A Novel Technique to Retrieve a Snagged Stent Retriever: Technical Note

Objective

Currently, there are no established approaches for removal of devices, such as stents, which sometimes become difficult to recover during endovascular treatment. We report a new method to successfully remove a stent that has become snagged during thrombus removal.

Case Presentation

An 82-year-old female who had undergone a mitral valve annuloplasty developed sudden aphasia, right hemiplegia, and right unilateral spatial neglect on postoperative day 10. Cranial MRI indicated occlusion of the horizontal segment of the left middle cerebral artery. During mechanical thrombectomy, a vasospasm snagged the stent, and re-sheathing attempts failed repeatedly. We wedged the microcatheter into the spasm site and slowly injected a solution containing 1 cc of nicardipine, 2 cc of contrast medium, and 2 cc of heparin in normal saline intra-arterially. After several minutes, we retracted the Trevo wire slightly and easily removed the stent. The thrombus adhered to the retrieved stent. Post-retrieval imaging showed that the branch was completely recanalized.

Conclusion

In cases wherein a microwire or stent retriever becomes difficult to remove, we propose switching to a microcatheter with a sufficient diameter to allow vasodilator injection. If the microcatheter is difficult to remove, our method can be utilized by severing the hub, inserting a larger-bore catheter, and injecting vasodilators. Adding contrast medium to the intra-arterial injectate allows visualization of whether the solution has reached the spasm site. Furthermore, by injecting the solution through the wedged catheter, pooling of the solution at the spasm site can be confirmed.

[Clipping of a Large Unruptured Basilar Artery Trunk Large Aneurysm Using Rapid Ventricular Pacing:A Case Report]

Neck clipping of basilar trunk aneurysms, particularly those of a large size, is challenging because of its location. Here, we report a case of a basilar artery aneurysm successfully treated with neck clipping using rapid ventricular pacing(RVP). A 67-year-old woman was referred to our hospital for treatment of a large basilar artery aneurysm. Although coiling was considered, we performed neck clipping of this aneurysm because of the expected radical therapeutic effect. The patient was positioned in the right park-bench position, and right suboccipital craniotomy was performed. The aneurysm was mainly approached via the right supracerebellar route. RVP softened the aneurysm for easy dissection and insertion of multiple clips. The postoperative course was uneventful, and she was discharged 1 week later without neurological deficits. RVP should be considered for the treatment of complex aneurysms as adjunctive techniques.

[Relationship of Distal Anterior Cerebral Artery Aneurysm Arising from the Supracallosal Portion and Accessory Anterior Cerebral Artery]

Median artery of the corpus callosum(MACC)refers to the median artery of the triplicate anterior cerebral artery(ACA). When MACC distributes to one or to both hemispheres, it is known as the accessory ACA. We performed detailed angiographic analysis of 32 consecutive patients operated upon for distal ACA(DACA)aneurysms, and noted that all DACA aneurysms occurring in the supracallosal portion were accompanied by an accessory ACA as vascular malformation. Such relationship between accessory ACA and DACA aneurysm in the supracallosal portion has not been previously reported.

Significance of urinary glucaric acid measurement and its application to paclitaxel therapy

Individual variations in P-450 activity affect the in vivo pharmacokinetics as well as the efficacy and side effect of drugs. It is proposed that urinary glucaric acid (GA) level may indirectly represent P-450 activity and may therefore be an indicator of P- 450 activity in the clinical setting. However, no standard method has been developed so far. Metabolism of paclitaxel (PTX), an anticancer drug, is mediated by P-450. If P-450 activity could be predicted by measuring urinary GA level during PTX administration and individual blood PTX concentration could be inferred, urinary GA level would be a potent tool to predict the efficacy and side effects of the drug. We therefore measured the urinary GA levels of patients on antiepileptics that are suggested to induce P-450 and those of control subjects, to determine whether urinary GA level could be an indicator of P-450 activity. Then, we examined the relationship between urinary GA level and blood PTX concentration and looked into the possibility of predicting pharmacokinetics based on the relationship between urinary GA level and area under the blood concentration-time curve (AUC). The means+/-S. D. of urinary [(GA level)/(Cr level) x 10] levels of 16 patients on antiepileptic medication and 24 control subjects were 0. 98 mg/mL+/-0. 91 and 0. 19 mg/mL+/-0. 07, respectively. The urinary GA levels of patients on antiepileptic medication were significantly higher than those of control subjects. On the other hand, the relationship between AUC and urinary GA levels in eight patients on PTX showed that AUC tended to become large when urinary GA levels were low. The above results reveal that measuring urinary GA level by the easy and noninvasive way of urine collection would enable us to predict P-450 activity and infer blood PTX concentration.

Expression of ciliary neurotrophic factor (CNTF), CNTF receptor alpha (CNTFR-alpha) following experimental intracerebral hemorrhage in rats

Ciliary neurotrophic factor (CNTF) is known as a neuro-survival factor in the developing and developed CNS, as well as in the CNS following injury. However, little is known about the expression of CNTF or that of its receptor (CNTFR-alpha) in cases of intracerebral hemorrhage (ICH). We investigated the temporal and spatial profiles of CNTF and CNTFR-alpha expression using a collagenase-induced ICH rat model. CNTF expression was up-regulated from the day following ICH induction and reached a peak level at 5 to 14 days, with increased expression observed in brain tissue surrounding the hematoma lesion and white matter structures in association with astroglial proliferation. Further, CNTFR-alpha was transiently expressed in the cerebral cortex surrounding the hematoma, with a peak at 5 days. Administration of exogenous CNTF into the lesion following initiation of ICH resulted in a prolonged expression of CNTFR-alpha on cortical neurons neighboring the hematoma. Our findings suggest differential regulation of CNTF and CNTFR-alpha, and the possibility of a therapeutic strategy using CNTF administration for ICH.

[Vascular endothelial growth factor expression in the rat dural arteriovenous fistula model]

Although various mechanisms of the development of dural arteriovenous fistula (DAVF) have been proposed, the pathogenesis of these lesions are still unclear. Recent experimental evidence suggested a role of angiogenic growth factors in the genesis of vascular malformations of the central nervous system. To further investigate the pathogenesis of DAVF, we examined the expression of the angiogenic growth factor, vascular endothelial growth factor (VEGF), in rat DAVF model.

MATERIAL AND METHODS

Male Wistar rats (weighting 280 to 300 g, n = 40) were used. Each rat was mounted on a stereotaxic frame under general anesthesia. DAVF model (Spetzler et al.) was made by common carotid artery-external jugular vein anastomosis, bipolar coagulation of the vein draining the transverse sinus, and superior sagittal sinus thrombosis (SSS). SSS was thrombosed by a hemostatic agent through 16-gauge needle. Venous hypertension was induced in 30 rats, which were divided into two experimental groups; (1) immunohistological study group (n = 15) and (2) angiography group (n = 15). Immunohistological analysis was performed by VEGF antibody 1 week after, and angiography was done 90 days after the surgery. Developing of angiographical DAVF was observed with the magnifying X-ray camera. Each 5 rats served as sham-operated controls, which received a similar surgery without induction of venous hypertension.

RESULTS

VEGF expression and DAVF were not observed in sham group. In immunohistological study group, VEGF expression in the endothelium and the connective tissues of the dura mater in the five rats (33%) and in the neurons in the eleven rats (73%) of the cerebral cortex and the basal ganglia were identified. In angiography group, DAVF formed in 6 among 15 rats (40%).

CONCLUSION

The findings of this study provide the first experimental evidence that angiogenic growth factors VEGF may participate in the genesis of DAVF. These results suggest a novel strategy for the management and prevention of DAVF and related disorders.

Brain metastases from urachal carcinoma

We present a case of brain metastases of the urachal carcinoma, which is extremely rare and malignant. Contrast-enhanced MRI was employed to detect them. A large mass was removed surgically and 4 other small metastases were treated by gamma knife radiosurgery. Six weeks after radiosurgery, the 4 lesions had disappeared on MRI. We emphasise the importance of early diagnosis using MRI and treatment by radiosurgery for this rare condition.

Color Doppler flow imaging of the superior ophthalmic vein in dural arteriovenous fistulas

BACKGROUND AND PURPOSE

This article evaluates the intracranial venous hemodynamics of dural arteriovenous fistula (DAVF) on the basis of data from color Doppler flow imaging (CDFI) findings of the superior ophthalmic vein (SOV) and discusses the clinical application of the SOV CDFI to the DAVFs.

METHODS

We examined the diameter, flow direction, flow waveform, and flow velocity of the SOV using CDFI in 20 patients with intracranial DAVF. Six patients were asymptomatic; the other 14 patients were symptomatic. Angiographic retrograde cortical venous filling was seen in 14 patients.

RESULTS

In the DAVFs, the average SOV diameter was 2.95+/-1.15 mm, which was significantly broad compared with that of the control subjects (P<0.05). The flow direction was reversed in 2 patients and normal in the other 18 patients. Three patients showed an abnormal waveform. A reversed pulsatile waveform was observed in 2 patients, and a normograde pulsatile waveform was seen in 1 patient. The other 17 patients showed normal waveform. The average SOV diameter and resistance index values were significantly higher (P<0.05) in patients with clinical symptoms, angiographic retrograde cortical venous fillings, or large DAVFs compared with those in the other patients.

CONCLUSIONS

The SOV CDFI findings in DAVFs correlated well with the patient's clinical symptoms, angiographic findings, and DAVF size. These findings were useful to evaluate the intracranial venous hemodynamics in DAVFs.

Effect of carotid endarterectomy on the ophthalmic artery

BACKGROUND

To evaluate the effect of carotid endarterectomy on ophthalmic artery flow direction and peak systolic flow velocity, the authors examined the ophthalmic artery on 32 patients who had undergone carotid endarterectomy.

METHODS

The 32 patients had more than 70% stenosis of the internal carotid artery at its origin on angiography. The ophthalmic artery ipsilateral to the carotid endarterectomy was evaluated by the ophthalmic artery color Doppler flow imaging before surgery and then at one week, one month, and three months after surgery.

FINDINGS

(1) Before carotid endarterectomy: eight patients showed reversed ophthalmic artery direction. In the other 24 patients with antegrade ophthalmic artery flow direction, the average peak systolic flow velocity was 0.17+/-0.10 m/sec. (2) At one week after carotid endarterectomy: The reversed ophthalmic artery flow direction was resolved in each patient. The average peak systolic flow velocity in the patients with preoperative antegrade flow rose significantly to 0.28+/-0.10 m/sec (p<0.05). (3) At one month and three months after carotid endarterectomy: All patients showed the antegrade ophthalmic artery flow direction. The average peak systolic flow velocities showed no significant change compared to the value at one week after carotid endarterectomy. (4) During the followed up period, there was no patient showing worsening or recurrence of clinical symptoms including the visual symptoms.

INTERPRETATION

Carotid endarterectomy brought about the correction of the reversed flow and an increase in the peak systolic flow velocity of the ipsilateral ophthalmic artery immediately after surgery.

Further study of CD31 protein and messenger ribonucleic acid expression in human cerebral vascular malformations

OBJECTIVE

In a previous study, we documented lower levels of immunoexpression of platelet endothelial cell (EC) adhesion molecule (CD31) in paraffin sections of cerebral cavernous malformations (CCMs), compared with arteriovenous malformations (AVMs) or normal brain tissue. We hypothesized that down-regulation of CD31 in CCMs might represent a distinctive phenotypic feature of ECs in this disease. To confirm this hypothesis, we further examined both protein and messenger ribonucleic acid (mRNA) expression of CD31, using immunohistochemical and in situ hybridization analyses, in fresh-frozen specimens of CCMs, AVMs, and control brain tissue.

METHODS

Fresh-frozen sections of four AVMs, five CCMs, and four control brain tissue specimens obtained from surgical resections were immunohistochemically stained with antibodies to von Willebrand factor and two distinct epitopes of CD31. In two AVMs, four CCMs, and three control brain tissue samples from the aforementioned group, the expression of CD31 mRNA was also examined by using in situ hybridization. Large (>100-microm) and small (<100-microm) vessels were counted and assessed for protein and mRNA expression.

RESULTS

In all tissues, ECs in the majority of vessels were immunopositive for CD31 with two distinct antibodies. CD31 mRNA was expressed in some but not all vessels in AVMs, CCMs, and control brain tissue. There were no statistically significant differences in CD31 protein or mRNA expression in CCMs, AVMs, and control brain tissue.

CONCLUSION

The expression of CD31 in CCMs can be underestimated in paraffin sections. There does not seem to be a unique phenotypic differentiation of CD31 expression in ECs of CCMs or AVMs, compared with control brain tissue.

Radiosurgery-induced brain tumor. Case report

The authors describe a case of glioblastoma multiforme (GBM) associated with previous gamma knife radiosurgery for a cerebral arteriovenous malformation (AVM). A 14-year-old boy had undergone radiosurgery for an AVM, which was performed using a 201-source 60Co gamma knife system at another institution. The maximum and margin radiation doses used in the procedure were 40 and 20 Gy, respectively. One year after radiosurgery, the patient noticed onset of mild left hemiparesis due to radiation necrosis. Six and one-half years after radiosurgery, at the age of 20 years, the patient experienced an attack of generalized tonic-clonic seizure. Magnetic resonance (MR) imaging revealed the existence of a brain tumor in the right parietal lobe. The patient underwent an operation and the histological diagnosis of the lesion was GBM. Ten months following the operation, that is, 99 months postradiosurgery, this patient died. To the best of the authors' knowledge, this is the first reported case of a neoplasm induced by radiosurgery for an AVM and the second case in which it occurred following radiosurgery for intracranial disease.

Vascular smooth muscle cell differentiation in human cerebral vascular malformations

OBJECTIVE

The pathogenesis of central nervous system vascular malformations likely involves the abnormal assembly, differentiation of vascular smooth muscle cells (VSMC), or both in association with dysmorphic vessel wall. We hypothesize that intracranial arteriovenous malformations (AVMs) and cerebral cavernous malformations (CCMs) exhibit distinct patterns of expression of molecular markers of differentiation and maturity of VSMCs. We further speculate that the unique VSMC phenotype in the different lesions is not necessarily maintained in cell culture.

METHODS

Paraffin-embedded sections of five AVMs, CCMs, and control brain tissues were stained immunohistochemically with antibodies to alpha-smooth muscle actin (alpha-SMA), myosin heavy chain, and smoothelin, a novel marker for contractile VSMC phenotype. Large (> or =100 microm) and small (<100 microm) vessels were counted and assessed for immunoexpression of each protein, then categorized according to expression of one or more of these markers. Cultured nonendothelial cells isolated from four other excised AVM and CCM lesions were assessed for immunoexpression of the same antibodies.

RESULTS

Alpha-SMA was universally expressed in all vessels in AVMs and in control brains. It was expressed in the subendothelial layer of 97% of large caverns and 85% of small caverns and in scattered intercavernous connective tissue fibrocytes in CCMs. Myosin heavy chain was expressed in the majority of brain and AVM vessels, except for normal veins, and in the subendothelial layer of more than half of the caverns in CCMs. Smoothelin expression was less prevalent in large vessels in AVMs than in control brains and was not found in any caverns in CCMs (large vessels in control brains, 40.9%; AVMs, 21.9%; CCMs, 0%; P < 0.0001). Cultured AVM and CCM nonendothelial cells expressed alpha-SMA, but myosin heavy chain was expressed weakly in cells from only one CCM. Smoothelin was negative in all cells.

CONCLUSION

We describe vessels with various stages of VSMC differentiation in AVMs and CCMs. The subendothelial layer of CCMs commonly expresses alpha-SMA and less commonly expresses myosin heavy chain. Expression of smoothelin was less prevalent in large AVM vessels than in normal brain, which may reflect the loss of contractile property associated with hemodynamic stress. It is difficult to evaluate VSMC differentiation in culture because of phenotypic change.

Expression of endothelial cell angiogenesis receptors in human cerebrovascular malformations

OBJECTIVE

To further understand the role of angiogenic growth factors in the development of cerebral cavernous malformations (CCMs) and arteriovenous malformations (AVMs), we investigated endothelial cell (EC) expression of receptors for vascular endothelial growth factor (VEGF) and angiopoietin systems in patients with surgically resected lesions.

METHODS

Paraffin-embedded sections of five AVMs, CCMs, and normal control brain tissue samples were stained immunohistochemically with antibodies to von Willebrand factor and CD31 (to characterize ECs) and angiogenesis growth factor receptors Flt-1 (VEGF-R1), Flk-1 (VEGF-R2), Tie-1, and Tie-2. We counted large and small vessels in each specimen, assessed each specimen's immunoexpression of each antigen, and analyzed differences between CCMs, AVMs, and the normal control brain tissue samples.

RESULTS

The ECs of CCMs, AVMs, and normal control brain tissue samples expressed the von Willebrand factor uniformly, but the ECs of CCMs were largely negative for CD31 (P < 0.05). Flk-1, Flt-1, and Tie-2 were not expressed in the control brain tissue samples. The proportion of immunopositive vessels to VEGF receptors Flk-1 and Flt-1 was significantly greater in AVMs and CCMs than in the control brain tissue samples (P < 0.05). Tie-2 in AVMs and CCMs was expressed in a higher percentage of immunopositive vessels than in the control brain tissue samples, but the difference was not statistically significant. Tie-1 was expressed in rare vessels of all lesion types and control brain tissue samples.

CONCLUSION

ECs of CCMs do not seem to express CD31 to the same extent that AVMs and normal brain tissue do. AVMs and CCMs show greater expression of VEGF receptors, but not of angiopoietin receptors, than normal brain tissue does.

Colour Doppler flow imaging of the superior ophthalmic vein in dural arteriovenous fistulas before and after surgery

The aim of this study was to examine the clinical significance of the colour Doppler flow imaging (CDFI) findings of the superior ophthalmic vein (SOV) in intracranial dural arteriovenous fistulas (DAVF). The SOV was examined by CDFI in 12 cases of DAVF before and after surgery. Before surgery, the average SOV diameter was 3.57+/-1.18 mm (mean +/- standard deviation, which was significantly wide (P<0.05) compared with the control value. One case showed reversed flow. Four cases showed an abnormal waveform. The cases with the more severe clinical symptoms showed wider SOV diameters and more abnormal waveforms than those with mild clinical symptoms. Postoperatively, the mean SOV diameter and mean resistance index improved significantly (P< 0.05); the flow direction and waveform became normal in each. The SOV CDFI findings were found to be useful as screening and follow-up techniques for the intracranial DAVFs.

Early-onset tolerance in rat global cerebral ischemia induced by a mitochondrial inhibitor

It was studied whether a subtoxic dose of the mitochondrial neurotoxin, 3-nitropropionic acid (3-NPA), can initiate early-onset tolerance induction for subsequent ischemic injury. Wistar rats were pretreated for 3 h by intraperitoneal 3-NPA (20 mg/kg body weight; n=13) or solvent (n=12). Fifteen minutes global cerebral ischemia was induced by bilateral carotid artery occlusion and hypobaric hypotension. rCBF and tissue hemoglobin oxygen saturation were measured by laser Doppler scanning and a microspectrophotometric method. Ischemic insult and brain temperature were identical in both groups. Body weight and neurological scores recovered in the pretreated group but further deteriorated in the non-treated group (P<0.05). Quantitative histology demonstrated a better neuronal density in neocortex and hippocampal CA2, CA3, and CA4 of pretreated animals (P<0.05).

Extensive cervical laminoplasty for patients with long segment OPLL in the cervical spine: an alternative to the anterior approach

We investigated treatment of long segment cervical OPLL by posterior decompression using a laminoplasty technique. Our aim was to both decompress the spinal cord and also to preserve neck motion. There were 38 patients treated by this posterior approach. Twenty-eight patients underwent C1-C7 expanding laminoplasty, 4 patients underwent C1-T1 expanding laminoplasty, and 6 patients C2-C7 expanding laminoplasty. The transverse width of the open-door laminoplasty was sufficient to achieve decompression of not only the spinal cord but also the nerve root outlets at each laminoplasty level. There were no complications related to this surgical technique, nor late deterioration in the mean follow up period of 4. 5 years. We propose expanding laminoplasty as an important option for the treatment of long segment cervical OPLL.

Expression of angiogenic growth factors in dural arteriovenous fistula

OBJECT

Although various mechanisms of the development of dural arteriovenous fistula (AVF) have been described, the exact course of its pathogenesis, including molecular processes mediating its genesis, is still unknown. Recently, the importance of sinus thrombosis and venous hypertension has been reported in experimental and clinical studies. Additionally, a role of angiogenic growth factors in the pathogenesis of vascular malformations of the central nervous system has been reported. In this study, the authors investigated the existence of sinus thrombosis in dural AVF and the expression of angiogenic growth factors (basic fibroblast growth factor [bFGF] and vascular endothelial growth factor [VEGF]) in nine patients with dural AVFs that were surgically resected.

METHODS

The authors examined histological features of dural AVFs that involved the transverse/sigmoid sinus in seven patients and the superior sagittal sinus in two. Sinus thrombosis was verified angiographically in seven cases and histologically in all cases. In surgically resected specimens the angiogenic growth factors bFGF and VEGF were examined immunohistochemically in nine patients with dural AVFs, with five dural sinuses from cadavers with unrelated central nervous system diseases serving as a normal control group. The media and perivascular connective tissues of the arteries in the wall of the normal dural sinuses stained faintly for bFGF; on the other hand, the expression of VEGF was not detected. In all patients with dural AVFs, the thick wall of the dural sinus stained strongly for bFGF, mainly in the subendothelial layer and media of the strongly proliferative vessels in the sinus wall, in addition to the perivascular connective tissues. In all nine cases VEGF was expressed in the endothelium of the sinus and perivascular connective tissues. In two cases, VEGF was expressed in many capillaries proliferating in the granulation-like tissues in sinuses that were obliterated by organized thrombi.

CONCLUSIONS

It is concluded that the pathogenesis of dural AVF is still unknown, but that angiogenic growth factors, which might be produced by the healing process due to sinus thrombosis, may participate in the genesis of dural AVF. Understanding the mechanism of molecular pathogenesis in the development of dural AVF might aid in the establishment of a new therapeutic strategy for this dynamic vascular disease.

Effects of bypass on CO2 cerebrovascular reactivity in ischaemic cerebrovascular diseases--based on the intra-operative LCBF and CO2 cerebrovascular reactivity studies

The authors evaluated the effects of superficial temporal to middle cerebral artery (STA-MCA) bypass on CO2 cerebrovascular reactivity (CVR) in ischaemic cerebrovascular diseases (CVDs). Local cerebral blood flow (LCBF) and CO2 CVR in 19 patients with ischaemic CVD subjected to standard STA-MCA bypasses were examined during surgery. Single photon emission computed tomography (SPECT) with acetazolamide (ACZ) activation was also performed before and at 1 month after surgery. The results are as follows. 1) Before bypass, the average CO2 CVR value was -1.50 +/- 2.30%/mmHg (mean +/- SD). SPECT showed disturbed response to ACZ in all cases. Fifteen cases showed the steal phenomenon. After bypass, the mean CO2 CVR value significantly (p < 0.05) increased, and four cases resolved their steal phenomenon. 2) Before bypass, the mean LCBF was significantly (p < 0.05) lower than the control level. After bypass, the mean LCBF significantly (p < 0.05) increased. 3) In the postoperative SPECT findings, 13 cases showed a disturbed response to ACZ. The CO2 CVR value in these 13 cases was -1.21 +/- 1.19%/mmHg, which was significantly (p < 0.05) low compared to the values for the 6 cases showing normal postoperative ACZ responses. In ischaemic CVDs before bypass, the CO2 CVR values were extremely low. After bypass, however, CO2 CVR and LCBF values significantly improved. SPECT findings, including ACZ challenge, correlated well to the LCBF and CO2 CVR values. STA-MCA by pass exerted a favourable effect on the CO2 CVR and LCBF values immediately after bypass in the cases showing a reduced pre-operative response to CO2.

Evaluation of absolute cerebral blood flow by laser-Doppler scanning-- comparison with hydrogen clearance

A major limitation of laser-Doppler (LD) flowmetry, which enables noninvasive and continuous recording of tissue perfusion, is its inability to evaluate the absolute cerebral blood flow (CBF). Using a computer-controlled micromanipulator, the LD scanning technique provides information on the brain microcirculation in many different locations, information which is not available from a single stationary probe. The purpose of the current study was to examine whether LD scanning estimates can be calibrated for the absolute CBF by comparing LD scanning with the hydrogen clearance (HC) method. In Wistar rats (n = 31) including old rats (122-123 weeks old, n = 8), the CBF was altered using the global ischemia model by bilateral carotid artery occlusion coupled with hypobaric hypotension. The CBF was determined simultaneously by the LD scanning technique and HC at each mean arterial blood pressure step, and the correlation of CBF between the two techniques was analyzed. CBF measured by LD scanning was expressed as LD units. Absolute CBF values obtained by methods were correlated (r = 0.87), and the formula to calibrate absolute CBF values from LD units was y = 1.8x - 0.6. On the other hand, in old rats the formula to calibrate the absolute values was different (y = 1.3x + 8.3, r = 0.85). The results suggest that CBF data obtained by LD scanning could be calibrated into absolute blood flow values in particular circumstances, and that LD scanning could compensate in part for the weakness of LD flowmetry.

A case of internal carotid artery occlusion complicating embolization of the external carotid artery system

A case of visual disturbance by embolization through the external carotid artery (ECA) after internal carotid artery (ICA) occlusion is reported. A 65-year-old female presented left ICA occlusion 14 years ago. She was admitted with acute deterioration of left visual acuity. Ophthalmologically, the retinal central artery was occluded. Cerebral angiography disclosed an irregular wall at the left ICA stump and stenosis of the maxillary artery. Carotid endarterectomy of the common carotid artery, ECA and residual ICA was performed and atheromatous plaque with ulceration was removed. The postoperative course was uneventful. We discuss cases of ICA occlusion in relation to visual impairment.

Eosinophilic granuloma associated with intratumoral hemorrhage--case report

A 2-year-old boy presented with a rapidly growing soft scalp mass in the left parietal region. Surgical exploration and histological examination demonstrated an eosinophilic granuloma associated with intratumoral hemorrhage. Eosinophilic granuloma should also be considered when a scalp mass lesion exhibits rapid growth.

[Complex partial status epilepticus in a patient with a frontal cavernous angiomas]

We described a 34-year-old woman with a right frontal cavernous angioma who presented with complex partial status epilepticus (CPSE). In the first CPSE, complex partial seizure with complete unresponsiveness and tonic motor manifestation on her left arm occurred repeatedly at short intervals. Her consciousness was mildly disturbed between the seizures. An hour after the intra-venous administration of diazepam, her consciousness returned to normal. In the second CPSE, no motor manifestation was found, but complete unresponsiveness of short duration accompanied with stare and moderately impaired consciousness continued to occur. We emphasize the importance of not missing this rare non-convulsive epileptic status, especially when it does not present motor manifestations.

[Cerebral aneurysms associated with von Recklinghausen neurofibromatosis: report of two cases]

The authors reported two cases of aneurysms associated with von Recklinghausen's neurofibromatosis. The first case, a 60-year-old woman was referred to our hospital because of disturbance of consciousness and right hemiparesis of acute onset. On admission, she was almost alert but developed right hemiparesis and lower cranial nerve palsy. Computed tomographic (CT) scanning and magnetic resonance imaging (MRI) demonstrated a huge mass compressing the brain stem and another mass lesion in the suprasellar cistern. Cerebral angiography disclosed left vertebral and left internal carotid artery giant aneurysms. Since she suffered respiratory distress because of aspiration pneumonia, conservative therapy was carried out. However, she developed cardiac arrest suddenly and died fourteen days after admission. On autopsy, it was shown that the left sided medulla oblongata had necrosis due to compression by the giant aneurysm and that the hemorrhagic infarction of the left cerebellar hemisphere was caused by a thrombus from the giant aneurysm of the left vertebral artery. The second case, a 40-year-old woman presented a disturbance of consciousness. A CT scanning demonstrated subarachnoid hemorrhage with a thick hematoma in the left sylvian fissure. An aneurysm at the junction of the right internal carotid artery and the posterior communicating artery was found, while the left middle cerebral artery was shown to be normal on cerebral angiography. Additionally an arteriovenous fistula of the left vertebral artery was found. Although no aneurysm was seen in the territory of the left internal carotid artery, left sided craniotomy was performed based on the CT findings.(ABSTRACT TRUNCATED AT 250 WORDS)

[A distal posterior inferior cerebellar artery aneurysm in the fourth ventricle: a case report]

The authors reported a case of a fourth ventricle aneurysm originating from the choroidal branch of the posterior inferior cerebellar artery (PICA). A 65-year-old woman became comatose following the acute onset of a severe headache and vomiting. She was moribund on admission, showing decerebrate posture. CT scan revealed a massive hematoma in the fourth ventricle up to the lateral ventricle. Extension of blood to the cisterna magna through the cerebellar vermis was also noted. Angiography demonstrated an aneurysm distally located on the right PICA across the midline. The aneurysm lodged in the choroid plexus which was exclusively fed by the right PICA was excised without difficulty through suboccipital craniectomy. Postoperative course was uneventful. She regained her full consciousness by two days after the operation, and was discharged with a minimal truncal ataxia. To our knowledge, this is the first report of a ruptured aneurysm developing in the choroid plexus of the fourth ventricle. Hemodynamic stress is speculated to be a causative factor of such a lesion.