Rapid Implementation of a 3-Dimensional-Printed Patient-Specific Titanium Sacrum Implant for Severe Neuropathic Spinal Arthropathy and Guide to Compassionate US Regulatory Approval.

BACKGROUND AND OBJECTIVE: Rapid design and production of patient-specific 3-dimensional-printed implants (3DPIs) present a novel opportunity to restore the biomechanically demanding integrity of the lumbopelvic junction. We present a unique case of a 61-year-old patient with severe neuropathic spinal arthropathy (Charcot spine) who initially underwent a T4-to-sacrum spinal fusion. Massive bone destruction led to dissociation of his upper body from his pelvis and legs. Reconstruction of the spinopelvic continuity was planned with the aid of a personalized lumbosacral 3DPI. METHOD: Using high-resolution computed tomography scans, the custom 3DPI was made using additive titanium manufacturing. The unique 3DPI consisted of (1) a sacral platform with iliac screws, (2) modular corpectomy device with rigid connection to the sacral platform, and (3) anterior plate connection with screws for proximal fixation. The procedures to obtain compassionate use Food and Drug Administration approval were followed. The patient underwent debridement of a chronically open wound before undertaking the 3-stage reconstructive procedure. The custom 3DPI and additional instrumentation were inserted as part of a salvage rebuilding procedure. RESULTS: The chronology of the rapid implementation of the personalized sacral 3DPI from decision, design, manufacturing, Food and Drug Administration approval, and surgical execution lasted 28 days. The prosthesis was positioned in the defect according to the expected anatomic planes and secured using a screw-rod system and a vascularized fibular bone strut graft. The prosthesis provided an ideal repair of the lumbosacral junction and pelvic ring by merging spinal pelvic fixation, posterior pelvic ring fixation, and anterior spinal column fixation. CONCLUSION: To the best of our knowledge, this is the first case of a multilevel lumbar, sacral, and sacropelvic neuropathic (Charcot) spine reconstruction using a 3DPI sacral prosthesis. As the prevalence of severe spine deformities continues to increase, adoption of 3DPIs is becoming more relevant to offer personalized treatment for complex deformities.

The World Neurosurgery Global Champions Program: First-Year Experience of a Model Initiative for Reducing Disparities in Global Neurosurgical Literature.

OBJECTIVE: Most surgical journals are published in English, representing a challenge for researchers from non-Anglophone countries. We describe the implementation, workflow, outcomes, and lessons learned from the WORLD NEUROSURGERY Global Champions Program (GCP), a novel journal-specific English language editing program for articles rejected because of poor English grammar or usage. METHODS: The GCP was advertised via the journal website and social media. Applicants were selected to be a reviewer for the GCP if they demonstrated English proficiency on writing samples supplied in their application. The demographics of GCP members and characteristics and outcomes of articles edited by the GCP during its first year were reviewed. Surveys of GCP members and authors who used the service were conducted. RESULTS: Twenty-one individuals became part of the GCP, representing 8 countries and 16 languages apart from English. A total of 380 manuscripts were peer reviewed by the editor-in-chief, who determined these manuscripts to have potentially worthwhile content but needed to be rejected due to poor language. The authors of these manuscripts were informed of the existence of this language assistance program. Forty-nine articles (12.9%) were edited by the GCP in 41.6 ± 22.8 days. Of 40 articles resubmitted to WORLD NEUROSURGERY, 24 (60.0%) were accepted. GCP members and authors understood the purpose and workflow of the program and recognized improvements in article quality and the probability of acceptance through their participation. CONCLUSIONS: The WORLD NEUROSURGERY Global Champions Program mitigated a critical barrier to publication in an English language journal for authors from non-Anglophone countries. This program promotes research equity by providing a free, largely medical student and trainee operated, English language editing service. This model or a similar service can be replicated by other journals.

Current landscape of social media use pertaining to glioblastoma by various stakeholders.

Background: Given the potential for social media to allow widespread public engagement, its role in healthcare, including in cancer care as a support network, is garnering interest. To date, the use of social media in neuro-oncology has not been systematically explored. In the current manuscript, we sought to review Twitter use on glioblastoma among patients, caregivers, providers, researchers, and other stakeholders. Methods: The Twitter application programming interface (API) database was surveyed from inception to May 2022 to identify tweets about glioblastoma. Number of tweet likes, retweets, quotes, and total engagement were noted for each tweet. Geographic location, number of followers, and number of Tweets were noted for users. We also categorized Tweets based on their underlying themes. A natural language processing (NLP) algorithm was used to assign a polarity score, subjectivity score, and analysis label to each Tweet for sentiment analysis. Results: A total of 1690 unique tweets from 1000 accounts were included in our analyses. The frequency of tweets increased from 2013 and peaked in 2018. The most common category among users was MD/researchers (21.6%, n = 216), followed by Media/News (20%, n = 200) and Business (10.7%); patients or caregivers accounted for only 4.7% (n = 47) while medical centers, journals, and foundations accounted for 5.4%, 3.7%, and 2.1%. The most common subjects that Tweets covered included research (54%), followed by personal experience (18.2%) and raising awareness (14%). In terms of sentiment, 43.6% of Tweets were classified as positive, 41.6% as neutral, and 14.9% as negative; a subset analysis of "personal experience" tweets revealed a higher proportion of negative Tweets (31.5%) and less neutral tweets (25%). Only media (ß = 8.4; 95% CI [4.4, 12.4]) and follower count (minimally) predicted higher levels of Tweet engagement. Conclusion: This comprehensive analysis of tweets on glioblastoma found that the academic community are the most common user group on Twitter. Sentiment analysis revealed that most negative tweets are related to personal experience. These analyses provide the basis for further work into supporting and developing the care of patients with glioblastoma.

Robotic assistance in lumbar fusion surgery: trends and patterns from 2016-2019.

PURPOSE: Robotic-assisted spine surgery is an emerging field that is growing in utilization. Intraoperative robotic surgical units cost upwards of $600,000 for medical facilities to purchase. Despite significant cost barriers, these devices are highly marketable for hospitals and physicians. METHODS: The Nationwide Inpatient Sample database from 2016 to 2019 was reviewed. Inclusion criteria were patients over 18 years of age who underwent elective lumbar spinal fusion. Trends of robotic-assisted lumbar fusion were examined over time, as well as stratified based on patient and surgical characteristics. RESULTS: A total of 176,377 patients met the inclusion criteria. The overall rate of robotic-assisted lumbar fusion was 1.2% (2,131/174,246). Patients with private insurance were more likely to receive robotic-assisted lumbar fusion (40.3% vs. 37.5%; p < 0.05). Stratifying by race, whites were more likely to receive robotic-assisted lumbar fusion (84.1% vs. 79.5%; p < 0.05). Patients who underwent robotic-assisted lumbar fusion were significantly more likely to have a diagnosis of spondylolisthesis compared to those that underwent non-robotic-assisted lumbar fusion (25.9% vs. 22.0%; p < 0.05). Patients with lumbar fusion done via the anterior approach were more likely to have robotic-assisted surgery compared to other approaches (25.2% vs. 21.3; p < 0.05). Overall, there was a steady increase in its use over time, with patients who underwent lumbar fusion procedures four times more likely to receive robotic assistance in 2019 compared to 2016 (OR: 4.0; 95% CI: 3.5-4.6; p < 0.0001). Robotic-assisted lumbar fusion was associated with higher inpatient costs ($170,036.40 vs. $139,026.10; p < 0.0001) despite having equivalent length of stay (3.31 ± 2.6 vs.3.37 ± 2.6; p = 0.06). CONCLUSION: Robotic-assisted lumbar fusion is on the rise. Patients who had private insurance, were diagnosed with spondylolisthesis, and who had lumbar fusion via the anterior approach were more likely to undergo lumbar fusion using robotic assistance.

Analysis of Neurosurgery Influencers on Instagram: Trends and Patterns of the Neurosurgeon's Social Media Footprint.

OBJECTIVE: Social media outlets such as Instagram have recently become a popular tool for medical professionals to disseminate medical information to a large public audience. In this study, we identify the top neurosurgery influencers on Instagram and analyze trends between content type, audience interaction, and user engagement. METHODS: A list of neurosurgeon Instagram profiles based on the number of followers, user engagement, and average interaction were compiled. Outcome variables such as the numbers of followers, likes, comments, hashtags, caption words, user engagement, and average user activity were collected and analyzed. The most recent 30 posts from each included profile were stratified into categories on the basis of type of content. RESULTS: A total of 73 neurologic surgeon "influencer" Instagram profiles met our inclusion and exclusion criteria (67 male [91.8%]; 6 female [8.2%]). Of the most recent 30 posts for each influencer, clinical and professional posts represented the majority (67.4%), while lifestyle and patient posts made up 30.3% and 2.3%, respectively. In comparison to the rest of the field (n = 43), the 30 profiles with the most followers had a significantly higher average interaction (418.77 vs. 126.79; P < 0.001), number of uploads (578.87 vs. 184.58; P = 0.004), average number of likes given in the top posts (770.71 vs. 2150.40; P < 0.001), average posts per week (2.40 vs. 1.12; P = 0.041), and average posts per month (9.91 vs. 4.02.; P = 0.015). CONCLUSIONS: Neurosurgeon influencers on Instagram post content that predominantly features educational and academic subject matter. Post content regarding the individual's personal life or extracurricular activities made up a lesser portion of content, and there were few posts categorized as patient testimonials.

Palliative Care Effects on Survival in Glioblastoma: Who Receives Palliative Care?

BACKGROUND: High-grade glioma has a poor overall survival with profoundly negative effects on the patient's quality of life and their caregivers. In this study, we investigate the factors associated with receiving palliative care in patients diagnosed with glioblastoma (GBM) and the association of receiving or not receiving palliative care with overall survival. METHODS: The National Cancer Database was analyzed for patterns of care in patients ≥18 years old who were diagnosed with histologically confirmed grade IV GBM between 2004 and 2017. All statistical analyses were conducted based on univariate and multivariate regression models. RESULTS: A total of 85,380 patients with the diagnosis of GBM were identified. Of the study population, 2803 patients (3.28%) received palliative therapy. On multivariate logistic regression analysis, age ≥70 years (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.04-1.58; P < 0.001), Medicare (OR, 1.348; CI, 1.13-1.61; P = 0.001), tumor size ≥5 cm (OR, 1.15; CI, 1.01-1.31; P = 0.036), tumor multifocality (OR, 1.69; CI, 1.47-1.96; P < 0.001), lobe overlapping tumor (OR, 2.09; CI, 1.13-3.86; P = 0.018), Charlson-Deyo score >0, receiving treatment at a nonacademic/research program, and medium volume of cancers managed at the treatment facility (OR, 1.19; CI, 1.02-1.38; P = 0.026) were independent risk factors associated with an increased chance of receiving palliative care. In contrast, a household income of ≥$40,227 and high volume of cancer managed at the treatment facility (OR, 0.75; CI, 0.58-0.96; P = 0.02) were independent risk factors associated with decreased palliative care. Patients who received no palliative care had a 2-year overall survival longer than those who received palliative care (22% vs. 8.8%; P < 0.001). In patients receiving palliative care, those who received recommended treatment had a 2-year overall survival longer than those who declined part or whole recommended treatment (9.1% vs. 3.8%; P = 0.009). CONCLUSIONS: In patients with high-grade glioma, receiving palliative care is associated with decreased survival. When receiving palliative care, recommended treatment increases the number of patients who survive more than 2 years approximately 3-fold compared with those declining part or whole treatment.

Tumor Derived Extracellular Vesicles Modulate Gene Expression in T cells.

Extracellular vesicles (EVs) are excreted from all cells in the human body and are heterogeneous lipid bilayer particles containing proteins, RNA, DNA, and other cargo. T cells are primary players of the adaptive immune system and have a significant role in anti-cancer immunotherapies. Tumor derived EVs have diverse effects on host cells including modulating the immune response. In this study, we investigate the role acute myeloid leukemia (AML) derived EVs have on modulation of gene expression levels in three different T cell populations (CD8+, CD4+, and CD4 + CD39 + T cells). AML derived EVs modulate gene expression levels in all three cell populations with transcripts associated with major immunoregulatory pathways being significantly altered. Genes whose expression were significantly upregulated or downregulated were analyzed for gene ontogeny category expression and for the impact of the changes on specific immunoregulatory pathways. CD8 + T cells were modulated to a larger extent than other T cell populations and gene expression levels associated with proliferation and differentiation were influenced by AML-derived EVs.

Cerebrospinal fluid (CSF) leak after elective lumbar spinal fusion: Who is at risk?

PURPOSE: CSF leaks are a known complication of lumbar fusion surgery. There is a scarcity of literature describing the incidence and risk factors associated with this complication. The aim of this study was to identify patients who are at risk of developing postoperative CSF leak. METHODS: The Nationwide Inpatient Sample database was used to identify patients who had lumbar fusion in the US from 2002 to 2014. Inpatient outcomes included the incidence and risk of developing CSF leak based on selected patient-specific characteristics. Secondary outcomes included average length of stay, mean costs, and mortality rates. All statistical analyses were conducted based on multivariate regression models using the SPSS software. RESULTS: A total of 439,220 patients who underwent elective lumbar fusion procedures were identified. Of these patients, 2.6% (11,636 /439,220) were found to have CSF leak. Independent important risk factors for CSF leak development included: older age (OR: 1.025; 95% CI: 1.02-1.03; p < 0.0001), posterior approach (OR: 1.71; 95% CI: 1.59-1.85; p < 0.0001) compared to anterior approach, chronic deficiency anemia (OR: 1.21; 95% CI:1.14-1.30; p < 0.0001), obesity (OR: 1.22; 95% CI: 1.15-1.30; p < 0.0001), and pulmonary circulatory disease (OR: 1.44; 95% CI: 1.18-1.75; p < 0.0001). CSF leak was associated with increased length of stay (5.39 ± 3.86 vs. 3.74 ± 2.55; p < 0.0001), hospitalization costs (120,129.0 ± 88,123.5 vs. 89,226.8 ± 65,350.3; p < 0.0001) and mortality (0.3% vs. 0.1%; p < 0.05). CONCLUSION: Spine surgeons should be aware of certain patient and procedure-specific characteristics that increase the risk of developing postoperative CSF leak after lumbar fusion in order to improve patient outcomes.

Thirty-Day Stroke and Mortality After Carotid Revascularization Among Octogenarians with Symptomatic Carotid Stenosis: Real-World Evidence from a National Surgical Quality Registry.

BACKGROUND: The outcomes of carotid revascularization among octogenarians are not well studied. We present analyses of 30-day stroke and mortality of patients aged ≥80 years using real-world data from a national surgical quality registry. METHODS: The National Surgical Quality Improvement Program targeted data set for carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) was queried for patients aged ≥80 years undergoing CEA and CAS between 2012 and 2019. RESULTS: A total of 122 and 3013 patients aged ≥80 years with symptomatic carotid stenosis undergoing CAS and CEA, respectively, were identified. Patients with CAS were more likely to be older than 90 years (P = 0.006) and have diabetes (P = 0.036), were more likely to have high-risk anatomy (P < 0.001), but had lower American Society of Anesthesiologists score (P < 0.001). An ipsilateral stroke had been experienced by 43.6% of patients with CAS and 44.7% of patients with CEA. The rate of 30-day composite outcome was 6.4% in the CAS group and 4.5% in the CEA group (P = 0.326). The f 30-day mortality was significantly higher for CAS (5.6% vs. 1.7%, P = 0.001); however, the difference between the cohorts was not significant (CAS, 2.4% vs. CEA, 3.4%, P = 0.555). On multivariable analysis, CEA was associated with significantly lower odds of mortality (odds ratio [OR], 0.32; P = 0.0145). Symptom presentation other than ipsilateral stroke was associated with significantly decreased odds of 30-day outcome (amaurosis fugax/transient monocular blindness, OR, 0.39, P = 0.004; transient ischemic attack, OR, 0.57, P = 0.003), whereas higher age had significantly increased odds (OR, 1.95; P = 0.0172). CONCLUSIONS: Real-world analyses from a surgical quality registry show that CEA may be associated with lower odds of mortality compared with CAS among octogenarians.

Murine Leukemia-Derived Extracellular Vesicles Elicit Antitumor Immune Response.

BACKGROUND: Extracellular vesicles (EVs) are heterogeneous lipid bilayer particles secreted by cells. EVs contain proteins, RNA, DNA and other cargo that can have immunomodulatory effects. Cancer-derived EVs have been described as having immunomodulating effects in vivo with immunosuppressive and pro-tumor growth capabilities. However, cancer-derived EVs have also been harnessed and utilized for anti-cancer potential. METHODS: To assess the immunomodulatory effect of EVs produced by acute myeloid leukemia (AML) cells, we isolated vesicles secreted by the murine AML cell line, C1498, and investigated their effect on in vitro and in vivo immune responses. RESULTS: These leukemia-derived EVs were found to induce increased proliferation of CD3+ cells and enhanced cytolytic activity of CD3+ cells directed toward leukemic cells in vitro. Injection of leukemia-derived EVs into syngeneic naïve mice induced T cell responses in vivo and resulted in enhanced immune responses upon T cell re-stimulation in vitro. CONCLUSION: These findings indicate that C1498-derived EVs have immunomodulatory effects on cell-mediated immune responses that could potentially be utilized to facilitate anti-leukemia immune responses.

The Use of Probiotic Therapy to Modulate the Gut Microbiota and Dendritic Cell Responses in Inflammatory Bowel Diseases.

: Recent investigations have shown that different conditions such as diet, the overuse of antibiotics or the colonization of pathogenic microorganisms can alter the population status of the intestinal microbiota. This modification can produce a change from homeostasis to a condition known as imbalance or dysbiosis; however, the role-played by dysbiosis and the development of inflammatory bowel diseases (IBD) has been poorly understood. It was actually not until a few years ago that studies started to develop regarding the role that dendritic cells (DC) of intestinal mucosa play in the sensing of the gut microbiota population. The latest studies have focused on describing the DC modulation, specifically on tolerance response involving T regulatory cells or on the inflammatory response involving reactive oxygen species and tissue damage. Furthermore, the latest studies have also focused on the protective and restorative effect of the population of the gut microbiota given by probiotic therapy, targeting IBD and other intestinal pathologies. In the present work, the authors propose and summarize a recently studied complex axis of interaction between the population of the gut microbiota, the sensing of the DC and its modulation towards tolerance and inflammation, the development of IBD and the protective and restorative effect of probiotics on other intestinal pathologies.

Induction of anti-leukemic responses by stimulation of leukemic CD3+ cells with allogeneic stimulator cells.

BACKGROUND: Immunotherapeutic protocols have focused on identification of stimuli that induce effective anti-leukemic immune responses. One potent immune stimulus is the encounter with allogeneic cells. Our group previously showed that the infusion of haploidentical donor white blood cells (1-2 × 108 CD3+ cells/kg) into patients with refractory hematological malignancies induced responses of varying magnitude in over half of the patients. Because donor cells were eliminated within 2 weeks in these patients, it is presumed that the responses of recipient lymphocytes were critically important in achieving prolonged anti-leukemic responses. METHODS: The role of patient CD3+ cells in anti-leukemic responses was examined by isolating peripheral blood mononuclear cells from newly diagnosed leukemic patients. Immunophenotyping was performed on these peripheral blood mononuclear cells. CD3+ cells were isolated from the peripheral blood mononuclear cells and tested for their ability to proliferate and lyse autologous leukemic cells when stimulated with unrelated allogeneic cells. RESULTS: Allostimulated CD3+ cells effectively generated cytolytic responses to autologous CD3-cells in 11/21 patients. Increased numbers of CD4+ cells expressing high levels of granzyme A, B and perforin and CD8+CD39+ cells were found in nonresponsive CD3+ cells. CONCLUSIONS: These results indicate that CD3+ cells from leukemic patients are capable of generating anti-leukemic responses when stimulated with unrelated allogeneic cells. This model can be used to identify approaches using alloreactive responses by patient lymphocytes to enhance in vivo anti-leukemic responses.

Extracellular vesicles in leukemia.

Extracellular vesicles (EV) are nano-sized membrane enclosed vehicles that are involved in cell-to-cell communication and carry cargo that is representative of the parent cell. Recent studies have highlighted the significant roles leukemia EVs play in tumor progression, and ways in which they can lead to treatment evasion, thus meriting further investigation. Leukemia EVs are involved in crosstalk between the leukemia cell and its surroundings, transforming it into a cancer favorable microenvironment. Due to the diverse biological content found in leukemia EVs, they have an assortment of effects on the cells they interact with and can be harnessed as candidates for diagnostic and therapeutic treatments. This review focuses on EVs in the context of leukemia and the means by which they modulate their microenvironment, hematopoiesis, and the immune system to facilitate malignancy. We will also address current and prospective EV-based therapeutics.

Eye-Movement Training Results in Changes in qEEG and NIH Stroke Scale in Subjects Suffering from Acute Middle Cerebral Artery Ischemic Stroke: A Randomized Control Trial.

CONTEXT: Eye-movement training (EMT) can induce altered brain activation and change the functionality of saccades with changes of the brain in general. OBJECTIVE: To determine if EMT would result in changes in quantitative electroencephalogram (qEEG) and NIH Stroke Scale (NIHSS) in patients suffering from acute middle cerebral artery (MCA) infarction. Our hypothesis is that there would be positive changes in qEEG and NIHSS after EMT in patients suffering from acute MCA ischemic stroke. DESIGN: Double-blind randomized controlled trial. SETTING AND PARTICIPANTS: Thirty-four subjects with acute MCA ischemic stroke treated at university affiliated hospital intensive care unit. INTERVENTIONS: Subjects were randomized into a "control" group treated only with aspirin (125 mg/day) and a "treatment" group treated with aspirin (125 mg/day) and a subject-specific EMT. MAIN OUTCOME MEASURES: Delta-alpha ratio, power ratio index, and the brain symmetry index calculated by qEEG and NIHSS. RESULTS: There was strong statistical and substantive significant improvement in all outcome measures for the group of stroke patients undergoing EMT. Such improvement was not observed for the "control" group, and there were no adverse effects. CONCLUSION: The addition of EMT to a MCA ischemic stroke treatment paradigm has demonstrated statistically significant changes in outcome measures and is a low cost, safe, and effective complement to standard treatment.

Vegetative state is a pejorative term.

The term persistent vegetative state (PVS) refers to the only circumstance in which an apparent dissociation of both components of consciousness is found, characterized by preservation of wakefulness with an apparent loss of awareness. Several authors have recently demonstrated by functional neuroimaging studies that a small subset of unresponsive "vegetative" patients may show unambiguous signs of consciousness and command following that is inaccessible to clinical examination at the bedside. The term "estado vegetativo" used in Spanish to describe the PVS syndrome by physicians came from the English-Spanish translation. The Spanish term "vegetativo" is related to unconscious vital functions, and "vegetal" is relative to plants. According to our experience, when a physician informs to patients' relatives that his/her family member's diagnosis is a "estado vegetativo", they understand the he/she is no more a human being, that there is no hope of recovery. The European Task Force on Disorders of Consciousness has recently proposed a new term, unresponsive wakefulness syndrome (UWS), to assist society in avoiding the depreciatory term vegetative state. Our group has embraced the use of the new term UWS and might suggest that we change our concept and use of the term MCS to minimally responsive wakefulness state (MRWS), or minimally aware wakefulness state (MAWS). Medical terms must be current and avoid any pejorative description of patients, which will promote our abilities to serve humankind and challenge neuroscientists to offer society new and realistic hopes for neurorehabilitation.

A Cuban perspective on management of persistent vegetative state.

The Cuban Group for Study of Disorders of Consciousness is developing several research protocols to search for possible preservation of residual brain and autonomic functions in cases of persistent vegetative and minimally conscious states. We present examples showing the importance of 3D anatomic reconstruction of brain structures and MRI tractography for assessing white matter connectivity. We also present results of use of proton magnetic resonance spectroscopy technique to follow up cognitive recovery in persistent vegetative state patients transitioning to minimally conscious state. We have demonstrated recognition of a mother's voice with emotional content after zolpidem administration, indicating high-level residual linguistic processing and brain activation despite the patient's apparent inability to communicate. Hence we differ with current thinking that, by definition, subjects in persistent vegetative state are isolated from the outside world and cannot experience pain and suffering. We also consider "vegetative state" a pejorative term that should be replaced. KEYWORDS Persistent vegetative state, minimally conscious state, consciousness disorders, magnetic resonance imaging, electroencephalography, heart rate variability.

Brain death diagnosis and apnea test safety.

The apnea test is a mandatory examination for determining brain death (BD), because it provides an essential sign of definitive loss of brainstem function. However, several authors have expressed their concern about the safety of this procedure as there are potential complications such as severe hypotension, pneumothorax, excessive hypercarbia, hypoxia, acidosis, and cardiac arrhythmia or asystole. These complications may constrain the examiner to abort the test, thereby compromising BD diagnosis. Nevertheless, when an appropriate oxygen-diffusion procedure is used, this technique is safe. We review here the prerequisites to begin the test, its procedure, potential complications, and the use of alternative ancillary tests. We recommend that the apnea test be retained as a mandatory procedure for the diagnosis of BD. In those situations when the apnea test is terminated by the examiner for some reason or when it is impossible to carry it out in a patient due to the presence of some pathologic condition, alternative ancillary tests should be used to confirm BD.

Assessing acute middle cerebral artery ischemic stroke by quantitative electric tomography.

This paper focuses on the application of quantitative electric tomography (qEEGT) to map changes in EEG generators for detection of early signs of ischemia in patients with acute middle cerebral artery stroke. Thirty-two patients were studied with the diagnosis of acute ischemic stroke of the left middle cerebral artery territory, within the first 24 hours of their clinical evolution. Variable Resolution Electrical Tomography was used for estimating EEG source generators. High resolution source Z-spectra and 3- dimensional images of Z values for all the sources at each frequency were obtained for all cases. To estimate statistically significant increments and decrements of brain electric activity within the frequency spectra, the t-Student vs. Zero test was performed. A significant increment of delta activity was observed on the affected vascular territory, and a more extensive increment of theta activity was detected. A significant alpha decrement was found in the parieto-occipital region of the affected cerebral hemisphere (left), and in the medial and posterior region of the right hemisphere. These findings suggest that qEEGT Z delta images are probably related to the main ischemic core within the affected arterial territory; penumbra, diaschisis, edema, might explain those observed theta and alpha abnormalities. It was concluded that qEEGT is useful for the detection of early signs of ischemia in acute ischemic stroke.