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Find video protocols related to scientific articles indexed in Pubmed.
Severe paraspinal muscle involvement in facioscapulohumeral muscular dystrophy.
Neurology
PUBLISHED: 08-20-2014
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In this study, involvement of paraspinal muscles in 50 patients with facioscapulohumeral dystrophy (FSHD) was evaluated using MRI.
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Single-mode pumped high air-fill fraction photonic crystal fiber taper for high-power deep-blue supercontinuum sources.
Opt Lett
PUBLISHED: 02-25-2014
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Dispersion control with axially nonuniform photonic crystal fibers (PCFs) permits supercontinuum (SC) generation into the deep-blue from an ytterbium pump laser. In this Letter, we exploit the full degrees of freedom afforded by PCFs to fabricate a fiber with longitudinally increasing air-fill fraction and decreasing diameter directly on the draw-tower. We demonstrate SC generation extending down to 375 nm in one such monolithic fiber device that is single-mode at 1064 nm at the input end.
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Neoadjuvant bevacizumab and irinotecan versus bevacizumab and temozolomide followed by concomitant chemoradiotherapy in newly diagnosed glioblastoma multiforme: A randomized phase II study.
Acta Oncol
PUBLISHED: 01-23-2014
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Surgery followed by radiotherapy and concomitant and adjuvant temozolomide is standard therapy in newly diagnosed glioblastoma multiforme (GBM). Bevacizumab combined with irinotecan produces impressive response rates in recurrent GBM. In a randomized phase II study, we investigated the efficacy of neoadjuvant bevacizumab combined with irinotecan (Bev-Iri) versus bevacizumab combined with temozolomide (Bev-Tem) before, during and after radiotherapy in newly diagnosed GBM.
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The effect of exercise on hippocampal volume and neurotrophines in patients with major depression--a randomized clinical trial.
J Affect Disord
PUBLISHED: 01-04-2014
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The hippocampal volume is reduced in patients with major depression. Exercise leads to an increased hippocampal volume in schizophrenia and in healthy old adults. The effect of exercise on hippocampal volume is potentially mediated by brain derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), and insulin like growth factor 1 (IGF-1). The aim of this trial was to assess the effect of an aerobic exercise intervention on hippocampal volume and serum BDNF, VEGF, and IGF-1 in patients with major depression.
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Orbital Volumetry in Graves' Orbitopathy: Muscle and Fat Involvement in relation to Dysthyroid Optic Neuropathy.
ISRN Ophthalmol
PUBLISHED: 01-01-2014
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Purpose. We wanted to investigate the relative significance of fat and muscle enlargement in the development of dysthyroid optic neuropathy (DON) in Graves' orbitopathy (GO). Methods. Preoperative coronal CT scans of 13 patients with and without DON who subsequently underwent orbital decompression were retrospectively analyzed. Thirteen patients imaged for unilateral orbital fractures served as controls. Results. The retrobulbar muscle volume was 2.1 ± 0.5?cm(3) (mean ± SD) in controls, 4.3 ± 1.5?cm(3) in GO without DON, and 4.7 ± 1.7?cm(3) in GO with DON. The retrobulbar fat volume was 5.4 ± 1.6?cm(3) in controls, 8.7 ± 8.0?cm(3) in GO without DON, and 9.4 ± 3.1?cm(3) in GO with DON. The muscle and fat volumes were higher in patients with GO than in controls (P < 0.001), but the volumes in orbits with and without DON were not significantly different. The volume of the optic nerve were similar in the 3 groups. The number of apical, coronal 2?mm thick slices with no fat was 2.9 ± 0.9 in normal orbits, it was 4.1 ± 1.0 in GO orbits without DON and 5.3 ± 0.8 in GO orbits with DON (P = 0.007). Conclusion. Apical muscle enlargement may be more important than orbital fat enlargement in the development of DON. However, the fact that apical crowding and muscle enlargement also occur in orbits without DON suggests that other factors also play a role in the development of DON.
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Von Hippel-Lindau disease (vHL).
Dan Med J
PUBLISHED: 12-21-2013
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These clinical guidelines outline the criteria and recommendations for diagnostic and genetic work-up of families suspected of von Hippel-Lindau disease (vHL), as well as recommendations for prophylactic surveillance for vHL patients. The guideline has been composed by the Danish Coordination Group for vHL which is comprised of Danish doctors and specialists interested in vHL. The recommendations are based on longstanding clinical experience, Danish original research, and extensive review of the international literature. vHL is a hereditary multi-tumour disease caused by germline mutations in the VHL gene. vHL is inherited in an autosomal dominant manner. Predisposed individuals are advised to undergo prophylactic examinations, as they are at lifelong risk of developing multiple cysts and tumours, especially in the cerebellum, the spinal cord, the retina (hemangioblastomas), the kidneys (renal cell carcinoma), the adrenal glands (pheochromocytoma), the pancreas, as well as in other organs. As many different organs can be affected, several medical specialities often take part in both diagnosis and treatment of manifestations. vHL should be suspected in individuals with a family history of the disease, and/or in individuals with a vHL-associated manifestation; i.e. a hemangioblastoma in the retina or the central nervous system, familial or bilateral pheochromocytomas, familial, multiple, or early onset renal cell carcinomas, and in individuals with an endolymphatic sac tumour in the inner ear. Individuals suspected of vHL should be referred to a department of clinical genetics for genetic work-up and counselling as well as have a clinical work-up to identify any undiagnosed vHL-associated manifestations. This guideline describes the elements of the clinical diagnostic work-up, as well as the genetic work-up, counselling, and mutation screening. Individuals who are affected with vHL, individuals at risk of vHL, and VHL-mutation carriers are advised to follow the surveillance program which consists of regular prophylactic examinations relevant to different age groups. The examinations are recommended to start in infancy with annual paediatric examinations and ophthalmoscopy until the age of five years. From five to 14 years, annual plasma-metanephrine and plasma-normetanephrine tests, as well as annual hearing examinations are added. Also, an MRI (Magnetic Resonance Imaging) examination of the CNS and abdomen should be done between the ages of eight and 14 years. After the age of 15 years, individuals should be referred to: a) annual ophthalmoscopy in dilation, b) annual neurological examination, c) every two years: MRIs of the CNS, including the inner ear, d) annual ultrasound/MRI of the abdomen, e) annual plasma-metanephrine, plasma-normetanephrine, and plasma-chromogranin A tests, and f) annual hearing examination at a department of audiology. It is advised that one doctor takes on the responsibility of coordination of and referral to the many examinations, and the communication with the patient. To facilitate the coordination, and especially for the patients own use, a mobile chart can be used. In 2012, the Danish vHL Coordination Group established a national vHL database comprising individuals with vHL and their relatives, as well as individuals examined for vHL. The database is designated to be a treatment and diagnostic instrument, as well as a tool in future vHL research in Denmark.
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NORMAL PHYSICAL ACTIVITY OBLITERATES THE DELETERIOUS EFFECTS OF A HIGH-CALORIC INTAKE.
J. Appl. Physiol.
PUBLISHED: 11-07-2013
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A high-caloric intake combined with a sedentary lifestyle is an important player in the development of type 2 diabetes mellitus (T2DM). The present study was undertaken to examine if the level of physical activity has impact on the metabolic effects of a high-caloric (+2,000 kcal/day) intake. Therefore, healthy individuals on a high caloric intake were randomized to either 10,000 or 1,500 steps per day for 14 days. Step-number, total energy expenditure, dietary records, neuropsychological tests, maximal oxygen uptake (VO2max), whole body dual-energy X-ray absorptiometry (DXA)- and abdominal magnetic resonance imaging (MRI)- scans, continuous glucose monitoring (CGM), and oral glucose tolerance tests (OGTT) with stable isotopes were performed before and after the intervention. Both study groups gained the same amount of body weight. However, the inactive group accumulated significantly more visceral fat compared to the active group. Following the two-week period, the inactive group also experienced a poorer glycaemic control, increased endogenous glucose production, decreased hepatic insulin extraction, increased baseline plasma levels of total cholesterol and LDL, and a decreased cognitive function with regard to capacity of attention. In conclusion, we find evidence to support that habitual physical activity may prevent pathophysiological symptoms associated with diet-induced obesity.
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Semi-supervised adaptation in ssvep-based brain-computer interface using tri-training.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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This paper presents a novel and computationally simple tri-training based semi-supervised steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI). It is implemented with autocorrelation-based features and a Naïve-Bayes classifier (NBC). The system uses nine characters presented on a 100 Hz CRT-monitor, three scalp electrodes for signal acquisition, a gUSB-amp for preamplification and two PCs for data-processing and stimulus control respectively. Preliminary test results of the system on nine healthy subjects, with and without tri-training, indicates that the accuracy improves as a result of tri-training.
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DTU BCI speller: An SSVEP-based spelling system with dictionary support.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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In this paper, a new brain computer interface (BCI) speller, named DTU BCI speller, is introduced. It is based on the steady-state visual evoked potential (SSVEP) and features dictionary support. The system focuses on simplicity and user friendliness by using a single electrode for the signal acquisition and displays stimuli on a liquid crystal display (LCD). Nine healthy subjects participated in writing full sentences after a five minutes introduction to the system, and obtained an information transfer rate (ITR) of 21.94 ± 15.63 bits/min. The average amount of characters written per minute (CPM) is 4.90 ± 3.84 with a best case of 8.74 CPM. All subjects reported systematically on different user friendliness measures, and the overall results indicated the potentials of the DTU BCI Speller system. For subjects with high classification accuracies, the introduced dictionary approach greatly reduced the time it took to write full sentences.
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Enrichment of autologous fat grafts with ex-vivo expanded adipose tissue-derived stem cells for graft survival: a randomised placebo-controlled trial.
Lancet
PUBLISHED: 10-01-2013
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Autologous fat grafting is increasingly used in reconstructive surgery. However, resorption rates ranging from 25% to 80% have been reported. Therefore, methods to increase graft viability are needed. Here, we report the results of a triple-blind, placebo-controlled trial to compare the survival of fat grafts enriched with autologous adipose-derived stem cells (ASCs) versus non-enriched fat grafts.
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von Hippel-Lindau disease: deafness due to a non-MRI-visible endolymphatic sac tumor despite targeted screening.
Int J Audiol
PUBLISHED: 09-05-2013
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Endolymphatic sac tumours (ELSTs) of the inner ear occur in 16% of patients with the hereditary tumor syndrome von Hippel-Lindau disease (vHL). ELSTs of all sizes can cause irreversible hearing loss which can, however, be prevented through early diagnosis and treatment. We aim to emphasize the challenges of prophylactic ELST screening and to explore the role of audiometry in pre-symptomatic ELST screening.
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The decrease of cardiac chamber volumes and output during positive-pressure ventilation.
Am. J. Physiol. Heart Circ. Physiol.
PUBLISHED: 07-26-2013
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Positive-pressure ventilation (PPV) is widely used for treatment of acute cardiorespiratory failure, occasionally at the expense of compromised cardiac function and arterial blood pressure. The explanation why has largely rested on interpretation of intracardiac pressure changes. We evaluated the effect of PPV on the central circulation by studying cardiac chamber volumes with cardiac magnetic resonance imaging (CMR). We hypothesized that PPV lowers cardiac output (CO) mainly via the Frank-Starling relationship. In 18 healthy volunteers, cardiac chamber volumes and flow in aorta and the pulmonary artery were measured by CMR during PPV levels of 0, 10, and 20 cmH2O applied via a respirator and a face mask. All cardiac chamber volumes decreased in proportion to the level of PPV. Following 20-cmH2O PPV, the total diastolic and systolic cardiac volumes (±SE) decreased from 605 (±29) ml to 446 (±29) ml (P < 0.001) and from 265 (±17) ml to 212 (±16) ml (P < 0.001). Left ventricular stroke volume decreased by 27 (±4) ml/beat; heart rate increased by 7 (±2) beats/min; and CO decreased by 1.0 (±0.4) l/min (P < 0.001). From 0 to 20 cmH2O, right and left ventricular peak filling rates decreased by -146 (±32) and -187 (±64) ml/s (P < 0.05) but maximal emptying rates were unchanged. Cardiac filling and output decrease with increasing PPV in healthy volunteers. The decrease is seen even at low levels of PPV and should be taken into account when submitting patients to mechanical ventilation with positive pressures. The decrease in CO is fully explained by the Frank-Starling mechanism.
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Microbial translocation in HIV infection is associated with dyslipidemia, insulin resistance, and risk of myocardial infarction.
J. Acquir. Immune Defic. Syndr.
PUBLISHED: 06-26-2013
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Microbial translocation has been suggested to be a driver of immune activation and inflammation. It is hypothesized that microbial translocation may be related to dyslipidemia, insulin resistance, and the risk of coronary heart disease in HIV-infected individuals.
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Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging.
Eur J Radiol
PUBLISHED: 05-14-2013
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Magnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics of intraluminal thrombus specimens to the appearance on magnetic resonance imaging.
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Cerebral Magnetic Resonance Spectroscopy Demonstrates Long-Term Effect of Bone Marrow Transplantation in ?-Mannosidosis.
JIMD Rep
PUBLISHED: 03-01-2013
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?-Mannosidosis, OMIM #248500, is an autosomal recessive lysosomal storage disease caused by acidic ?-mannosidase deficiency. Treatment options include bone marrow transplantation (BMT) and, possibly in the future, enzyme replacement therapy. Brain magnetic resonance spectroscopy (MRS) enables non-invasive monitoring of cerebral treatment effect. Accumulated cerebral mannose-containing oligosaccharides were demonstrated by MRS in a patient who at age 2 years and 11 months received a BMT from a haploidentical non-carrier sibling. The cerebral mannose-containing oligosaccharides had disappeared as early as 9½ months after BMT. MRS furthermore demonstrated the persistent treatment effect at regular intervals up to 5½ years after BMT. MRS is a non-invasive tool that can demonstrate the effect of BMT treatment. Likewise, MRS may be used to demonstrate the cerebral effect of other potential treatments such as enzyme replacement therapy.
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Peritumoral brain edema in angiomatous supratentorial meningiomas: an investigation of the vascular endothelial growth factor A pathway.
APMIS
PUBLISHED: 02-11-2013
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The aim of this work was to study the vascular endothelial growth factor A (VEGF-A) pathway and peritumoral brain edema (PTBE) through comparison of non-angiomatous and angiomatous meningiomas. Meningiomas are common intracranial tumors, which often have PTBE. VEGF-A is an integral part of PTBE formation and angiogenesis, and the capillary-rich angiomatous meningiomas are known for their PTBE. The VEGF-A receptor VEGFR-2 is responsible for the angiogenic effect of VEGF-A on endothelial cells, which is enhanced by the co-receptor neuropilin-1. Forty non-angiomatous, 22 angiomatous meningiomas, and 10 control tissue samples were collected for the study. Magnetic resonance images were available for 40 non-angiomatous and 10 angiomatous meningiomas. Tissue sections were immunostained for CD34, MIB-1, estrogen- and progesterone receptors. ELISA, chemiluminescence, and RT-qPCR were used for VEGF-A, VEGFR-2, and neuropilin-1 protein and mRNA quantification. Angiomatous meningiomas had larger PTBE (695 vs 218 cm(3) , p = 0.0045) and longer capillary length (3614 vs 605 mm/mm(3) , p < 0.0001). VEGF-A mRNA, neuropilin-1 mRNA, and VEGFR-2 protein levels were higher in angiomatous meningiomas independently of the capillary length (p < 0.05). Neuropilin-1 protein levels were lower in angiomatous meningiomas (p < 0.0001). The VEGF-A pathway and tumor capillary length may be essential for PTBE-formation in meningiomas. Further investigations of this pathway could lead to earlier therapy and targeted pharmacological treatment options.
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Optimal labeling dose, labeling time, and magnetic resonance imaging detection limits of ultrasmall superparamagnetic iron-oxide nanoparticle labeled mesenchymal stromal cells.
Stem Cells Int
PUBLISHED: 02-09-2013
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Background. Regenerative therapy is an emerging treatment modality. To determine migration and retention of implanted cells, it is crucial to develop noninvasive tracking methods. The aim was to determine ex vivo magnetic resonance imaging (MRI) detection limits of ultrasmall superparamagnetic iron-oxide (USPIO) labeled mesenchymal stromal cells (MSCs). Materials and Methods. 248 gel-phantoms were constructed and scanned on a 1.5T MRI-scanner. Phantoms contained human MSCs preincubated with USPIO nanoparticles for 2, 6, or 21 hours using 5 or 10? ? g?USPIO/10(5) MSCs. In addition, porcine hearts were scanned after injection of USPIO labeled MSCs. Results. Using 21?h incubation time and 10? ? g?USPIO/10(5) MSCs, labeled cells were clearly separated from unlabeled cells on MRI using 250.000 (P < 0.001), 500.000 (P = 0.007), and 1.000.000 MSCs (P = 0.008). At lower incubation times and doses, neither labeled nor unlabeled cells could be separated. In porcine hearts labeled, but not unlabeled, MSCs were identified on MRI. Conclusions. As few as 250.000 MSCs can be detected on MRI using 21?h incubation time and 10? ? g?USPIO/10(5) MSCs. At lower incubation times and doses, several million cells are needed for MRI detection. USPIO labeled cells can be visualized by MRI in porcine myocardial tissue.
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BCI using imaginary movements: the simulator.
Comput Methods Programs Biomed
PUBLISHED: 02-04-2013
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Over the past two decades, much progress has been made in the rapidly evolving field of Brain Computer Interface (BCI). This paper presents a novel concept: a BCI-simulator, which has been developed for the Hex-O-Spell interface, using the sensory motor rhythms (SMR) paradigm. With the simulator, it is possible to evaluate how the model parameters such as error classifications, delay between classifications and success rate affect the communication rate. Another advantage of the simulator is that it allows us to study for more classes than most online BCI systems which are limited to only two classes. Results show that the BCI simulator is able to give a deeper understanding of the feedback systems. We also find that a 3-class system is more efficient than a 2-class system if it obtains a success rate of at least 55% of the 2-class system.
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Endurance training improves insulin sensitivity and body composition in prostate cancer patients treated with androgen deprivation therapy.
Endocr. Relat. Cancer
PUBLISHED: 01-01-2013
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Insulin resistance and changes in body composition are side effects of androgen deprivation therapy (ADT) given to prostate cancer patients. The present study investigated whether endurance training improves insulin sensitivity and body composition in ADT-treated prostate cancer patients. Nine men undergoing ADT for prostate cancer and ten healthy men with normal testosterone levels underwent 12 weeks of endurance training. Primary endpoints were insulin sensitivity (euglycemic-hyperinsulinemic clamps with concomitant glucose-tracer infusion) and body composition (dual-energy X-ray absorptiometry and magnetic resonance imaging). The secondary endpoint was systemic inflammation. Statistical analysis was carried out using two-way ANOVA. Endurance training increased VO2max (ml(O2)/min per kg) by 11 and 13% in the patients and controls respectively (P<0.0001). The patients and controls demonstrated an increase in peripheral tissue insulin sensitivity of 14 and 11% respectively (P<0.05), with no effect on hepatic insulin sensitivity (P=0.32). Muscle protein content of GLUT4 (SLC2A4) and total AKT (AKT1) was also increased in response to the training (P<0.05 and P<0.01 respectively). Body weight (P<0.0001) and whole-body fat mass (FM) (P<0.01) were reduced, while lean body mass (P=0.99) was unchanged. Additionally, reductions were observed in abdominal (P<0.01), subcutaneous (P<0.05), and visceral (P<0.01) FM amounts. The concentrations of plasma markers of systemic inflammation were unchanged in response to the training. No group × time interactions were observed, except for thigh intermuscular adipose tissue (IMAT) (P=0.01), reflecting a significant reduction in the amount of IMAT in the controls (P<0.05) not observed in the patients (P=0.64). In response to endurance training, ADT-treated prostate cancer patients exhibited improved insulin sensitivity and body composition to a similar degree as eugonadal men.
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Vascular endothelial growth factor A protein level and gene expression in intracranial meningiomas with brain edema.
APMIS
PUBLISHED: 10-17-2011
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Meningiomas are the second most common primary intracranial tumors in adults. Although meningiomas are mostly benign, more than 50% of patients with meningioma develop peritumoral brain edema (PTBE), which may be fatal because of increased intracranial pressure. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and angiogen. VEGF-A protein, which is identical to vascular permeability factor, is a regulator of angiogenesis. In this study, 101 patients with meningiomas, and possible co-factors to PTBE, such as meningioma subtypes and tumor location, were examined. Forty-three patients had primary, solitary, supratentorial meningiomas with PTBE. In these, correlations in PTBE, edema index, VEGF-A protein, VEGF gene expression, capillary length, and tumor water content were investigated. DNA-branched hybridization was used for measuring VEGF gene expression in tissue homogenates prepared from frozen tissue samples. The method for VEGF-A analysis resembled an ELISA assay, but was based on chemiluminescence. The edema index was positively correlated to VEGF-A protein (p = 0.014) and VEGF gene expression (p < 0.05). The capillary length in the meningiomas was positively correlated to the PTBE (p = 0.038). If VEGF is responsible for the formation of PTBE, the edema may be treated with the anti-VEGF drug Bevacizumab (Avastin), which has been shown to reduce PTBE in patients with glioblastoma multiforme.
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von Hippel-Lindau disease: surveillance strategy for endolymphatic sac tumors.
Genet. Med.
PUBLISHED: 09-14-2011
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: Up to 16% of patients with the hereditary von Hippel-Lindau disease develop endolymphatic sac tumors of the inner ear. Early diagnosis and treatment of endolymphatic sac tumors can prevent audiovestibular morbidity, but optimal endolymphatic sac tumor surveillance strategy has yet to be determined. We aimed to evaluate endolymphatic sac tumor surveillance to determine the best surveillance strategy.
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Generic single-channel detection of absence seizures.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 08-29-2011
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A long-term EEG-monitoring system, which automatically marks seizure events, is useful for diagnosing and treating epilepsy. A generic method utilizing the low inter-and intra-patient variabilities in EEG-characteristics during absence seizures is proposed. This paper investigates if the spike-and-wave behaviour during absence seizures is so distinct that a single-channel implementation is possible. 18 channels of scalp electroencephalography (EEG), from 19 patients suffering from childhood absence epilepsy, are analysed individually. The characteristics of the seizures are captured using the energy content of wavelet transform subbands and classified using a support vector machine. To ease the evaluation of the method, we present a new graphical visualization of the performance based on the topographical distribution on the scalp. The presented seizure detection method shows that the best result is obtained for the derivation F7-FP1. Using this channel a sensitivity of 99.1 %, positive predictive value of 94.8 %, mean detection latency of 3.7 s, and false detection rate value of 0.5/h was obtained. The topographical visualization of the results clearly shows that the frontal, midline, and parietal channels outperform detection based on the channels in the occipital region.
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An auditory Go/No-Go study of event-related potentials in children with fetal alcohol spectrum disorders.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 08-29-2011
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In this study event-related potentials (ERPs) were used to investigate the effects of prenatal alcohol exposure on response inhibition identified during task performance. ERPs were recorded during a auditory Go/No Go task in two groups of children with mean age of 12.8 years (11 years to 14.7 years): one diagnosed with fetal alcohol syndrome (FAS) or partial FAS (FAS/PFAS; n = 12) and a control group of children of same age whose mothers abstained from alcohol or drank minimally during pregnancy (n = 11). The children were instructed to push a button in response to the Go stimulus and not to press the button when the No Go stimulus were heard. Task performance accuracy did not differ between the two groups, however differences were observed in the ERP components: P2, N2, and P3. The P2 amplitude were larger for Go trials in both groups. The FAS/PFAS group showed slower N2 response to Go trials, suggesting a less efficient early classification of the stimulus. P3 showed larger amplitudes to No-Go vs. Go in both groups. The study has provided new evidence for inhibition deficits in FAS/PFAS subjects identified by ERPs.
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Assessment of sleep quality in powernapping.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 08-29-2011
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The purpose of this study is to assess the Sleep Quality (SQ) in powernapping. The contributed factors for SQ assessment are time of Sleep Onset (SO), Sleep Length (SL), Sleep Depth (SD), and detection of sleep events (K-complex (KC) and Sleep Spindle (SS)). Data from daytime nap for 10 subjects, 2 days each, including EEG and ECG were recorded. The SD and sleep events were analyzed by applying spectral analysis. The SO time was detected by a combination of signal spectral analysis, Slow Rolling Eye Movement (SREM) detection, Heart Rate Variability (HRV) analysis and EEG segmentation using both Autocorrelation Function (ACF), and Crosscorrelation Function (CCF) methods. The EEG derivation FP1-FP2 filtered in a narrow band and used as an alternative to EOG for SREM detection. The ACF and CCF segmentation methods were also applied for detection of sleep events. The ACF method detects segment boundaries based on single channel analysis, while the CCF includes spatial variation from multiple EEG derivation. The results indicate that SREM detection using EEG is possible and can be used as input together with power spectral analysis to enhance SO detection. Both segmentation methods could detect SO as a segment boundary. Additionally they were able to contribute to detection of KC and SS events. The CCF method was more sensitive to spatial EEG changes and the exact segment boundaries varied slightly between the two methods. The HRV analysis revealed, that low and very low frequency variations in the heart rate was highly correlated with the EEG changes during both SO and variations in SD. Analyzing the relationship between the sleep events and SD showed a negative correlation between the Delta and Sigma activity. Analyzing the subjective measurement (SM) showed that there were a positive correlation between the SL and rated SQ. This preliminary study showed that the factors contributing to the overall SQ during powernapping can be assessed markedly better using a fusion of multiple methods. Future studies will include measures of individual performance before and after powernapping and investigate its relation to the assessed SQ.
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Nonlinear soliton matching between optical fibers.
Opt Lett
PUBLISHED: 07-05-2011
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In this Letter, we propose a generic nonlinear coupling coefficient, ?(NL)²=?|?/??|(fiber2)/|?/??|(fiber1), which gives a quantitative measure for the efficiency of nonlinear matching of optical fibers by describing how a fundamental soliton couples from one fiber into another. Specifically, we use ?(NL) to demonstrate a significant soliton self-frequency shift of a fundamental soliton, and we show that nonlinear matching can take precedence over linear mode matching. The nonlinear coupling coefficient depends on both the dispersion (??) and nonlinearity (?), as well as on the power coupling efficiency ?. Being generic, ?(NL) enables engineering of general waveguide systems, e.g., for optimized Raman redshift or supercontinuum generation.
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[Diffusion-weighted imaging can differentiate cerebral abscesses from tumours of the brain].
Ugeskr. Laeg.
PUBLISHED: 05-13-2011
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Early diagnosis of cerebral abscess, which is decisive for the prognosis, is often complicated by the lack of clinical signs. Conventional computed tomography and magnetic resonance imaging cannot always differentiate a cystic or necrotic tumor from an abscess. An abscess is therefore sometimes misdiagnosed as e.g. a glioblastoma or metastasis. Unfortunately, this is sometimes seen at our department and could maybe have been prevented. Diffusion-weighted imaging and apparent diffusion coefficient facilitate differentiation between cerebral tumor and abscess with a sensitivity of 95.2% (76.2-99.9%) and a specificity of 95.7% (78.1-99.9%).
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Ultrasonography and color Doppler of proximal gluteal enthesitis in juvenile idiopathic arthritis: a descriptive study.
Pediatr Rheumatol Online J
PUBLISHED: 05-05-2011
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The presence of enthesitis (insertional inflammation) in patients with juvenile idiopathic arthritis (JIA) is difficult to establish clinically and may influence classification and treatment of the disease. We used ultrasonography (US) and color Doppler (CD) imaging to detect enthesitis at the small and deep-seated proximal insertion of the gluteus medius fascia on the posterior iliac crest where clinical diagnosis is difficult. The findings in JIA patients were compared with those obtained in healthy controls and with the patients MRI results.
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Concentration-dependent neurotoxicity of articaine: an electrophysiological and stereological study of the rat sciatic nerve.
Anesth. Analg.
PUBLISHED: 04-05-2011
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We performed this study to quantify the detrimental effect of intraneural injection of 50 ?L of saline, articaine 2%, or articaine 4% in the rat sciatic nerve.
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Optimum fiber tapers for increasing the power in the blue edge of a supercontinuum-group-acceleration matching.
Opt Lett
PUBLISHED: 03-16-2011
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We demonstrate how the gradient of the tapering in a tapered fiber can significantly affect the trapping and blueshift of dispersive waves (DWs) by a soliton. By modeling the propagation of a fundamental 10?fs soliton through tapered fibers with varying gradients, it is shown that the soliton traps and blueshifts an increased fraction of the energy in its DW when the gradient is decreased. This is quantified by the group-acceleration mismatch between the soliton and DW at the entrance of the taper. These findings have direct implications for the achievable power in the blue edge of a supercontinuum generated in a tapered fiber and explain observations of a lack of power in the blue edge.
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Myocardial area at risk and salvage measured by T2-weighted cardiovascular magnetic resonance: reproducibility and comparison of two T2-weighted protocols.
J Cardiovasc Magn Reson
PUBLISHED: 03-10-2011
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Late gadolinium enhancement (LGE) and T2-weighted cardiovascular magnetic resonance (CMR) provides a means to measure myocardial area at risk (AAR) and salvage. Several T2-weighted CMR sequences are in use, but there is no consensus in terms of which sequence to be the preferred. Therefore, the aim of the present study was to: (1) Assess the reproducibility and (2) compare the two most frequently used T2-weighted CMR protocols for measuring AAR and salvage.
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Channel selection for automatic seizure detection.
Clin Neurophysiol
PUBLISHED: 01-27-2011
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To investigate the performance of epileptic seizure detection using only a few of the recorded EEG channels and the ability of software to select these channels compared with a neurophysiologist.
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Automatic epileptic seizure onset detection using matching pursuit: a case study.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 11-25-2010
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An automatic alarm system for detecting epileptic seizure onsets could be of great assistance to patients and medical staff. A novel approach is proposed using the Matching Pursuit algorithm as a feature extractor combined with the Support Vector Machine (SVM) as a classifier for this purpose. The combination of Matching Pursuit and SVM for automatic seizure detection has never been tested before, making this a pilot study. Data from red different patients with 6 to 49 seizures are used to test our model. Three patients are recorded with scalp electroencephalography (sEEG) and three with intracranial electroencephalography (iEEG). A sensitivity of 78-100% and a detection latency of 5-18s has been achieved, while holding the false detection at 0.16-5.31/h. Our results show the potential of Matching Pursuit as a feature extractor for detection of epileptic seizures.
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Automatic seizure detection: going from sEEG to iEEG.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 11-25-2010
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Several different algorithms have been proposed for automatic detection of epileptic seizure based on both scalp and intracranial electroencephalography (sEEG and iEEG). Which modality that renders the best result is hard to assess though. From 16 patients with focal epilepsy, at least 24 hours of ictal and non-ictal iEEG were obtained. Characteristics of the seizures are represented by use of wavelet transformation (WT) features and classified by a support vector machine. When implementing a method used for sEEG on iEEG data, a great improvement in performance was obtained when the high frequency containing lower levels in the WT were included in the analysis. We were able to obtain a sensitivity of 96.4% and a false detection rate (FDR) of 0.20/h. In general, when implementing an automatic seizure detection algorithm made for sEEG on iEEG, great improvement can be obtained if a frequency band widening of the feature extraction is performed. This means that algorithms for sEEG should not be discarded for use on iEEG - they should be properly adjusted as exemplified in this paper.
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[Safety of magnetic resonance imaging in patients with pacemaker and implantable defibrillator].
Ugeskr. Laeg.
PUBLISHED: 06-11-2010
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The presence of a cardiac implantable device is ICD considered an absolute contraindication to magnetic resonance imaging (MRI). The purpose of this study was to evaluate the safety of performing MRI in patients with cardiac pacemakers and ICDs that had a compelling clinical need for MRI examination.
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A comparative study between a simplified Kalman filter and Sliding Window Averaging for single trial dynamical estimation of event-related potentials.
Comput Methods Programs Biomed
PUBLISHED: 03-12-2010
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The classical approach for extracting event-related potentials (ERPs) from the brain is ensemble averaging. For long latency ERPs this is not optimal, partly due to the time-delay in obtaining a response and partly because the latency and amplitude for the ERP components, like the P300, are variable and depend on cognitive function. This study compares the performance of a simplified Kalman filter with Sliding Window Averaging in tracking dynamical changes in single trial P300. The comparison is performed on simulated P300 data with added background noise consisting of both simulated and real background EEG in various input signal to noise ratios. While both methods can be applied to track dynamical changes, the simplified Kalman filter has an advantage over the Sliding Window Averaging, most notable in a better noise suppression when both are optimized for faster changing latency and amplitude in the P300 component and in a considerably higher robustness towards suboptimal settings. The latter is of great importance in a clinical setting where the optimal setting cannot be determined.
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Hereditary spastic paraplegia caused by the PLP1 rumpshaker mutation.
J. Neurol. Neurosurg. Psychiatr.
PUBLISHED: 12-01-2009
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Hereditary spastic paraplegia (HSP) is a group of clinically and genetically heterogeneous neurodegenerative disorders characterised by progressive spasticity and weakness in the lower limbs. Mutations in PLP1 on the X chromosome cause spastic paraplegia type 2 (SPG2) or the allelic Pelizaeus-Merzbacher Disease (PMD). The PLP1 protein is a major myelin protein involved in stabilisation and maintenance of the myelin sheath. The function of the protein has been studied in the rumpshaker mouse, which is a model of SPG2/PMD.
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Functional aspects of treatment with implant-supported single crowns: a quality control study in subjects with tooth agenesis.
Clin Oral Implants Res
PUBLISHED: 10-21-2009
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No comprehensive patient-centered and clinical evaluations of the functional effect of treatment with implant-supported single crowns (ISSC) have been reported previously.
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Cognitive performance, symptoms and counter-regulation during hypoglycaemia in patients with type 1 diabetes and high or low renin-angiotensin system activity.
J Renin Angiotensin Aldosterone Syst
PUBLISHED: 08-28-2009
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High basal renin-angiotensin system (RAS) activity is associated with increased risk of severe hypoglycaemia in type 1 diabetes. We tested whether this might be explained by more pronounced cognitive dysfunction during hypoglycaemia in patients with high RAS activity than in patients with low RAS activity.
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Signal intensity of normal breast tissue at MR mammography on midfield: applying a random coefficient model evaluating the effect of doubling the contrast dose.
Eur J Radiol
PUBLISHED: 05-29-2009
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To prospectively investigate the effect on signal intensity (SI) of healthy breast parenchyma on magnetic resonance mammography (MRM) when doubling the contrast dose from 0.1 to 0.2 mmol/kg bodyweight.
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Glucose ingestion during endurance training does not alter adaptation.
J. Appl. Physiol.
PUBLISHED: 02-19-2009
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Glucose ingestion during exercise attenuates activation of metabolic enzymes and expression of important transport proteins. In light of this, we hypothesized that glucose ingestion during training would result in 1) an attenuation of the increase in fatty acid uptake and oxidation during exercise, 2) lower citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (beta-HAD) activity and glycogen content in skeletal muscle, and 3) attenuated endurance performance enhancement in the trained state. To investigate this we studied nine male subjects who performed 10 wk of one-legged knee extensor training. They trained one leg while ingesting a 6% glucose solution (Glc) and ingested a sweetened placebo while training the other leg (Plc). The subjects trained their respective legs 2 h at a time on alternate days 5 days a week. Endurance training increased peak power (P(max)) and time to fatigue at 70% of P(max) approximately 14% and approximately 30%, respectively. CS and beta-HAD activity increased and glycogen content was greater after training, but there were no differences between Glc and Plc. After training the rate of oxidation of palmitate (R(ox)) and the % of rate of disappearance that was oxidized (%R(dox)) changed. %R(dox) was on average 16.4% greater during exercise after training whereas, after exercise %R(dox) was 30.4% lower. R(ox) followed the same pattern. However, none of these parameters were different between Glc and Plc. We conclude that glucose ingestion during training does not alter training adaptation related to substrate metabolism, mitochondrial enzyme activity, glycogen content, or performance.
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In vivo validation of a blood vector velocity estimator with MR angiography.
IEEE Trans Ultrason Ferroelectr Freq Control
PUBLISHED: 02-14-2009
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Conventional Doppler methods for blood velocity estimation only estimate the velocity component along the ultrasound beam direction. This implies that a Doppler angle under examination close to 90 degrees results in unreliable information about the true blood direction and blood velocity. The novel method transverse oscillation (TO), which combines estimates of the axial and the transverse velocity components in the scan plane, makes it possible to estimate the vector velocity of the blood regardless of the Doppler angle. The present study evaluates the TO method with magnetic resonance phase contrast angiography (MRA) by comparing in vivo measurements of stroke volume. Eleven healthy volunteers were included in this prospective study. From the obtained data sets recorded with the 2 modalities, vector velocity sequences were constructed and stroke volume calculated. Angle of insonation was approximately 90 degrees for TO measurements. The correlation between the stroke volume estimated by TO and MRA was 0.91 (p < 0.01) with the equation for the line of regression: MRA = 1.1.TO-0.4. A Bland-Altman plot was additionally constructed where the mean difference was 0.2 ml with limits of agreement at -1.4 ml and 1.9 ml. The results indicate that reliable vector velocity estimates can be obtained in vivo using the presented angle-independent 2-D vector velocity method. The TO method can be a useful alternative to conventional Doppler systems by avoiding the angle artifact, thus giving quantitative velocity information.
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Painful tonic heat stimulation induces GABA accumulation in the prefrontal cortex in man.
Pain
PUBLISHED: 01-23-2009
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Relatively little is known on pain-induced neurotransmitter release in the human cerebral cortex. We used proton magnetic resonance spectroscopy (1H-MRS) during tonic painful heat stimulation to test the hypothesis of increases in both glutamate and GABA, two neurotransmitters with a key role in pain processing. Using a 3T MR scanner, we acquired spectra from the rostral anterior cingulate cortex (rACC) in 13 healthy right-handed subjects at rest and during painful heat stimulation. The painful stimulus consisted of a suprathreshold painful tonic heat pulse, which was delivered to the right upper leg via a fMRI-compatible Peltier element. Compared to non-painful stimulation, painful tonic heat was associated with a significant increase in GABA concentrations in the rACC. No changes in glutamate concentrations were detected during noxious stimulation. This study provides the first evidence that GABA is released in the human cerebral cortex during painful stimulation. The results are in line with animal findings on the role of GABA in pain processing and with studies in humans showing analgesic efficacy of GABA-related drugs in clinical pain conditions.
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1H MR spectroscopy of gray and white matter in carbon monoxide poisoning.
J. Neurol.
PUBLISHED: 01-13-2009
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Carbon monoxide (CO) intoxication leads to acute and chronic neurological deficits, but little is known about the specific noxious mechanisms. (1)H magnetic resonance spectroscopy (MRS) may allow insight into the pathophysiology of CO poisoning by monitoring neurochemical disturbances, yet only limited information is available to date on the use of this protocol in determining the neurological effects of CO poisoning. To further examine the short-term and long-term effects of CO on the central nervous system, we have studied seven patients with CO poisoning assessed by gray and white matter MRS, magnetic resonance imaging (MRI) and neuropsychological testing. Five patients suffered from acute high-dose CO intoxication and were in coma for 1-6 days. In these patients, MRI revealed hyperintensities of the white matter and globus pallidus and also showed increased choline (Cho) and decreased N-acetyl aspartate (NAA) ratios to creatine (Cr), predominantly in the white matter. Lactate peaks were detected in two patients during the early phase of high-dose CO poisoning. Two patients with chronic low-dose CO exposure and without loss of consciousness had normal MRI and MRS scans. On follow-up. five of our seven patients had long-lasting intellectual impairment, including one individual with low-dose CO exposure. The MRS results showed persisting biochemical alterations despite the MRI scan showing normalization of morphological changes. In conclusion, the MRS was normal in patients suffering from chronic low-dose CO exposure; in contrast, patients with high-dose exposure showed abnormal gray and white matter levels of NAA/Cr, Cho/Cr and lactate, as detected by (1)H MRS, suggesting disturbances of neuronal function, membrane metabolism and anaerobic energy metabolism, respectively. Early increases in Cho/Cr and decreases of NAA/Cr may be related to a poor long-term outcome, but confirmation by future studies is needed.
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Correlation between intra- and extracranial background EEG.
Conf Proc IEEE Eng Med Biol Soc
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Scalp EEG is the most widely used modality to record the electrical signals of the brain. It is well known that the volume conduction of these brain waves through the brain, cerebrospinal fluid, skull and scalp reduces the spatial resolution and the signal amplitude. So far the volume conduction has primarily been investigated by realistic head models or interictal spike analysis. We have set up a novel and more realistic experiment that made it possible to compare the information in the intra- and extracranial EEG. We found that intracranial EEG channels contained correlated patterns when placed less than 30 mm apart, that intra- and extracranial channels were partly correlated when placed less than 40 mm apart, and that extracranial channels probably were correlated over larger distances. The underlying cortical area that influences the extracranial EEG is found to be up to 45 cm(2). This area is larger than previously reported.
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Cognitive functions in middle aged individuals are related to metabolic disturbances and aerobic capacity: a cross-sectional study.
PLoS ONE
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Metabolic disturbances may contribute to cognitive dysfunction in patients with type 2 diabetes. We investigated the relation between cognitive impairment and metabolic deteriorations, low physical fitness, low-grade inflammation and abdominal obesity in middle aged individuals.
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DEMO-II trial. Aerobic exercise versus stretching exercise in patients with major depression-a randomised clinical trial.
PLoS ONE
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The effect of referring patients from a clinical setting to a pragmatic exercise intervention for depressive symptoms, cognitive function, and metabolic variables has yet to be determined.
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The role of phase coherence in seeded supercontinuum generation.
Opt Express
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The noise properties of a supercontinuum can be controlled by modulating the pump with a seed pulse. In this paper, we numerically investigate the influence of seeding with a partially phase coherent weak pulse or continuous wave. We demonstrate that the noise properties of the generated supercontinuum are highly sensitive to the degree of phase noise of the seed and that a nearly coherent seed pulse is needed to achieve a coherent pulse break-up and low noise supercontinuum. The specific maximum allowable linewidth of the seed laser is found to decrease with increasing pump power.
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Intravenous immunoglobulin treatment in a patient with adrenomyeloneuropathy.
BMC Neurol
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Adrenomyeloneuropathy (AMN) is one of several phenotypes of the adrenoleukodystrophy spectrum caused by mutations in the ABCD1 gene on the X chromosome. An inflammatory component is part of the disease complex ranging from severe childhood CNS demyelination to spinal cord and peripheral nerve degeneration.
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The effects of free-living interval-walking training on glycemic control, body composition, and physical fitness in type 2 diabetic patients: a randomized, controlled trial.
Diabetes Care
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To evaluate the feasibility of free-living walking training in type 2 diabetic patients and to investigate the effects of interval-walking training versus continuous-walking training upon physical fitness, body composition, and glycemic control.
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Outcome of accidental hypothermia with or without circulatory arrest: experience from the Danish Præstø Fjord boating accident.
Resuscitation
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Resuscitation guidelines for the treatment of accidental hypothermia are based primarily on isolated cases. Mortality rates are high despite aggressive treatment aimed at restoring spontaneous circulation and normothermia.
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Changes in insulin sensitivity precede changes in body composition during 14 days of step reduction combined with overfeeding in healthy young men.
J. Appl. Physiol.
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A lifestyle characterized by inactivity and a high-calorie diet is a known risk factor for impaired insulin sensitivity and development of Type 2 diabetes mellitus. To investigate possible links, nine young healthy men (24 ± 3 yr; body mass index of 21.6 ± 2.5 kg/m(2)) completed 14 days of step reduction (10,000 to 1,500 steps/day) and overfeeding (+50% kcal). Body composition (dual X-ray absorptiometry, MRI), aerobic fitness (maximal O(2) consumption), systemic inflammation and insulin sensitivity [oral glucose tolerance test (OGTT), hyperinsulinemic euglycemic clamp] were assessed before (day 0), during (days 3 and 7), and immediately after the intervention (day 14), with follow-up tests (day 30). Body weight had increased at days 7 and 14 (P < 0.05). The amount of visceral fat had increased at day 14 compared with day 0 (P < 0.05). The insulin response to the OGTT had increased at days 7 and 14 (P < 0.05). Insulin sensitivity, estimated using the Matsuda index, had decreased at days 3 and 7 (P < 0.01). At day 14, glucose infusion rates had decreased by ?44% during the euglycemic clamps (P < 0.05). Also, plasma levels of leptin and adiponectin had increased (P < 0.05), whereas no changes were seen in inflammatory markers. At day 30, body weight and whole body adiposity were still elevated compared with day 0 (P < 0.05), whereas the insulin sensitivity as well as the insulin response to the OGTT did not differ from baseline. The glucose response to the OGTT was only affected at day 30, with a decrease compared with day 0. Our data show that insulin sensitivity was impaired after 3 days of inactivity and overfeeding. Impairments in insulin sensitivity occurred before changes in body composition, supporting the notion that the initial steps in impairment of insulin sensitivity may be linked directly to the effects of inactivity and a high calorie intake.
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Automatic detection of childhood absence epilepsy seizures: toward a monitoring device.
Pediatr. Neurol.
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Automatic detections of paroxysms in patients with childhood absence epilepsy have been neglected for several years. We acquire reliable detections using only a single-channel brainwave monitor, allowing for unobtrusive monitoring of antiepileptic drug effects. Ultimately we seek to obtain optimal long-term prognoses, balancing antiepileptic effects and side effects. The electroencephalographic appearance of paroxysms in childhood absence epilepsy is fairly homogeneous, making it feasible to develop patient-independent automatic detection. We implemented a state-of-the-art algorithm to investigate the performance of paroxysm detection. Using only a single scalp electroencephalogram channel from 20 patients with a total of 125 paroxysms >2 seconds, 97.2% of paroxysms could be detected with no false detections. This result leads us to recommend further investigations of tiny, one-channel electroencephalogram systems in an ambulatory setting.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.