a horizontal and vertical target, performed horizontal and vertical active sinusoidal head rotations in light and darkness while looking straight ahead (VOR task) or fixated straight ahead and in four directions of gaze. The eyes of each participant were videotaped and reviewed twice to determine the SBR. Parametric and non-parametric tests were used to analyze the data.Results:The median SBR during fixation straight ahead was seven blinks/minute, which was similar to the SBR during horizontal saccades and horizontal smooth pursuit tasks. The median SBR during vertical smooth pursuit and vertical saccades were significantly lower than during fixation (p≤0.042). The median SBR during the VOR task in light and horizontal VOR in darkness were significantly higher than during fixation (p=0.019-0.024).Conclusions:The median SBR during visual fixation was lower than that reported previously in 5-14 years-old children during rest or 11-20 years-old subjects during quiet conversation. The median SBR was even lower during vertical smooth pursuit and saccades tasks. This may be due to differences in concentration required for visual fixation in general and vertical visual tasks more specifically. The higher SBR during the VOR may be due to drying of the eyes during head shaking.
Quantitative Volumetric Analysis Post Transsphenoidal Pituitary Adenoma Surgery
Authors: Mansouri Alireza , Symons Sean , Schwartz Michael , Chen Joseph , Pirouzmand Farhad 
Published: December 2014

Background:Computed tomogram (CT) imaging is often used for immediate postoperative assessment of transsphenoidal pituitary adenoma resection while magnetic resonance imaging (MRI) is used for follow-up. The residual mass is known to decrease in size over time but the difference between the two imaging modalities has not been quantified. Our objective was to quantify the size difference of the residual mass on immediate postoperative CT compared with delayed MRI.Methods:Retrospective analysis of 69 patients who had undergone pituitary adenoma resection at our institution between 2004-2010. Sellar and suprasellar diameter, along with the overall volume of the residual mass were measured on both the immediate postoperative CT and delayed MRI.Results:Average preoperative sellar and suprasellar diameter was 22.2 ± 4.6mm and 20.9 ± 5.9mm, respectively. Average sellar residual diameter on immediate postoperative CT (16.5 ± 5.4 mm, 25% reduction) was significantly larger than delayed MRI (10.6 ± 6.2mm, 52% reduction). The average suprasellar component on CT (15.5±6.5mm, 26% reduction) was also significantly larger than that on MRI (3.3 ± 5.4 mm, 84% reduction). The postoperative CT showed a 46% reduction in volume while a 71% reduction was noted on the delayed MRI.Conclusion:A significant reduction in residual mass is noted on delayed MR imaging compared with immediate postoperative CT. Therefore, from a resource management and prognostication point of view, CT should be used for immediate postoperative assessment while delayed MRI should be used to assess operative success and for communication with patients.
Is this Subarachnoid Hemorrhage Significant? A National Survey of Neurosurgeons
Authors: Perry Jeffrey J. , Symington Cheryl , Mansour Marlène , Taljaard Monica , Stiell Ian G. 
Published: December 2014

Background:Previously all subarachnoid hemorrhage (SAH) patients were admitted, whereas now patients with angiography may be discharged.Objective:To survey neurosurgeons to determine current practice and what constitutes a clinically significant subarachnoid hemorrhage.Methods:We surveyed all neurosurgeons listed in the Canadian Medical Directory. We used a modified Dillman technique with up to five mailed surveys plus a pre-notification letter. Neurosurgeons rated the significance of 13 scenarios of subarachnoid hemorrhage. Scenarios varied from aneurysmal subarachnoid hemorrhage to patients with isolated xanthochromia in cerebrospinal fluid. Each scenario was rated for clinical significance using a 5-point scale [1(always) to 5(never)].Results:Of the 224 surveyed, 115 neurosurgeons responded. Scenarios with aneurysms requiring intervention, arteriovenous malformations, death or any surgical intervention all had median responses of 1 (IQR 1, 1). Scenarios having xanthochromia and few red blood cells in cerebrospinal fluid with negative computerized tomogram (CT) and angiography had median responses of 3 (IQR 1, 4). Scenarios with perimesencephalic pattern on CT with negative angiography had median of 3 (IQR 2, 4). Scenarios where patient is discharged from the emergency department had median of 4 (IQR 3, 5).Conclusion:Subarachnoid hemorrhages due to aneurysms or arteriovenous malformations causing death or requiring surgical intervention are always clinically significant. Other types of nonaneurysmal subarachnoid hemorrhages had inconsistent ratings for clinical significance. These survey results highlight the need for further discussions to standardize the diagnosis of what constitutes a clinically significant subarachnoid hemorrhage and what care should be afforded to these patients.
Tractography in the Study of the Human Brain: A Neurosurgical Perspective
Authors: Fortin David , Aubin-Lemay Camille , Boré Arnaud , Girard Gabriel , Houde Jean-Christophe , Whittingstall Kevin , Descoteaux Maxime 
Published: December 2014

Background:The brain functions as an integrated multi-networked organ. Complex neurocognitive functions are not attributed to a single brain area but depend on the dynamic interactions of distributed brain areas operating in large-scale networks. This is especially important in the field of neurosurgery where intervention within a spatially localized area may indirectly lead to unwanted effects on distant areas. As part of a preliminary integrated work on functional connectivity, we present our initial work on diffusion tensor imaging tractography to produce in vivo white matter tracts dissection.Methods:Diffusion weighted data and high-resolution T1-weighted images were acquired from a healthy right-handed volunteer (25 years old) on a whole-body 3 T scanner. Two approaches were used to dissect the tractography results: 1) a standard region of interest technique and 2) the use of Brodmann's area as seeding points, which represents an innovation in terms of seeds initiation.Results:Results are presented as tri-dimensional tractography images. The uncinate fasciculus, the inferior longitudinal fasciculus, the inferior fronto-occipital fasiculus, the corticospinal tract, the corpus callosum, the cingulum, and the optic radiations where studied by conventional seeding approach, while Broca's and Wernicke's areas, the primary motor as well as the primary visual cortices were used as seeding areas in the second approach.Conclusions:We report state-of-the-art tractography results of some of the major white matter bundles in a normal subject using DTI. Moreover, we used Brodmann's area as seeding areas for fiber tracts to study the connectivity of known major functional cortical areas.
Occipital Stimulation for Chronic Migraine: Patient Selection and Complications
Authors: Kiss Zelma H. T. , Becker Werner J. 
Published: December 2014

Background:Chronic migraine is a significant cause of disability world-wide and occipital region stimulation (OS) has been proposed to treat it. While participating in an industry-sponsored pilot trial of OS, we aimed to collect data regarding our surgical complications and long term usage of OS in our chronic migraine patients.Methods:Ten patients (8 female, median age 46.5 years) were enrolled based on criteria established by the sponsoring company, screened in the headache clinic, and followed for a median of 33 months. We did not access data collected by industry for this report and instead collected our own data prospectively, including predominant location of headache, location of paresthesia evoked by OS, and complications.Results:Adverse events included three possible early infections requiring antibiotics but not hardware removal, one late implantable pulse generator erosion requiring removal, one generator malfunction requiring revision, and loss of paresthetic coverage requiring four revisions in four patients. Two patients experienced new symptoms requiring psychiatric intervention. Five patients had no benefit and have been explanted. Of those who remain using their device, the proportion of their pre-operative pain located in the occipital region was 0.62 ± 0.14, whereas in those patients who have been explanted, the proportion was 0.31 ± 0.18 (t = 3.15, p=0.01).Conclusions:Complication rates with OS are higher than those seen with other stimulation techniques, despite identical hardware and similar surgery. The location of migraine pain did predict outcome, and suggests that only those with primarily occipital region headache are candidates for this therapy.
The Potential Impact of Delayed Radiation Therapy on Patients with Glioblastoma
Authors: Alnaami Ibrahim , VanderPluym Juliana , Murtha Albert , Walling Simon , Mehta Vivek , Gourishankar Sita , Senthilselvan Ambikaipakan 
Published: December 2014

Background:Radiation therapy (RT) is the major component of glioblastoma treatment; however, the time to initiate RT after surgical intervention varies between institutions. Our study examined the time from diagnosis to the initiation of RT and its effects on overall patient survival.Methods:We retrospectively examined 267 patients with glioblastoma who received RT as part of their therapy in two Canadian tertiary care centers. The primary goal of the study is to assess if time to RT can predict/impact survival in glioblastoma patients.Results:The following variables were associated with an increased risk of death: hazard ratio (HR) of time to RT was 0.95 [95% confidence interval (CI), 0.91–0.99] for every extra week. HRs for the type of surgery (resection or biopsy) and type of management received (standard of care in comparison with RT regardless of chemotherapeutic agents other than concomitant and adjuvant temozolomide) were 0.50 (95% CI, 0.37–0.66) and 0.53 (95% CI, 0.38–0.75), respectively. HR for age was 1.02 (95% CI, 1.01–1.03) for every extra year. Standard 60 Gy RT HR was 0.70 [95% confidence interval (CI), 0.51–0.97] in younger patients.Conclusions:The time from diagnosis to the initiation of RT was found to be a significant prognostic factor for overall patient survival. The addition of temozolomide to the treatment protocol, age, standard RT dose in younger patients and extent of surgery are others factors associated with longer survival periods.
The Incidence and Prevalence of Multiple Sclerosis in Nova Scotia, Canada
Authors: Marrie Ruth Ann , Fisk John D. , Stadnyk Karen J. , Yu Bo Nancy , Tremlett Helen , Wolfson Christina , Warren Sharon , Bhan Virender ,   CIHR Team in the Epidemiology and Impact of Comorbidity on Multiple Sclerosis
Published: December 2014

Background:Estimates of incidence and prevalence are needed to determine disease risk and to plan for health service needs. Although the province of Nova Scotia, Canada is located in a region considered to have a high prevalence of multiple sclerosis (MS), epidemiologic data are limited.Objective:We aimed to validate an administrative case definition for MS and to use this to estimate the incidence and prevalence of MS in Nova Scotia.Methods:We used provincial administrative claims data to identify persons with MS. We validated administrative case definitions using the clinical database of the province's only MS Clinic; agreement between data sources was expressed using a kappa statistic. We then applied these definitions to estimate the incidence and prevalence of MS from 1990 to 2010.Results:We selected the case definition using ≥7 hospital or physician claims when >3 years of data were available, and ≥3 claims where less data were available. Agreement between data sources was moderate (kappa = 0.56), while the positive predictive value was high (89%). In 2010, the age-standardized prevalence of MS per 100,000 population was 266.9 (95% CI: 257.1- 277.1) and incidence was 5.17 (95% CI: 3.78-6.56) per 100,000 persons/year. From 1990-2010 the prevalence of MS rose steadily but incidence remained stable.Conclusions:Administrative data provide a valid and readily available means of estimating MS incidence and prevalence. MS prevalence in Nova Scotia is among the highest in the world, similar to recent prevalence estimates elsewhere in Canada.
Motion Analysis of Normal Patellar Tendon Reflex
Authors: Tham Lai Kuan , Osman Noor Azuan Abu , Abas Wan Abu Bakar Wan , Lim Kheng Seang 
Published: December 2014

Background:Reflex assessment, an essential element in the investigation of the motor system, is currently assessed through qualitative description, which lacks of normal values in the healthy population. This study quantified the amplitude and latency of patellar tendon reflex in normal subjects using motion analysis to determine the factors affecting the reflex amplitude.Methods:100 healthy volunteers were recruited for patellar tendon reflex assessments which were recorded using a motion analysis system. Different levels of input strength were exerted during the experiments.Results:A linear relationship was found between reflex input and reflex amplitude (r = 0.50, P <0.001). The left knee was found to exhibit 26.3% higher reflex amplitude than the right (P <0.001). The Jendrassik manoeuvre significantly increased reflex amplitude by 34.3% (P = 0.001); the effect was especially prominent in subjects with weak reflex response. Reflex latency normality data were established, which showed a gradual reduction with increasing input strength.Conclusion:The quantitative normality data and findings showed that the present method has great potential to objectively quantify deep tendon reflexes.
The Autonomic Reflex Screen in Healthy Participants from Southwestern Ontario
Authors: Ives Colleen T. , Berger Michael J. , Kimpinski Kurt 
Published: December 2014

Background:The autonomic reflex screen (ARS) is a composite of well-defined tests of various autonomic domains and is an essential part of the diagnosis of autonomic disorders. Institutional and regional differences exist and necessitate the ongoing development of control values for the ARS. Here we present data obtained from healthy participants from Southwestern Ontario.Methods:A total of 121 healthy individuals underwent quantitative sudomotor axon reflex testing (QSART), heart rate response to deep breathing (HRDB), and Valsalva maneuver using standard protocols as part of the ARS.Results:Sweat volumes obtained during QSART are presented by site (forearm, proximal leg, distal leg and foot) and by gender. Data is expressed as the mean sweat volume per site with the associated 2.5th, 5th and 95th percentiles. Data for males and females is also stratified by age group (14-25, 26-40 and 41-76 years). Measurements of cardiovagal parasympathetic function including HRDBand Valsalva ratio are stratified by age group (14-25, 26- 40 and 41-76 years). Data is expressed as the mean with associated percentiles (2.5, 5, 95 and 97.5 percentiles).Conclusions:The current manuscript provides control data for the various components of the ARS to aid in the diagnosis of autonomic disorders.
Screening of Key Genes Associated with Ischemic Stroke via Microarray Data
Authors: Wang Jianmin , Zhou Dongliang , Qin Hongwei , Xu Ying , Guan Ying , Zang Weidong 
Published: December 2014

Objective:To promote understandings about the pathogenesis of ischemic stroke (IS) through mining key genes, functions and pathways with microarray technology.Methods:Differentially expressed genes (DEGs) in blood between patients with IS and healthy people were screened out through comparing microarray data obtained from Gene Expression Omnibus. Overrepresented functions in DEGs were revealed by Gene Ontology (GO) enrichment analysis. Interaction network was constructed for the top 24 DEGs with information from Human Protein Reference Database (HPRD). Relevant microRNAs (miRNAs) were retrieved from three databases: TargetScan, miRBase and miRanda.Results:A total of 503 DEGs were obtained. Functional enrichment analysis showed that immune response, signaling pathways and apoptosis were significantly over-represented. Six key genes with big degree, betweenness and clustering coefficient were then revealed, which might play important roles in the development of IS. In addition, 57 differentially expressed miRNAs targeting the 6 genes were retrieved.Conclusions:Our study provides insights into the pathogenesis of IS and potential targets to treat the disease.