Browsing by Author "Krishnamoorthy, T."

Now showing 1 - 12 of 12
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    Advanced MR imaging in Lhermitte-Duclos disease: moving closer to pathology and pathophysiology
    (NEURORADIOLOGY, 2007)
    Introduction Lhermitte-Duclos disease (LDD, dysplastic gangliocytoma) is an extremely rare cerebellar lesion of uncertain etiology. The debate as to whether it constitutes a neoplastic, malformative, or hamartomatous lesion is still continuing. In this report we explore the usefulness of susceptibility-weighted imaging (SWI), diffusion weighted imaging (DWI), perfusion imaging, and chemical shift imaging (CSI) in demonstrating the pathology and pathophysiology in two patients with LDD.Methods MR imaging of the brain and the cervicodorsal spine was performed on a 1.5-T scanner in a 47-year-old woman presenting with numbness and paresthesia of both upper and lower limbs, and in a 17-year-old male with right frontal headache associated with neck pain.Results Routine imaging in the first patient showed a leftside cerebellar mass with characteristic 'tiger-striped' thick folia associated with Chiari I malformation, tonsillar herniation and cervicodorsal syringomyelia and in the second patient a right cerebellar mass with similar findings. The SWI demonstrated the characteristic deep running veins between the folia, which is thought to be the cause for vascular contrast enhancement. Diffusion showed a T2 shine-through effect with mild increased diffusivity, and perfusion showed increase in relative cerebral blood volume, relative cerebral blood flow, and mean transit time in the lesion. MR spectroscopy demonstrated reduction in metabolites and a prominent lactate peak in both the patients. The pathological and pathophysiological significance of these findings is discussed.Conclusion MRI with the newer imaging capabilities can demonstrate the pathology and pathophysiology in Lhermitte-Duclos disease better. SWI helps in detecting the veins around the thickened folia.
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    Alanine peak in central neurocytomas on proton MR spectroscopy
    (NEURORADIOLOGY, 2007)
    Introduction We present three consecutive patients with central neurocytoma in whom proton MRS demonstrated the presence of alanine.Materials and methods Three patients in the age range 24 to 30 years underwent MRI and proton MRS using a 1.5-T system. MRS was performed with the multivoxel PRESS sequence. All three patients underwent surgery and the diagnosis of central neurocytoma was established by histopathological examination and immunostaining.Results With an echo time of 135 ms glycine, high choline, small NAA and alanine were observed in all three patients.Conclusion Alanine may be observed in central neurocytomas as it is in meningiomas. Other spectral peaks such as those for glycine and NAA should help to identify this tumor correctly.
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    Anomalous origin of the callosomarginal artery from the A1 segment with an associated saccular aneurysm
    (AMERICAN JOURNAL OF NEURORADIOLOGY, 2006)
    Although anatomic variations are well known in the A1 segment of the anterior cerebral artery (ACA), anomalous origin of a cortical artery from the A1 segment is extremely rare. The only reported cortical branch to arise from the A1 segment is the fronto-orbital artery. We report a case of anomalous origin of the callosomarginal artery (CMA) in association with a saccular aneurysm from the A1 segment of the left ACA in a 35-year-old man who presented with intracerebral hemorrhage. To our knowledge, this is the first report of anomalous origin of the CMA from the A1 segment.
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    Disseminated necrotizing leukoencephalopathy following low-dose oral methotrexate
    (EUROPEAN JOURNAL OF NEUROLOGY, 2007)
    Leukoencephalopathy is a recognized complication with intrathecal or intravenous methotrexate (MTX). We report a 59-year-old lady who developed MTX leukoencephalopathy with long-term low-dose oral MTX. She developed posterior leukoencephalopathy (PLE) that initially was reversible on discontinuation of oral MTX. Four months later, she developed disseminated necrotizing leukoencephalopathy (DNL), and was left with devastating neurological deficits. The sequential conventional magnetic resonance imaging (MRI), diffusion weighted imaging (DWI), MR perfusion (MRP) and MR spectroscopic (MRS) changes are highlighted in this report. MRP and MRS showed more wide spread abnormalities than DWI. Stereotactic biopsy from the lesion revealed demyelination with macrophagic infiltration, pericapillary lymphomononucear aggregation,fibrinoid changes in the capillaries and neovascularization. Of the two cases of PLE with oral MTX reported in literature, one reversed clinically and radiologically with the discontinuation of MTX. To the best of our knowledge, this is the first reported case of DNL following oral MTX in the world literature.
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    Endovascular treatment of direct carotid cavernous fistulae: a pictorial review
    (NEURORADIOLOGY, 2006)
    Introduction Direct carotid-cavernous fistulae (CCFs) are type A fistulae according to Barrow's classification. Endovascular treatment of these lesions is challenging.Methods The purpose of this review was to evaluate the endovascular treatment of direct CCFs. We also describe the technique, symptomatology and complications associated with the procedure and report on the long-term follow-up in our treated patients.Results A total of 89 patients with a direct CCF were treated. All patients had baseline brain CT or MR imaging. Treatment comprised transarterial balloon or coil embolizations. The patients were followed up at 1 month and then every 6 months thereafter. Detachable balloons were used in 79 fistulae. In 12 fistulae the balloon could not be negotiated through the fistula and these fistulae were treated with transarterial coil occlusion. Clinical outcomes of the treated patients evaluated at 1 month were: 79 patients (88.8%) cured, 9 (10.1%) significantly improved, 1 (1.1%) remaining static.Conclusion Endovascular treatment of direct CCFs is safe and effective and results in long-term cure.
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    Endovascular treatment of scalp cirsoid aneurysms
    (NEUROLOGY INDIA, 2008)
    Background: Scalp is the most common site of soft tissue arteriovenous fistulae and surgical excision has been the primary mode of treatment. Endovascular treatment has evolved as an alternative to the surgery. Aims: To evaluate the effectiveness of percutaneous direct-puncture embolization of cirsoid aneurysms. Materials and Methods: From January 1995 to December 2004, 15 patients underwent percutaneous direct-puncture embolization of cirsoid aneurysms. Plain X-ray, computerized tomography scan and complete selective cerebral angiogram were done in all. Seven patients had forehead lesions, four had temporal and the remaining four patients had occipital region cirsoid aneurysms. Lesions were punctured with 21-gauge needle and embolized with 20-50% cyanoacrylate-lipiodol mixture. Circumferential compression was applied during injection. Results: Post-embolization angiogram showed complete obliteration in 11 patients. The remaining four patients required adjunctive transarterial embolization with polyvinyl alcohol particles for complete lesion devascularization. Two patients had post procedure surgery for removal of disfiguring and hard glue cast. There were no major procedure-related complications. No patients had any recurrence in the follow-up. Conclusion: Percutaneous direct puncture embolization of cirsoid aneurysms is a safe and effective procedure. It can be effectively used as an alternative to surgery. Sometimes adjunctive transarterial embolization is also required to deal with deeper feeders.
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    Eosinophilic meningitis and an ocular worm in a patient from Kerala, south India
    (JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY, 2008)
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    Fluoroscopic-guided balloon dilatation and stenting in tracheal stenosis with metallic self-expandable stents and long-term follow-up results
    (AUSTRALASIAN RADIOLOGY, 2007)
    The purpose of this study was to assess the safety and long-term efficacy of self-expandable stents in the treatment of benign tracheal stenosis. Nine patients (seven men) with tracheal stenosis (including one with fistula) of varied cause were treated by fluoroscopically guided balloon dilatation and stenting with self-expandable metallic stents. The procedure was carried out under topical spray in eight patients and under general anaesthesia in one patient. The patients were followed up for a period ranging between 13 and 60 months. in eight of the nine patients, satisfactory positioning of the stent was achieved at the first instance, with immediate relief of dyspnoea. One patient with innominate artery aneurysm died 16 days after the procedure because of renal failure. At 1 month of follow up, six out of eight (75%) of our live patients were without any respiratory embarrassment. This dyspnoea-free result reached almost 90% by the end of 1 year especially so in the fibrous strictures. Four out of the eight live patients (50%) had cough for 2 months and two (25%) had mild blood-tinged sputum treated by inhalation and mucolytic agents. Secondary intervention was required in one patient at 1 month because of recurrent symptoms. The patient with tracheo-oesophageal fistula required surgical intervention because of fracture of the stent. Fluoroscopically guided balloon dilatation and stenting of the tracheal stenosis is an effective non-surgical therapy resulting in cure of fibrous strictures and palliation in cases of malignancy.
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    Hemimegalencephalic appearance of normal hemisphere in unilateral heterotopia and absent corpus callosum
    (EPILEPSY & BEHAVIOR, 2006)
    We report two patients with medically refractory epilepsy who had MRI evidence of unilateral subcortical nodular heterotopia and agenesis of corpus callosum. The abnormal hemisphere was small, whereas the contralateral normal hemisphere appeared large and crossed the midline. Although the normal hemisphere was initially mistaken for hemimegalencephaly, there were no typical radiological features. Moreover, the electroencephalographic abnormalities lateralized to the hemisphere showing heterotopia. Because contralateral hemispheric abnormalities like heterotopia, hemimicrencephaly, and hemimegalencephaly can occur in patients with hemispheric heterotopias, we emphasize the importance of careful scrutiny of the contralateral hemisphere in patients with unilateral heterotopia. Absence of typical radiological features and appropriately lateralized electroencephalographic abnormalities will help differentiate the two. This is crucial when planning epilepsy surgery. (C) 2006 Elsevier Inc. All rights reserved.
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    Percutaneous laser disc decompression: Clinical experience at SCTIMST and long term follow up
    (NEUROLOGY INDIA, 2006)
    Background: Low backache (LBA) is now increasing in younger population due to misdirected spinal kinetics secondary to improper posture, heavy load lifting and motorbike driving. Hence minimally invasive procedures are increasingly sought after. Among these, PLDD is currently popular and in use. We present our long term follow-up in the use of Nd:YAG laser for PLDD. Aim: To herniation of lumbar discs & long term follow up results. Materials and Methods: Forty patients with contained lumbar disc herniation on MRI and who did not respond to 6 weeks conservative treatment were subjected to PLDD. L4-5 disc was treated in 31, L5-S1 in 12 and L1-2 and L3-4 in one each. Nd:YAG laser at 1064 nm was used for the procedure. Total laser energy of 1500-2000 Joules was delivered at the disc space depending upon the size. Results: There was immediate pain relief in 32/40 (80%). According to MacNab criteria good to fair response was seen in 37/40 (92%) and 3 patients (7.5%) responded poorly to this treatment. On follow up which ranged from 1 to 7 years, 34/40 (85%) had pain relief with no need for further treatment. Complications: Significant pain at local puncture site was experienced by 8 (20%), pain during lasing was experienced by one. One patient developed muscular spasm. Conclusion: Percutaneous laser disc decompression is a safe, relatively noninvasive and effective treatment modality for contained, nonsequestered, herniated lumbar disc disease in carefully selected patients.
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    Reversible periictal MRI abnormalities: Clinical correlates and long-term outcome in 12 patients
    (EPILEPSY RESEARCH, 2007)
    Although a wide spectrum of reversible periictal magnetic resonance imaging (MRI) abnormalities (RPMA) are being increasingly identified, the clinicians are often in a dilemma about their localization significance. This prompted us to analyze the clinical, MRI, electroencephalographic (EEG) and follow-up data of 12 patients with RPMA seen in a tertiary referral epilepsy center. RPMA occurred after a single or a cluster of focal seizures with or without secondary generalization. The interictal and ictal EEG abnormalities were localized to the site of RPMA in nine patients. RPMA involved areas remote from the site of EEG abnormalities in four patients. We have developed a comprehensive classification to account for the wide spectrum of RPMA involving gray matter, white matter and teptomeninges with or without contrast enhancement or mass effect. Follow-up MRIs showed complete resolution of RPMA in all, except in four patients, who developed residual focal atrophy. During median follow-up period of 3 years, recurrence of RPMA was observed in two patients. Diffusion weighted MRI in two patients and histopathological finding in one patient favored causal rote of hypoxia in the pathogenesis of RPMA. Our observations help to understand the electroclinical profile, radiological spectrum, localization significance and natural history of RPMA better. (c) 2006 Elsevier B.V. All rights reserved.
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    Spinal angiolipoma with acute subarachnoid hemorrhage
    (JOURNAL OF CLINICAL NEUROSCIENCE, 2007)
    Angiolipoma is a rare tumor of the spine commonly presenting with compressive myelopathy. We report a spinal angiolipoma in a 14-year-old patient with acute spinal subarachnoid hemorrhage (SAH). To our knowledge this is the first reported case of a spinal angiolipoma presenting with SAH, associated with post-subclavian coarctation with diffuse hypoplasia of the descending aorta. This association of coarctation of aorta, aortic hypoplasia and spinal angiolipoma has also not been reported previously. (c) 2006 Elsevier Ltd. All rights reserved.