Occipital intraosseous epidermoid cyst producing a clinical picture simulating benign intracranial hypertension. A clinical case

The authors describes a 17 years old woman with a small occipital intradiploic epidermoid cyst simulating a benign intracranial hypertension on an initial CT scanner. Digital angiography showed torcular compression by the tumor. Intracranial pressure and sagittal sinus pressure were analysed and implicated the epidermoid cyst as the cause of the intracranial hypertension.     

Increased intracranial pressure caused by obstruction of torcular herophili with hemangiopericytoma: a case report

A 49-year-old male had experienced diplopia for half a year. The intracranial pressure was markedly elevated (450 mmH2O). Neuroimaging revealed a tumor incompletely occluding the torcular herophili and the bilateral transverse sinuses without cerebral or cerebellar compression by the tumor. Both cortical veins and cervical veins were enlarged, and the Sylvian vein and Rabbe's vein and the tentorial sinus were collateral vessels. Biopsy was performed and histologic examination proved hemangiopericytoma. The patient underwent Gamma-knife treatment and the tumor decreased in size 3 months after the treatment.     

Endovascular stenting of the transverse sinus in a patient presenting with benign intracranial hypertension

The authors present a 37-year-old lady with symptoms and signs suggestive of benign intracranial hypertension (BIH). Routine CT and MRI scans were normal. Further investigations were performed with magnetic resonance venography (MRV) and cerebral venography. These revealed obstruction of the right transverse sinus with high pressure (40 mmHg) proximal to the obstruction and low pressure (15 mmHg) distally. She was treated by transvenous stent deployment with resolution of her symptoms and the bilateral papilloedema. Evaluation of the cerebral venous system with MRV and or with formal cerebral venography should be included in routine investigations of patients with suspected BIH.     

Endovascular treatment of idiopathic intracranial hypertension. Analysis of eight consecutive patients

INTRODUCTION: Optic nerve sheath fenestration or ventricular shunting are classically proposed after failure of medical treatment. Idiopathic intracranial hypertension is caused by venous sinus obstruction in an unknown percentage of cases. Recently, endoluminal venous sinus stenting was proposed as an alternative treatment. PATIENTS AND METHOD: Between September 2003 and December 2004, eight consecutive patients with a diagnosis of idiopathic intracranial hypertension underwent MRI venography and direct retrograde cerebral angiography. RESULTS: There were five females and three males aged 22 to 55 years. All patients had vision disorders. The cerebrospinal fluid pressure ranged from 27 to 45 mmHg with normal composition. All patients presented at least one sinus stenosis. Endovascular stenting of the stenotic venous sinus was performed under intravenous heparin administration. Anti-platelet therapy was administered for 3 months post treatment. Intra-sinus pressures were invariably reduced by stenting. Mean follow-up was 18 months. All patients improved clinically. The cerebrospinal fluid pressure had normalized at 3-month follow-up in all patients. In all patients, multidetector row CT-angiography or MRI venography was performed at 3-, 6- and 12-month follow-up and demonstrated the patency of the stent. DISCUSSION: The importance of venous sinus disease as a cause of idiopathic intracranial hypertension is probably underestimated. Patients with idiopathic intracranial hypertension should be evaluated with direct retrograde cerebral venography and manometry. In patients with venous sinus lesions, treatment by an endoluminal venous sinus stent is a safe and effective alternative for amenable lesions.     

Anomaly of venous system in congenital occipital dermal sinus

Summary We report two cases of congenital occipital dermal sinus in which elongation of the vein of Galen, elevation of the straight sinus, division of the superior sagittal sinus, elevation of the confluence of sinuses, elevation of transverse sinus and narrowing of the torcular angle were observed in the venous phase of cerebral angiography. Enhanced computed tomography (CT) revealed enlargement of the supracerebellar cistern, elevation of the straight sinus and of the confluence of sinuses, but no evidence of intracranial lesions. In order to study the relationship between anomalies in the dural venous sinuses and congenital occipital dermal sinus, we examined both cases from an embryological viewpoint.     

Intracranial venous hypertension and the effects of venous outflow obstruction in a rat model of arteriovenous fistula

A model of rat arteriovenous fistula (AVF) was created using a proximal common carotid artery to distal external jugular vein anastomosis. Anatomical dissections revealed that the external jugular vein is the primary vessel draining intracranial venous blood. Physiological measurements were made with the AVF open and closed, and during venous outflow occlusion of the contralateral external jugular vein. Opening the AVF increased torcular pressure from 6.5 +/- 0.6 to 13.5 +/- 1.1 mm Hg and decreased mean arterial pressure from 82.7 +/- 1.8 to 62.8 +/- 1.8 mm Hg (both P less than .05), decreasing cerebral perfusion pressure from 76.2 +/- 1.7 to 49.3 +/- 2.2 mm Hg (P less than .05). Middle cerebral artery blood flow velocity (MCA BFV) decreased from 6.8 +/- 1.1 to 4.2 +/- 0.7 cm/s (P less than 0.05). In rats with an AVF, occlusion of venous outflow increased torcular pressure to 34.8 +/- 3.1 mm Hg (P less than 0.05), MCA BFV decreased to 1.8 +/- 0.5 cm/s (P less than 0.05), and severe ischemic changes were seen on the electroencephalogram. Under this condition, torcular pressure and systemic arterial pressure had a positive linear relationship (P less than 0.05), whereas in control rats torcular pressure and arterial pressure had no relationship. Restoration of cerebral perfusion pressure by release of venous outflow occlusion and AVF closure transiently increased MCA BFV to 69% above baseline (P less than 0.05). Histological examination 1 week after permanent venous outflow occlusion revealed venous infarction, subarachnoid hemorrhage, and severe brain edema in rats with an AVF but not in control rats without an AVF. This model of cerebrovascular steal with venous hypertension reproduces both hemodynamic and hemorrhagic complications of human AVF and emphasizes the importance of venous outflow obstruction and venous hypertension in the pathophysiology of these lesions.     

Clinical and hemodynamic responses to balloon test occlusion of the straight sinus: technical case report

OBJECTIVE AND IMPORTANCE: Surgical sacrifice of the straight sinus may be performed during intracranial tumor resection. Sacrifice of the straight sinus is associated with an unpredictable risk of venous infarction. We describe a patient with a falcine meningioma who underwent endovascular balloon test occlusion of the straight sinus before surgical resection. CLINICAL PRESENTATION: A 48-year-old woman presented with symptoms resulting from a 4-cm-diameter meningioma in the left occipital region. Along its inferior margin, the tumor abutted the straight sinus. Cerebral angiography demonstrated occlusion of the posterior one-third of the superior sagittal sinus but patency of the straight sinus. TECHNIQUE: A 4-mm angioplasty balloon was directed into the straight sinus via the right jugular vein. In addition to clinical assessments, the pressure within the proximal straight sinus, upstream from the balloon, was measured before and during inflation. Severe headaches followed balloon inflation, and the pressure in the proximal straight sinus increased 18 mm Hg. With balloon deflation, the clinical and hemodynamic findings immediately returned to normal. On the basis of these findings, the straight sinus was preserved during surgery. CONCLUSION: This technique is straightforward and allows some assessment of the physiological responses and individual tolerance to sinus occlusion before surgery.     

Non-communicating hydrocephalus caused by dural arteriovenous malformation.

The case of a female infant with a non-communicating hydrocephalus caused by an enormously dilated straight sinus and the dilated posterior one third of the sagittal sinus is presented. These sinuses drained a torcular dural arteriovenous malformation. Conray ventriculography revealed a complete obstruction of the junction of the aqueduct and fourth ventricle with cephaloventral displacement of the ventricular system by the dilated sinuses. Placement of a ventriculoperitoneal shunt was followed by artificial embolization, by selective catheterization, into the dural feeding arteries.     

Dural sinus thrombosis and pseudotumor cerebri: unexpected complications of suboccipital craniotomy and translabyrinthine craniectomy.

OBJECT: The goal of this study was to document the hazards associated with pseudotumor cerebri resulting from transverse sinus thrombosis after tumor resection. Dural sinus thrombosis is a rare and potentially serious complication of suboccipital craniotomy and translabyrinthine craniectomy. Pseudotumor cerebri may occur when venous hypertension develops secondary to outflow obstruction. Previous research indicates that occlusion of a single transverse sinus is well tolerated when the contralateral sinus remains patent. METHODS: The authors report the results in five of a total of 107 patients who underwent suboccipital craniotomy or translabyrinthine craniectomy for resection of a tumor. Postoperatively, these patients developed headache, visual obscuration, and florid papilledema as a result of increased intracranial pressure (ICP). In each patient, the transverse sinus on the treated side was thrombosed; patency of the contralateral sinus was confirmed on magnetic resonance (MR) imaging. Four patients required lumboperitoneal or ventriculoperitoneal shunts and one required medical treatment for increased ICP. All five patients regained their baseline neurological function after treatment. Techniques used to avoid thrombosis during surgery are discussed. CONCLUSIONS: First, the status of the transverse and sigmoid sinuses should be documented using MR venography before patients undergo posterior fossa surgery. Second, thrombosis of a transverse or sigmoid sinus may not be tolerated even if the sinus is nondominant; vision-threatening pseudotumor cerebri may result. Third, MR venography is a reliable, noninvasive means of evaluating the venous sinuses. Fourth, if the diagnosis is made shortly after thrombosis, then direct endovascular thrombolysis with urokinase may be a therapeutic option. If the presentation is delayed, then ophthalmological complications of pseudotumor cerebri can be avoided by administration of a combination of acetazolamide, dexamethasone, lumbar puncture, and possibly lumboperitoneal shunt placement.     

C-P angle epidermoid carcinoma: a case report

The patient, a 39-year-old man, underwent initial surgery for total removal of a left C-P angle tumor histologically diagnosed as epidermoid carcinoma. Postoperative irradiation therapy was administered over the whole brain and spinal cord, 50 Gy and 20 Gy respectively. The patient was then released without symptoms. 15 months later, he was readmitted for paraparesis and urinary retention. CT scan revealed no tumor recurrence in the intracranial area but did show intraspinal cyst of the lower thoracic level. After cyst-subarachnoid shunt, severe acute hydrocephalus was shown on CT scan. His general condition progressively deteriorated. Ten days after the shunt operation, he died of systemic bleeding tendency and cachexia. During surgery, the authors obtained dark yellowish fluid from the intraspinal cyst. Gene survey of the specimen from the cyst wall disclosed abnormality. It is important in the diagnosis of primary intracranial epidermoid carcinoma that we rule out the existence of extracranial cancer and direct invasion through the dura. Though epidermoid carcinoma can be fatal, radiotherapy was an efficacious treatment in the present case, as well as in three other reported cases.     

Pseudotumor cerebri syndrome: venous sinus obstruction and its treatment with stent placement

OBJECT: Pseudotumor cerebri, or benign intracranial hypertension, is a condition of raised intracranial pressure in the absence of a mass lesion or cerebral edema. It is characterized by headache and visual deterioration that may culminate in blindness. Pseudotumor cerebri is caused by venous sinus obstruction in an unknown percentage of cases. The purpose of this study was to investigate the role of cerebral venous sinus disease in pseudotumor cerebri and the potential of endoluminal venous sinus stent placement as a new treatment. METHODS: Nine consecutive patients in whom diagnoses of pseudotumor cerebri had been made underwent examination with direct retrograde cerebral venography (DRCV) and manometry to characterize the morphological features and venous pressures in their cerebral venous sinuses. The cerebrospinal fluid (CSF) pressure was measured simultaneously in two patients. If patients had an amenable lesion they were treated using an endoluminal venous sinus stent. Five patients demonstrated morphological obstruction of the venous transverse sinuses (TSs). All lesions were associated with a distinct pressure gradient and raised proximal venous sinus pressures. Four patients underwent stent insertion in the venous sinuses and reported that their headaches improved immediately after the procedure and remained so at 6 months. Vision was improved in three patients, whereas it remained poor in one despite normalized CSF pressures. CONCLUSIONS: Patients with pseudotumor cerebri should be evaluated with DRCV and manometry because venous TS obstruction is probably more common than is currently appreciated. In patients with a lesion of the venous sinuses, treatment with an endoluminal venous sinus stent is a viable alternative for amenable lesions.     

Pseudotumour cerebri,CSF rhinorrhoea and the role of venous sinus stenting in treatment

We present a case of pseudotumour cerebri (PTC), which is important as it illustrates the effects of chronically raised CSF pressure, the relationship between PTC and venous sinus obstruction and the successful treatment of PTC using a venous sinus stent. A 38-year-old woman, previously diagnosed with PTC and unsuccessfully treated 10 years previously re-presented with spontaneous CSF rhinorrhoea. Imaging revealed dramatic changes of chronically raised CSF pressure and a defect in the anterior cranial fossa. The CSF leak was corrected surgically and a lumbo-peritoneal shunt inserted to correct a large postoperative subgaleal CSF collection. Direct retrograde cerebral venography (DRCV) demonstrated venous sinus obstruction due to a filling defect. This was associated with a pressure gradient and a high superior sagittal sinus pressure. The venous sinus obstruction was successfully treated with a venous sinus stent and the lumbo-peritoneal shunt was removed. Chronically raised CSF pressure in untreated cases of PTC may cause widespread changes in the skull, which in this case, culminated in a spontaneous CSF leak despite relatively mild headache and visual symptoms. Furthermore, cases of PTC secondary to venous sinus obstruction may be successfully treated using venous sinus stenting. The index of suspicion for venous sinus stenosis or obstruction should be raised in the investigation of patients with PTC.     

A case of membranous obstruction of inferior vena cava at the hepatic associated with hepatocellular carcinoma and liver cirrhosis

A case of inferior vena cava obstruction at the hepatic portion associated hepatocellular carcinoma with and liver cirrhosis is reported, which was treated with lateral segmentectomy of the liver after transcatheter angioplasty. A 36-year-old male, who had noticed venous dilatation in the abdominal wall and legs from his childhood, visited a doctor complaining of right upper quadrate pain and was diagnosed liver cirrhosis. One year later ultrasonography revealed a liver tumor, which was diagnosed as hepatocellular carcinoma by ultrasonically guided aspiration cytology. Inferior and superior vena cavography revealed complete membranous obstruction of inferior vena cava at the hepatic portion with marked collateral circulation through azygos, hemiazygos and phrenic veins. The caval pressure difference between above and below the obstruction was 16.5 cm H2O. The membranous obstruction was perforated and dilated by transluminal angioplasty using Dotter's balloon catheter. The obstructive segment of inferior vena cava changed into 8mm in diameter after the second angioplasty, and the caval pressure difference between above and below the stenosis decreased to 10 cm H2O. Lateral segmentectomy of the liver was performed. Histopathologic diagnosis was clear cell type hepatocellular carcinoma with liver cirrhosis. Marked postoperative liver damage was observed and transcatheter caval dilatation was performed again. The pressure of inferior vena cava below the stenosis decreased to 8 cm H2O. One year and 8 months after the operation, the patient is healthy without recurrence of cancer.     

Spontaneous peritumoral haemorrhage associated with sinus confluence meningioma: case report

BACKGROUND: Torcular or sinus confluence meningioma is rare and surgically formidable. This reported sinus confluence meningioma was associated with peritumoral intracerebral hemorrhage. The surgical strategy and the mechanism of peritumoral hemorrhage are discussed. CASE DESCRIPTION: A 42-year-old woman presented with a history of headache, vomiting, and cerebellar dysfunction for 2 months. Plain computed tomography (CT) scan and magnetic resonance imaging (MRI) demonstrated a high-density mass in the torcular region involving both lateral sinuses. MR angiography demonstrated complete occlusion of the left lateral sinus and straight sinus and stenosis of the right lateral sinus. Two years after her first operation she experienced sudden headache and left upper quadrant hemianopsia. Plain CT scan and MRI showed a hyperintense tumor in the torcular region with an intracerebral hematoma in the right occipital lobe. An angiogram demonstrated occlusion of the caudal part of the superior sagittal sinus, bilateral transverse sinuses, and straight sinus.Gross total removal of the tumor was done along with the left lateral sinus through a suboccipital and a supratentorial occipital craniotomy in the first operation. The patient underwent total resection of the tumor at second operation through a bilateral occipital and suboccipital craniotomy along with resection of the dura including the confluence, the caudal part of the superior sagittal sinus, the right lateral sinus, and the straight sinus. The postoperative course was uneventful and postoperative MRI showed total removal of the tumor. CONCLUSION: Sinus confluence meningioma may present with peritumoral hemorrhage. Radical removal may be possible when the sinus confluence is completely occluded and there is good collateral drainage.     

数字减影全脑血管造影在连头婴显微分离术前及术中的应用

目的 探讨全脑血管造影在连头婴显微分离手术术前和术中的作用。方法 术前在出生后3个月进行股动脉入路脑血管造影，16个月时经股动脉和股静脉入路对双婴颈内动脉，颈外动脉，椎动脉及超选静脉窦内进行造影；术中行脑血管造影监测，判断脑血管情况。结果 术前造影显示双婴连接部颅内动脉无交通，双婴上矢状窦后1/3，窦汇，右婴的左侧横窦起始部融合共用；术中实时脑血管造影对显微分离过程中有关静脉窦的处理进行较好的监测。结论 全脑血管造影是了解连头婴脑血管复杂情况的最佳方法。尤其静脉窦内造影可以充分了解静脉窦变异相融处的解剖和血流动力学变化。术中脑血管造影在静脉窦转流和血管重建手术中有重要的指导意义及监测作用。     

Effect of sevoflurane on intracranial pressure, sagittal sinus pressure, and the intracranial volume-pressure relation in cats

The effect of sevoflurane on intracranial pressure (ICP), sagittal sinus pressure (SSP), and the intracranial volume-pressure (V-P) relation was examined in cats. In experiment 1, on nine cats, changes in ICP and SSP were studied for 180 min during anesthesia with 1 MAC sevoflurane (2.6%, inspired) and 50% nitrous oxide (N2O) in oxygen (O2). ICP significantly (p <0.01) increased from 8.4 +/- 3.8 cm H2O (mean +/- SD), the control level to 10.6 +/- 5.1 cm H2O immediately after the administration of sevoflurane. ICP was unchanged for the subsequent 120 min but then increased significantly (p <0.05) 140 min after administration, being 15.5 +/- 9.0 cm H2O at 180 min. There were no changes in SSP or blood gases. In experiment 2, the rapid injection technique of mock cerebrospinal fluid was used to determine the intracranial V-P relation in ten cats. Measures of V-P relationships included (a) ICP before volume injection (Po), (b) peak ICP caused by volume injection (Pp), (c) intracranial compliance (C) calculated as the ratio of change of intracranial volume Delta V) to change of ICP (Delta P), and (d) the pressure volume index (PVI) calculated as the ratio of Delta V to log Pp/Po. The subjects were divided into two groups, one administered 2.6% sevoflurane and 50% N2O in O2 (n = 6) and the other 50% N2O in O2 (n = 4). Each cat in both groups was given two bolus injections into the lateral ventricle at 180 min after the start of anesthesia. Then, C and PVI were calculated. C and PVI in the group treated with sevoflurane were significantly (p <0.05) lower than in the other group. These findings suggest that prolonged use of sevoflurane increases the intracranial elastance.     

Recovery of airway protection compared with ventilation in humans after paralysis with curare

d-Tubocurarine (dTc) was administered intravenously to six healthy unanesthetized volunteers to assess the sensitivity to neuromuscular blockade of those muscles involved in protecting the airway against obstruction and/or aspiration relative to the muscles of inspiration. Each subject was given an intravenous bolus of dTc followed by an infusion to allow three different levels of inspiratory muscle weakness as measured by maximum inspiratory pressure (MIP). Levels of MIP were control (-90 cm H2O), -60, -40, and -20 cm H2O. Vital capacity (VC), hand grip strength (HGS), and end-tidal CO2 (PETCO2) were obtained at each level. At each level of weakness and at intermediate values during recovery, muscles of airway protection were functionally assessed by noting the MIP at which the maneuver could be accomplished and the MIP at which they could not. The mean of these two values was calculated for each subject. The tests were: 1) ability to swallow, 2) ability to perform a valsalva maneuver, 3) prevent obstruction of the airway, and 4) ability to approximate teeth. These were compared with head lift and straight leg raising. At maximum neuromuscular blockade (MIP of -20 cm H2O), VC was 2.0 liters, HGs was 0, and PETCO2 was normal. Muscles of airway protection were still incapacitated. Swallowing returned above MIP of -43 cm H2O, approximation of teeth above -42 cm H2O, airway obstruction above -39 cm H2O, and valsalva above -33 cm H2O. Thus, although ventilation may be adequate at MIP = -25 mmHg, the muscles of airway protection are still nonfunctional.(ABSTRACT TRUNCATED AT 250 WORDS)     

Functional characteristics of idiopathic hydronephrosis

The functional characteristics of idiopathic hydronephrosis were studied in 171 patients. Conventional renography and measurement of the glomerular filtration rate were performed in all subjects, 137 (79%) of whom had normal parenchymal function despite severely reduced drainage function. Proximal tubular function, measured by determination of beta 2-microglobulin excretion was not reduced. Distal tubular function, evaluated as the maximum concentration ability, was not reduced in 35 of the 89 patients studied. During urography and diuresis renography were both useful tools for verifying the presence of obstruction in doubtful cases. Intrapelvic pressure was measured during constant perfusion at a rate of 7.5 ml/min and during furosemide-induced diuresis. The basal intrapelvic pressure varied from 6 to 10 cm H2O and was not increased in any kidney regardless of the degree of duration of obstruction. During perfusion, the pressure increased and varied from 28 to 52 cm H2O. During diuresis, an increase in pressure above 20 cm H2O was registered only in obstructed kidneys with a normal urinary concentrating ability. The pressure rise never exceeded 20 cm H2O during diuresis in obstructed kidneys with complications such as calculi of previous episodes of upper urinary tract infection. From these studies it is concluded that, besides cases with complications such as urinary tract infection and renal calculi, surgery should be offered to patients with idiopathic hydronephrosis with reduced urinary concentrating ability. In doubtful cases with wide pelves, renography and urography during increased diuresis can be used provided kidney function is not reduced. When kidney function is reduced, a pressure increase above 20 cm H2O during constant perfusion at a rate of 7.5 ml/min indicates obstruction.     

Pressure changes within a chronic subdural hematoma during hemodialysis

Spontaneous intracranial hemorrhage is not an infrequent complication of systemic anticoagulation, as occurs in hemodialysis. The neurological symptoms of subdural hematoma may be similar to those of dialysis disequilibrium. The pressure within a subdural fluid collection was monitored in a patient undergoing hemodialysis. The patient was known to become unresponsive during previous dialysis treatments. The initial pressure within the subdural cavity was measured to be -10.0 cm H2O prior to dialysis. The pressure within the collection decreased to a minimum value of -19.4 cm H2O during dialysis and stabilized at -16.4 cm H2O at the termination of dialysis. The neurological status changed subjectively during the procedure, with the patient becoming unresponsive to verbal stimuli as the intracranial pressure reached a minimum. These findings represent a syndrome similar to aliquorrhea, or low cerebrospinal fluid pressure within an otherwise asymptomatic subdural hematoma. Previously only increased intracranial pressure has been reported with hemodialysis.     

High-frequency oscillatory ventilation in adults with traumatic brain injury and acute respiratory distress syndrome

BACKGROUND: This study observed adverse events of rescue treatment with high-frequency oscillatory ventilation (HFOV) in head-injured patients with acute respiratory distress syndrome (ARDS). METHODS: Data of five male patients with ARDS and traumatic brain injury, median age 28 years, who failed to respond to conventional pressure-controlled ventilation (PCV) were analyzed retrospectively during HFOV. Adjusted mean airway pressure at initiation of HFOV was set to 5 cm H2O above the last measured mean airway pressure during PCV. Frequency of pulmonary air leak, mucus obstruction, tracheal injury, and need of HFOV termination due to increased intracranial pressure, decreased cerebral perfusion pressure, or deterioration in P(a)CO2 were analyzed. RESULTS: During HFOV we found no complications. We recorded 390 datasets of intracranial pressure, cerebral perfusion pressure and P(a)CO2 simultaneously. Intracranial pressure increased (>25 mmHg) in 11 of 390 datasets, cerebral perfusion pressure was reduced (<70 mmHg) in 66 of 390 datasets, and P(a)CO2 variations (<4.7 kPa; >6.0 kPa) were observed in eight of 390 datasets after initiation of HFOV. All these alterations were responsive to treatment. P(a)O2/F(I)O2-ratio improved in four patients during HFOV. Conclusion: High-frequency oscillatory ventilation appears to be a promising alternative rescue treatment in head-injured patients with ARDS if continuous monitoring of intracranial pressure, cerebral perfusion pressure and P(a)CO2 are provided, in particular during initiation of HFOV.