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Biomedical subjects

N Yunten

Publications and source records attributed to N Yunten.

16 recordsLinked to original sources
PubMed2006

Cerebral cortical and deep venous thrombosis without sinus thrombosis: clinical MRI correlates.

BACKGROUND: Cortical and/or deep vein thrombosis (CDVT) without dural sinus involvement is uncommon and presents diagnostic difficulty for many reasons. Our aim is to determine the relationship between magnetic resonance imaging (MRI) findings and clinical findings in patients with CDVT. METHODS: Forty-six patients with venous stroke proved on MRI included in our Registry, corresponding to 0.1% of 4650 patients with stroke, were studied. Magnetic resonance angiography (MRA) was performed in all patients, and 18 of them had follow-up MRA. Outcome was evaluated by using the Glasgow Outcome Scale at the time of discharge and during follow-up. RESULTS: Thirty-two patients presented cortical venous stroke; 21 of them had involvement of the dorsomedial venous system, six had a defect in the posteroinferior venous group, and five had a defect in the anteroinferior venous group. Thirteen patients presented simultaneous involvement of the superficial and deep venous system; seven with a defect in the parietal and internal cerebral veins (three with involvement of vein of Gallen), four with a defect in the temporooccipital (vein of Labbé) and basal vein of Rosenthal, two with a deficit in the anterior frontotemporal and uncal-pterygoid venous system. One patient had deep venous thrombosis primarily localized to the thalami bilaterally and the basal ganglia on the right because of occlusion of the thalamostriate veins. The main presenting symptoms of CDVT were headache, focal neurologic signs, partial complex or secondary generalized seizures, and consciousness disturbances in those with deep venous thrombosis, presented alone or in combination at onset. CDVT was more than twofold more frequent in women than in men. Pregnancy, puerperium, oral contraceptive use, and infections were the most common predisposing factors. CONCLUSION: Computerized tomography, conventional MRI and diffusion-weighted imaging showing ischemic and/or hemorrhagic lesion that does not follow the boundary of classical arterial boundaries without signs of sinus thrombosis, and partial or generalized seizures followed by focal neurologic signs may predict CDVT. The outcome of patients with cortical venous stroke was good, but not in those with cortical plus deep venous infarction.

Adult↗
PubMed2004

Wallenberg's lateral medullary syndrome: diffusion-weighted imaging findings.

PURPOSE: To investigate the efficacy of diffusion-weighted imaging in patients with Wallenberg's lateral medullary syndrome. MATERIAL AND METHODS: Thirteen patients with Wallenberg's lateral medullary syndrome were examined with conventional and echoplanar diffusion-weighted magnetic resonance (MR) imaging in a 1.5 T magnetic resonance unit. MR examinations were obtained in the acute or subacute stage of clinical syndrome, and diffusion-weighted imaging (DWI) was considered to be positive for infarction when an increase in signal was seen on b = 1000 s/mm2 images in the posterolateral medullary localization. RESULTS: DWIs were positive in 12 patients in the acute or subacute stages of this clinical syndrome. A false-negative result was obtained in only one patient examined within the first day, 10 h after onset of the symptoms. In the visual evaluation of the DWI, the contrast between normal and infarcted brainstem area was better in the high b-value images than in the apparent diffusion coefficient map images. CONCLUSION: DWI is a valuable technique for examining patients presenting with the signs and symptoms of Wallenberg's syndrome and high b-value images can provide complementary data to T2-weighted images. However, because most of our case group were in either the acute or subacute stage, true sensitivity of the method in the hyperacute stage of the syndrome remains unclear.

Adult↗
PubMed2004

Report of diffusion-weighted MRI in two cases with different cerebral hydatid disease.

PURPOSE: To present MRI findings in two cases of cerebral hydatid disease with an emphasis on diffusion-weighted imaging (DWI) findings of Echinococcus granulosus (EG) versus Echinococcus alveolaris (EA). RESULTS: EG lesions were isointense with cerebrospinal fluid in all sequences including DWI. On DWI, EA lesions remained hypointense on b = 1000 s/mm2 diffusion-weighted images. Apparent diffusion coefficient (ADC) values of EG and EA lesions were completely different from each other, 2.88 +/- 0.24 x 10(-3) s/mm2 and 1.33 +/- 0.15 x 10(-3) s/mm2, respectively. CONCLUSION: The ADC values could not be used to discriminate from other differential diagnoses.

Adult↗
PubMed2002

Spectrum of anterior cerebral artery territory infarction: clinical and MRI findings.

To evaluate and review the clinical spectrum of anterior cerebral artery (ACA) territory infarction, we studied 48 consecutive patients who admitted to our stroke unit over a 6-year period. We performed magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) in all patients, and diffusion magnetic resonance imaging (DWI) in 21. In our stroke registry, patients with ACA infarction represented 1.3% of 3705 patients with ischemic stroke. The main risk factors of ACA infarcts was hypertension in 58% of patients, diabetes mellitus in 29%, hypercholesterolemia in 25%, cigarette smoking in 19%, atrial fibrillation in 19%, and myocardial infarct in 6%. Presumed causes of ACA infarct were large-artery disease and cardioembolism in 13 patients each, small-artery disease (SAD) in the territory of Heubner's artery in two and atherosclerosis of large-arteries (<50% stenosis) in 16. On clinico-radiologic analysis there were three main clinical patterns depending on lesion side; left-side infarction (30 patients) consisting of mutism, transcortical motor aphasia, and hemiparesis with lower limb predominance; right side infarction (16 patients) accompanied by acute confusional state, motor hemineglect and hemiparesis; bilateral infarction (two patients) presented with akinetic mutism, severe sphincter dysfunction, and dependent functional outcome. Our findings suggest that clinical and etiologic spectrum of ACA infarction may present similar features as that of middle cerebral artery infarction, but frontal dysfunctions and callosal syndromes can help to make a clinical differential diagnosis. Moreover, at the early phase of stroke, DWI is useful imaging method to locate and delineate the boundary of lesion in the territory of ACA.

Aged↗
PubMed1999

Isolated pontine infarction due to rhinocerebral mucormycosis.

We report a patient with rhinocerebral mucormycosis whose initial central nervous system involvement was isolated pontine infarction due to basilar arteritis caused by the fungus. The patient was diagnosed and followed by MRI and CT and basilar arteritis was demonstrated well on MRI studies. Involvement of the skull base was shown on CT in the later stage of the disease. The unusual initial presentation of the infection is discussed.

Adult↗
PubMed1999

Multiple intracranial aneurysms in polyarteritis nodosa: MRI and angiography.

In polyarteritis nodosa involvement of the central nervous system is infrequent; small cerebral infarcts are the most common neuroradiological finding. We report a 10-year-old boy with polyarteritis nodosa and intracranial haemorrhage. MRI showed an intracerebral haemorrhage. Angiography revealed two peripheral aneurysms in the posterior cerebral circulation, previously reported on only two occasions, and multiple microaneurysms in the hepatic, renal, mesenteric and even the lumbar arteries.

Cerebral Angiography↗
PubMed1999

Adhesive arachnoiditis causing cauda equina syndrome in ankylosing spondylitis: CT and MRI demonstration of dural calcification and a dorsal dural diverticulum.

We present the radiological features of a 42-year-old man with long-standing inactive ankylosing spondylitis (AS), demonstrating that arachnoiditis is a cause of a cauda equina syndrome (CES) in this disease. CT showed a dorsal arachnoid diverticulum causing scalloped erosion of the laminae, and punctate and curvilinear dural calcification. MRI revealed adhesion and convergence of the cauda equina dorsally into the arachnoid pouch, causing the dural sac to appear empty canal. To the best of our knowledge, dural calcification on CT is a new finding in AS, which may be related to the CES. Our findings support the hypothesis that chronic adhesive arachnoiditis with subsequent loss of meningeal elasticity may be the main cause of CES in AS.

Adult↗
PubMed1999

Hypertrophic cranial pachymeningitis involving dural sinuses: a pseudo signal-void appearance on MRI.

A case of hypertrophic cranial pachymeningitis with an unusual and misleading manifestation is reported. CT detected calcified tentorium and superior sagittal sinus. MR imaging and MR angiography depicted tentorial thickening as well as occlusion of all major dural sinuses. Fibrocalcific occlusion of dural sinuses showed interestingly signal-void appearance on spin-echo images which could readily be interpreted as being patent sinuses.

Adult↗
PubMed1999

Varix of the inferior pulmonary vein: computed tomography and magnetic resonance angiography findings.

A 37-yr-old male presented with a 2-week history of intermittent episodes of mild haemoptysis. Computed tomography and magnetic resonance imaging revealed a varix of the inferior pulmonary vein. The diagnosis was confirmed using magnetic resonance angiography and conventional angiography. This condition is relatively rare, and few cases have previously been demonstrated by means of magnetic resonance imaging and angiography.

Adult↗
PubMed1998

Retroclival epidural hematoma secondary to decompressive craniectomy in cerebellar infarction: MR demonstration.

Epidural hematomas of the clivus are very uncommon. We, hereby, present a case of retroclival epidural hematoma as a complication of posterior fossa decompressive surgery for the management of acute cerebellar infarction. Serial MRI examinations of the patient was documented and demonstrated. In addition, the etiology of retroclival epidural hematomas were also discussed.

Adult↗
PubMed1996

Cerebral astroblastoma resembling an extra-axial neoplasm.

A case of a cerebral astroblastoma is described in which MR imaging findings suggested the diagnosis of an extra-axial neoplasm. The lesion was proven to be intracerebral both surgically and histopathologically. Calvarial erosion, and buckling of the cerebral cortex by a peripherally located well circumscribed, highly enhancing mass, were the main MR findings leading to an errogenous preoperative diagnosis of an extra-axial mass. An astroblastoma should be included to the differential diagnosis of a superficially located tumor presenting with the findings of an extra-axial mass, especially in a young patient.

Arachnoid↗
PubMedDate not supplied

Spinal cord compression due to costal Echinococcus multilocularis.

We present computerized tomography (CT) and magnetic resonance imaging (MRI) findings of a costal hydatid cyst (Echinococcus multilocularis) causing spinal cord compression. The hydatid disease was proved histologically. MRI was not only very useful for determining the spinal extension of the disease by its multiplanar imaging capability, but also gave important information about the texture of the cyst, thus aiding the preoperative diagnosis.

Adult↗
PubMedDate not supplied

The so-called transcerebral veins: appearance in three different cases.

The radiologic findings in three patients with dilated transcerebral (medullary) veins detected on routine computed tomography and/or magnetic resonance imaging were reviewed. Sectional imaging showed the dilatation of transcerebral veins as well as the dilated superior ophthalmic veins in all patients. It also demonstrated the primary pathology: vein of Galen aneurysmal malformation; dural sinus fistula with varix; and dural arteriovenous fistula. All three patients had both arteriovenous fistula and sinovenous occlusion. We concluded that the dilated transcerebral veins developing secondary to elevation of the cerebral venous pressure, might be the useful radiologic finding of some dural vascular pathologies on sectional imaging.

Adult↗