bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complex I and ATP Content Deficiency in Lymphocytes from Friedreich's Ataxia
Authors: Heidari Mohammad Mehdi , Houshmand Massoud , Hosseinkhani Saman , Nafissi Shahriar , Khatami Mehri 
Published: December 2014

Background:Friedreich's ataxia (FRDA) is an inherited recessive disorder characterized by progressive neurological disability and heart abnormalities. A deficiency in the protein frataxin causes this disease. Frataxin deficiency leads to progressive iron accumulation in mitochondria, excessive free radical production and dysfunction of respiratory chain complexes. The expansion (GAA) repeat in the first intron causes decreased frataxin expression by interfering with transcription.Methods:Activity of mitochondrial respiratory chain complex I (measured as NADH ferricyanide reductase) and intracellular ATP measurement was performed on lymphocyte of FRDA patients (n=12) and control subjects (n=25).Results:Our findings showed that complex I activity and intracellular ATP were significantly reduced (P=0.001) in patients compared with controls and we found strong correlation between complex I activity and intracellular ATP content in FRDA patients (r = 0.93; P<0.002). 8.6 and 9.0 kb deletion in mtDNA was detected in 9 patients out of 12 (75%) by multiplex polymerase chain reaction (PCR) and Southern blot analysis.Conclusions:This study suggested that a biochemical defect in complex I activity and ATP production, which may be due to iron accumulation in mitochondria, can be involved in age of onset of FRDA.
Potentially Life-Threatening Ictal Bradycardia in Intractable Epilepsy
Authors: Odier Céline , Nguyen Dang Khoa , Bouthillier Alain , Giard Normand , Saint-Hilaire Jean-Marc , Cossette Patrick 
Published: December 2014

Background:Recently a high prevalence of asystole was found in individuals with refractory epilepsy.Objective:To measure the prevalence and characterize the pattern of ictal bradycardia (IB) in our cohort.Method:We analyzed ictal heart rate (HR) and seizure localization in 69 consecutive individuals with intractable epilepsy. Ictal bradycardia was defined by HR less than 60 beat per min (bpm) and a fall of more than 30 bpm.Results:Ictal bradycardia was observed in 1.9% of seizures and in five individuals (7.2%), who presented IB in 5.7% of their seizures. Four of them had also relative IB (a decrease of HR of more than10 bpm) in the majority of their seizures. Four additional individuals showed relative IB.Conclusion:Ictal bradycardia occurs more frequently than previously thought in individuals with refractory epilepsy. Recognition of individuals with small to moderate ictal HR decrease may help to identify those at greatest risk for asystole.
Regional Variability in the Use of CT for Patients with Suspected Mild Traumatic Brain Injury
Authors: Ryu Won Hyung A. , Feinstein Anthony , Colantonio Angela , Streiner David L. , Dawson Deirdre 
Published: December 2014

Objective:To investigate the use of computed tomography (CT) scans in patients with suspected acute mild traumatic brain injury (mTBI) presenting to emergency departments.Method:850 potential mTBI cases were identified through reviews of three months of health records from nine selected emergency departments across the province of Ontario. Records for review were selected using the International Classification of Disease, 9th revision, Clinical Modification codes and Injury codes.Results:Patients who received head CT were significantly older (p<0.01), had documented loss-of-consciousness (LOC) &/or Post-TraumaticAmnesia (PTA) (p<0.001), documented nausea (p<0.01), documented vomiting (p<0.001), abnormal neurological exam results (p<0.01), had visited an urban center (p<0.001), and/or arrived by ambulance (p<0.001). The significant predictors of CT scan prescription (in a forward stepwise logistic regression) were urban location of hospital (OR=5.14; p≤0.001), LOC &/or PTA (OR=4.83; p≤0.001), vomiting (OR=2.56; p≤0.01), arrival by ambulance (OR=2.15; p≤0.001), nausea (OR=1.92; p=≤0.02) and older age (OR=1.02; p≤0.01).Conclusion:These data extend our knowledge regarding the use of CT during acute diagnosis and management of suspected mTBI patients. In addition to confirming previously reported risk factors of intracranial complication, geographical location of hospital and arrival mode were found to be significant predictors of CT use. The results suggest that the management patterns for acute mTBI are inconsistent. The implications of this are discussed.
Superficial Anastomotic Veins: Neurosurgical View Depending on 251 Cranitotomies
Authors: Tanriverdi Taner , Al-Jehani Hosam , Poulin Nicole , Olivier Andre 
Published: December 2014

Background:Superficial anastomotic veins (SAVs) have been studied extensively but little attention has been paid to clinical studies. The aim of this study is to provide variations in the drainage patterns of SAVs depending on the intraoperative findings.Methods:A total of 251 craniotomies due to intractable temporal lobe epilepsy were performed between 1972 and 1987 at the Montreal Neurological Institute. The courses of the three largest SAVs including the vein of Trolard (VT), vein of Labbe (VL) and superficial Sylvian vein (SSV) were studied.Results:All three veins showed variable courses. The most common predominant vein was the combination of the VL + SSV. The VT and VL were frequently coursed at the level of the central vein and middle temporal vein, respectively. On the right hemisphere the SSV was the predominant type while the VL tended to be predominant on the left hemisphere. A combination of VL and SSV was predominant in patients with right and/or left hemispheric dominance.Conclusions:The SAVs showed considerable variation in their courses and it is difficult to define an exact pattern although some courses showed constant directions. Attention should be paid not to damage these veins since in a considerable number of cases a single dominant vein may be responsible for draining a majority of the lateral surface of cerebral hemisphere.
TMS Neuro-Cardiovascular Coupling in Vascular Compression Cranial Neuropathy
Authors: Kirton Adam , Gunraj Carolyn , Chen Robert 
Published: December 2014

Background:Neurovascular compression (NVC) may cause cranial mononeuropathy but lacks a definitive diagnostic investigation. We hypothesized that the arterial pressure wave (APW) would interact at the neurovascular interface in NVC to inhibit transmission of transcranial magnetic stimulation (TMS) stimuli to affected muscles.Methods:We report a novel neurophysiological method coupling cardiovascular physiology with TMS. The electrocardiogram (ECG) and arterial pressure wave (APW) were coupled to triggering of cortical TMS in a patient with NVC-induced spinal accessory (CNXI) mononeuropathy. Outcome measures included motor evoked potential (MEP) amplitudes and firing probabilities of normal and affected trapezieus (TPZ). Values at intervals in proximity to the APW (40/80/120/160ms) were compared to baseline (800ms) using ANOVA and student t-test.Results:Electrocardiogram triggered TMS of CNXI pathways with 100% reliability. MEP amplitudes were decreased in proximity to the APW, particularly at 120ms (0.21±0.04 mV versus 0.39±0.10mV, p=0.003). TPZ firing probabilities were similarly inhibited (43.8% versus 88.2%, p=0.009). No effect of APW proximity was observed on the unaffected side (p=0.868). Procedures were well tolerated.Conclusions:Vascular compression causes CNXI mononeuropathy. Transcranial magnetic stimulation-cardiovascular coupling may evaluate neurovascular junction interactions and non-invasively diagnose NVC.
Optimization of Visual Evoked Potential (VEP) Recording Systems
Authors: Karanjia Rustum , Brunet Donald G. , ten Hove Martin W. 
Published: December 2014

Objective:To explore the influence of environmental conditions on pattern visual evoked potential (VEP) recordings.Methods:Fourteen subjects with no known ocular pathology were recruited for the study. In an attempt to optimize the recording conditions, VEP recordings were performed in both the seated and recumbent positions. Comparisons were made between recordings using either LCD or CRT displays and recordings obtained in silence or with quiet background music. Paired recordings (in which only one variable was changed) were analyzed for changes in P100 latency, RMS noise, and variability.Results:Baseline RMS noise demonstrated a significant decrease in the variability during the first 50msec accompanied by a 73% decrease in recording time for recumbent position when compared to the seated position (p<0.05). Visual evoked potentials recorded using LCD monitors demonstrated a significant increase in the P100 latency when compared to CRT recordings in the same subjects. The addition of background music did not affect the amount of RMS noise during the first 50msec of the recordings.Conclusion:This study demonstrates that the use of the recumbent position increases patient comfort and improves the signal to noise ratio. In contrast, the addition of background music to relax the patient did not improve the recording signal. Furthermore, the study illustrates the importance of avoiding low-contrast visual stimulation patterns obtained with LCD as they lead to higher latencies resulting in false positive recordings. These findings are important when establishing or modifying a pattern VEP recording protocol.
Comparison of CTA to DSA in Determining the Etiology of Spontaneous ICH
Authors: Yeung Robert , Ahmad Tabassum , Aviv Richard I. , de Tilly Lyne Noel , Fox Allan J. , Symons Sean P. 
Published: December 2014

Background and Purpose:To compare the efficacy of computed tomographic angiography (CTA) to that of digital subtraction angiography (DSA) in the detection of secondary causes of intracerebral hemorrhage (ICH).Methods:Between January 2001 and February 2007 there were 286 patients that had both CTA and DSA for intracranial hemorrhage of all types. Those with primarily subarachnoid hemorrhage or recent trauma were excluded. Fifty-five patients formed the study cohort. Three reviewers independently analyzed the CTAs in a blinded protocol and classified them based on presence or absence of a secondary etiology. Results were compared with the reference standard DSA and kappa values determined for interobserver variability.Results:The overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CTA were 89%, 92%, 91%, 91% and 91%, respectively. Kappa value for interobserver agreement ranged from 0.78 to 0.89. Two of four dural arteriovenous fistulas (dAVF) were missed on CTA by all three reviewers.Conclusion:CTA is nearly as effective as DSA at determining the cause of secondary intracerebral hemorrhage, but with a lower sensitivity for dAVFs. This supports the use of CTA as the first screening test in patients presenting with spontaneous ICH.
Lumbar Discectomy: A National Survey of Neurosurgeons and Literature Review
Authors: Cenic Aleksa , Kachur Edward 
Published: December 2014

Background:To ascertain neurosurgical practices in the surgical management of one-level lumbar discectomies in the Canadian adult population.Methods:One page questionnaire faxed to each Neurosurgeon in Canada with questions relating to their practice in the management of this common neurosurgical procedure. All data analyzed using Chi-square statistics.Results:112 completed surveys were returned hence, giving a 64% response rate with the respondents being predominantly adult neurosurgeons. Of the respondents, 88% perform lumbar discectomy in adults. Only 15% of respondents had a Spine Fellowship. For preoperative imaging, 44% use BOTH CT and MRI whereas 28% use only MRI and 15% use only CT. Prior to initial skin incision, 57% use a localization X-ray image. Preoperative antibiotics are prescribed by 92% of respondents. Majority of respondents (60%) use a pre-incision local anesthetic, whereas only a minority (44%) of respondents employ pre-closure intramuscular injection. With respect to magnification, 70% use microscope, 19% loupes, and 8% neither. Only 12% use minimally invasive tubular retractors. 68% remove “as much disc as possible”, while 31% remove “ONLY herniated part”. In the case of dural tears, 77% of respondents use fibrin glue (Tisseel®). Prior to skin closure, majority of neurosurgeons do NOT use a fat graft (72%), whereas 61% of respondents use epidural steroids. With respect to discharge from the hospital, 58% are discharged on the next day, 18% on the same day, and 23% in two days. Return to work is not recommended until at least six weeks post-op (96%). Most neurosurgeons (93%) would not operate on an individual with a chief complaint of low back pain.Conclusions:Our survey has identified variations in practice patterns amongst Canadian Neurosurgeons with respect to performing one-level lumbar discectomies. This survey is expected to form a basis for the design of a randomized controlled trial in the evaluation of the best management approach for this common neurosurgical procedure.
LRRK2 is not a Significant Cause of Parkinson's Disease in French-Canadians
Authors: Dupré Nicolas , Rivière Jean-Baptiste , Myers Richard H. , Provencher Pierre , Pourcher Emmanuelle , Émond François , Rouleau Guy A. 
Published: December 2014

Background:An old founder mutation (G2019S) was found with high frequency in the North African Arabs (30%) and Ashkenazi Jews (18%).Objective:Demonstrate if mutations in the LRRK2 gene are a significant cause of Parkinson's disease (PD) in the French-Canadian founder population.Methods:Cases were recruited through a designated movement disorder clinic in Quebec City. Every index case had to meet the Ward and Gibb criteria for PD. Controls consisted of a non-disease group of similar age and ethnicity as the cases. Exons 31 and 41 of LRRK2 were amplified by PCR with intronic primers in all 125 PD cases and directly sequenced on an ABI 3700 sequencer. Six single nucleotide polymorphism were typed in 125 PD cases and 95 normal controls. Associations between unrelated cases and matched controls were analyzed. Single marker analysis and haplotype association tests were performed.Results:Sequencing analysis did not reveal any reported or novel mutations in exons 31 and 41 of LRRK2. The G2019S mutation as well as mutations affecting amino acid 1441 were absent in the 125 patients. The case-control association study performed to detect the presence of a common variant in LRRK2 did not provide any positive signal. Single-marker and haplotype analyses systematically gave non-significant P values.Conclusions:We performed a case-control association study in 125 French-Canadian (FC) patients with PD and 95 FC controls and found that common variants in LRRK2 are unlikely to be a significant cause of late-onset PD in this founder population.
Sema4D/CD100 Deficiency Leads to Superior Performance in Mouse Motor Behavior
Authors: Yukawa Kazunori , Tanaka Tetsuji , Takeuchi Noriko , Iso Hiroyuki , Li Li , Kohsaka Akira , Waki Hidefumi , Miyajima Masayasu , Maeda Masanobu , Kikutani Hitoshi , Kumanogoh Atsushi 
Published: December 2014

Background:Sema4D/CD100 is a type of class 4 semaphorin, exhibiting crucial rôles in growth cone guidance in developing neurons. Sema4D is widely expressed throughout the central nervous system in embryonic mouse brain, and is selectively localized to oligodendrocytes and myelin in the postnatal brain. However, direct evidence of the actual involvement of Sema4D in the neuronal network development crucial for neurobehavioral performance is still lacking. The present study therefore examined whether Sema4D deficiency leads to abnormal behavioral development.Methods:Both wild-type and Sema4D-deficient mice were subjected to behavioral analyses including open-field, adhesive tape removal, rotarod tests and a water maze task.Results:Open-field tests revealed increased locomotor activity in Sema4D-deficient mice with less percentage of time spent in the center of the field. In both the adhesive tape removal and rotarod tests, which examine motor coordination and balance, Sema4D-deficient mice showed significantly superior performance, suggesting facilitated motor behavior. Both Sema4D-deficient and wild-type mice successfully learnt the water maze task, locating a hidden escape platform, and also showed precise memory for the platform position in probe tests. However, the swimming speed of Sema4D-deficient mice was significantly faster than that of wild-type mice, providing further evidence of their accelerated motor behavior.Conclusion:Our mouse behavioral analyses revealed enhanced motor activity in Sema4D-deficient mice, suggesting the crucial involvement of Sema4D in the neurodevelopmental processes of the central structures mediating motor behavior in mice.
The Effects of Maternal Deprivation on the Hippocampal Structure in Adult Rats
Authors: Karakaş Pınar , Bozkır Memduha Gülhal , Dere Fahri , Melik Enver , Melik Emine Babar , Kaya Mehmet , Polat Sait 
Published: December 2014

Objectives:To examine the ultrastructural effects of maternal deprivation during developmental periods of limbi-chypothalamo-pituitary-adrenal system on hippocampal dendritic structures in adult rats.Methods:The experiments were carried out with male and female wistar rats in our department. The rats were mated and, after birth, the pups were divided into four groups. The first group (control group) pups remained undisturbed with their dam until postweaning day 22. Maternal deprived groups were separated from their dams for 24 hours at postnatal day 4, 9 and 18. The subjects were provided with food and water ad libitum until 3-months-of-age. At the third month, the rats were transcardially perfused, samples were taken from CA1 and CA3 regions of the hippocampus. Tissues were prepared for electron microscopy.Results:When the data were analyzed, there were no differences between male and female rats in both ultrastructure and semiquantitative analysis of axodendritic synapses. The ultrastructure of Group 1 was seen as normal while in the second Group some neurons nuclear envelope made deep invagination into the nucleus. Additionally, axodendritic synapses were found normal. In Group 3, micrographs and axodendritic synapses were showed normal structure. However, in Group 4 in some neurons invaginations were seen similar to Group 2. Axodendritic synapses were found to be normal.Conclusion:These experiments establish that MD in rats produces slight ultrastructural changes and decreases the number of synapses in CA1 and CA3 subregions of the hippocampus.
Reliability of Visual Temporal Thresholds
Authors: Brown L N , Eliasziw M , Metz L M 
Published: December 2014

Background:Visual processing deficits involving temporal characteristics are typically not captured by the widely used outcome measures (i.e., Expanded Disability Status Scale, Multiple Sclerosis Functional Composite) in multiple sclerosis (MS). Visual temporal thresholds (i.e., measurements of the temporal aspects in visual processing) are typically significantly higher (i.e., prolonged) in MS patients when compared to controls. The test-retest reliability of these thresholds was examined in patients with MS.Methods:Visual temporal thresholds were measured in 21 stable MS patients during two separate test sessions. Test-retest reliability and the standard error of measurement were calculated. The threshold of change in visual temporal thresholds in MS patients that would correspond to real change beyond measurement error with 95% certainty was also calculated. For comparisons, a control group (n = 10) was included.Results:The test-retest reliability of this measure of visual temporal thresholds was 0.97. The threshold indicating change beyond chance or measurement error with 95% certainty was 11 ms. Higher thresholds were significantly correlated with longer durations of disease.Conclusions:This measure of visual temporal thresholds has excellent test-retest reliability and a change of greater than 11 ms is highly likely to represent real change in MS patients. The findings indicate that these measurements may provide useful clinical information about functional changes regarding the temporal aspects of the visual system, which is currently not captured by the Extended Disability Status Scale.
Clinical Practice Regarding Dopamine-Agonist Use and Driving in Parkinson's Disease
Authors: de Bie R. M.A. , Miyasaki J. , Lang A. E. , Fox S. H. 
Published: December 2014

Background:Current Health Canada instructions for use of the dopamine agonists (DA), pramipexole and ropinirole, state that Parkinson's disease (PD) patients should be told not to drive. The objective was to assess neurologists' actual clinical practice concerning driving advice they give to PD patients starting a DA.Methods:An online survey was created consisting of 4 items regarding demographics, 5 regarding PD and driving, and 9 regarding DA use and driving. The survey was distributed to 563 neurologists.Results:In total 96 neurologists (17.9%) responded. 4.4% tell patients with PD not to drive, solely because they are taking a DA. Respondents assess the patient's tendency for excessive daytime sleepiness and sleep attacks after starting a DA more frequently than after starting other dopaminergic drugs (p<0.001).Discussion:A minor proportion of the clinicians responding to our survey advise PD patients not to drive, solely because they use a DA. Such being the case, we propose that current Health Canada guidelines need revision.
Histopathological Examination of Intervertebral Disc Specimens: A Cost-Benefit Analysis
Authors: Wu Adam S. , Fourney Daryl R. 
Published: December 2014

Object:Routine histopathological examination of intervertebral disc specimens is commonly performed in North American hospitals, but recent studies have questioned the utility of this practice in cases where the indication for surgery is a benign process such as degenerative disc disease. In this study, we have performed a cost-benefit analysis of this practice.Methods:We performed a cost-benefit analysis of routine histopathological examination of 1775 routine (non-neoplastic and non-infectious indications for surgery) and 70 non-routine (suspected neoplastic or infectious indications for surgery) discectomy specimens obtained over an eight-year period (1996 and 2004). Chart reviews were used to determine if any histopathology findings were clinically significant (i.e., affected subsequent patient care). Total costs were calculated. A literature review was conducted to compare our results with other published series.Results:We found four unexpected histopathology results among 1775 specimens obtained from routine cases, one of which was clinically significant. We calculated costs of $42,165.25 per unexpected histopathological finding and $168,625 per clinically significant histopathological finding. For non-routine surgeries, the cost per abnormal pathological finding was $116.67.Conclusions:In routine cases, histopathological examination of disc specimens is not justified. The decision to send specimens for pathological examination should be based on the surgeon's judgment.