The Displacement Patterns of Petrous Internal Carotid Artery and Its Morphometric Relations with Vidian Canal in Petroclival Chondrosarcomas Relevant to Extended Endoscopic Endonasal Approaches: A Radiological Study.

BACKGROUND: Extended endoscopic endonasal approaches (EEAs) to petroclival chondrosarcomas (PCs) require a thorough understanding of skullbase anatomy, especially the anatomy of petrous internal carotid artery (pICA), as ICA injury is the most dreaded complication of extended EEAs. We conducted this study to determine the displacement patterns of pICA in patients with PCs. METHODS: Contrast enhanced computed tomography scan and angiography images of patients with PCs were analyzed for following parameters-antero-posterior, cranio-caudal, medio-lateral, and direct distances between anterior genu of petrous internal carotid artery (AGpICA) and posterior end of Vidian canal (pVC). pICA encasement/narrowing by tumor was noted on magnetic resonance imaging. RESULTS: We studied 11 patients with histopathologically proven PCs. pICA encasement/narrowing and pVC destruction were observed in one patient each. The mean antero-posterior and cranio-caudal distances on tumor side/normal side were 7.7 ± 1.9/6.4 ± 1.0 mm & 4.5 ± 1.5/3.4 ± 0.9 mm, respectively. The overall displacement was posterior & superior. Medio-lateral displacement was seen in 4 patients (lateral in 3 and medial in 1). In rest, AGpICA was centered on pVC. The mean direct distance was 9.4 ± 2.5 mm. In 3 patients with displacement seen in all three axes, direct distance was measured by the "cuboid method." Overall, posterior-superior-lateral, posterior-superior, and anterior-inferior were the common displacement patterns of AGpICA relative to pVC. CONCLUSIONS: The displacement patterns of AGpICA in PCs are variable. An individualized approach with meticulous analysis of preoperative imaging can help in determining the relation between AGpICA and pVC. This detailed morphometric information can facilitate better orientation to altered anatomy, which can be helpful in preventing pICA injury during extended EEAs.

Primary intradural extramedullary lesions: a longitudinal study of 212 patients and analysis of predictors of functional outcome.

BACKGROUND: Primary intradural extramedullary (IDEM) lesions are rare, with an incidence of about 1/100,000 person-years. The aim of this study was to investigate their demographic, clinical, imaging, management, histopathological and outcome parameters. Another objective was to evaluate the various predicting factors leading to long-term favorable outcomes, thereby answering the controversial question: when to operate? METHODS: This study observed 212 patients of primary IDEM lesions and followed-up for a mean of 53.80 months. The patient's outcome using McCormick grade at follow-up was correlated with age, sex, duration of symptoms, preoperative McCormick grade, tumor location and extent, extradural spread, extent of excision, vascularity, WHO grade and histopathological tumor type. RESULTS: Benign nerve sheath tumors were the commonest lesions (47.17% schwannoma, 4.72% Neurofibroma), followed in incidence by meningioma (19.34%). There was predominance of males (57.08%), except in meningiomas (male: female ratio 1:2.15). Pain was the commonest initial symptom (51.88%). Limb weakness was the most common presenting complaint (88.68%). Gross total excision was achieved in 81.60% of cases and 70.75% of patients improved following surgery. The significant factors predicting favorable outcome included preoperative McCormick grade (P=0.001), the vertical extent of the tumor (P=0.027), histopathological tumor type (P=0.023) and WHO grading (P=0.015); and extent of excision had an odds ratio of 1: 2.5. CONCLUSIONS: Significant predictors of functional outcome following surgery in IDEM lesions included preoperative McCormick grade, extent of the tumor, tumor type, WHO grading and extent of resection. The authors recommend surgery with the intent of complete tumor excision, before the onset of substantial symptoms, for better outcome.

Carotid Artery Stenting for a Nonagenarian Presenting as Stuttering Stroke.

Carotid artery stenting (CAS) is performed in patients with minor strokes and transient ischemic attacks (TIAs) to prevent further strokes. However, most operators do not intervene in older adults. We had a 92-year patient with recurrent minor strokes with two possible proximate causes - cardioembolism and significant symptomatic left carotid stenosis. This patient continued to have recurrent ischemic events in the left carotid territory despite optimum management of the cardioembolic source with dual antiplatelets and anticoagulation and was successfully treated with left CAS. The role of carotid revascularization in older patients with high-grade symptomatic carotid stenosis and cardiac comorbidities is discussed.

Primary CNS vasculitis (PCNSV): a cohort study.

Primary CNS Vasculitis (PCNSV) is a rare inflammatory disorder affecting the blood vessels of the central nervous system. Patients present with a combination of headaches, seizures, and focal neurological deficits. There is usually a diagnostic delay. Treatment is based on observational studies and expert opinion. Our objective was to identify clinical, laboratory, neuroimaging, pathologic or management-related associations with 2 year outcome in patients with primary CNS vasculitis. We conducted a cohort study at a single tertiary care referral centre of prospectively (2018-2019) and retrospectively (2010-2018) identified individuals with primary CNS vasculitis (diagnosis was proven by either brain biopsy or cerebral digital subtraction angiography). Clinical, imaging and histopathologic findings, treatment, and functional outcomes were recorded. Univariate and stepwise multiple logistic regression were applied. P-value<0.05 was considered statistically significant. The main outcome measures were documentation of clinical improvement or worsening (defined by mRS scores) and identification of independent predictors of good functional outcome (mRS 0-2) at 2 years. We enrolled eighty-two biopsy and/or angiographically proven PCNSV cases. The median age at presentation was 34 years with a male predilection and a median diagnostic delay of 23 months. Most patients presented with seizures (70.7%). All patients had haemorrhages on MRI. Histologically lymphocytic subtype was the commonest. Corticosteroids with cyclophosphamide was the commonest medication used. The median mRS at follow-up of 2 years was 2 (0-3), and 65.2% of patients achieved a good functional outcome. Myelitis and longer duration of illness before diagnosis were associated with poorer outcomes. The presence of hemorrhages on SWI sequence of MRI might be a sensitive imaging marker. Treatment with steroids and another immunosuppressant probably reduced relapse rates in our cohort. We have described the third largest PCNSV cohort and multi-centre randomised controlled trials are required to study the relative efficacy of various immunosuppressants.Study registration: CTRI/2018/03/012721.

Determination of Availability of Safety Margin for Placement of C3-C6 Pedicle Screw on CT Angiography.

BACKGROUND: Cervical pedicle screws (CPS) in the subaxial cervical spine (C3-C6) are faced with high incidence of perforating the lateral pedicular cortex endangering the vertebral artery (VA). The present study analyzes the pedicle width (PW) from C3 to C6 and defines the relation of VA with regard to pedicle and transverse foramen (TF) to determine the safety margin in cases of lateral pedicular breach. METHODS: Computed tomography angiograms of 500 patients were retrospectively studied to identify the pedicle width (PW), VA area, TF area, and the lateral pedicle to vertebral artery distance (LPVA). Occupancy ratio (OR; the percentage area of transverse foramen occupied by VA) and safety margin (SM; permissible displacement of VA in TF), along with LPVA were considered to be protective parameters against VA injury if lateral pedicle breach happens. RESULTS: PW was 4.7 mm at C3, 4.83 mm at C4, 5.26 mm at C5 and 5.41 mm at C6. Mean LPVA at different levels was between 0.97 mm and 1.15 mm, OR was around 20% at all levels, and mean SM was between 2.34 mm and 2.92 at various levels. Sex differences were statistically significant for PW but not for LPVA, SM, or OR. CONCLUSIONS: This study gives us an idea about the various parameters in placement of cervical pedicle screw in subaxial cervical spine and the probable reasons there are few vertebral artery injuries despite high incidence of cervical pedicle breach. LPVA, safety margin, and OR may explain why even very significant CPS misplacement does not lead to vascular injury or neurologic deficit.

Clinical profile and outcome of non-COVID strokes during pandemic and the pre pandemic period: COVID-Stroke Study Group (CSSG) India.

BACKGROUND: As the health systems around the world struggled to meet the challenges of COVID-19 pandemic, care of many non-COVID emergencies was affected. AIMS: The present study examined differences in the diagnosis, evaluation and management of stroke patients during a defined period in the ongoing pandemic in 2020 when compared to a similar epoch in year 2019. METHODS: The COVID stroke study group (CSSG) India, included 18 stroke centres spread across the country. Data was collected prospectively between February and July 2020 and retrospectively for the same period in 2019. Details of demographics, stroke evaluation, treatment, in-hospital and three months outcomes were collected and compared between these two time points. RESULTS: A total of 2549 patients were seen in both study periods; 1237 patients (48.53%) in 2019 and 1312 (51.47%) in 2020. Although the overall number of stroke patients and rates of thrombolysis were comparable, a significant decline was observed in the month of April 2020, during the initial period of the pandemic and lockdown. Endovascular treatment reduced significantly and longer door to needle and CT to needle times were observed in 2020. Although mortality was higher in 2020, proportion of patients with good outcome were similar in both the study periods. CONCLUSIONS: Although stroke admissions and rates of thrombolysis were comparable, some work flow metrics were delayed, endovascular stroke treatment rates declined and mortality was higher during the pandemic study period. Reorganization of stroke treatment pathways during the pandemic has likely improved the stroke care delivery across the globe.

Interplay of Dynamic Extension Reserve and T1 Slope in Determining the Loss of Cervical Lordosis Following Laminoplasty: A Novel Classification System.

BACKGROUND: Laminoplasty causes destruction of the posterior musculoligamentous complex, which may result in cervical kyphosis, or more commonly loss of cervical lordosis (LOCL). In this study, we evaluated the role of various preoperative radiologic parameters in predicting not only the LOCL/kyphosis but also the functional outcomes in the form of change in Oswestry Disability Index (ODI) score following laminoplasty. METHODS: Patients were evaluated both clinically and radiologically with dynamic cervical spine radiograph, noncontrast-enhanced computed tomography, and magnetic resonance imaging of the cervical spine preoperatively as well as at 1 year follow-up. RESULTS: One hundred twenty-one patients who underwent laminoplasty for cervical spondylotic myelopathy/ossified posterior longitudinal ligament from 2011 to 2018 at our center were included in final analysis. In multivariate analysis, preoperative Cobb angle (P = 0.001), T1 slope (TIS; P = 0.001), and dynamic extension reserve (P < 0.001) were found to have an independent effect on LOCL. The receiver operating characteristic curve using the regression model significantly predicted LOCL >10° with an area under the curve of 88.3% (P < 0.001). Similarly, preoperative T1S (P = 0.036) and SVA (P < 0.001) were found to be independent predictors of significant improvement in ODI after laminoplasty. The receiver operating characteristic curve using the regression model significantly predicted change in ODI with an area under the curve of 83.7% (P < 0.001). Based on these findings, classification and scoring systems with good accuracy have been proposed for prediction of LOCL and improvement in ODI. CONCLUSIONS: We have found that the chances of significant LOCL is determined by an interplay of preoperative Cobb angle, T1S, and dynamic extension reserve.

Management and Outcome Analysis of Conus and Filum ependymoma: A Tertiary Center Study.

BACKGROUND: Spinal ependymomas constitute approximately 2%-8% of primary adult central nervous system tumors. Authors analyzed demographic, clinical, radiological, surgical, and histopathological factors which correlated with the postoperative neurological outcome of patients who underwent surgery for conus and filum ependymoma (CFE). MATERIALS AND METHODS: A retrospective analysis of 31 patients regarding clinical feature, imaging study, surgical management, and McCormick grading system for assessing functional neurological status was carried out, who underwent surgical management for CFE between January 2009 and April 2014. Final neurological outcome at follow-up period was correlated with various factors in search to find out probable prognostic factors affecting final neurological outcome following surgical management. RESULTS: The myxopapillary ependymoma was observed in 55% of cases (n = 17), while 39% cases (n = 12) had Grade II ependymoma and rest 6% (n = 2) cases had anaplastic ependymomas. The mean age was 30 years (range 7-60 years) with male to female ratio of 1:0.82. Patients predominantly presented with pain (80.65%); mean duration of symptoms was 28.61 months. Only, the preoperative McCormick grade was found to be the statistically significant prognostic factor (P = 0.045), affecting neurological outcome however, the age, sex, duration of symptoms, location of the tumor, extent of the tumor, extradural spread, degree of surgical excision, vascularity of tumor, and histopathological World Health Organization grades were not found to be significant prognostic factors in the current study. CONCLUSION: The preoperative McCormick score was found to be the only statistically significant factor predicting the functional and neurological outcome after surgery, so surgical treatment should be offered early in the course of the disease to provide chance of preservation and good neurological recovery.

Cerebral venous thrombosis: An Indian perspective.

Cerebral venous thrombosis (CVT) is an uncommon cause of stroke with extremely varied clinical presentations, predisposing factors, imaging findings, and outcomes, and thus can be extremely challenging to diagnose. Accurate and prompt diagnosis of CVT is crucial because timely and appropriate therapy can reverse the disease process and significantly reduce the risk of acute complications and long-term squel. In this article, we have reviewed the epidemiology, causative factors, clinical features, diagnosis and treatment of CVT from an Indian perspective. Over the last decade, a change in trends in the causative factors has been noted from India.

Cervical rib with stroke as the initial presentation.

Cervical ribs rarely become symptomatic. Cerebral ischemia or infarct due to cervical rib is extremely rare and, invariably, these patients have a history of upper limb symptoms before presenting with stroke. We report a young boy with cervical rib who presented with stroke. A right sided cervical rib was noted during angiogram, causing mild stenosis and post stenotic dilatation of right subclavian artery distal to the rib. An abduction angiogram showed complete occlusion of the right subclavian artery and visualization of collaterals. Right carotid angiogram also showed evidence of thromboembolic episodes in the right middle cerebral artery territory.