Browsing by Author "Bodhey, Narendra"

Now showing 1 - 6 of 6
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    Adult onset moyamoya disease: institutional experience.
    (Neurology India, 2011)
    Moyamoya disease is a progressive steno-occlusive disease of bilateral carotid forks with the formation of fine collateral vascular network and is an angiographic diagnosis. We analyzed case records of 11 patients with "adult-onset moyamoya disease." Six patients presented with intracranial hemorrhage (intracerebral and/or intraventricular) and 5 with focal ischemia. Angiography revealed bilateral Internal carotid artery involvement in 8 patients and unilateral involvement in 3. Posterior cerebral artery involvement was seen in 3 patients. Saccular aneurysm involving posterior circulation was seen in only 1 patient. Although rare, adult-onset moyamoya disease should be considered as one of the causes for intracerebral and intraventricular hemorrhage in adults.
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    Can diffusion tensor metrics help in preoperative grading of diffusely infiltrating astrocytomas? A retrospective study of 36 cases
    (NEURORADIOLOGY, 2011)
    Diffusion weighted imaging and diffusion tensor imaging (DTI) give information about the amount and directionality of water diffusion occurring in a given tissue. Here we study the role of diffusion tensor metrics including fractional anisotropy (FA) and spherical anisotropy (CS) in preoperative grading of diffusely infiltrating astrocytomas.We performed DTI in 38 patients with pathologically proven diffusely infiltrating astrocytomas, who were classified into two groups, i.e., 15 patients with high-grade astrocytoma (HGAs, WHO grade III and IV) and 23 patients with low-grade astrocytoma (LGAs, WHO grade II). We measured maximum FA and minimum CS values in all cases from tumor. Histopathological diagnosis was established in all cases.The mean maximum FA values were higher in HGA (0.583 +/- 0.104) than LGA (0.295 +/- 0.058), while mean minimum CS values were lower in HGA (0.42 +/- 0.121) than LGA (0.722 +/- 0.061). The difference in the diffusion tensor indices between HGA and LGA was found to be statistically significant with P value of < 0.001. Keeping cutoff FA value of 0.4, all HGAs showed higher maximum FA values, and all LGAs showed lower maximum FA values. Also, all HGAs showed minimum CS values less than a cutoff value of 0.6, and all LGAs showed minimum CS values higher than 0.6.Diffusion tensor metrics such as maximum FA and minimum CS can help to differentiate HGA from LGA.
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    Diffusion restriction in thrombosed superior ophthalmic veins: two cases of diverse etiology and literature review.
    (Journal of radiology case reports, 2011)
    Thrombosis of superior ophthalmic veins (SOV) is a well known entity occurring secondary to varied etiologies. We describe diffusion restriction in thrombosed SOV in two cases of different etiologies- bilateral involvement in a patient with septic cavernous sinus thrombosis (CST) and another where embolisation of an indirect carotico-cavernous fistula (CCF) resulted in complete SOV thrombosis accompanied by clinical worsening. Our cases add to the limited literature on diffusion findings in SOV thrombosis.
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    Diffusion tensor mode in imaging of intracranial epidermoid cysts: one step ahead of fractional anisotropy
    (NEURORADIOLOGY, 2009)
    The signal characteristics of an epidermoid on T2-weighted imaging have been attributed to the presence of increased water content within the tumor. In this study, we explore the utility of diffusion tensor imaging (DTI) and diffusion tensor metrics (DTM) in knowing the microstructural anatomy of epidermoid cysts.DTI was performed in ten patients with epidermoid cysts. Directionally averaged mean diffusivity (D (av)), exponential diffusion, and DTM-like fractional anisotropy (FA), diffusion tensor mode (mode), linear (CL), planar (CP), and spherical (CS) anisotropy were measured from the tumor as well as from the normal-looking white matter.Epidermoid cysts showed high FA. However, D (av) and exponential diffusion values did not show any restriction of diffusion. Diffusion tensor mode values were near -1, and CP values were high within the tumor. This suggested preferential diffusion of water molecules along a two-dimensional geometry (plane) in epidermoid cysts, which could be attributed to the parallel-layered arrangement of keratin filaments and flakes within these tumors.Thus, advanced imaging modalities like DTI with DTM can provide information regarding the microstructural anatomy of the epidermoid cysts.
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    Perioperative implications of retrograde flow in both the subclavian arteries in an adult undergoing surgical repair of coarctation of aorta.
    (Interactive cardiovascular and thoracic surgery, 2011)
    During surgical repair of coarctation of aorta (CoA), management of spinal cord ischemia and prevention of paraplegia is an important issue. The risk factors for paraplegia include level and duration of aortic-clamping, clamping of left subclavian artery (SCA), intraoperative temperature, variability of collateral circulation to the spinal cord, cerebrospinal fluid pressure, upper body arterial pressure, and aortic pressure beyond the aortic clamp. A short clamp time (<30 min), and distal aortic pressure>60 mmHg, minimizes the risks of spinal cord injury. In an adult patient during surgical repair of CoA, the arterial pressure in the femoral artery remained around 45 mmHg and repair took 83 min of aortic-clamping. Neurological assessment on regaining consciousness showed no deficit of lower limbs. Aortic root angiogram had shown retrograde filling of both SCAs. A unique situation in which clamping of SCAs would increase flow to the spinal cord as their clamping would stop stealing of blood and aortic-clamping proximal to CoA will further increase collateral flow; because of these reasons, the patient tolerated prolonged aortic-clamping despite low distal aortic pressure without neurological deficit. However, aortic-clamping increased left ventricular after-load and the patient developed worsening of mitral regurgitation and pulmonary hypertension during aortic clamping.
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    Signal changes in cortical laminar necrosis-evidence from susceptibility-weighted magnetic resonance imaging
    (NEURORADIOLOGY, 2009)
    Two types of infarcts can be identified depending on the circumstances leading to its generation-infarcts with pannecrosis and infarcts with selective neuronal loss. Cortical laminar necrosis (CLN) can occur due to various etiologies of which infarctions and hypoxia are the commonest. Infarction results in pannecrosis whereas hypoxia and incomplete infarction result in selective neuronal loss with the presence of viable cells, glial proliferations, and deposition of paramagnetic substances. We investigated patients with CLN with susceptibility-weighted imaging (SWI), a technique highly sensitive to even traces of paramagnetic agents or hemorrhagic components.We retrospectively reviewed medical records of patients diagnosed with CLN as per standard criterion. Demographic characteristics and etiologies were recorded. Findings in magnetic resonance images including SWI were analyzed.We identified 11 patients with CLN, six males and five females with age range of 4-64 years. Etiologies included hypoxia in two patients and infarction in the nine patients. SWI detected diffuse linear hypointensities along the gyral margins in CLN due to hypoxic ischemic encephalopathy. Linear dot like hypointensities were identified in one patient with infarction.CLN due to hypoxic ischemic encephalopathy display linear gyral hypointensities and basal ganglia hypointensities that are identifiable in SWI and may represent mineralization. This might be related to iron transport across the surviving neurons from basal ganglia to the cortex, which is not possible in complete infarction. SWI may be helpful in understanding the pathophysiological aspects of CLN due to complete infarction and hypoxia.