Spontaneous occlusion of ruptured vertebral artery dissection at the extradural fenestration associated with extradural origin of the posterior inferior cerebellar artery--case report

A 69-year-old female suffered from sudden onset of severe headache. Computed tomography showed subarachnoid hemorrhage primarily located in the posterior fossa. Initial angiography demonstrated a fenestration of the vertebral artery and an extracranial origin of the posterior inferior cerebellar artery. However, no bleeding points could be clearly detected. The operative findings revealed a massive clot in subarachnoid space, but no bleeding point. Serial angiography demonstrated dissection in one of the limbs of the fenestrated vertebral artery on the 25th day after the onset. On the 100th day, the lesion was spontaneously occluded. The patient is presently doing well at 8 years after surgery.

Late hemorrhage from persistent pseudoaneurysm in vertebral artery dissection presenting with ischemia: case report

BACKGROUND

Vertebral artery dissection lesions tend to resolve spontaneously, but abnormal findings such as aneurysmal-dilatation occasionally persist. However, the clinical features and pathological findings in such cases have never been verified.

CASE DESCRIPTION

A 62-year-old man presented with left cerebellar infarction. Angiography showed the "pearl and string sign" in the left vertebral artery, and he was diagnosed as having left vertebral artery dissection. Repeated angiography showed persistent aneurysmal dilatation with irregular stenosis. Eleven years after the cerebellar infarction, the patient presented with a subarachnoid hemorrhage from an aneurysm of the left vertebral artery, and the lesion was explored via the left suboccipital approach. The vertebral artery was firm, making the placement of a clip impossible, so the lesion was treated by coating of the bleeding point. The patient died of pneumonia and hyperglycemia on postoperative day 15. Postmortem examination revealed an organized intramural hematoma, thickening of the intima, and fibrous degeneration of the media of the vertebral artery, a fusiform, distended thin arterial wall with intimal disruption at the aneurysmal dilatation, and arteriosclerosis of all cerebral arteries.

CONCLUSION

This case indicates that persistent aneurysmal dilatation of a dissection is a pseudoaneurysm prone to rupture, and that healing of the affected vessels might be severely compromised in the presence of pathological conditions such as arteriosclerosis and disturbed intraluminal blood flow in the dissected lesions.

Probable lymphocytic hypophysitis diagnosed by short-term serial computed tomography and gallium-67 scintigraphy--case report

A 61-year-old female presented with headache, malaise, and left oculomotor nerve paralysis. Computed tomography (CT) demonstrated a diffuse pituitary mass and enlarged pituitary stalk with homogeneous contrast enhancement. Her symptoms gradually resolved without treatment. Gallium-67 scintigraphy showed abnormal uptake in the pituitary lesion. Serial CT every 2 weeks after admission showed homogeneous contrast enhancement and shrinking of the pituitary mass to a normal size 12 weeks after the onset. The final diagnosis was lymphocytic adenohypophysitis without biopsy. Recurrence has not been observed for 8 years after discharge. The patient did not need hormone replacement therapy. Histological examination is not always necessary to diagnose probable lymphocytic adenohypophysitis with the characteristic feature of rapid onset, abnormal gallium-67 uptake in the lesion, and resolution of symptoms in the acute stage with shrinking of the lesion on neuroimaging.

Clinical importance of c-Met protein expression in high grade astrocytic tumors

The clinical importance of the expression of c-Met protein, the receptor of hepatocyte growth factor/scatter factor, was evaluated in neuroepithelial tissue tumors. c-Met immunohistochemistry was performed using the streptavidin-biotin-peroxidase complex method with anti-c-Met polyclonal antibody. Specimens were classified as c-Met negative (< 30%) or c-Met positive (> or = 30%) according to the proportion of immunopositive cells under microscopic examination. All c-Met-positive cases occurred in high grade astrocytic tumors, not in other neuroepithelial tissue tumors. Most c-Met-positive astrocytic tumors were classified histologically as high grade tumors. Epidermal growth factor-receptor (EGFR) and MIB-1 immunohistochemistry were also performed for high grade astrocytic tumors. Survival analysis was performed for patients with these tumors with variables including c-Met positivity, EGFR positivity, and MIB-1 labeling index. Positivity of c-Met was independent from EGFR positivity and MIB-1 labeling index, and the c-Met-positive group showed a significant shorter survival (p < 0.05). c-Met immunopositivity may be a parameter of biological aggressiveness in high grade astrocytic tumors. Examination of c-Met expression in astrocytic tumors provides significant clinical information, especially as a prognostic factor.

Secondary glioblastoma remarkably reduced by steroid administration after anaplastic transformation from gliomatosis cerebri--case report

A 45-year-old female presented with gliomatosis cerebri manifesting as hemiballismus-like involuntary movement in the arm, motor weakness in the leg, and hypesthesia in her left side. Computed tomography showed only diffuse swelling of the right cerebral hemisphere, but T2-weighted magnetic resonance imaging revealed a diffuse lesion spreading from the right thalamus to the temporal, parietal, and occipital lobes on the same side. No abnormal enhancement was recognized. Cerebral angiography showed no specific finding. A right occipital lobectomy was performed to confirm the diagnosis of gliomatosis cerebri. Anaplastic transformation was recognized 5 months later. The disease did not resolve with radiation or interferon administration, but steroid therapy achieved remarkably effective tumor regression. The patient died due to pneumonia. Autopsy showed the features of diffuse glioblastoma. Steroid therapy may be an effective treatment for gliomatosis cerebri before the terminal stage.

Hemangiopericytoma arising at the site of a dural graft 13 years after total removal of a benign meningioma--case report

A 64-year-old female presented with hemangiopericytoma arising from a dural fascia graft placed after a previous operation for the total removal of a benign meningioma. The patient also had multiple pulmonary metastases identified as hemangiopericytoma. The tumor resected at the first operation was benign based on all grading systems for meningiomas. We considered that the tumor was a kind of scar tumor. The hemangiopericytoma probably developed from a scar tumor at the graft. We emphasize the importance of long-term follow-up for patients who have undergone surgery for benign tumors.

[A survey of malignant gliomas accompanied with visceral malignancies]

From January 1984 to December 1997, a total of six patients with malignant gliomas accompanied with visceral malignancies were treated in our department. We reviewed their radiological findings and clinical course. They consisted of four patients with glioblastoma and two patients with anaplastic astrocytoma. Classified according to visceral malignancies, three cases had colon cancer and the rest consisted of thyroid, uterus and prostate cancers. In radiological examinations of the brain (CT scans and MR images), these gliomas were relatively well-circumscribed, as if they were metastatic brain tumors. Of all these six cases, two cases survived more than five years and there were two cases in which there was recurrence within a year. Particularly, in four cases, whose gliomas developed after the treatment for visceral malignancies, two cases survived long-term (more than five years) and there was recurrence in only one case. We speculated that visceral malignancies could affect the nature of glioma progression. Thinking about its mechanisms, we hypothesized as follows; (1) visceral malignancies may activate non-specific, or common antitumor, immunity. (2) visceral malignancies may produce some factors which could affect the biological nature of gliomas. (3) glioma accompanied with visceral malignancy may have genetic uniqueness. Although the cases were limited in number, the present study may be helpful in designing the treatment for such cases and in elucidating the invasive nature of gliomas.

Ossification of transverse ligament of the atlas associated with atlanto-axial dislocation--case report

A 68-year-old male presented with progressive quadriparesis. Twelve years previously he had undergone anterior decompression with bone grafting for cervical ossification of the posterior longitudinal ligament associated with spinal trauma. Radiological examination showed ossification of the transverse ligament of the atlas (TLA) and severe stenosis of the upper cervical canal. Anterior dislocation of the atlas was also present, but the occiput/atlas/axis unit was perfectly stable due to the prior anterior fusion. Suboccipital decompression and laminectomy of the atlas were performed, and his symptoms improved. Based on the atlanto-axial dislocation, the TLA might have been damaged at the time of the primary trauma and became the trigger for the ossification of the TLA, showing that marked ossification of a vertebral ligament can occur after injury.

Abducens nerve palsy caused by basilar impression associated with atlanto-occipital assimilation

A 47-year-old male presented with abducens nerve palsy due to basilar impression associated with atlanto-occipital assimilation manifesting as slowly progressive bilateral trigeminal neuralgia and diplopia in the right lateral gaze. X-ray and computed tomography of the skull confirmed the diagnosis of basilar impression and atlanto-occipital assimilation, and magnetic resonance imaging disclosed tightness of the posterior cranial fossa. Surgical suboccipital decompression resulted in gradual resolution of the patient's complaints, and no additional symptoms were recognized. Impairment of the sixth cranial nerve is a rare symptom compared to those of the fifth or the eighth cranial nerve in a patient with a craniocervical malformation. However, the present case shows the possibility of cranial nerve dysfunction due to tightness of the posterior cranial fossa, and suggests that surgical treatment for basilar impression with atlanto-occipital assimilation should be considered in patients with uncommon and unusual symptoms.

Immunohistochemical examination of c-Met protein expression in astrocytic tumors

Hepatocyte growth factor/scatter factor (HGF/SF), which has various physiological functions, and its receptor c-Met, the human c-met proto-oncogene product, are thought to be determinant in the pathological processes of various malignancies. To investigate the possible role of HGF/SF in the progression of development of astrocytic tumors, we examined the expression of c-Met in these tumors. Immunohistochemistry using the streptavidin-biotin peroxidase complex method and immunofluorescence double staining with anti-c-Met polyclonal and anti-glial fibrillary acidic protein monoclonal antibodies were performed. Positive c-Met expression was detected in 31 of the 42 astrocytic tumors and some of the control cases analyzed. c-Met-positive cells showed morphological characteristics of astrocytes. Especially in the cases of high-grade tumors, c-Met positivity was abundant in cells in both vascular-rich and peripheral regions of the tumors but not in the cells with distinctly malignant features. Immunofluorescence double staining revealed that the c-Met-positive cells were in part of astrocytic origin. We suggest that c-Met-positive cells are affected by some factors in the lesions where the pathological processes are in a state of development. Our studies indicated that c-Met expression might take part in glioma invasion but not in the development of malignancy.

[Imaging of myocardial perfusion and metabolism with positron emission tomography]

Positron emission tomography (PET) has been providing new information in the diagnosis and the pathophysiological assessment of heart diseases. The PET tracers commonly used in Japan are 13N-ammonia, 18F-fluorodeoxyglucose (FDG) for imaging of myocardial perfusion and metabolism, respectively. Measurement of regional myocardial blood flow by 13N-ammonia dynamic PET scan and a compartment model analysis is applied to the functional estimation of coronary stenotic lesions and the detection of perfusion abnormalities in hypertrophic heart diseases, familial hyperchlesterolemia and other diseases with possible microvascular lesions. 18F-FDG is commonly used to differentiate ischemic but viable tissue from myocardial scar in coronary artery disease and also used to detect cardiac tumor and the cardiac involvement in sarcoidosis. In addition to these two tracers, 11C-acetate is now expected to provide the clinical analysis of pathophysiology of heart failure by estimating the efficiency of energy conversion of the heart into external work.

Occlusive cerebrovasculopathy after internal radiation and bleomycin therapy for craniopharyngioma--case report

A 34-year-old female presented with occlusive cerebrovasculopathy without definite ischemic symptoms and regrowth of a cystic tumor in the third ventricle. She had been treated for a craniopharyngioma 19 years previously by internal irradiation with 198Au colloid combined with intracavitary administration of bleomycin via an Ommaya reservoir. Cerebral angiography demonstrated complete occlusion of the clinoid portion of the left internal carotid artery and stenosis of the left posterior cerebral artery, and numerous transdural anastomoses which had developed after craniotomy. Endoscopic management achieved collapse of the cystic tumor. No treatment for the occlusive cerebrovasculopathy was necessary because of the collateral blood supply. Careful follow-up examinations to detect occult cerebrovasculopathy after such treatment is recommended.

Prediction of consistency of meningiomas with preoperative magnetic resonance imaging

BACKGROUND

The consistency of a meningioma is one of the important factors in determining the surgical outcome. If the surgeon is aware of the consistency of a meningioma preoperatively, the surgical plans will be influenced. A few papers have described the correlation between consistency of meningiomas and their magnetic resonance imaging (MRI) findings. However, prediction of consistency with MRI is still difficult. We have tried to predict the consistency of meningiomas with MRI findings more precisely.

METHODS AND RESULTS

Fifty patients diagnosed as having intracranial meningiomas were studied with 1.5 Tesla MRI. We compared the MRI findings with tumor consistency. The intensities of the tumors were categorized into three grades (low, iso, and high) compared to that of the gray matter. T1-weighted images had no specifics, but T2-weighted images and proton density images were useful for the prediction of tumor consistency. Hyperintensity on protein density (PD) and T2-weighted images was a sign of a soft tumor.

CONCLUSION

We presume that T2 and PD are useful for predicting consistency of meningiomas, and their water content is one of the main factors in their consistency. Histology may be one of the factors helpful in defining the consistency of a tumor. In this series, we found no relationship between histology and MRI findings, nor between histology and consistency. If the meningioma is believed to be hard, preoperative endovascular embolization is beneficial, which will induce necrosis of the meningioma and make it soft enough to be removed more easily and safety.

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.

The outcome of early surgical management of ruptured posterior circulation aneurysms

Since 1990, early surgery within 3 days following subarachnoid hemorrhage has been performed routinely in our hospital even for ruptured posterior circulation aneurysms. Our experience with early surgical management of 25 patients with posterior circulation aneurysms, including two patients who underwent endovascular surgery, is reported. Fourteen patients had an aneurysm on the basilar, the posterior cerebral or superior cerebellar artery (BA), and 11 patients had an aneurysm on the vertebral or posterior inferior cerebellar artery (VA). The mortality and morbidity of the BA group were 7% and 29%, respectively, and those of the VA group were 27% and 9%, respectively. In BA, the incidence of symptomatic vasospasm and hydrocephalus was definitely high compared with VA, and the outcome in elderly patients was significantly unfavorable. Early surgery for posterior circulation aneurysms to prevent rebleeding might be considered in selected cases.

Cerebellar infarction with hydrocephalus caused by spontaneous extracranial vertebral artery dissection--case report

A 38-year-old male suffered sudden onset of rotational vertigo without headache. Consciousness disturbance developed on the 3rd day after the onset. Computed tomography showed cerebellar infarction with obstructive hydrocephalus. External ventricular drainage was performed. Angiography showed bilateral extracranial vertebral artery dissection. Antiplatelet therapy was given. Repeat angiography showed improvement of the dissection. His neurological deficits completely resolved. Vertebral artery dissections may cause both lateral medullary or cerebellar infarction and hydrocephalus due to the cerebellar infarction manifesting as various symptoms so careful evaluation and treatment are required.

[Idiopathic intracranial hypotension associated with decreased blood concentration of vitamin A]

We report a case of idiopathic intracranial hypotension, a clinically rare syndrome. A 28-year-old woman was admitted with orthostatic headaches associated with nausea secondary to intracranial hypotension. Lumbar puncture yielded an opening pressure of 4 cmH2O in the lateral recumbent position, and the spinal fluid protein concentration was 56 mg/dl. There was no history of lumbar puncture or clear history of head trauma before the onset of symptoms. Spinal and cranial MRI showed no evidence of CSF leakage, and there was diffuse meningeal enhancement following gadolinium infusion. Cranial MRI showed no evidence of brain displacement due to low CSF pressure, such as tonsillar herniation. Radioisotope cisternography (RIC) showed rapid accumulation of isotope within the bladder and early disappearance of radioactivity from the head. About 2 months later the headaches resolved spontaneously, and repeated lumbar puncture yielded opening pressure elevation to 10.5 cmH2O with a decrease in protein concentration to 28 mg/dl. The abnormal MRI and RIC findings had become normal. On the other hand, the patient had a low blood concentration of vitamin A, which is thought to play some role in the production of CSF. The results of RIC suggested that the patient may have become symptomatic because of undetectable CSF leakage or hyperabsorption, but diminished production of CSF due to lower blood vitamin A concentrations may also have been a factor predisposing to this syndrome.

[Skull base metastasis from renal cell carcinoma presenting as abducens nerve paresis: report of two cases]

We report two cases of skull base metastasis from renal cell carcinoma. Case 1: A 55-year-old female presented with a skull base tumor located on the clivus. Partial removal of the tumor was performed via the transsphenoidal approach. Case 2: A 44-year-old male presented with a skull base tumor occupying the orbital, nasal, and paranasal cavities. The first operation, partial removal of the tumor, was performed via the transsphenoidal approach. Thereafter, the tumor regrowth and the patient's symptoms were progressive, so a second operation was performed via Le-Forte I craniotomy to prevent cranial nerve dysfunction and air way obstruction. The initial symptom of these two cases was abducens nerve paresis, which is caused by the tumor extending from the clivus to the cavernous sinus. The neuroradiological features were the destruction of skull base bone and angiographic tumor stain. Histopathological examination of the surgically resected specimens revealed clear cell carcinoma, and thereafter they were diagnosed as skull base metastasis from renal cell carcinoma. We emphasize the necessity of a thorough medical workup to enable speedy diagnosis of renal cell carcinoma in such cases.

Large diffuse arteriovenous malformation affecting the right cerebral and cerebellar hemispheres: case report

A cerebral vascular malformation was triggered in a 24-year-old man by left hemiparesis resembling transient ischemic attack. Cerebral angiography revealed slight dilation of the right anterior cerebral artery, middle cerebral artery, superior cerebellar artery, and posterior inferior cerebellar artery, as well as marked capillary blush and dilation of medullary veins involving the right cerebral hemisphere, especially the frontal lobe and cerebellar hemispheres. This vascular malformation, a clinical rarity, seemed to be in the same family as diffuse arteriovenous malformation or "medullary venous malformation." Single photon emission computed tomography showed a decline in cerebral blood flow in the right cerebral hemisphere, which was the probable cause of the left hemiparesis.

Secondary exposure of medical staff to sarin vapor in the emergency room

OBJECTIVE

To clarify the risk of secondary exposure of medical staff to sarin vapor in the emergency room, and to warn emergency room staffs of the hazard.

DESIGN

Retrospective observational survey.

SETTING

Emergency department of a university hospital in a metropolitan area of Japan.

PARTICIPANTS

Fifteen doctors treating victims of a terrorist attack with sarin in the Tokyo subways on the day of the attack.

MEASUREMENTS AND RESULTS

Of the 15 doctors who worked in the emergency room treating the victims, 13 became simultaneously aware of symptoms during the resuscitation of two victims who were exposed to sarin. Among 11 doctors (73%) who complained of dim vision, the pupils were severely miotic (<2 mm) in 8 (73%). Other symptoms included rhinorrhea in eight (53%), dyspnea or tightness of the chest in four (27%), and cough in two (13%). Atropine sulfate was given to six, and pralidoxime was given to one of these six doctors. To decontaminate the emergency room of sarin vapor, ventilation was facilitated and all belongings of the patients were sealed up. None of the doctors noticed worsening of their symptoms thereafter.

CONCLUSIONS

Careful attention to the risks of secondary exposure to toxic gas in the emergency room and prompt decontamination if such exposure should occur are necessary in the case of large-scale disasters caused by sarin.

Release of ciliary neurotrophic factor from cultured astrocytes and its modulation by cytokines

CNTF rescues various types of lesioned neurons in vivo, and it needs to be released from astrocytes into the extracellular space to have the effect. However, direct evidence for CNTF release has not been unequivocally demonstrated. We hypothesized that the rapid sequestration by CNTF receptor present on cultured astrocytes might be the cause of the inability to detect CNTF released into astrocyte-conditioned medium (ACM). Therefore, we measured CNTF immunoreactivity in medium conditioned by astrocytes treated with phosphatidylinositol-specific phospholipase C (PI-PLC) which was used to prevent released CNTF from binding to the CNTF receptor, since PI-PLC cleaves glycosyl-phosphatidylinositol anchor of CNTFR alpha, the unique component involved in CNTF binding. CNTF was not detectable in untreated ACM, but was detectable in PI-PLC-treated ACM. These results together with the evidence that PI-PLC treatment did not have a toxic effect on astrocytes prove the fact that CNTF can be released from astrocytes without cell lysis. Subsequently, the effect of cytokines such as IL-1 beta, TNF-alpha, and EGF on CNTF release was examined. These cytokines increased CNTF protein levels in ACMs without increasing CNTF protein levels in astrocyte-extracts, indicating that they enhanced CNTF release from astrocytes.

Accumulation of nerve growth factor in cerebrospinal fluid and biological activity following neurosurgery

Perioperative nerve growth factor (NGF) levels in cerebrospinal fluid (CSF) of patients with acoustic neurinoma (14 cases), tentorial meningioma (1 case), or subarachnoid hemorrhage (1 case) were examined. Preoperative NGF levels in CSF were below the level of detection in all patients. However, NGF was found to accumulate transiently in CSF following neurosurgery. Pre- and postoperative CSF obtained from a patient with acoustic neurinoma enhanced the proliferation of astrocytes in neuronal cell cultures derived from embryonic rat cortex grown in serum-free defined medium, and increased choline acetyltransferase activity of cholinergic neurons derived from embryonic rat septal area and brainstem. The effect of postoperative CSF on septal and brainstem neurons was more potent than that of preoperative CSF. These results indicate that NGF and non-NGF-type neurotrophic activities accumulate in the CSF following neurosurgery. These neurotrophic activities are probably important in the regeneration of damaged neural networks in the central nervous system.