Manual Instruments as an Alternative to Drilling for Bony Exposure in Skull Base Surgery: Concept and Technique.

Background Drilling in neurosurgery is an integral part of surgical exposure, especially in skull base approaches and craniovertebral junction (CVJ) surgeries. Most of such drillings are done in close proximity to the neurovascular structures in skull base surgeries and cervical-medullary junction or facet/pedicle in CVJ surgeries. Reluctance to drilling among young neurosurgeons is due to less hands-on experience during training and also, in the early part of the career, due to fear of injury to neurovascular structures. Methods Five commonest bone removals for skull base region and CVJ surgeries that can be safely done using manual instruments were identified based on experiences of senior authors. The authors highlight key technical nuances to widen surgical corridors using manual instruments safely for skull base surgical approaches. Results Basic neuroanatomical concepts and basic physics help in using manual instruments safely for bone removals in various skull base surgical approaches. Conclusions Manual instruments may be used for bone removals in selected skull base surgical approaches, which help young neurosurgeons to perform these surgeries in limited-resource settings.

Comparison of depth of electrode insertion between cochleostomy and round window approach: a cadaveric study.

INTRODUCTION: Round window approach and cochleostomy approach can have different depth of electrode insertion during cochlear implantation which itself can alter the audiological outcomes in cochlear implant. OBJECTIVE: The current study was conducted to determine the difference in the depth of electrode insertion via cochleostomy and round widow approach when done serially in same temporal bone. METHODOLOGY: This is a cross-sectional study conducted in the Department of Otorhinolaryngology in conjunction with Department of Anatomy and Department of Diagnostic and Interventional Radiology over a period of 1 year. 12-electrode array insertion was performed via either approach (cochleostomy or round window) in the cadaveric temporal bone. HRCT temporal bone scan of the implanted temporal bone was done and depth of insertion and various cochlear parameters were calculated. RESULT: A total of 12 temporal bones were included for imaging analysis. The mean cochlear duct length was 32.892 mm; the alpha and beta angles were 58.175° and 8.350°, respectively. The mean angular depth of electrode insertion via round window was found to be 325.2° (SD = 150.5842) and via cochleostomy 327.350 (SD = 112.79) degree and the mean linear depth of electrode insertion via round window was found to be 18.80 (SD = 4.4962) mm via cochleostomy 19.650 (SD = 3.8087) mm, which was calculated using OTOPLAN 1.5.0 software. There was a statically significant difference in linear depth of insertion between round window and cochleostomy. Although the angular depth of insertion was higher in CS group, there was no statistically significant difference with round window type of insertion. CONCLUSION: The depth of electrode insertion is one of the parameters that influences the hearing outcome. Linear depth of electrode insertion was found to be more in case of cochleostomy compared to round window approach (p = 0.075) and difference in case of angular depth of electrode insertion existed but not significant (p = 0.529).

Blueprinting of Assessment for the Lower Limb in Undergraduate Anatomy Curriculum.

BACKGROUND:  Competency-based medical education is followed by most of the medical schools in India. Health universities are changing their question paper pattern and practical assessment pattern to ensure valid and reliable evaluation of student learning but assessment of entire curriculum competencies is a difficult task to achieve. Assessment blueprinting can provide a guiding map for balanced and rational assessment. It ensures similar exam content from year to year (over- or under-representing a topic can be avoided). The assessment blueprint provides ideas of appropriate formats for the knowledge/skills being assessed. The study aims to observe facilitators' perceptions and develop an assessment blueprint for the anatomy curriculum. METHODS:  This educational mixed-method study was conducted in the Department of Anatomy of All India Institute of Medical Sciences, Jodhpur, India. Perceptions of 13 facilitators of the Anatomy Department about assessment blueprinting were observed on a five-point Likert scale. Topics of the lower limb were identified based on the Undergraduate Curriculum Volume-1 document provided by the National Medical Council of the Government of India. Weightage to each topic was given on the basis of anatomical importance and clinical significance at the undergraduate level. Marks for the topic as per relative weightage were calculated. The blueprint was prepared and validated by the subject expert of the institute. An example question paper template was prepared as per the assessment blueprint. RESULTS:  In the present study, all 13 (100%) participants agreed that there is a need for a valid assessment framework to maintain the reliability of assessment, 11 (85%) participants agreed that an assessment blueprint can provide a valid tool for assessment, and 10 (77%) participants agreed that assessments are not planned as per learning domain requirement, and planning of assessment as per blueprint requires more time and resource. Of the participants, eight (62%) agreed that all topics or competencies are not included while setting the question paper. The blueprint for assessment of the lower limb provided an idea of high-weightage and low-weightage topics and the suitable types of questions for these topics. CONCLUSION: Assessment is the key element of competency-based medical education. For a complete, valid, and reliable assessment, a blueprint for assessment is the need of the hour. Assessment blueprinting in this study showed that the anterior thigh region, hip joint, knee joint, and vascular and nerve supply of the lower limb are topics with maximum weightage for the lower limb in the medical anatomy undergraduate curriculum. It can help in reducing under or over-representation of content. With the help of a blueprint, the examiners can assess the majority of content without any intentional or unintentional bias.

Skull base dural reflection models: tool for teaching neuroanatomy at resource-scarce centers.

Skull base dural reflections are complex, and along with various ligaments joining sutures of the skull base, are related to most important vessels like internal carotid arteries (ICA), vertebral arteries, jugular veins, cavernous sinus, and cranial nerves which make surgical approaches difficult and need thorough knowledge and anatomy for a safe dissection and satisfactory patient outcomes. Cadaver dissection is much more important for the training of skull base anatomy in comparison to any other subspecialty of neurosurgery; however, such facilities are not available at most of the training institutes, more so in low- and middle-income countries (LMICs). A glue gun (100-Watt glue gun, ApTech Deals, Delhi, India) was used to spread glue over the superior surface of the bone of the skull base over desired area (anterior, middle, or lateral skull base). Once glue was spread over the desired surface uniformly, it was cooled under running tap water and the glue layer was separated from the skull base. Various neurovascular impressions were colored for ease of depiction and teaching. Visual neuroanatomy of the inferior surface of dural reflections of the skull base is important for understanding neurovascular orientations of various structures entering or exiting the skull base. It was readily available, reproducible, and simple for teaching neuroanatomy to the trainees of neurosurgery. Skull base dural reflections made up of glue are an inexpensive, reproducible item that may be used for teaching neuroanatomy. It may be useful for trainees and young neurosurgeons, especially at resource-scarce healthcare facilities.

Systematic Review of Morphometric Analysis of Anterior Cerebral Artery (ACA) Emphasizing on Its Clinical Implications.

Thorough data of morphometric measurements of arteries forming Circle of Willis (CW) is crucial for radiological and neurosurgical interventions. This systematic review has been conducted with the objective to find an effective range of length and diameter of anterior cerebral artery (ACA) and to observe whether there is any change in the length and diameter of ACA depending on age or sex. Articles based on length and diameter of ACA via any mode of study like cadaveric or radiological were considered in this systematic review. A comprehensive literature search using databases Cochrane Library, PubMed, and Scopus for relevant articles was done. Research papers which answered the focused questions were selected for data analysis. It was observed that the range of length and diameter of ACA were 8.1 mm-21 mm and 0.5 Å-3.4 mm, respectively. In majority of the studies, length and diameter of ACA were more in the younger age group (>40 years); and the length of ACA was more in females whereas the diameter of ACA was more in males. These data will be applicable for better construction and decipherment of angiographic images. This will help in the proper and guided treatment of intracranial pathologies.

Morphological Study of Variations of the Human Cadaveric Liver and Its Clinical Implications.

Introduction With increasing dependence on laparoscopic procedures, precise knowledge of external variations of the liver is essential for good surgical and interventional outcomes, preventing imaging misdiagnosis, and curtailing complications. The present study aims to evaluate the gross anatomical variations of the liver. Materials and Methods The 40 adult cadaveric livers of age 60-80 years were removed during the routine dissection for undergraduate medical students and examined for morphological variations in the form of size, shape, and fissures. Results Accessory fissures were observed on the caudate lobe (CL) in 23 (57.5%), on the quadrate lobe (QL) in seven (17.5%), on the right lobe (RL) in 29 (72.5%), and on the left lobe (LL) in 12 (30%) specimens. Netter's Type 2, Type 4, Type 5, Type 6, and Type 7 liver were observed in four (10%), seven (17.5%), one (2.5%), three (7.5%), and three (7.5%) specimens respectively. The most common shapes of the CL and QL were rectangular in 16 (40%) and quadrangular in 10 (25%) specimens respectively. Pons hepatis were seen in three (7.5%) specimens. The mean length (cm) of RL and LL were 17.75 ±3.09 and 16.9±3.69 respectively, whereas the mean transverse diameter (TD) (cm) of RL and LL were 7.98±1.20 and 7.85±1.58 respectively. The mean length and TD (cm) of CL were 5.62±1.67 and 2.48±1.00 respectively. The mean length and TD (cm) of the QL were 6.00±1.51 and 2.81±0.83 respectively. Conclusion Precise knowledge of these variations would be helpful for surgeons in planning and performing surgical procedures and for anatomists.

Anomalous retrogressive palmaris longus.

An interesting case of unusual unilateral variant of palmaris longus (PL) tendon of forearm was noticed by us. We found two bellies of PL as well as their different insertions. These observations will help in understanding morphological variations of this muscle and its clinical implications. PL is a fusiform muscle in the superficial flexor group of muscles of forearm. It originates from medial epicondyle of humerus by common flexor tendon. We found PL having one origin, i.e., from medial epicondyle from common tendinous origin of flexor muscles and then it divided to form two bellies having two long tendons distally. Understanding of presence or absence or anomalies of PL is not only important for medical professionals but also for evolutionary biologists. Awareness of anatomy and variations of flexor tendons is important for health care practitioners for the correct diagnosis and management of pain, disease, and trauma of forearm and hand.

Résumé Nous avons remarqué un cas intéressant de variante unilatérale inhabituelle du tendon du long palmaire (PL) de l'avant-bras. Nous avons retrouvé deux ventres de PL ainsi que leurs différentes insertions. Ces observations aideront à comprendre les variations morphologiques de ce muscle et ses implications cliniques. Le PL est un muscle fusiforme du groupe des muscles fléchisseurs superficiels de l'avant-bras. Il provient de l'épicondyle médial de l'humérus par le tendon fléchisseur commun. Nous avons trouvé que le PL avait une origine, c'est-à-dire de l'épicondyle médial provenant de l'origine tendineuse commune des muscles fléchisseurs, puis il s'est divisé pour former deux ventres ayant deux longs tendons distalement. Comprendre la présence, l'absence ou les anomalies de PL est non seulement important pour les professionnels de la santé mais également pour les biologistes évolutionnistes. La connaissance de l'anatomie et des variations des tendons fléchisseurs est importante pour les praticiens de la santé afin de diagnostiquer et de gérer correctement la douleur, la maladie et les traumatismes de l'avant-bras et de la main. Mots-clés: Palmaris longus, greffe tendineuse, variation, contracture ischémique de Volkmann.

Protocol for induction and characterization of microglia extracellular traps in murine and human microglia cells.

Extracellular traps (ETs) are composed of decondensed chromatin and are embedded with various antimicrobial proteins like myeloperoxidase and histones. Recently, we reported that dopamine (DA) induces ETs in BV2 microglia cell line and primary adult human microglia in a manner independent of cell death, reactive oxygen species, and actin polymerization. This protocol details how to characterize DA-induced ETs in BV2 microglia and human microglia. The protocols for characterization of ETs may also be used for other adherent cell lines. For complete details on the use and execution of this protocol, please refer to Agrawal et al. (2021).

Vertical integration in postgraduate teaching for anaesthesiology residents: A questionnaire based descriptive cross-sectional study.

BACKGROUND: Medical education has observed numerous reforms in the last hundred years. While most of the reforms are applied to the undergraduate teaching, postgraduate education and training have lagged behind in keeping the pace. Anesthesiology curriculum has witnessed a few new methods inducted into practice like problem-based learning, flipped classroom etc. We introduced vertical integration with anatomy at our department and assessed its impact. METHODS: After a five-week schedule of integrated anatomy classes, a self-structured questionnaire was circulated amongst the 41 anesthesiology residents to know their perceptions and attitudes towards the classes. Their suggestions were also sought. The responses were analyzed with descriptive statistics (percentages). RESULTS: Thirty-six responses were received leading to a response rate of 87.8%. Fourteen residents (38.9%) believed that the integrated classes would be very helpful in their clinical practice, 20 (55.5%) residents believed them to be helpful while two (5.5%) residents believed that the classes would be little helpful in clinical practice. Hundred percent of the residents recommended the classes to be continued for the future batches. Half of the residents wanted the classes to be conducted twice in the three-year tenure (in the first and last semester) while 11 (30.5%) residents wanted the classes to be conducted every year. Seven (19.4%) residents thought that it's enough to conduct the classes once during the three-year tenure. Resident's suggested that they would like to have integrated classes with other departments like physiology, radiology, emergency medicine etc. CONCLUSION: The integrated classes with anatomy were well perceived by the anesthesiology residents. Vertically integrated curriculum should be introduced in postgraduate training of various specialties for better education and hence, better patient care.

Dopamine induces functional extracellular traps in microglia.

Dopamine (DA) plays many roles in the brain, especially in movement, motivation, and reinforcement of behavior; however, its role in regulating innate immunity is not clear. Here, we show that DA can induce DNA-based extracellular traps in primary, adult, human microglia and BV2 microglia cell line. These DNA-based extracellular traps are formed independent of reactive oxygen species, actin polymerization, and cell death. These traps are functional and capture fluorescein (FITC)-tagged Escherichia coli even when reactive oxygen species production or actin polymerization is inhibited. We show that microglial extracellular traps are present in Glioblastoma multiforme. This is crucial because Glioblastoma multiforme cells are known to secrete DA. Our findings demonstrate that DA plays a significant role in sterile neuro-inflammation by inducing microglia extracellular traps.

Renal Histopathological Changes in Coronavirus Disease 2019 Patients: A Systematic Review and Meta-analysis of Individual Patient Data.

The major targets of coronavirus disease 2019 (COVID-19) are the respiratory and immune systems. However, a significant proportion of hospitalized patients had kidney dysfunction. The histopathological surveys have principally focused on respiratory, hematopoietic, and immune systems, whereas histopathologic data of kidney injury are lacking. Our study aimed to summarize the renal histopathological findings in COVID-19 from the published case report and case series. We conducted a systematic searching of databases such as MEDLINE, EMBASE, and Cochrane Library for published reports of COVID-19 patients with renal histopathological changes from autopsy studies and from "for cause" indication biopsies. Included in our study are case reports and case series with extractable quantitative data on patient demographics such as age, sex, ethnicity, as well as data on renal function tests, their comorbidities, and biopsy to study the histopathological changes. Data were analyzed with Microsoft Excel. To evaluate the methodological quality, we chose the framework for appraisal, synthesis, and application of evidence suggested by Murad et al. Systematic searches of literature found 31 studies that fulfilled the eligibility criteria. These studies included a total of 139 cases, where individual case details including clinical and histopathological findings were available. The median age of the cases was 62 years with a male:female ratio of 2.5:1. Associated comorbidities were noted in 78.4% of cases. The majority of the cases had renal dysfunction with proteinuria which was documented in more than two-thirds of the cases. The histopathological findings observed the frequent tubular involvement manifested by acute tubular injury. Regarding glomerular pathology, collapsing glomerulopathy emerged as a distinct lesion in these patients and was noted among 46.8% of cases with glomerular lesions. A small subset of cases (4.3%) had thrombotic microangiopathy. Collapsing glomerulopathy emerged as a hallmark of glomerular changes among COVID-19 patients. Tubular damage is common and is linked to multiple factors including ischemia, sepsis among others. In the form of thrombotic microangiopathy seen in a subset of patients, vascular damage hints toward the hyper-coagulable state associated with the infection. The demonstration of viral particles in renal tissue remains debatable and requires further study.

Morphometric Analysis of parameters of Internal Carotid Artery-Potential Clinical Implications.

BACKGROUND: The study in consideration aimed to do morphometry of internal carotid artery (ICA) and substantiate any differences significant in relation to sex and age on digital subtraction angiography (DSA) imaging. OBJECTIVES: Our study aims to ascertain morphometric parameters of ICA through DSA evaluation and to build a normative data which is accurate enough for the neurovascular procedures to be performed. The study will also carry out correlation of morphometry of intracerebral blood vessels with sex, age, and side-related dimorphism. MATERIAL AND METHODS: Our study, cross-sectional in design was done on 70 patients (>20 years). Diameter of different segments of ICA were measured after imaging was done on DSA using a Philips biplane system clarity (Allura FD20/20). Statistical analysis was done. RESULT AND CONCLUSION: In males, mean diameter of petrous, cavernous, supraclinoid, and choroidal segments of ICA were more when compared to females. Statistically significant differences were found in supraclinoid segment of ICA between males and females. The mean diameter of supraclinoid and choroidal segments of ICA showed a decreasing trend from younger to older age groups. The difference in the mean diameter of petrous segment of ICA with increasing age was statistically significant. The results of our study show that differences were statistically significant in supraclinoid segment of ICA in males and females. Neurosurgeons in order to be confident in tackling the various emergencies in this region need to have in-depth knowledge of morphometery of cerebral arterial circle.

Transverse cerebellar diameter: a reliable predictor of gestational age.

OBJECTIVES: To determine accuracy of transverse cerebellar diameter (TCD) measurement in the prediction of gestational age (GA) in normal fetuses; to develop reference chart for TCD according to GA in Indian population. DESIGN: A retrospective cross-sectional study. METHOD: Ultrasonographic measurements in 300 singleton pregnant women included biparietal diameter (cm), head circumference (cm), abdominal circumference (cm), femur length (cm) and transverse cerebellar diameter (cm). Reference chart with mean TCD for corresponding gestational age (GA) in weeks was developed. RESULTS: Statistically significant relationship found between TCD and gestational age (R2=0.92, p=0.0006). Regression formulae based on TCD with other parameter can be used to predict gestational age of foetus. When TCD is compared with findings in other studies in different ethnic population, it is found that there is significant difference exists. CONCLUSION: In normally developing fetuses the TCD has linear correlation with advancing gestational age. A separate reference chart is required for every different population because ethnicity, nutrition and environmental factors can have impact on normal TCD values. This will help to avoid misinterpretation of data to determine gestational age.

Estrogen receptor, progesterone receptor and CD8+ expression in endometrium of women of unexplained infertility.

OBJECTIVE: The present study aimed to investigate the changes of endometrial progesterone and estrogen receptors in luteal phase biopsy specimens of infertile women and find a correlation, if any, between these and CD8+ receptors in the same. METHODS: The study was conducted on luteal phase endometrial biopsy specimens of 30 women of unexplained infertility and 15 age matched controls. Paraffin sections were first H & E stained. A standardized immunohistochemical protocol was then used to localize the estrogen, progesterone and CD8+ receptors in these samples that were expressed as percentage positivity. Unpaired T test was applied between the controls and cases both for epithelial and stromal cells. The data was also analyzed for correlation in cases for the positivity of CD8+ Cells with that of ER and PR. RESULTS: The positivity of estrogen receptors (ER) in stromal cells was significantly lower (p<0.001) in the infertile women when compared to controls and in both the epithelial and stromal cells for progesterone receptors (p<0.001). The results were non significant for CD8+ cells (p=0.19) and also showed no significant correlation in the positivity of CD8+ cells with that of ER and PR. CONCLUSIONS: The development of molecular probe like ER and PR positivity in endometrial epithelial and stromal cells allows a new approach to be made to the characterization of normal and defective endometrial function.

Low fidelity model making activity by students: A novel way of learning concepts of neuroanatomy.

Teaching and learning anatomy has always been an integral part of medical education. Teaching neuroanatomy has always faced innate and contextual challenges therefore various innovative teaching-learning methods have been devised on the idea of engaging learners in meaningful learning activities through apt guidance, communication among peers and cluster activities. The present study aims at such an innovative method. The study was conducted in practical sessions of first year MBBS at the Institute during second semester. Neuroanatomy topic selected for present study was 'Neural Pathways/tracts'. Participants were divided into 8 groups and each was allotted a specific activity related to a particular cross-sectional level and allowed to build with the material provided by the department. Student feedback was taken through a structured questionnaire. 81 and 82.4% of students stated that the activity was clearly explained and should be offered more frequently in curriculum. The activity also developed a positive attitude and good coordination amongst peers with increase in communication skills (89.1%, 91.8%, 89% respectively). 87.8% of students agreed that small group learning is better than didactic lectures in neuroanatomy. In current medical scenario with reduced anatomy teaching hours and a continuous pressure on undergraduates, a low-cost learning intervention formulated to deliver a complex 3-D model of tracts passing through various parts of nervous system by simple materials would show better access and understanding of the tracts with improvement of 3D visualization skills.