Resolution of clinical symptoms after reopening of an occluded inferior petrosal sinus in a patient with a cavernous sinus dural arteriovenous fistula. A case report

We describe a rare case with a cavernous sinus (CS) dural arteriovenous fistula (DAVF) in which the clinical symptoms disappeared after the patient underwent reopening of an occluded inferior petrosal sinus (IPS). A 66-year-old woman presented with increased intraocular pressure, chemosis, and proptosis on the left side. Angiography demonstrated a left CS DAVF supplied by the dural branches of bilateral internal carotid arteries. The shunt flow was directed to the superior and inferior ophthalmic veins, while the bilateral IPSs were not opacified. Accordingly, a transvenous embolization of the fistula was attempted. Although the microcatheter was navigated to the cavernous sinus through the occluded left IPS, obliteration of the fistula was unsuccessful because of the failure of superselective catheterization at the fistulous point. However, the final image demonstrated the development of an antegrade shunt flow through the left IPS to the internal jugular vein and disappearance of the retrograde reflux to the superior and inferior ophthalmic veins. The patient's clinical symptoms immediately resolved after the operation, and the symptoms have not recurred during a one-year follow-up period. Inappropriate transvenous embolization of CS DAVFs can result in vascular complications arising from the unintentional redistribution of shunt flow. The present case illustrates that the disappearance of retrograde shunt flow to the ophthalmic veins after reopening of the occluded IPS may be sufficient if a superselective approach fails or is anticipated to result only in an incomplete embolization of the fistulous point.

Effect of scatter and attenuation correction in ROI analysis of brain perfusion scintigraphy

The aim of this study was to evaluate the effect of scatter and attenuation correction in region of interest (ROI) analysis of brain perfusion single-photon emission tomography (SPECT), and to assess the influence of selecting the reference area on the calculation of lesion-to-reference count ratios. Patients, methods: Data were collected from a brain phantom and ten patients with unilateral internal carotid artery stenosis. A simultaneous emission and transmission scan was performed after injecting 123I-iodoamphetamine. We reconstructed three SPECT images from common projection data: with scatter correction and nonuniform attenuation correction, with scatter correction and uniform attenuation correction, and with uniform attenuation correction applied to data without scatter correction. Regional count ratios were calculated by using four different reference areas (contralateral intact side, ipsilateral cerebellum, whole brain and hemisphere). Results: Scatter correction improved the accuracy of measuring the count ratios in the phantom experiment. It also yielded marked difference in the count ratio in the clinical study when using the cerebellum, whole brain or hemisphere as the reference. Difference between nonuniform and uniform attenuation correction was not significant in the phantom and clinical studies except when the cerebellar reference was used. Calculation of the lesion-to-normal count ratios referring the same site in the contralateral hemisphere was not dependent on the use of scatter correction or transmission scan-based attenuation correction. Conclusion: Scatter correction was indispensable for accurate measurement in most of the ROI analyses. Nonuniform attenuation correction is not necessary when using the reference area other than the cerebellum.

Effect of scatter and attenuation correction in ROI analysis of brain perfusion scintigraphy: phantom experiment and clinical study in patients with unilateral cerebrovascular disease

The AIM of this study was to evaluate the effect of scatter and attenuation correction in region of interest (ROI) analysis of brain perfusion single-photon emission tomography (SPECT), and to assess the influence of selecting the reference area on the calculation of lesion-to-reference count ratios.

PATIENTS, METHODS

Data were collected from a brain phantom and ten patients with unilateral internal carotid artery stenosis. A simultaneous emission and transmission scan was performed after injecting 123I-iodoamphetamine. We reconstructed three SPECT images from common projection data: with scatter correction and nonuniform attenuation correction, with scatter correction and uniform attenuation correction, and with uniform attenuation correction applied to data without scatter correction. Regional count ratios were calculated by using four different reference areas (contralateral intact side, ipsilateral cerebellum, whole brain and hemisphere).

RESULTS

Scatter correction improved the accuracy of measuring the count ratios in the phantom experiment. It also yielded marked difference in the count ratio in the clinical study when using the cerebellum, whole brain or hemisphere as the reference. Difference between nonuniform and uniform attenuation correction was not significant in the phantom and clinical studies except when the cerebellar reference was used. Calculation of the lesion-to-normal count ratios referring the same site in the contralateral hemisphere was not dependent on the use of scatter correction or transmission scan-based attenuation correction.

CONCLUSION

Scatter correction was indispensable for accurate measurement in most of the ROI analyses. Nonuniform attenuation correction is not necessary when using the reference area other than the cerebellum.

Glomus jugulare tumor presenting with intracerebellar hemorrhage

What is believed to be the first case of a glomus jugulare tumor presenting with intracerebellar hemorrhage is described. A 25-year-old normotensive man suddenly suffered from severe headache, nausea, vomiting, vertigo, and ataxia due to an intracerebellar hemorrhage. Magnetic resonance imaging and angiography revealed a highly vascular jugulare foramen tumor extending into the intracranial space adjacent to the hematoma. Total removal of the tumor was performed successfully via the combined pre- and retrosigmoid approach, and the histologic diagnosis was a glomus jugulare tumor. We concluded that one of the numerous draining veins on the surface of intracranial tumor, which were observed during the operation, was the origin of the intracerebellar hemorrhage.

Two Cases of Hemorrhage in Benign Brain Tumors during Systemic Heparinization. Case Reports

SUMMARY

Anticoagulant therapy is usually used after endovascular operations like coil embolization of aneurysms, or for thromboembolic diseases such as myocardial infarction. Few data exist regarding hemorrhage from benign brain tumors during systemic heparinization with the exception of pituitary adenomas (1,2). We experienced two cases of hemorrhage from benign brain tumors during systemic heparinization. The first patient had an unruptured aneurysm in her suprasellar tumor. She underwent coil embolization to prevent hemorrhage during the subsequent tumorectomy. During and after the endovascular operation, she was heparinized and she suffered a hemorrhage from the tumor on the first postoperative day. The second patient had a suprasellar tumor and was heparinized prophylactically for myocardial infarction. He had an intratumoral hemorrhage on the fifth day after the start of the heparinization. This small series suggests that systemic heparinization with brain tumors, even when they are benign, is very dangerous, and further studies with a larger patient base are warranted.

Long-term outcome of 17 cases of large-giant posterior fossa aneurysm

Long-term outcome of 17 patients who harbored a large or giant aneurysm of posterior fossa was summarized. The anatomical distribution of aneurysms included eight cases of basilar artery (BA) bifurcation aneurysms, three cases of BA trunk aneurysms, and six cases of vertebral artery (VA) aneurysms. Eight patients received surgical or endovascular treatment for their lesion. The clinical outcome was good recovery in six, moderate disability in one, and vegetative state in one case, respectively. The other nine patients were followed conservatively. Four of them had fatal aneurysmal rupture, and another two patients suffered from aggravation of pre-existing symptoms related to their aneurysm. Only three patients remain intact. Comparison of the radiographic parameters between those who bled and those who did not bleed revealed that those with subsequent rupture had significantly higher rate of aneurysmal thrombus and had a trend for larger diameter of the aneurysm. Although more aggressive and multidisciplinary measure should be taken to these patients to improve their long-term outcome, our results showed the limitation of treatment for these patients in the present era at the same time. The patients with broad neck BA bifurcation aneurysm in which efferent vessels were incorporated into aneurysmal dome, and those with fusiform, giant BA trunk aneurysm with thrombus were the least amenable to treatment in our series.

Lateral ventricular meningioma encapsulated by the dura-like membrane

The first case of a ventricular meningioma that was encapsulated by the dura-like membrane is reported. Magnetic resonance imaging (MRI) showed a heterogeneous mass with a low intensity rim in the trigone of the right lateral ventricle of a 63-year-old male. Histological examination revealed that the tumor was a transitional meningioma encapsulated by a thick dura-like membrane. Moreover, abundant clusters of the dura-like connective tissue existed in the tumor, indicating that both the dura-like capsule and the dura-like clusters in the tumor were created by the tumor cells.

[A case of enlarged infundibular dilatation diagnosed by vertebral angiograms with carotid compression and neuroendoscope]

A case of enlarged infundibular dilatation diagnosed by vertebral angiograms with carotid compression was reported. A 57-year-old woman suffered from headache. She underwent MRA which revealed left internal carotid artery aneurysm. Left common carotid angiograms suggested a left saccular internal carotid artery aneurysm (4 mm x 6 mm) without a posterior communicating artery. However, it was confirmed to be an enlarged infundibular dilatation on left vertebral angiograms with carotid compression. It was confirmed at operation microscopically and neuroendoscopically, and the dilatation was treated by coating. When carotid angiograms reveal no posterior communicating artery, it is difficult to differentiate the origin of posterior communicating artery from internal carotid artery-posterior communicating artery junction aneurysms. Vertebral angiograms with carotid compression is useful for the differentiation for the exact diagnosis.

Successful removal of meningioma of the pineal region after embolization

A 69-year-old female presented with a meningioma of the pineal region manifesting as gait disturbance and mental dysfunction. Magnetic resonance imaging revealed a homogeneously well-enhanced circumscribed round mass of about 5 cm in diameter in the pineal region. Angiography demonstrated that the tumor was fed mainly by the bilateral middle meningeal arteries (MMAs), and preoperative intravascular embolization was performed through the bilateral MMAs using estrogen-alcohol and polyvinyl acetate. The tumor was very soft and easily totally resected via the right occipital transtentorial approach. Preoperative embolization is a very useful technique to facilitate removal of deep-seated tumors.

[A case with an isolated cortical vein thrombosis]

A 45-year-old man was admitted to our hospital because of generalized seizure. He had epilepsy and mental retardation since age of two. On admission temperature was 37.9 degrees C but, nuchal rigidity and Kernig's sign were not present. There were no other abnormal findings on physical examination. Neurological examination revealed consciousness disturbance, generalized seizure and mental retardation. Right hemiparesis gradually developed after generalized seizure. Laboratory data did not show any abnormalites to induce cerebral venous thrombosis. A brain MRI revealed hyperintensity on T2-weighted images and slightly enhanced on T1-weighted images in the left frontal lobe, using Gd-DTPA. An increased signal was also noted in the superior sagittal sinus on T1-weighted images. The superior sagittal sinus was patent but the cortical vein in the left frontal lobe was not demonstrated on cerebral angiography. A diagnosis of an isolated cortical vein thrombosis was made by exploratory craniotomy. Anticoagulation with heparin was started. Although the cortical vein thrombosis usually co-exsists with dural sinus thrombosis, an isolated cortical vein thrombosis like this case was rather rare. A case with cerebral venous thrombosis localized only in the left frontal cortical vein is reported, but definitive etiology is not known.

[Natural history for residual intracranial AVM: compared with that for conservatively treated AVM]

It is generally accepted that the most suitable treatment of AVM is surgical removal which does not cause neurological deficits. But in some cases, it is impossible to treat surgically because of size or location, so the patient is unfortunately discharged with some part of the nidus remaining. In this paper, we report the natural history of residual AVMs in which part of the nidus remained after initial therapy, and try to ascertain whether therapeutic reduction of the nidus is more effective in preventing intracranial hemorrhage than conservative treatment. Of 362 cases, residual AVMs were found in 35 cases, and were followed up for 9.2 years on average. Eighty cases treated with only conservative therapy were also followed up for 10.9 years on average. The annual risk of intracranial hemorrhage for residual AVMs was 2.9% and that for conservatively treated AVMs was 3.0%, not a significant difference. There was no difference between the two groups in mortality or ADL. We conclude that therapeutic reduction of the nidus was not effective in preventing intracranial hemorrhage.

Variation in sensitivity of alpha 1-adrenoceptor stimulants and alpha 1-adrenoceptor mechanisms in rabbit arteries

Sensitivity (pD2 value, negative logarithm of the molar concentration producing the half maximum response) and affinity (pKA value, negative logarithm of dissociation constant) of norepinephrine were determined in 6 arteries from rabbits. A positive correlation was found in the pD2 and pKA values of norepinephrine. The slope was not significantly different from 1. The pD2 and pKP (a negative logarithm of dissociation constant of a partial agonist) values of tizanidine, an alpha 1-partial agonist, were also determined. There were positive correlations between the pD2 and pKP values of tizanidine and also between the two pD2 values of norepinephrine and tizanidine. The slopes were not significantly different from 1. These results suggest that the regional differences in pD2 values of norepinephrine and tizanidine in the arteries are partly due to the affinity and suggest that both drugs interact with one recognition site in the alpha 1-adrenoceptors. The dissociation constants, KD values, and the maximum binding sites, Bmax, for [125I]-HEAT were also estimated by Scatchard analysis of the specific binding of [125I]-HEAT to the membrane fractions from rabbit arteries. The KD values for [125I]-HEAT were also identical. However, Bmax varied considerably among rabbit arteries. There was a positive correlation between the logarithm of Bmax and the pD2 values for norepinephrine. The present results suggest that the regional difference in the pD2 values for norepinephrine in rabbit arteries is due to variations in the affinities to the alpha 1-adrenoceptors as well as the receptor densities.

Contractile responses of rat aorta to phenylephrine and serotonin, and aging

1. The potency (pD2 value) of phenylephrine increased with age from 3 to 10 weeks, but decreased thereafter from 10 to 80 weeks, while the affinity (pKA value) of phenylephrine to alpha 1-adrenoceptors did not alter with aging. 2. The potency (pD2 value) of serotonin did not alter with aging. 3. There is no significant difference between slopes of regression lines between a cytosolic free Ca2+ level ([Ca2+]i) and tension in the presence of phenylephrine in aorta strips from 10- and 60-week-old rats, suggesting that the sensitivity of contractile system to Ca2+ did not alter with aging. 4. Effect of ryanodine on the transient increase of [Ca2+]i and the followed sustained contraction induced by phenylephrine or serotonin in Ca2+ free solution did not alter with aging.

Alpha 1-adrenergic partial agonists utilize cytosolic Ca2+ more effectively for contraction in aortic smooth muscle

Fura 2 loaded thoracic aorta strips from rabbits were used. Norepinephrine, phenylephrine, clonidine, and tizanidine induced an increase in cytosolic Ca2+ concentration [( Ca2+]i) and muscle tension in a concentration-dependent manner. A positive correlation between [Ca2+]i and tension development owing to the agonists was noted. The slope of regression lines between [Ca2+]i and tension development for clonidine and tizanidine, alpha 1-adrenergic partial agonists, were significantly steeper than those for norepinephrine and phenylphrine, alpha 1-adrenergic full agonists. The intrinsic activities of the partial agonists obtained from tension development were greater than those from changes in [Ca2+]i. These results suggest that the partial agonists cause a greater muscle tension than the full agonists at the same level of [Ca2+]i.

Greater tension is developed at the same level of cytosolic Ca2+ concentration in the presence of clonidine, an adrenergic partial agonist, than in the presence of norepinephrine

Fura 2-loaded thoracic aorta strips from rabbits were used. Norepinephrine and clonidine induced an increase in cytosolic Ca2+ concentration ([Ca2+]i) and in muscle tension in a concentration-dependent manner. A positive correlation between [Ca2+]i and tension development due to norepinephrine and clonidine was noted in muscle strips both untreated and treated with phenoxybenzamine (PBZ). As the total receptor population was reduced by the PBZ treatment, norepinephrine acted as a partial agonist in the treated strips. The slope of a regression line for norepinephrine in the untreated muscle strips was significantly smaller than the slopes for the same drug in PBZ-treated strips and for clonidine, suggesting that norepinephrine in the PBZ-treated strips and clonidine induced a greater tension at same [Ca2+]i than did norepinephrine in the untreated strips.

Nonfamilial turcot syndrome presenting with astrocytoma--case report

A nonfamilial case of Turcot syndrome (glioma-polyposis syndrome) is described. A 16-year-old male with no siblings first developed a frontal astrocytoma, and was later found to have colonic polyposis with adenocarcinoma. The family history was negative for the syndrome, but his parents were first cousins.

A regional difference in alpha 1-adrenoceptors in canine arteries

Noradrenaline sensitivity (pD2-value) and agonist dissociation constant (pKA-value) were determined in the following 4 canine arteries: thoracic and abdominal aorta, mesenteric and renal. The experiments were done in the presence of beta- and alpha 2-adrenoceptor blockers, and inhibitors of neuronal and non-neuronal uptake of catecholamine. A positive correlation was found in the pD2- and pKA-values for noradrenaline (r = 0.976, P less than 0.05). The slope (0.92) was not significantly different from 1. The pD2- and pKp (negative log of dissociation constant of partial agonist)-values of clonidine, an alpha 1-adrenergic partial agonist, were also determined. There was a positive correlation between the pD2- and pKp-values (r = 0.974, P less than 0.05). Again, the slope (1.39) was not significantly different from 1. These results indicate that the regional difference in the pD2-values for noradrenaline and clonidine in canine arteries is due to the affinities to alpha 1-adrenoceptors and that there is a qualitative difference between alpha 1-adrenoceptor mechanisms in the arteries and veins. However, no positive correlation between the pD2-values for noradrenaline and clonidine was observed (r = 0.182, P greater than 0.05). Thus, it may be suggested that either the recognition sites for noradrenaline, clonidine and prazosin are different or else their mode of attachment to the same recognition site is not identical.