Practical Considerations When Performing Neurodiagnostic Studies on Patients with COVID-19 and Other Highly Virulent Diseases.
We present a case of a patient with COVID-19 who had a seizure-like spell for which an EEG was performed. In early to mid-March, there were no clear guidelines or recommendations available from neurodiagnostic-related organizations or hospitals on how to adapt procedure workflow to those with COVID-19. When caring for COVID-19 patients, as when caring for any patient with an infectious disease, it is hospital protocol to follow contact, droplet/airborne precautions by wearing appropriate PPE. However, because we knew very little about the coronavirus, this case was different. In this article, we discuss our experience with...
Source: The Neurodiagnostic Journal - May 8, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Waveform Window #48: Eye Blink Induced Spikes in EEG.
Authors: Poothrikovil RP PMID: 32364428 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - May 6, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

An Overview of the Electroencephalographic (EEG) Features of Epilepsy with Eyelid Myoclonia (Jeavons Syndrome).
Authors: Zawar I, Pestana Knight EM Abstract Epilepsy with eyelid myoclonia or Jeavons Syndrome is a unique idiopathic generalized epilepsy with onset in childhood. It is characterized by eyelid myoclonia which may be associated with absence seizures, eyelid closure-induced epileptiform discharges and/or seizures and photosensitivity. It is frequently underrecognized and misdiagnosed because it may be mistaken for some other type of generalized epilepsy or facial tic disorder. The intent of this narrative review is to focus on existing literature and highlight the distinct electroencephalographic features including...
Source: The Neurodiagnostic Journal - May 6, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Multimodality Intraoperative Neurophysiological Monitoring (IONM) During Shoulder Surgeries.
Conclusions: In this small series, we were able to identify real-time impending nerve injury. The use of IONM alerted and may have prevented intraoperative nerve injury in 30% of the patients in this series. In one patient, SSEP and TCeMEP did not recover even after the intervention due to severe blood loss. The patient woke up with sensory and motor deficits. The utilization of multimodality IONM can be helpful due to signal changes, therefore minimizing the frequency of nerve injury and deficits. PMID: 32298207 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - April 18, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Editorial: 60th Volume Anniversary.
Authors: PMID: 32101106 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - February 28, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Use of Combined Electroencephalography and Tilt Table Testing to Determine Etiology of Loss of Consciousness.
We report a series of patients who underwent simultaneous tilt table testing with EEG. Diagnostic benefits are not exclusively the verification of EEG correlates secondary to clinical and cardiovascular changes during syncope, but also confirmation of nonphysiological events, including psychogenic nonepileptic seizures and psychogenic pseudosyncope. Fifty tilt table studies were combined with EEG over a six-year period. Seven studies (14%) captured episodes of behavioral unresponsiveness with normal EEG and EKG patterns, diagnostic of psychogenic pseudosyncope. Whereas psychogenic nonepileptic events are well established i...
Source: The Neurodiagnostic Journal - February 28, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Credentialing Organizations.
Authors: PMID: 32101110 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - February 28, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

ASET-CEU Quiz.
Authors: PMID: 32101111 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - February 28, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Acute Necrotizing Encephalopathy Associated with Influenza A.
Authors: Bailey HE Abstract A severe and unusual complication found in children with influenza is an acute necrotizing encephalopathy. A 20-month-old female with no significant past medical history was admitted to our facility, presenting with a 4-day history of worsening fever, upper respiratory symptoms, new-onset altered mental status and episodes of extensor posturing. The initial concern was a dystonic reaction secondary to promethazine following a recent diagnosis of influenza A virus. A head computed tomography scan indicated concern for widespread edema, and the video EEG revealed focal slowing in the front...
Source: The Neurodiagnostic Journal - February 28, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

A Novel EEG Artifact in the ICU: Ultrasound Transducer Simulates Ictal Activity.
Authors: Ramírez-Molina JL, Mayor LC PMID: 31995713 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - January 30, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Infection Prevention: 2020 Review and Update for Neurodiagnostic Technologists.
Authors: Bonner AM, Davidson P Abstract Since 1995, ASET has published recommendations for infection prevention. With the aim of keeping our readers current with updates in infection prevention initiatives, this article reviews ASET's past publications by Altman 1995, Altman 2000, Scott 2013, and Sullivan & Altman 2008, and incorporates new information from published scientific literature, online resources, print publications, national and international guidelines, OSHA and other regulatory agencies. Knowledge of current infection control practices and recommendations is essential for every Neurodiagnostic tech...
Source: The Neurodiagnostic Journal - January 23, 2020 Category: Neurology Tags: Neurodiagn J Source Type: research

Volume 59 Contents.
Authors: PMID: 31825731 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

In Memoriam: Robert G. Ford, M.D.
Authors: Ghigo J PMID: 31825732 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

The Janet Ghigo Award.
Authors: PMID: 31825733 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

The Theda Sannit Outstanding Educator Award.
Authors: PMID: 31825734 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Kathleen Mears Memorial Lecture: How We Can Solidify the Future of Neurodiagnostic Technology.
Authors: Boldery C PMID: 31825735 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

The Maureen Berkeley Award.
Authors: PMID: 31825736 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

ASET-CEU Quiz.
Authors: PMID: 31825737 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

ASET 60th Annual Conference Proceedings.
Authors: PMID: 31825738 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Editorial: Upcoming Changes to The Neurodiagnostic Journal.
Authors: PMID: 31825740 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Credentialing Organizations.
Authors: PMID: 31825741 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - December 13, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Waveform Window #46: Radial Nerve SSEP (Rn-SSEP): Is It Reliable?
Authors: Jahangiri FR, Qadir N, Blaylock J, Cronce-Solano L, Ramsey J PMID: 31662040 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - November 1, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

EEG Electrode-induced Skin Injury among Adult Patients Undergoing Ambulatory EEG Monitoring.
Conclusion: The patient discomfort and inflammatory burden associated with this procedure were high. Inflammation was shown to increase with the duration of electrode application. PMID: 31639313 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - October 24, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Credentialing Organizations.
Authors: PMID: 31498758 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - September 11, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

ASET-CEU Quiz.
Authors: PMID: 31498760 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - September 11, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Central Sulcus Misfolding: Polarity Reversal of SSEP N20 Potential in "layered" Polymicrogyria.
Central Sulcus Misfolding: Polarity Reversal of SSEP N20 Potential in "layered" Polymicrogyria. Neurodiagn J. 2019 Sep 05;:1-7 Authors: Hale T, Knecht A, Barbarevech K, Yue Q Abstract Paradoxical cortical potential polarity of the upper extremity somatosensory evoked potential (SSEP) has been reported in cases of polymicrogyria (PMG) syndrome. To date, the pathophysiological basis of this electrophysiological aberration remains under investigation. Here we present a case of mild PMG that showed "layered" microgyri in the left frontoparietal cortices affecting both hand and foot sens...
Source: The Neurodiagnostic Journal - September 7, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Review of "Atlas of Artifacts in Clinical Neurophysiology," by William O. Tatum, IV Atlas of Artifacts in Clinical Neurophysiology by William O. Tatum , IV, Demos Medical Publishing, 2018 , 419 pages. ISBN: 9780826169341 . E-book ISBN: 978-0826169358 . List Price: $185.00; Amazon New: $154.02; Amazon Used: $144.00; Kindle: $129.36.
Review of "Atlas of Artifacts in Clinical Neurophysiology," by William O. Tatum, IV Atlas of Artifacts in Clinical Neurophysiology by William O. Tatum , IV, Demos Medical Publishing, 2018 , 419 pages. ISBN: 9780826169341 . E-book ISBN: 978-0826169358 . List Price: $185.00; Amazon New: $154.02; Amazon Used: $144.00; Kindle: $129.36. Neurodiagn J. 2019 Aug 23;:1-2 Authors: Clark-Bash RJ PMID: 31441708 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - August 25, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Nonketotic Hyperglycinemia: Two Case Reports and Review.
We describe two neonates who presented with neonatal encephalopathy, apnea, and progressive lethargy. Increased CSF glycine level along with an elevated CSF to plasma glycine ratio was suggestive of classic NKH. Burst suppression EEG and agenesis of the corpus callosum were supportive findings. Evolution of the EEG patterns and course of the disease are discussed in detail. Transient phases of clinical stabilization and normalized plasma biochemical results may not necessarily reflect the actual encephalopathic process. Serial EEGs are helpful to assess the efficacy of treatment and to modify the therapeutic approach. ...
Source: The Neurodiagnostic Journal - August 24, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Collodion Remover Can Degrade Plastic-Containing Medical Devices Commonly Used in the Intensive Care Unit.
We report that collodion remover is capable of degrading the hard plastic components of multiple medical devices after prolonged exposure; however, intermediate duration exposure was also capable of producing damage to clave connectors used with intravenous and central lines, which could plausibly lead to adverse events given the widespread use of these devices. These data suggest a pathway-based approach to collodion remover use might be beneficial in minimizing the potential impact of this solvent on plastic-containing medical devices. PMID: 31411943 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - August 16, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Triggered EMG (T-EMG) Values of Pedicle Screws with a Powered Screwdriver vs A Standard Probe in Adolescent Idiopathic Scoliosis Do Not Agree: A Prospective Validation Study.
This study tests the validity of t-EMG values obtained with a standard ball-tipped probe after completion of screw placement versus t-EMG values obtained during screw insertion with a powered screwdriver. t-EMG values were collected for screws spanning T7-L5 using both a standard probe and a powered screwdriver. A power analysis determined that a sample size of 300 screws would provide enough precision to estimate limits of agreement within ±2 mA. A monopolar constant current stimulation technique (0.2 ms duration and 3.11 Hz stimulation rate) was used at each level. EMG was acquired with placement of bipolar pairs ...
Source: The Neurodiagnostic Journal - June 30, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Waveform Window #45: Cortical Amplitude Reduction of Somatosensory Evoked Potentials during Epileptic Seizure.
Authors: Diaczun C, Lüders HO PMID: 31237526 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - June 27, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Electrophysiological Mapping and Monitoring during an Awake Craniotomy for Low-Grade Glioma: Case Report.
We present an illustrative case where the patient's gross motor function deteriorated during the resection of a LGG and mapping techniques using the phase reversal technique and Taniguchi direct cortical stimulation technique while the patient was awake proved to be valuable in determining continuity of the corticospinal tracts. PMID: 31233378 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - June 26, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Credentialing Organizations.
Authors: PMID: 31210605 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - June 20, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Technical Tips: A Checklist for Responding to Intraoperative Neuromonitoring Changes.
Authors: Rendahl R, Hey LA Abstract When changes occur in neurological responses during a surgical case, it is very important that all staff in the operating room (OR) understand their role in resolving or improving these conditions. Timely interventions are needed, and each personnel team is responsible for very specific tasks. Our intent was to cut down on confusion and delay by implementing a checklist that assigns tasks and designates a coordinator, so we incorporated the use of a checklist developed by Vitale et al. into our process for neuromonitoring cases. Staff members who used the checklist were surveyed ...
Source: The Neurodiagnostic Journal - June 20, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Percutaneous Threshold of Facial Nerve Stimulation Predicts Facial Canal Dehiscence.
In this study, our aim was to determine if preoperative percutaneous FN stimulation could predict middle ear facial canal dehiscence. Between January 2015 and February 2017, we performed preoperative HRCT and percutaneous FN stimulation on adult patients who underwent otologic surgery at our institution. Stimulation was performed with a monopolar probe placed on the skin over the stylomastoid foramen. Electrical stimuli ranged from 0 to 40 milliamperes (mA). Recordings were made from ipsilateral facial muscles. Dependent variables included threshold to compound muscle action potential (CMAP), threshold to maximum amplitude...
Source: The Neurodiagnostic Journal - June 20, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

A Rare Case of Prolonged Ictal Aphasia.
We report the case of a 62-year-old man with focal motor status epilepticus manifested initially as episodic right cheiro-oral clonic movements with preserved awareness and expressive aphasia for 48 hours. EEG showed left frontal and central lateralized periodic discharges (LPDs) without plus features (rhythmicity, overlying fast) and electrographic seizures that correlated with right clonic movements. Treatment with two seizure medications (levetiracetam and lacosamide) resulted in complete electrographic and clinical resolution of his symptoms, including aphasia. In this case, aphasia was determined to be an ictal s...
Source: The Neurodiagnostic Journal - June 20, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

ASET-CEU Quiz.
Authors: PMID: 31210609 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - June 20, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Waveform Window #44: Epileptiform Discharges in REM.
Authors: Sullivan L, Dunn C, Trudeau P PMID: 31021280 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - April 27, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Left Ventricular Assist Device Artifact in EEG.
This report describes a case of a patient with altered mental status and history of congestive heart failure with a left ventricular assist device who developed seizures following left subdural hematoma and emergent evacuation. While being treated for seizures, the EEG showed a diffuse continuous and regular delta, predominant on the left that mirrored the electrocardiogram (EKG) rhythm strip and appeared to indicate an external artifact. Moving the amplifier farther away from the heart and repositioning the patient resolved the artifact. It is important to recognize potential sources of interference and artifacts when the...
Source: The Neurodiagnostic Journal - April 17, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Review of "Handbook of Neurosurgery, Neurology, and Spinal Medicine for Nurses and Advanced Practice Health Professionals," edited by Michael Y. Wang, Andrea L. Strayer, Odette A. Harris, Cathy M. Rosenberg, and Praveen V. Mummaneni.
Review of "Handbook of Neurosurgery, Neurology, and Spinal Medicine for Nurses and Advanced Practice Health Professionals," edited by Michael Y. Wang, Andrea L. Strayer, Odette A. Harris, Cathy M. Rosenberg, and Praveen V. Mummaneni. Neurodiagn J. 2019 Apr 16;:1-2 Authors: Spradlin ML PMID: 30990390 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - April 17, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Review of "Spasticity: Diagnosis and Management," edited by Allison Brashear and Elie Elovic.
Review of "Spasticity: Diagnosis and Management," edited by Allison Brashear and Elie Elovic. Neurodiagn J. 2019 Apr 12;:1-2 Authors: Neiman ES, Rosenberg SJ PMID: 30978298 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - April 14, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Correction.
Authors: PMID: 30916630 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - March 28, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Technical Tips: Surviving a Joint Commission Visit in the Neurodiagnostic Department.
Authors: Johnson K Abstract An accreditation site visit from The Joint Commission (TJC) can strike fear in the heart of staff, but knowing what surveyors expect can go a long way toward reducing anxiety. Embedding TJC standards into our everyday routine increases the likelihood of a positive survey. Although TJC accredits many different types of organizations (and specialty services within organizations), the focus of this article will be on hospital-based, neurodiagnostic (ND) departments and includes information specific to infection prevention; medication management; provision of care, treatment, and services; r...
Source: The Neurodiagnostic Journal - March 28, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Waveform Window #43: "As Focal as Can Be and Buzzes Like a Bee"-High-Frequency Oscillations in Regions of Possible Epileptiform Discharges.
Waveform Window #43: "As Focal as Can Be and Buzzes Like a Bee"-High-Frequency Oscillations in Regions of Possible Epileptiform Discharges. Neurodiagn J. 2019;59(1):58-61 Authors: Neiman ES, Rosenberg SJ, Arnold AZ PMID: 30916632 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - March 28, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Credentialing Organizations.
Authors: PMID: 30916633 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - March 28, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Reusable Electroencephalography Electrodes: Variability in Cleaning and Reprocessing Practices.
In this study, personnel who supervised cleaning of electroencephalography cup electrodes/lead wires completed an investigator-developed survey. Generalized mixed-effect models compared sites, including storage area within site as a random effect, to adjust for correlation between wires stored in the same location. Odds ratios and 95% confidence intervals were calculated. Of nine characteristics (transportation time, wait time pre-cleaning, storage pre-cleaning [covered or not covered], disinfection time, cleaning time, bundled cleaning [always, frequently, or occasionally], drying practice [towel or air], drying time, and...
Source: The Neurodiagnostic Journal - March 28, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

ASET-CEU Quiz.
Authors: PMID: 30916635 [PubMed - in process] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - March 28, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Motor Evoked Potential Recordings from the Urethral Sphincter Muscles (USMEPs) during Spine Surgeries.
This study demonstrates the ability to acquire transcranial electrical motor evoked potentials (TCeMEPs) from the urethral sphincter muscles (USMEPs) by utilizing a urethral catheter with an embedded electrode. A retrospective analysis of intraoperative neurophysiological monitoring (IONM) data from nine intradural tumors, four tethered cord releases, and two spinal stenosis procedures was performed (n = 15). The cohort included seven females and eight males (median age: 38.91 years). A catheter with embedded urethral electrodes was used for recording TCeMEPs and spontaneous electromyograph (s-EMG) from the external u...
Source: The Neurodiagnostic Journal - March 28, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

Review of "Imaging Anatomy of the Human Spine: A Comprehensive Atlas Including Adjacent Structures," by Scott E. Foreseen and Neil M. Borden.
Review of "Imaging Anatomy of the Human Spine: A Comprehensive Atlas Including Adjacent Structures," by Scott E. Foreseen and Neil M. Borden. Neurodiagn J. 2019 Jan 24;:1-2 Authors: Johnson K PMID: 30677324 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - January 26, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research

The Use of Neuromuscular Ultrasound and NCS/EMG Testing in the Differential Diagnosis of Carpal Tunnel Syndrome and Radiculopathy.
DISCUSSION: Neuromuscular ultrasound and NCS/EMG combined techniques helped in the differential diagnosis between CTS and C6-7 nerve roots radiculopathy. In this case, physical examination could not give an immediate conclusive answer. PMID: 30601727 [PubMed - as supplied by publisher] (Source: The Neurodiagnostic Journal)
Source: The Neurodiagnostic Journal - January 3, 2019 Category: Neurology Tags: Neurodiagn J Source Type: research