Browsing by Author "Nair, SN"

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    A Retrospective Analysis of Stridor After Vestibular Schwannoma Surgery
    (JOURNAL OF NEUROSURGICAL ANESTHESIOLOGY, 2014) Arulvelan, A; Gayatri, P; Smita, V; Nair, SN
    Background:Transient lower cranial nerve deficits may occur after surgery in the posterior cranial fossa. Stridor has been reported after cerebellopontine angle epidermoid resection. The aim of this retrospective study is to find out whether any preoperative, intraoperative, and postoperative factors lead to stridor after resection of vestibular schwannoma.Methods:Data of patients who underwent vestibular schwannoma resection from 2006 to 2011 were collected. We collected the following factorsage, sex, weight, diabetes, hypertension, preoperative cranial nerve deficits, tumor characteristics, intraoperative use of nitrous oxide, difficult endotracheal intubation, duration of surgery, postoperative cough and swallowing difficulty, limb weakness, and facial edema. Data of patients who developed stridor were compared with those who did not develop stridor. Odds ratio (OR) was used to assess the risk of developing stridor with each factor.Results:Thirteen patients (4.65%) developed stridor in immediate postextubation period. The risk of stridor was significantly high in patients who had difficult intubation (OR=9.56), longer duration of surgery (P=0.034) and in patients who developed facial edema (OR=13.33), upperlimb weakness (OR=32.88), poor cough (OR=7.72), and swallowing difficulty (OR=24.97) in the postoperative period.Conclusions:The identification of the exact etiology of stridor often is difficult. Our results suggest that stridor may be more likely in patients who were difficult to intubate, had longer duration of surgery, who develop facial and neck edema and upperlimb weakness, poor cough, and swallowing after surgery. Establishing airway patency with intubation of the trachea may be required if patients develop oxygen desaturation due to stridor.
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    Are Indian neuroscience clinicians perishing without publishing?
    (NEUROLOGY INDIA, 2015) Vilanilam, GC; Sudhir, BJ; Kumar, KK; Abraham, MA; Nair, SN
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    Correlation between anatomic landmarks and fMRI in detection of the sensorimotor cortex in patients with structural lesions
    (Acta Radiol. 2013, 2013-07) Hingwala, D; Thomas, B; Radhakrishnan, A; Nair, SN; Kesavadas, C
    BACKGROUND: Structural lesions in/near the sensorimotor cortex may cause distortion/obscuration of the anatomic landmarks. PURPOSE: To compare the localization of the sensorimotor cortex using anatomical landmarks and fMRI in the clinical setting in patients with structural lesions in/near the central sulcus. MATERIAL AND METHODS: We analyzed the anatomic and fMRI data of 68 consecutive patients (42 tumors, 15 gliotic lesions, 11 focal cortical dysplasias [FCD]) who underwent MRI to assess the relationship of these lesions to the sensorimotor cortex. Anatomical data was analyzed on conventional two- and three-dimensional sequences. BOLD fMRI was performed with block design hand/leg or lip movement paradigm and general linear model was used for detecting the activated cortex. fMRI was considered as a valid method for identifying the sensorimotor cortex based on previously reported literature. RESULTS: The sensorimotor cortex could not be identified with anatomical landmarks in 9/68 (13.2%) patients. fMRI detected activation in areas different from that predicted by anatomical landmarks in 11/68 (16.2%) cases. This occurred in 5/42 (11.9%) tumors, 6/15 (40%) gliotic lesions, and 0/11 (0%) FCDs. The kappa value for concordance between fMRI and anatomic landmarks was 0.883 overall, 1.0 for tumors, 0.721 for gliotic lesions, and in none of the patients with focal cortical dysplasias. CONCLUSION: In patients with lesions that obscure normal cerebral landmarks, fMRI supplies the information that is not available from the anatomic images. In patients with landmarks that can be recognized, the location of the rolandic cortex may be misjudged in some cases if functional imaging is not used. Anatomic landmarks may not correlate with the area of functional activation in gliotic lesions and tumors. Determining the risk of a postoperative neurologic defect from surgery is likely to be more reliable with functional imaging than with conventional anatomic imaging.
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    Surgical Management of Foramen Magnum Meningiomas
    (NEUROSURGERY QUARTERLY, 2012) Nair, SN; Vikas, V; Gopalakrishnan, CV; Menon, G
    Background and Objective: Meningiomas involving the foramen magnum (FM) region are rare and constitute 1% to 7% of intracranial meningiomas. Surgical excision is difficult in view of the complex anatomy and the proximity to critical neurovascular structures. Our aim was to analyze the clinical presentation and surgical outcome of patients operated for FM meningiomas. Materials and Methods: Thirty patients who underwent surgery for FM meningioma over a period of 21 years were studied retrospectively. Case records and imaging studies were reviewed for demographic data, presenting symptoms, tumor location, surgical approach, and postoperative complications. The outcome was assessed on the basis of the Glasgow Outcome Scale (GOS). Results: Twenty-three women and 7 men ranging in age between 18 and 75 years were diagnosed after a mean symptom duration of 20 months. The choice of surgical technique was guided by the tumor location (anterior: 6, lateral: 19, posterior: 5), the position of the vertebral artery, and the extent of dural attachment. Although 11 of the lateral meningiomas were resected through the posterior approach, 8 were operated by the posterolateral route. Five anterior meningiomas were operated by the posterolateral corridor, whereas 1 was excised by a posterior approach reaching the tumor from either side of the cervico-medullary junction. Radical resection was performed in 28 patients; 2 patients with extradural extension underwent subtotal removal. There were 2 postoperative deaths, of whom 1 patient died after a surgery for recurrent tumor. Of the 27 patients who came for follow-up, 18 had a GOS of 5, 6 patients were moderately disabled (GOS 4), and 3 were severely disabled (GOS 2 and 3). One patient underwent revision surgery for symptomatic recurrence. Conclusions: Meticulous surgical planning is required for a safe and complete resection of FM meningiomas with minimal morbidity and mortality.
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    Women and Neuroscience Publishing: Is the Gender Gap closing in?
    (NEUROLOGY INDIA, 2016) Vilanilam, GC; Easwer, HV; Vimala, S; Radhakrishnan, A; Devi, BI; Nair, SN