Neuroanatomical zones of human traumatic brain injury reveal significant differences in protein profile and protein oxidation: Implications for secondary injury events.

Traumatic brain injury (TBI) causes significant neurological deficits and long-term degenerative changes. Primary injury in TBI entails distinct neuroanatomical zones, i.e., contusion (Ct) and pericontusion (PC). Their dynamic expansion could contribute to unpredictable neurological deterioration in patients. Molecular characterization of these zones compared with away from contusion (AC) zone is invaluable for TBI management. Using proteomics-based approach, we were able to distinguish Ct, PC and AC zones in human TBI brains. Ct was associated with structural changes (blood-brain barrier (BBB) disruption, neuroinflammation, axonal injury, demyelination and ferroptosis), while PC was associated with initial events of secondary injury (glutamate excitotoxicity, glial activation, accumulation of cytoskeleton proteins, oxidative stress, endocytosis) and AC displayed mitochondrial dysfunction that could contribute to secondary injury events and trigger long-term degenerative changes. Phosphoproteome analysis in these zones revealed that certain differentially phosphorylated proteins synergistically contribute to the injury events along with the differentially expressed proteins. Non-synaptic mitochondria (ns-mito) was associated with relatively more differentially expressed proteins (DEPs) compared to synaptosomes (Syn), while the latter displayed increased protein oxidation including tryptophan (Trp) oxidation. Proteomic analysis of immunocaptured complex I (CI) from Syn revealed increased Trp oxidation in Ct > PC > AC (vs. control). Oxidized W272 in the ND1 subunit of CI, revealed local conformational changes in ND1 and the neighboring subunits, as indicated by molecular dynamics simulation (MDS). Taken together, neuroanatomical zones in TBI show distinct protein profile and protein oxidation representing different primary and secondary injury events with potential implications for TBI pathology and neurological status of the patients.

Minimally invasive foramen magnum decompression using tubular retractors (MIFT) for Chiari I malformations.

BACKGROUND: Chiari malformation type 1 has been traditionally treated with foramen magnum decompression and C1 arch excision with or without duroplasty depending on the surgeon's preference. Each of the various surgical modifications has its advantages and disadvantages. METHODS: We describe a minimally invasive tubular retractor-based approach to achieve bony decompression in these cases. We have had good results comparable to the open approach. CONCLUSIONS: Strict orientation to the midline using soft tissue landmarks in between the muscles and bony landmarks in the deeper planes is important to achieve good surgical results. Operative time decreases with expertise and is comparable to the open technique. Minimal blood loss and decreased hospital stay and an excellent cosmetic scar make this procedure more appealing.

Trapped fourth ventricle-treatment options and the role of open posterior fenestration in the surgical management.

BACKGROUND: Trapped fourth ventricle (TFV) is a rare and difficult to treat condition. Most patients have a past inciting event (infection, IVH, trauma) and history of prior CSF diversion. The symptoms are due to the mass effect on brainstem and cerebellum. Rarely, TFV can also be associated with syrinx formation due to a dissociated craniospinal CSF flow near the fourth ventricle outlets. We present our experience and outcomes of open posterior fenestration in 11 cases, along with an overview of the surgical management of TFV. METHODS: Between 2011 and 2018, 11 patients of TFV were operated by the posterior approach fenestration of the fourth ventricle outlets and arachnoid dissection. The clinical and radiological findings of the patients were retrieved from the hospital database. The surgical technique is described in detail. The patients' neurological status and imaging findings in the follow-up were recorded and compared. RESULTS: The average age of the patients was 23.55 years. The most common presenting symptoms were headache (9/11) and gait imbalance (7), with TB meningitis being the commonest etiology. Ten patients had a history of prior CSF diversion with two presenting with shunt malfunction. Mean follow-up duration was 33.33 months. The improvement in neurological status was observed in 9/11 patients, 2 remained status quo. On follow-up imaging, 8/11 (72.72%) patients had a decrease in the size of TFV while syrinx improved in 3/5 (60%). CONCLUSION: Multiple surgical approaches have been described for TFV. Endoscopic fourth ventriculostomy with aqueductoplasty is gaining popularity in the past two decades. However, an open posterior fenestration of the midline fourth ventricle outlet (magendieplasty) along with sharp arachnoid dissection (adhesiolysis) along the cerebello-medullary cisterns and paracervical gutters is relatively simple and provides physiological fourth ventricular CSF outflow. This is especially useful in TFV with syrinx as the craniospinal CSF circulation is established.

Cervical Spine Osteoblastoma with an Aneurysmal Bone Cyst in a 2-Year-Old Child: A Case Report.

Osteoblastomas and aneurysmal bone cysts are uncommon benign tumors of the spine. Their presentation can vary between diffuse pain, restriction of neck movements, torticollis, radiculopathy, and myelopathy. Complete excision is the best treatment to achieve a cure, but recurrence is not uncommon. A combination of the two conditions in the pediatric population is extremely rare. To the best of the authors' knowledge, only 2 cases of such a combination in the cervical spine have been reported in the literature. We report the case of a 2-year-old child having a right C4 lateral mass osteoblastoma with an aneurysmal bone cyst. The child underwent complete surgical excision of the lesion with fusion.

Hirayama disease/cervical flexion-induced myelopathy progressing to spastic paraparesis: A report on three cases with literature review.

Hirayama disease (HD)/cervical flexion-induced myelopathy (CFIM) is a lower motor neuron disease conventionally affecting a single upper extremity. We describe three men progressing after a long stable period to develop severe spastic paraparesis and bladder disturbances as a protracted implication of HD. The age at onset was 20, 24, and 15 years, while the age at presentation was 27, 41, and 57 years, respectively. The second phase of disease progression occurred after 4, 13, and 28 years of stationary period. All had CFIM with characteristic magnetic resonance imaging features as observed during progressive stages. The anterior dural shift extended variably from C4 to D4 levels with a median value of 5 mm and was maximum at C6 to C7 levels, pushing the cord anteriorly causing compression. This study emphasizes the need to recognize this unusual subgroup of HD and mandates long-term follow-up with timely intervention in arresting the progression/improving the deficits.

Epilepsy surgery for focal cortical dysplasia: Seizure and quality of life (QOLIE-89) outcomes.

AIM: Surgery for drug resistant epilepsy (DRE) with focal cortical dysplasia (FCD) often requires multiple non-invasive as well as invasive pre-surgical evaluations and innovative surgical strategies. There is limited data regarding surgical management of people with FCD as the underlying substrate for DRE among the low and middle-income countries (LAMIC) including India. METHODOLOGY: The presurgical evaluation, surgical strategy and outcome of 52 people who underwent resective surgery for DRE with FCD between January 2008 and December 2016 were analyzed. The 2011 classification proposed by Blumcke et al., was used for histo-pathological categorization. The Engel classification was used for defining the seizure outcome. The surgical outcome was correlated with the preoperative clinical presentation, video encephalogram (VEEG) recording, magnetic resonance imaging (MRI), invasive monitoring, surgical findings as well as histopathology and the quality of life in epilepsy (QOLIE)- 89 scores. RESULTS: Fifty-two patients underwent resective surgery for FCD (mean age at onset of seizure: 7.94 ± 6.23 years; duration of seizures prior to surgery: 12.95 ± 9.56 years; and, age at surgery: 20.88 ± 12.51 years). The following regional distribution was found; temporal-24 (language-13), frontal-15 (motor cortex- 5), parietal-5 (sensory cortex-4), occipital-1 and multilobar-7. Forty-seven percent of the cases had FCD in the right hemisphere and 53% had FCD in the left hemisphere. Invasive monitoring was performed for identification of the epileptogenic zone (EZ) as well as eloquent cortex in 7 cases and an intra-operative electro-corticography (ECoG) was used in 32 cases. Histopathology revealed the following distribution; FCD IA-4, IB- 1, IC-5, IIA-8, IIB-18, IIIA-13, IIIB -1, IIIC-1 and IIID-1. After a median follow up of 3.7 years after surgery, 84% of patients had Engel's Ia outcome. QOLIE-89 scores improved from 38.33 ± 4.7 (31.14-49.03) before surgery to 75.21 ± 8.44 (56.49-90.49) after surgery (P < 0.001). The younger age of the patient (<20 years) at surgery (P = 0.013), a lower pre-operative score (<9) on seizure severity scale (P = 0.012), focal discharges without propagation on ictal VEEG (P < 0.001), absence of acute post-operative seizures (P < 0.001) and Type II FCD (P = 0.045) were the significant predictors for a favorable seizure outcome. CONCLUSION: Surgical management of people with DRE and FCD is possible in countries with limited resources. Meticulous pre-surgical evaluation to localize the epileptogenic zone and complete resection of the focus and lesion can lead to the cure or control of epilepsy; and, improvement in the quality of life was observed along with seizure-free outcome.

Pediatric thoracolumbar spinal injuries: The etiology and clinical spectrum of an uncommon entity in childhood.

BACKGROUND: Pediatric thoracolumbar (TL) spinal injuries are uncommon entities with an incidence of 5-34% of all pediatric spinal injuries. There is a scarcity of studies done on the pediatric population in the developing countries like India. This study aims to review our experience with TL spine injuries in children over a 12-year period. MATERIALS AND METHODS: We retrospectively reviewed the epidemiology, risk factors, mechanisms, patterns of injury and management of pediatric TL injuries in our population. RESULTS: There were 90 children with TL spine injuries comprising 2% of all the spine injuries treated in our institute. The mean age was 15.9 ± 3.2 years (range: 2-18 years) with a male predominance (3:1). The most common mode of injury was fall from height. 64/90 (71.1%) children sustained injury due to fall from height, 18/90 (20%) children sustained injury following motor vehicle accident and rest of the children sustained injury due to the fall of a heavy object over the neck. Most of the patients (27.8%) sustained Grade A injury. Lumbar spine was the most common spinal level injured (53.3%), and fractures were the most common type of injury (93.3%). Surgical fixation was performed in 18/90 (20%) children. Follow-up was available for 21 children of which 13 (62%) were ambulant at follow-up. CONCLUSION: TL injuries are rare and are most common in children older than 10 years and mainly involve the lumbar region. When indicated, surgical fusion of the involved vertebrae is safe and effective.

Characterization of traumatic brain injury in human brains reveals distinct cellular and molecular changes in contusion and pericontusion.

Traumatic brain injury (TBI) contributes to fatalities and neurological disabilities worldwide. While primary injury causes immediate damage, secondary events contribute to long-term neurological defects. Contusions (Ct) are primary injuries correlated with poor clinical prognosis, and can expand leading to delayed neurological deterioration. Pericontusion (PC) (penumbra), the region surrounding Ct, can also expand with edema, increased intracranial pressure, ischemia, and poor clinical outcome. Analysis of Ct and PC can therefore assist in understanding the pathobiology of TBI and its management. This study on human TBI brains noted extensive neuronal, astroglial and inflammatory changes, alterations in mitochondrial, synaptic and oxidative markers, and associated proteomic profile, with distinct differences in Ct and PC. While Ct displayed petechial hemorrhages, thrombosis, inflammation, neuronal pyknosis, and astrogliosis, PC revealed edema, vacuolation of neuropil, axonal loss, and dystrophic changes. Proteomic analysis demonstrated altered immune response, synaptic, and mitochondrial dysfunction, among others, in Ct, while PC displayed altered regulation of neurogenesis and cytoskeletal architecture, among others. TBI brains displayed oxidative damage, glutathione depletion, mitochondrial dysfunction, and loss of synaptic proteins, with these changes being more profound in Ct. We suggest that analysis of markers specific to Ct and PC may be valuable in the evaluation of TBI pathobiology and therapeutics. We have characterized the primary injury in human traumatic brain injury (TBI). Contusions (Ct) - the injury core displayed hemorrhages, inflammation, and astrogliosis, while the surrounding pericontusion (PC) revealed edema, vacuolation, microglial activation, axonal loss, and dystrophy. Proteomic analysis demonstrated altered immune response, synaptic and mitochondrial dysfunction in Ct, and altered regulation of neurogenesis and cytoskeletal architecture in PC. Ct displayed more oxidative damage, mitochondrial, and synaptic dysfunction compared to PC.

Computed tomography-based classification of axis vertebra: choice of screw placement.

PURPOSE: The purpose of the study was to: (1) introduce a new CT-based parameter: free facet area and provide its normative data; (2) standardize the method of measuring isthmus width and height of the axis vertebra; (3) propose a new grading system to predict the difficulty in inserting transarticular and C2 pedicle screws. METHODS: Spiral CT scans of 47 adult dry axis vertebrae were studied. The methods of measuring isthmus width, isthmus height and free facet area are described. RESULTS: The mean isthmus width was 5.04 mm on the right side and 5.42 mm on the left side. The mean isthmus height was 5.21 mm on the right side and 5.45 mm on the left side. Mean free facet area was 61.23 % on the right side and 70.18 % on the left side. A novel grading system is proposed on the basis of these three parameters. As per this grading system, 40.4 % of the sides were found to be difficult for transarticular and 24.5 % sides for C2 pedicle screw insertion (total score 2, 3, 4). A Management protocol is suggested on the basis of the grading system. CONCLUSION: Inserting a transarticular screw was more frequently difficult as compared to pedicle screw. A new CT-based parameter (free facet area) and an efficient grading have been proposed to help surgeons choose the appropriate screw options, appreciate the complex anatomy of this region and compare data across various studies.

Profile of patients with craniovertebral junction anomalies with posterior circulation strokes.

BACKGROUND: Craniovertebral junction (CVJ) anomalies are rare and treatable risk factors for posterior circulation strokes (PCSs). Most of the literature comprises case reports and from varied specialities. METHODS: Chart review of patients with PCS with CVJ anomalies admitted in a single tertiary stroke care unit. We describe their clinical profile, investigative findings, and therapeutic outcomes. RESULTS: We saw 7 patients (6 males, mean age 20.1 ± 12.0 years), all previously undiagnosed during the 6-year period. Three patients had a combination of atlantoaxial dislocation (AAD), basilar invagination (BI) and Klippel-Feil anomalies, 2 patients had os odontoideum with AAD, and 1 patient each had isolated AAD and BI. Clinically, they presented with first or recurrent episodes of stroke with neck pain. Examination revealed noticeable skeletal markers and neurologic deficits involving the arterial territory. Routine stroke risk factors were absent. X-ray of CVJ was abnormal and diagnostic in all the patients. Other imaging modalities had their own contributions for identifying associated defects, demonstrating pathophysiology, and management of these patients. Acute care with anticoagulation and supportive measures helped in recovery of all of them. Posterior fusion was done in 4 patients, and 2 patients are awaiting the surgery. During follow-up all patients have improved and none had recurrences. CONCLUSIONS: In case of a young patient with PCS (first/recurrent) in the absence of routine risk factors for stroke, careful physical examination and imaging with basic X-ray may help in the diagnosis CVJ abnormalities, which may be effectively managed by a multidisciplinary team to prevent recurrences.

Use of Two Novel Dyes to Enhance Visualization of Cut Ends of the Vessel in Microvascular Anastomosis-An Experimental Study of 45 Rats.

BACKGROUND: Good visualization is a prerequisite for performing microvascular anastomosis. The most commonly used dye, methylene blue, has several limitations: it is washed off quickly and stains all the vessel layers. The objective of our study is to use 2 new novel dyes for improving visualization. METHODS: After ethical committee approval, 2 Dyes (2% cresyl violet, 1% eosin) were studied in 3 groups, 20 rats in each group and 5 rats in the combined group. End-to-side anastomosis was performed in the classic fashion in 45 rats. After venotomy, the dye was applied to the raw surface of the vessels and subsequently, anastomosis was performed. The improvement in visualization was judged by 3 blinded experts and nonexperts in 4 groups on a scale of 1-10. Scores were statistically analyzed. After 2 weeks, animals were re-explored to check the delayed patency, and segments were harvested for histopathologic analysis. RESULTS: The immediate and delayed patency rates were 100% (45/45) and 97% (33/34), respectively. In statistical analysis, the combined group (P = 0.005)was judged statistically significant because of the contrast in color. All the layers were stained by both dyes, staining lasted until the end of the surgery. Visibility of the cut ends was better in cresyl violet. All histopathologic findings suggested normal changes at the anastomotic site. CONCLUSIONS: This study showed that the use of these 2 dyes was not only feasible but highly efficacious. Even though all the layers were stained by both the dyes, the visibility of the cut ends was better. In both dyes, staining lasted until the end of surgery. To the best of our knowledge, this is the first study that has used these 2 novel dyes to improve visualization in microvascular anastomosis in an experimental setting.

Spinal melanoma with optic neuropathy -rare manifestation of Neurocutaneous melanosis and PET-MRI findings.

Neurocutaneous melanocytosis (NCM) is a rare, sporadic neuroectodermal dysplasia characterized by the presence of large or multiple congenital cutaneous nevi and melanocytic deposits in the central nervous system. Hitherto, unreported we describe a case of NCM with optic neuropathy and spinal cord melanoma from India. A 20 year-old-lady had headache and vomiting for 3 months followed by consecutive profound painless visual impairment. Visual acuity was counting of fingers at 1 m distance in both eyes with normal fundus. There were no symptoms of spinal cord involvement. Clinical examination showed multiple small to large melanocytic nevi over the face and body. Muscle power was normal. Tendon reflexes were exaggerated. Visual evoked potential showed bilateral prolonged P100 latency (Right eye - 144 msec; Left eye - 151 msec). Brain MRI revealed leptomeningeal enhancement of brainstem, cerebellum, oculomotor and facial-abducent nerve complex without optic nerve involvement. MRI spine showed extensive dorsal thoracic cord epidural lesion extending along the entire thoracic cord segment with dorsal cord compression. Positron Emission Tomography (PET) imaging showed Fludeoxyglucose F18 (FDG) avidity along D1-D12 levels of spinal cord. Biopsy from the cord lesion was suggestive of meningeal melanoma. Here we document a rare case of late onset NCM with intracranial meningeal infiltration and asymptomatic large epidural lesion of spinal cord, expanding its phenotypic spectrum. Optic neuropathy in NCM has not been reported earlier. Periodic screening of brain and spine is recommended for early prognostication and lesion identification in NCM.

Safety and Efficacy of Biopsy in Patients with Diffuse Intrinsic Pontine Gliomas.

BACKGROUND: Diffuse intrinsic pontine gliomas are aggressive tumors that carry a poor prognosis with a 2-year survival rate of <10%. The imaging appearance is often pathognomonic, and surgical biopsy is not mandatory to initiate treatment in children. Studies of biopsy samples provide insight into the disease's molecular pathobiology and open prospects for targeted therapy. This study was conducted to determine the diagnostic yield and safety of stereotactic biopsies. METHODS: This is a prospective observational study from a single tertiary health care center. All patients with clinical and radiological features diagnostic of diffuse intrinsic pontine gliomas (DIPGs) who underwent biopsy from July 2018 to June 2023 were included. Biopsies were performed using either stereotactic frame-based, frameless, or endoscopic techniques. RESULTS: A total of 165 patients with DIPGs were evaluated in the study period. The option of biopsy with its associated risks and benefits was offered to all patients. A total of 76 biopsies were performed in 74 patients (40 children and 34 adults, including 2 repeat biopsies). The median age was 15 years. Diffuse midline gliomas, H3K27M altered, was the most common histopathological diagnosis (85% pediatric and 55.9% adults). The diagnostic efficacy of the procedure was 94.7%. The complication rate was 10.8%, with no permanent neurological deficits due to surgery. There was no procedure-related mortality. CONCLUSIONS: Establishing the safety of the procedure could be an important step toward popularizing the concept, which might offer a better understanding of the disease. Brainstem eloquence and a lack of direct benefit to patients are the primary obstacles to brainstem biopsy.

Monomelic Amyotrophy/Hirayama Disease: Surgical Outcome in a Large Cohort of Indian Patients.

BACKGROUND: Hirayama disease (HD) is a cervical compressive myelopathy. Anterior cervical discectomy and fusion (ACDF) is identified as the best surgical approach. We evaluated surgical outcomes and factors influencing ACDF in HD. METHODS: Between 2015 and 2019, 126 patients with HD underwent ACDF. Contrast magnetic resonance imaging of the cervical spine in full flexion was performed. Clinical examination and preoperative/postoperative assessment of hand function using Fugl-Meyer assessment, Jebsen-Taylor hand function test, and handheld dynamometry were performed at 3-monthly intervals for 1 year. Surgical outcomes were assessed as per the Odom criteria and Hirayama outcome questionnaire. RESULTS: Age at onset and duration of illness were 12-31 years (mean, 18 ± 2.7) and 1-96 months (32.7 ± 24.4), respectively. All patients had progressive weakness and wasting of the affected limb. Cord atrophy was seen in 97.1%, with epidural detachment and engorgement of the posterior epidural venous plexus in all. All patients underwent ACDF. Of these patients, 54% had an excellent/good outcome and 39% had a satisfactory outcome as per the Odom scale at last follow-up (mean, 44.9 ± 16.5 months) after surgery. Handheld dynamometry showed improvement from preoperative values to 1 year follow-up. Duration of illness and age at onset had a negative correlation and the preoperative Fugl-Meyer score had a positive correlation with improvement. CONCLUSIONS: ACDF resulted in remarkable improvement or stabilization in neurologic deficits in many patients with HD. Because motor disability ensues over time, early surgical intervention during the progressive phase is advocated.

Microneurosurgical Anatomic Study of the Horizontal Fissure of the Cerebellum.

OBJECTIVE: The horizontal fissure of the cerebellum, which is the largest and most prominent fissure, has received less interest from anatomists and neurosurgeons. Hence, the current study aims to provide comprehensive detail about the horizontal fissure and its anatomic and surgical relationship with deeper structures such as the dentate nucleus and middle cerebellar peduncle for the benefit of the neurosurgeon. METHODS: Ten whole formalin-fixed human cadaveric cerebellar hemispheres were obtained from human cadavers donated to the institution. Different parameters of the horizontal fissure were studied, such as length, depth (medial end, lateral end, and middle), sulcal and gyral variations (superficial and deep), and its close relationship, especially at depth, with the dentate nucleus and middle cerebellar peduncle. RESULTS: The total length of the horizontal fissure on the right and the left side was 64.3 ± 7.9 mm (range, 53-77 mm) and 65.6 ± 8.01 mm (range, 53-79 mm), respectively. The medial third of the horizontal fissure, with the fewest vessels, was the most suitable place to puncture or start the dissection of the horizontal fissure. The surface projection of the center of the posterior border of the dentate nucleus lies within 20-21 mm on either side of the posterior midline along the horizontal fissure and is only approximately 4 mm deep from the horizontal fissure. CONCLUSIONS: The anatomic measurements and relationships provided in this description of the horizontal fissure will serve as a tool for surgery selection and planning, as well as an aid to improve microneurosurgical techniques, with the final goal being better patient outcomes.

Histopathological Validation of Microvascular Anastomosis using Two-Throw Reef Knots - An Experimental Study.

Background: Knot configuration is an important but relatively neglected topic in microvascular anastomosis literature. Objective: To study the differences between end-to-end microvascular anastomosis performed with two-throw reef knots as compared to traditional three-throw knots in a rat femoral artery model at the histological level. Material and Methods: Sprague Dawley rats underwent end-to-end microvascular anastomosis of the right femoral artery (one-way-up method). The rats were divided into two groups: two-throw reef knots versus traditional three-throw knots. The patency was checked by the standard empty refill method. After 2 weeks, the rats underwent re-exploration. An anastomotic segment was sent for histological analysis. Histological alterations including luminal patency and changes in Tunica intima, Tunica media, and Tunica adventitia were compared between the two groups. Results: Twenty-nine rats were operated on by the senior author (17 by three-throw and 12 by two-throw reef knots). In the two-throw reef knot group versus the traditional three-throw knot group, the immediate patency rates were 100% versus 82.4%, and the delayed patency rates were 90.9% versus 62.5%, respectively. The histopathological patency rates were concordant with delayed patency rates. Subintimal proliferation and fibrosis were comparable in both groups. Adventitial granulomas were noted in all, irrespective of the knotting technique. Tunica media preservation rates for the two-throw reef knot versus the traditional three-throw knot group were 63.6% versus 0%. Five rats were operated by the beginner in the field, all by two-throw reef knots (to assess the safety of this new method in the hands of a beginner). Conclusion: Microvascular anastomosis performed with two-throw reef knots appears not only feasible but better in terms of anastomosis patency. Histological superiority in terms of Tunica media preservation further validates the technique.

Correction: Comprehensive Normative Data for Objective Vestibular Tests.

[This corrects the article DOI: 10.7759/cureus.40080.].

Comprehensive Normative Data for Objective Vestibular Tests.

INTRODUCTION:  Vestibular dysfunction is a debilitating disorder frequently encountered in neurological and otological settings. The vestibular system is a complex network between peripheral and central mechanisms. This innate complexity of the vestibular system necessitates objective test procedures for evidence-based diagnostic formulations and intervention. Objective tests aid in the evaluation of both peripheral and central vestibular pathologies. Establishing and availability of comprehensive normative data for these objective tests is crucial for clinicians and researchers alike. MATERIALS AND METHODS: This is a prospective study involving 120 participants (both males and females) aged between 18 and 55 years. All participants were right-handed individuals and had no significant medical history. On pre-set protocols, cVEMP (cervical vestibular evoked myogenic potential), oVEMP (ocular vestibular evoked myogenic potential), vHIT (video head impulse test), and VNG (videonystagmography) were done. RESULTS: While all participants (n=120) underwent cVEMP, oVEMP, vHIT, saccade, smooth pursuit, and optokinetic tests, only 109 participants consented to the caloric test. Each test's mean, standard deviation, median, quartile, and third quartiles have been recorded. A right-left comparison yielded no significant difference on cVEMP, oVEMP, caloric test, smooth pursuit, and optokinetic test. However, few vHIT and saccade parameters did reveal significant differences. DISCUSSION: This study presents comprehensive normative data for cVEMP, oVEMP, vHIT, caloric test on VNG, and oculomotor tests (smooth pursuit, saccade, optokinetic) on VNG. The test results were in concordance with previously published data. The significant difference between the right and left sides in vHIT may be because of the monocular goggles used for the testing. CONCLUSION: This study brings out the normative data for various vestibular tests on individuals aged between 18-55 years. This information could aid both clinicians and researchers working in the field of vestibular science.

The Use of Retraction Sutures in End-To-Side Microvascular Anastomosis-A Novel Technical Innovation in Experimental Rat Femoral Model with Successful Use in STA-MCA Bypass in Moyamoya Disease.

BACKGROUND: A narrow working space, small diameters, and the tendency to collapse with clamps make cerebral microvascular anastomosis challenging. A retraction suture (RS) is a novel technique to keep the recipient vessel lumen open during the bypass. OBJECTIVE: To provide a step-by-step overview of RS for end-to-side (ES) microvascular anastomosis on rat femoral vessels and successful use for superficial temporal artery to middle cerebral artery (STA-MCA) bypass in Moyamoya disease patients. METHODS: A prospective experimental study with approval from the Institutional Animal Ethics Committee. Femoral vessels ES anastomoses were performed on Sprague Daley rats. The rat model used 3 types of RS (adventitial, luminal, and flap RSs). An ES-interrupted anastomosis was done. The rats were observed for an average period of 16.18 ± 5.65 days; the patency was assessed by reexploration. The immediate patency on the STA-MCA bypasses was confirmed with intraoperative indocyanine green angiography and micro-Doppler; delayed patency with magnetic resonance imaging and digital subtraction angiography after 3-6 months. RESULTS: In the rat model, 45 anastomoses were performed, 15 each using the 3 subtypes. The immediate patency was 100%. Delayed patency was 42/43 (97.67%), and 2 rats died during observation. In the clinical series, 59 STA-MCA bypasses were done in 44 patients (average age, 18.14 ± 11.09 years) using RS. The follow-up imaging was available for 41/59 patients. Both immediate patency and delayed patency (41/41 at 6 months) were 100%. CONCLUSION: The RS allows continuous visualization of the vessel lumen, reduces the handling of intimal edges, and avoids incorporating the back wall in sutures, thus improving anastomosis patency.