This protocol was supported by the National Institute on Aging grant K23 AG031925 and R01 AG038471.

1. Set up the EEG Equipment
<ol>
 <li>Our laboratory uses the 128-channel BioSemi ActiveTwo EEG acquisition system with "active" electrodes (Amsterdam, The Netherlands; <a href="http://www.biosemi.com">http://www.biosemi.com</a>) and the ActiveTwo electrode cap (Behavioral Brain Sciences Center, Birmingham, UK) to obtain ERP data.</li>
 <li>Make sure that the battery is fully charged and attached to the amplifier.</li>
 <li>Gather all materials necessary to complete participant set-up, including: syringe, gel, tape measure, various sized EEG caps, alcohol swabs, facial electrode stickers, and velcro straps to secure the electrode cables.</li>
 <li>Place stickers on five facial electrodes.</li>
</ol>
2. Set up the Stimuli Presentation and Data Acquisition Computers
<ol>
 <li>Turn on both the stimuli presentation computer and the data acquisition computer.</li>
 <li>Our Laboratory uses E-Prime software (Pittsburgh, PA) to present stimuli and acquire behavioral data.</li>
 <li>Check to make sure that the experiment is sending the appropriate trigger codes to the data acquisition computer.</li>
 <li>To do this:
 <ul>
 <li>Turn on the amplifier in the participant chamber (Note: no electrodes or cables need to be plugged in to do this), open data acquisition software on the data acquisition computer, hit start (do not save).</li>
 <li>Go to the stimuli presentation computer, open your experiment file, and hit run.</li>
 <li>You should now see the appropriate trigger codes that you programmed into your experiment file showing up on the data acquisition software program.</li>
 </ul>
 </li>
</ol>
3. Participant Preparation
<ol>
 <li>Detail all study procedures with the participant and address any safety concerns. Further, assure that patients fully understand the protocol by having them report the protocol back to the researcher in their own words.</li>
 <li>Have participant seated comfortably in medium height hard-backed chair.</li>
 <li>Once the participant is seated, ensure that his/her line of vision from the display is standard for the experiment (here we use 48 inches).</li>
 <li>Measure the circumference of the participant's head in order to determine which EEG cap should be used.</li>
 <li>Ask the participant to remove any jewelry or hair accessories so as to ensure proper fit of the EEG cap and accurate recording. Also, if the participant wears glasses, it is best to have him/her take them off at this point until all of the facial electrodes have been applied.</li>
 <li>It is also important to review the following with each subject:
 <ul>
 <li>Remove any chewing gum or candy/mints to reduce motor movements</li>
 <li>Ask participants to use facilities before starting as to not interrupt the EEG recording</li>
 <li>Ask participant to try and keep movements and eye blinks to a minimum, but not be overly concerned about doing so</li>
 </ul>
 </li>
 <li>Using the alcohol swab, cleanse the participant's skin of oil and/or makeup, where the facial electrodes will be placed: one on each mastoid, one on each temple, and one directly below the left eye.</li>
 <li>Place a small amount of conducting gel onto each facial electrode, remove the backing from the sticker and place on the participant, applying a small amount of pressure to ensure that the electrode will stay in place.</li>
 <li>Now place the EEG cap onto the participant's head and fasten the strap under his/her chin. If the participant wears glasses, have him/her put these on before putting on the cap.</li>
 <li>Next, measure (in centimeters) from the nasion (bridge of the nose) to the inion (protrusion on the lower back of the head). Multiply this measurement by .5 (finding the midpoint) and this is where electrode A1 should be placed from front to back. Next, measure from the pre-auricular on one ear to the other (indents above cartilage on ear). The midpoint of this measurement is where electrode A1 should be placed from side-to-side.</li>
</ol>
4. Digitizing for Source Localization and Electrode Placement
<ol>
 <li>Our laboratory uses the Polhemus Patriot Digitizer / Locator (Colchester, VT) to obtain three-dimensional representations (or head models) of electrode positions on each participant's head. This controls for variability in skull shape for each participant and makes for more accurate source localization. Further, these head models can be co-registered with structural magnetic resonance images to tie together the superior spatial resolution of MRI and the superior temporal resolution of ERPs.</li>
 <li>First, place the localization transmitter under the cap behind the left ear, with excess cord tucked in under the chinstrap to keep in place.</li>
 <li>Attach receiver to a wooden chair in a position below the participant's head, approximately 6 inches from the transmitter.</li>
 <li>Open digitizing software and take measurements of electrode locations with stylus as prompted by the software.</li>
 <li>Generate 3D head model of electrode positions using MR Locator software and accept for localization of raw EEG data.</li>
 <li>Once the 3D head model for the participant has been verified on the computer display, we are ready to place the electrode at each pre-defined location on the ActiveTwo cap.</li>
 <li>Fill the electrode wells on the cap with the conducting gel and plug in all electrodes. Gather all cables and facial electrodes behind the participant and plug them into the amplifier.</li>
 <li>Offer older participants a break, especially patients with Alzheimer's disease, who may require frequent breaks to maintain focus and sustained attention to the experimental task.</li>
 <li>ActiView software is used to assure that all electrodes are free of artifact and resistance levels are acceptable. After all electrodes are placed, and the participant is ready to begin the experiment, resistance levels of the electrodes should be checked on the data acquisition computer using ActiView software. Offset levels should be within +/-25&mu;V.</li>
 <li>Once all resistance levels are acceptable, the experiment is ready to be run.</li>
</ol>
5. Data Acquisition for both EEG Data and Experiment
<ol>
 <li>Our laboratory uses BioSemi's ActiView software to view and acquire raw EEG data.</li>
 <li>Load behavioral data presentation file. Enter participant number. The experimental software saves the participant's responses and automatically generates a data file once the experiment finishes running with this participant number.</li>
 <li>Perform a check to ensure the participant is seated 48 inches from the center of the display monitor.</li>
 <li>Once the experiment has loaded, behavioral instructions should be read and verified with participant.</li>
 <li>In our current recognition memory design, the experiment begins with the study phase, where the participant will be presented with either a series of pictures or words.</li>
 <li>Begin saving raw EEG data file on the data acquisition computer.</li>
 <li>Start stimulus delivery on the stimulus presentation computer.</li>
 <li>Have a researcher work with older adults to input responses on button box. This is particularly important for patients with cognitive impairment.</li>
 <li>Monitor participant during behavioral task, including need for breaks.</li>
 <li>Once all behavioral stimuli have been presented, raw EEG data must be saved. Again, behavioral data are automatically saved by E-Prime software.</li>
 <li>After saving the study or encoding data, the previous 9 steps will be repeated for the test phase, where the participant will again be presented with either a series of pictures or words. During the test phase, half of the items will be from the study phase and half of the items will be novel. Participants will identify the old/new status of the item by reporting their answer aloud to the researcher. The researcher will then input the participant's response on the button box.</li>
</ol>
6. Data Post-Processing Pipeline
<ol>
 <li>Our laboratory uses EMSE Suite 5.3</li>
 <li>The raw data must first be prepared and digitally filtered to remove noise and artifact from the signal before any type of analysis can be completed.</li>
 <li>First, temporal filters, such as infinite impulse response and bandpass filters must be applied.</li>
 <li>Next, the data must be referenced to some point on the head. Select reference. In the current protocol, we use the common average reference.</li>
 <li>Next, the data must be filtered spatially and bad channels interpolated. Visual inspection of the data is performed and appropriate filters are put in place.</li>
 <li>Finally, ocular artifact correction methods must be utilized to correct the signal for eyeblink and eye movement artifact.</li>
</ol>
7. Representative Results
Our work has shown that the early frontal old/new effect (hits &gt; correct rejections), typically associated with conceptual processing or memorial familiarity, remain intact for pictures in patients with mild Alzheimer's disease compared to healthy older adults, but not for words (Ally, McKeever, Waring, &amp; Budson, 2009). Ally et al. (2009) have shown that the parietal old/new effect, typically associated with recollection, is impaired in patients for both pictures and words compared to their peers. In other words, the frontal memorial processes associated with recognition appear to be similar for pictures between the patients with AD and healthy older adults. In contrast, these processes are impaired for words in patients when we examine differences between the two groups. This significant difference between the groups is evident for posterior memory processes for both pictures and words. Although there has been considerable debate as to the cognitive process associated with the early frontal effect, we hypothesize that patients with mild Alzheimer's disease can successfully utilize conceptual processing or memorial familiarity to increase their discrimination for pictures compared to words, and these processes likely underlie the robust picture superiority effect in patients with Alzheimer's disease.
Frontal ERP activity associated with the successful retrieval of words and pictures is demonstrated for patients with very mild Alzheimer's disease and healthy older controls (Figure 1). These images were taken during the 300 to 500 ms time interval typically associated with conceptual processing or memorial familiarity. Notice the similar frontal old/new effect for pictures (red pseudocolor) but diminished effect for words between groups. (cyan pseudocolor).
<img src="/files/ftp_upload/2715/2715fig1.jpg" alt="Figure 1" /> 
Figure 1:Representative ERP Activity During Retrieval Task in Alzheimer's Patients and Healthy Subjects.

<ol>
	<li>Ally, B. A., Budson, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+worth+of+pictures:+Using+high+density+event-related+potentials+to+understand+the+memorial+power+of+pictures+and+the+dynamics+of+recognition+memory.">The worth of pictures: Using high density event-related potentials to understand the memorial power of pictures and the dynamics of recognition memory.</a> Neuro Image. 35, 378-395 (2007).</li><li>Ally, B. A., McKeever, J. D., Waring, J. D., Budson, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pictures+preserve+frontal+memorial+processes+in+patients+with+mild+cognitive+impairment.">Pictures preserve frontal memorial processes in patients with mild cognitive impairment.</a> Neuro psychologia. 47, 2044-2055 (2009).</li><li>Ally, B. A., Budson, A. E., Kowall, N. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+EEG+and+MEG+to+understanding+brain+physiology+in+dementia.">Using EEG and MEG to understanding brain physiology in dementia.</a> The Handbook of Alzheimer's disease and other dementias. , (2011).</li></ol>

No conflicts of interest declared.

ERPs and behavioral data can provide us with different and complementary information. Whereas behavioral data informs us about the patients' performance, ERPs allow us to record discrete changes in brain activity. Due to their excellent temporal resolution, ERPs have proven very useful in dissociating and understanding the role of memorial processes (e.g., conceptual processing and familiarity, recollection, post-retrieval monitoring processes) that have been previously associated with specific old/new components of th...

<table border="1">
	<tbody>
		<tr>
			<td>Product</td>
			<td>Company</td>
		</tr>
		<tr>
			<td>BioSemi Active Two EEG Acquisition System*	</td>
			<td>Cortech Solutions, Inc.</td>
		</tr>
		<tr>
			<td>Polhemus Patriot Digitizer</td>
			<td>Cortech Solutions, Inc.</td>
		</tr>
		<tr>
			<td>E-Prime 2.0 Professional Software</td>
			<td>Psychology Software Tools, Inc. </td>
		</tr>
	</tbody>
</table>
* This system includes the amplifier, Active Two EEG caps, syringes, SignaGel (conductive gel), and facial electrode stickers.

examining the characteristics of episodic memory using event-related potentials in patients with alzheimer's disease

Our laboratory uses event-related EEG potentials (ERPs) to understand and support behavioral investigations of episodic memory in patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD). Whereas behavioral data inform us about the patients' performance, ERPs allow us to record discrete changes in brain activity. Further, ERPs can give us insight into the onset, duration, and interaction of independent cognitive processes associated with memory retrieval. In patient populations, these types of studies are used to examine which aspects of memory are impaired and which remain relatively intact compared to a control population. The methodology for collecting ERP data from a vulnerable patient population while these participants perform a recognition memory task is reviewed. This protocol includes participant preparation, quality assurance, data acquisition, and data analysis. In addition to basic setup and acquisition, we will also demonstrate localization techniques to obtain greater spatial resolution and source localization using high-density (128 channel) electrode arrays.

Watch this Scientific Journal Video about Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer's Disease at JoVE.com

Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer&#039;s Disease

The methodology for collecting high-density event-related potential data while patients with Alzheimer's disease perform a recognition memory task is reviewed. This protocol will include subject preparation, quality assurance, data acquisition, and data analysis.

Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer's Disease

Our laboratory uses event-related EEG potentials (ERPs) to understand and support behavioral investigations of episodic memory in patients with amnestic ...

examining-characteristics-episodic-memory-using-event-related

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Medicine

13.5K vistas.  Vanderbilt University. La metodología para la recolección de alta densidad de eventos relacionados con el potencial de datos mientras que los pacientes con enfermedad de Alzheimer realizar una tarea de memoria de reconocimiento se revisa. Este protocolo incluirá la preparación de materia, la garantía de calidad, adquisición de datos y análisis de datos.

Video: Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer's Disease

Assessment of Vascular Function in Patients With Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this is only partially explained by traditional CVD risk factors. Vascular dysfunction is an important non-traditional risk factor, characterized by vascular endothelial dysfunction (most commonly assessed as impaired endothelium-dependent dilation [EDD]) and stiffening of the large elastic arteries. While various techniques exist to assess EDD and large elastic artery stiffness, the most commonly used are brachial artery flow-mediated dilation (FMDBA) and aortic pulse-wave velocity (aPWV), respectively. Both of these noninvasive measures of vascular dysfunction are independent predictors of future cardiovascular events in patients with and without kidney disease. Patients with CKD demonstrate both impaired FMDBA, and increased aPWV. While the exact mechanisms by which vascular dysfunction develops in CKD are incompletely understood, increased oxidative stress and a subsequent reduction in nitric oxide (NO) bioavailability are important contributors. Cellular changes in oxidative stress can be assessed by collecting vascular endothelial cells from the antecubital vein and measuring protein expression of markers of oxidative stress using immunofluorescence. We provide here a discussion of these methods to measure FMDBA, aPWV, and vascular endothelial cell protein expression.

The degree of vascular dysfunction and contributing physiological mechanisms can be assessed in patients with chronic kidney disease by measuring brachial artery flow-mediated dilation, aortic pulse-wave velocity, and vascular endothelial cell protein expression.

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this ...

Motor and Hippocampal Dependent Spatial Learning and Reference Memory Assessment in a Transgenic Rat Model of Alzheimer's Disease with Stroke

Alzheimer&#39;s disease (AD) is a debilitating neurodegenerative disease that results in neurodegeneration and memory loss. While age is a major risk factor for AD, stroke has also been implicated as a risk factor and an exacerbating factor. The co-morbidity of stroke and AD results in worsened stroke-related motor control and AD-related cognitive deficits when compared to each condition alone. To model the combined condition of stroke and AD, a novel transgenic rat model of AD, with a mutated form of amyloid precursor protein (a key protein involved in the development of AD) incorporated into its DNA, is given a small unilateral striatal stroke.
For a model with the combination of both stroke and AD, behavioral tests that assess stroke-related motor control, locomotion and AD-related cognitive function must be implemented. The cylinder task involves a cost-efficient, multipurpose apparatus that assesses spontaneous forelimb motor use. In this task, a rat is placed in a cylindrical apparatus, where the rat will spontaneously rear and contact the wall of the cylinder with its forelimbs. These contacts are considered forelimb motor use and quantified during video analysis after testing. Another cost-efficient motor task implemented is the beam-walk task, which assesses forelimb control, hindlimb control and locomotion. This task involves a rat walking across a wooden beam allowing for the assessment of limb motor control through analysis of forelimb slips, hindlimb slips and falls. Assessment of learning and memory is completed with Morris water maze for this behavioral paradigm. The protocol starts with spatial learning, whereby the rat locates a stationary hidden platform. After spatial learning, the platform is removed and both short-term and long-term spatial reference memory is assessed. All three of these tasks are sensitive to behavioral differences and completed within 28 days for this model, making this paradigm time-efficient and cost-efficient.

Motor and Hippocampal Dependent Spatial Learning and Reference Memory Assessment in a Transgenic Rat Model of Alzheimer&#039;s Disease with Stroke

To investigate the co-morbid Alzheimer&#39;s disease (AD) and stroke condition in a novel model, three behavior tasks are described that assess both motor control and cognitive behaviors. These tasks include the beam-walk task, cylinder task and Morris water maze.

Alzheimer&#39;s disease (AD) is a debilitating neurodegenerative disease that results in neurodegeneration and memory loss. While age is a major risk ...

Quantitative 3D In Silico Modeling (q3DISM) of Cerebral Amyloid-beta Phagocytosis in Rodent Models of Alzheimer's Disease

Neuroinflammation is now recognized as a major etiological factor in neurodegenerative disease. Mononuclear phagocytes are innate immune cells responsible for phagocytosis and clearance of debris and detritus. These cells include CNS-resident macrophages known as microglia, and mononuclear phagocytes infiltrating from the periphery. Light microscopy has generally been used to visualize phagocytosis in rodent or human brain specimens. However, qualitative methods have not provided definitive evidence of in vivo phagocytosis. Here, we describe quantitative 3D in silico modeling (q3DISM), a robust method allowing for true 3D quantitation of amyloid-&#946; (A&#946;) phagocytosis by mononuclear phagocytes in rodent Alzheimer&#39;s Disease (AD) models. The method involves fluorescently visualizing A&#946; encapsulated within phagolysosomes in rodent brain sections. Large z-dimensional confocal datasets are then 3D reconstructed for quantitation of A&#946; spatially colocalized within the phagolysosome. We demonstrate the successful application of q3DISM to mouse and rat brains, but this methodology can be extended to virtually any phagocytic event in any tissue.

Quantitative 3D In Silico Modeling q3DISM of Cerebral Amyloid-beta Phagocytosis in Rodent Models of Alzheimer&#039;s Disease

We developed a methodology for quantitative 3D in silico modeling (q3DISM) of cerebral amyloid-&#946; (A&#946;) phagocytosis by mononuclear phagocytes in rodent models of Alzheimer&#39;s disease. This method can be generalized for the quantitation of virtually any phagocytic event in vivo.

Neuroinflammation is now recognized as a major etiological factor in neurodegenerative disease. Mononuclear phagocytes are innate immune cells responsible ...

Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer's Disease and Mild Cognitive Impairment

Impaired functional connectivity in the Default Mode Network (DMN) may be involved in the progression of Alzheimer&#39;s Disease (AD). The Posterior Cingulate Cortex (PCC) is a potential imaging marker for monitoring the progression of AD. Previous studies did not focus on the functional connectivity between the PCC and nodes in regions outside the DMN, but our study is an effort to explore these overlooked functional connections. For collecting data, we used functional Magnetic Resonance Imaging (fMRI) and Granger Causality Analysis (GCA). fMRI provides a non-invasive method for studying the dynamic interactions between the different brain regions. GCA is a statistical hypothesis test for determining whether one-time series is useful in forecasting another. In simple terms, it is judged by comparing the &#34;Known all the information on the last moment, the distribution of the probability of X at this time&#34; and the &#34;Known all the information on the last moment except Y, the distribution of the probability of X at this time&#34;, to determine whether there is a causal relationship between Y and X. This definition is based on the complete information source and stationary chronological sequence. The main step of this analysis is to use X and Y to establish the regression equation and draw a causal relationship by a hypothetical test. Since GCA can measure causal effects, we used it to investigate the anisotropy of the functional connectivity and explore the hub function of the PCC. Here, we screened 116 participants for MRI scanning, and after preprocessing the data obtained from neuroimaging, we used GCA to derive the causal relationship of each node. Finally, we concluded that the directed connection is significantly different between the Mild Cognitive Impairment (MCI) and AD groups, both from the PCC to the whole brain and from the whole brain to the PCC.

Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer&#039;s Disease and Mild Cognitive Impairment

Based on resting-state functional magnetic resonance imaging with Granger causality analysis, we investigated the alterations in the directed functional connectivity between the posterior cingulate cortex and whole brain in patients with Alzheimer&#39;s Disease (AD), patients with Mild Cognitive Impairment (MCI), and healthy controls.

Impaired functional connectivity in the Default Mode Network (DMN) may be involved in the progression of Alzheimer&#39;s Disease (AD). The Posterior ...

Multi-Modal Home Sleep Monitoring in Older Adults

The gold standard for sleep monitoring is attended in-lab polysomnography; however, this method may be cost-prohibitive and inconvenient for patients and research participants. Home sleep testing has gained momentum in the field of sleep medicine due to its convenience and lower cost, as well as being more naturalistic. The accuracy and quality of home sleep testing, however, may be variable because studies are not monitored by sleep technologists. There has been some success in improving the accuracy of home sleep studies by having trained sleep technicians assist participants inside their homes with putting on the devices, but this can be intrusive and time-consuming for those involved. In this protocol, participants undergo at-home sleep monitoring with multiple devices: 1) a single-channel EEG device; 2) a home sleep test for sleep-disordered breathing and periodic limb movements; 3) actigraphy; and 4) sleep logs. A major challenge of this study is obtaining high-quality sleep monitoring data on the first attempt in order to minimize participant burden. This protocol describes the implementation of educational manuals with step-by-step instructions and photos. The goal is to improve the quality of home sleep testing.

Here, we present a protocol to improve the quality of data from home sleep testing by providing a method to enhance instructions through a structured participant visit. This protocol includes the implementation of a step-by-step educational manual with photos to ensure proper placement of equipment.

The gold standard for sleep monitoring is attended in-lab polysomnography; however, this method may be cost-prohibitive and inconvenient for patients and ...

Fertility Preservation in Patients with Severe Ovarian Dysfunction

Ovarian function progressively declines during aging and in some pathophysiological conditions including karyotype abnormality, autoimmune diseases, chemo- and radiation-therapies, as well as ovarian surgeries. In unmarried women with severe ovarian dysfunction, fertility preservation is important for future pregnancies. Although oocyte cryopreservation is an established method for fertility preservation, these patients could only preserve a limited number of oocytes even after ovarian hyperstimulation, leading to repeated stimulations to ensure sufficient oocytes to guarantee future pregnancy. To solve this issue, we have recently developed a drug-free in vitro activation (IVA) procedure, which enable us to stimulate early stages of ovarian follicles to develop to the preantral follicle stage. These preantral follicles can respond to the unique protocol of gonadotropin stimulation, resulting in increased number of retrieved oocytes per ovarian stimulation for cryopreservation. The drug-free IVA comprised from the surgical approach and ovarian stimulation. We removed a part of cortex from one or both ovaries from patients under laparoscopic surgery. The ovarian cortical tissues were cut into small cubes to disrupt the Hippo signaling pathway and stimulate the development of early stage follicles. These cubes were grafted orthotropically into remaining ovaries as well as beneath the serosa of both Fallopian tubes. We have already published the surgical procedure of the drug-free IVA and the protocol of subsequent ovarian stimulation, but herein we present the details of laboratory methods required for drug-free IVA.

We present details of laboratory procedures for drug-free in vitro activation (IVA) of ovarian follicles for patients with severe ovarian dysfunction. This method could increase the number of retrievable oocytes per ovarian hyperstimulation and benefit fertility preservation for those patients.

Ovarian function progressively declines during aging and in some pathophysiological conditions including karyotype abnormality, autoimmune diseases, ...

Modified Posterior Vertebral Column Resection for Patients with Thoracolumbar Kyphotic Deformity

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may cause severe thoracolumbar kyphotic deformity, often accompanied by intractable low back pain or compression of the spinal cord, leading to severe neurological symptoms or even paralysis. If conservative treatment cannot relieve the symptoms or correct the deformities, surgical treatment is usually needed. For severe kyphotic deformity, reconstruction of the physiological curvature and rigid fixation determine the prognosis of the patients. Osteotomy and orthopedics are the standard procedure for deformities with severe compression of the front and middle column, but the trauma to the patients is high, with a long operation time and massive blood loss. To avoid these disadvantages, we have developed a modified technique to remove the diseased vertebra unilaterally. In this technique, we use a modified trephine to resect the vertebral columns like in the pedicle screw technique by adding a locking instrument that can restrict the trephine to lower the risk of osteotomy and shorten the surgery time and blood loss.

We describe a modified technique for resecting the posterior vertebral column unilaterally based on a modified trephine for patients with thoracolumbar kyphotic deformity.

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may ...

Laparoscopic Common Bile Duct Exploration in Patients with a Previous History of Biliary Tract Surgery

For recurrent choledocholithiasis, abdominal adhesions in previous surgeries lead to changes in anatomical structures, and a secondary injury occurs easily when performing another operation for laparoscopic common bile duct exploration (LCBDE), which was once considered a relative contraindication. In view of the limitations of the current surgical technique, this study summarized the surgical approaches and crucial anatomical landmarks for reoperation for LCBDE. Four general surgical approaches were proposed to expose the common bile duct, including the ligamentum teres hepatis approach, the anterior hepatic duodenal ligament approach, the right hepatic duodenal ligament approach, and the hybrid approach. Additionally, this study highlighted seven crucial anatomical landmarks: the parietal peritoneum, the gastrointestinal serosa, the ligamentum teres hepatis, the inferior margin of the liver, the gastric antrum, the duodenum, and the hepatic flexure of the colon, which were helpful to safely separate abdominal adhesions and expose the common bile duct. Moreover, to shorten the time of choledocholithotomy, a sequential method was innovatively applied for the removal of the stones in common bile duct. Mastering the above surgical approaches, including identifying crucial anatomical landmarks and adopting the sequential method will improve the safety of reoperation for LCBDE, shorten the operation time, promote the fast recovery of patients, reduce postoperative complications, and contribute to the popularization and application of this technique.

Programmed surgery based on surgical methods and anatomical markers helps shorten the operation time, reduce complications, and improve the safety of the surgery. This study investigated and summarized the surgical methods and anatomic markers of laparoscopic common bile duct exploration in patients with a history of biliary tract surgery.

For recurrent choledocholithiasis, abdominal adhesions in previous surgeries lead to changes in anatomical structures, and a secondary injury occurs ...

Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test

Ischemic heart disease (IHD) represents a group of clinical syndromes characterized by myocardial ischemia, leading to an impairment in the myocardial blood supply and compromised perfusion. Several clinical variables assessed through a stress test, such as oxygen uptake (VO2) and heart rate oxygen pulse (HR/O2), have been attributed as cardiopulmonary prognostic factors in patients with IHD. However, other factors like hydration status (HS), potentially affecting the cardiopulmonary response, have been barely addressed. Unbalanced HS has a short-term effect on plasma volume and the sympathetic nervous system, which impacts blood volume, and lowers VO2 and HR/O2. Recently, bioelectrical impedance analysis (BIA), a method based on the opposition of body tissues (including fluid volume) to a low electrical current, has been widely used to assess HS by obtaining two components: resistance (R) and reactance (Xc) and using prediction formulas. However, several limitations as chronic illness or abnormal fluid status, may affect the results. In this sense, alternative BIA methods, such as bioelectrical impedance vector analysis (BIVA), have become relevant. R and Xc (adjusted by height) result in a vector plotted on the R/Xc graph, which allows interpreting the HS as normal or abnormal according to the distance of the mean vector. This study aims to describe how to determine HS by BIVA using a single-frequency device and compare the results with the cardiopulmonary response in patients with IHD.

Hydration status imbalances can have a short-term effect on direct and indirect determinants of oxygen uptake and pulse, and morbidity and mortality prognostic factors in ischemic heart disease. This protocol describes the technique for assessment of hydration status through bioelectrical impedance vector analysis and cardiopulmonary response during exercise stress test.

Ischemic heart disease (IHD) represents a group of clinical syndromes characterized by myocardial ischemia, leading to an impairment in the myocardial ...

Technique for Salivary Gland Ultrasound Examination of Sjogren&#039;s Syndrome

Ultrasonographic Evaluation of Salivary Glands for Sjogren's Syndrome: Diagnostic and Monitoring Insights

Sjogren's syndrome (SS) is a chronic autoimmune condition commonly affecting the exocrine glands, causing oral or ocular dryness and extraglandular manifestations including arthralgia, cytopenia, and lymphoma. The presence of autoantibodies against SSA/Ro, labial salivary gland biopsy, ocular staining, Schirmer's test, or salivary flow assessment are included in the current classification criteria of SS. However, the availability and invasiveness of these procedures limit their widespread use in clinical settings. Salivary gland ultrasonography (SGUS) is a non-invasive imaging modality for the evaluation of the salivary gland parenchyma and is increasingly utilized to aid diagnosis and monitoring in SS. 
This article presents the protocol of SGUS for image acquisition at the parotid and submandibular glands. The objective is to present a standardized, reproducible, and practical approach to diagnostic SGUS for SS in daily clinical settings. Major salivary glands are scanned in a stepwise approach, beginning at the angle of the mandible for the superficial lobe of the parotid gland, followed by the deep lobe below the ramus of the mandible. Submandibular areas are then scanned for the submandibular glands. The steps in obtaining salivary gland images at each anatomical site are explained in the accompanying video. The echogenicity and echotexture at the thyroid gland are taken as a reference. The homogeneity, the presence and distribution of hypoechoic areas within the glands, and the border of the salivary glands are examined. The sizes and features of intra-/peri-glandular lymph nodes are recorded. The most distinctive sonographic feature in SS is glandular heterogeneity with the presence of hypoechoic/hyperechoic areas within the glands. 
In summary, while SGUS cannot diagnose SS on its own, it can supplement the current classification criteria of SS and guide the clinical decision for salivary gland biopsy to support the diagnosis of SS in patients with sicca syndrome or suspicious systemic features, combined with autoantibody testing.

Author Spotlight: A Focus on Standardized Salivary Gland Ultrasound Protocol in Connective Tissue Disease Research

Salivary gland ultrasonography is a promising tool for the diagnosis and evaluation of disease activity and complications in Sjogren's syndrome (SS). The scanning technique for salivary gland ultrasound examination relevant to SS is described in the article.

Sjogren's syndrome (SS) is a chronic autoimmune condition commonly affecting the exocrine glands, causing oral or ocular dryness and extraglandular ...