Motor evoked potentials in unilateral lingual paralysis after monohemispheric ischaemia

OBJECT: A retrospective analysis was conducted of 10 patients (three women and seven men) who were treated for spinal dural arteriovenous shunts (AVSs) located at the craniocervical junction. This analysis was performed to evaluate the characteristics of this unusual location in contrast with those of the more common thoracic and lumbar AVSs. METHODS: Seven patients presented with subarachnoid hemorrhage (SAH) and one with slowly progressive quadriparesis and dyspnea due to myelopathy. The other two cases were detected incidentally and included a transverse-sigmoid dural AVS and a cerebellar arteriovenous malformation. Angiographic studies revealed that the spinal dural AVSs at the C-1 and/or C-2 levels were fed by the dural branches of the radicular arteries that coursed from the vertebral artery and drained into the medullary veins. Venous drainage was caudally directed in the patient with myelopathy. In contrast, the shunt flow drained mainly into the intracranial venous system in patients with SAH. Furthermore, in four of these patients a varix was found on the draining vein. In all patients, the draining vein was interrupted surgically at the point at which this vessel entered the intradural space, using intraoperative digital subtraction angiography to monitor flow. The postoperative course was uneventful in all patients and no recurrence was confirmed on follow-up angiographic studies obtained in seven patients at 6 months after discharge. CONCLUSIONS: If computerized tomography scanning shows SAH predominantly in the posterior fossa and no abnormalities are found on intracranial four-vessel angiographic study, proximal vertebral angiography should be performed to detect dural AVS at the craniocervical junction. The results of surgical intervention for this disease are quite satisfactory.     

Dural fistulae of the cavernous sinus and interventional neuroradiology. Apropos of 4 cases

PURPOSE: Our purpose was to show how difficult it is to diagnose a dural fistula of the cavernous sinus, which is an anomalous arteriovenous shunt within the dura mater extending from meningeal arteries to the cavernous sinus. CASE REPORT: A dural fistula was suspected in four female patients aged between 61 and 80, presenting with a red eye, dilated episcleral veins, exophthalmos and elevated intraocular pressure. A cerebral hyperselective angiography was performed in all cases. RESULTS: The cerebral angiography confirmed the diagnosis of a dural fistula in all cases, showing the early filling of the cavernous sinus followed by the draining vessel (posterior in case n. 4, anterior in cases n degrees 1, 2, 3). Case n degrees 2 was unilateral and cases n. 1, 3, 3 were bilateral. The blood flow was low in all cases. A successful embolization was performed in all patients with resolution of all symptoms. CONCLUSION: The diagnosis of dural fistulas is often difficult because of misleading clinical signs. It is documented by a cerebral angiography showing the feeding vessels and helping to choose either venous or arterial embolization which is the most suitable treatment.     

Dural posterior fossa AVM producing raised sagittal simus pressure. Case report

A patient with raised intracranial pressure secondary to a dural arteriovenous malformation (AVM) of the posterior fossa is presented. Direct shunting of arterial blood into the transverse sigmoid sinus caused a considerable increase of the sagittal sinus pressure (SSP) and elevation of intracranial pressure (ICP). Both ICP and SSP returned to normal values following obliteration of the dural AVM by selective embolization.     

Recurrent and unexpected segregation of the FMR1 CGG repeat in a family with fragile X syndrome

STUDY DESIGN: This case report details intraoperative evoked potential changes during surgical removal of a T8 dural arteriovenous malformation. OBJECTIVES: The pattern of changes in somatosensory-evoked responses during surgical correction of spinal dural at arteriovenous malformation can illuminate the pathophysiologic process behind the clinical symptoms. SUMMARY OF BACKGROUND DATA: Arteriovenous malformation of the spinal dura can manifest with multiple symptoms, including progressive myelopathy and pain. The pathophysiologic process behind these symptoms could be either direct compression of the spinal cord by the arteriovenous malformation, ischemia resulting from the cord, or increased venous pressure. METHODS: To investigate these hypotheses further, the results of posterior tibial evoked potentials obtained during surgical removal of a T8 dural arteriovenous malformation were analyzed. RESULTS: At baseline, the cortical (P40) potential was markedly prolonged bilaterally. During surgery, just after the dura was opened, a marked increase was observed in the latencies of the P40 and P60 components of the evoked response on the right, which began to resolve as soon as the arteriovenous malformation was occluded. Only minimal changes were seen on the left. CONCLUSIONS: These results are most consistent with the increased venous pressure hypothesis for the pathogenesis of neurologic symptoms in dural arteriovenous malformations.     

Posterior fossa epidural hematomas: a review and synthesis

The authors report three patients with posterior fossa epidural hematomas and analyze 80 additional cases in the accessible literature. They occur in the younger age groups with a clear male predominance (3.6 to 1). The loss of consciousness at the time of impact and just before surgical intervention have both proved to be factors indicating a poor prognosis. The clinical symptoms and signs were classified in three general types: increased intracranial pressure, brainstem dysfunction, and cerebellar disturbances. A fracture of the occipital bone was seen in 84.2% of the patients. The source of bleeding often remained undetermined, although a tear of the dural sinuses was a most frequent finding. An associated intracranial lesion was found in 39.7% of the cases, this being another factor indicating a poor prognosis. The overall mortality was 26.5%, while the surgical mortality was only 11.5%. Excellent results were achieved in 65% of the cases.     

Coexistence of schizencephaly and intracranial arteriovenous malformation in an infant

A 9-month-old infant had unilateral closed-lip schizencephaly in the right parietal lobe, which coexisted with an arteriovenous malformation in the nearby temporal area. Cranial MR showed a right parietal cleft lined with gray matter between the right lateral ventricle and the subarachnoid space, and cluster hypointensities throughout the right temporal lobe. Cerebral angiography revealed a right temporal arteriovenous malformation with feeding arteries arising from the right middle and posterior cerebral arteries and draining into the right sigmoid sinus via the engorged vein of Labbé.     

A case of migraine with aura associated with meningioma

We reported a case of migraine with aura associated with meningioma. A 66-year-old female visited to our department in 1985, with occipital throbbing pain following visual hallucination and nausea. She had been diagnosed as migraine. CT scan, magnetic resonance image and angiography showed a right occipital tumor, which was totally removed in 1990. Postoperatively, the migraine disappeared completely. The tumor was histologically diagnosed as fibroblastic meningioma. We supposed that the migraine had been associated with meningioma. Although some previous papers reported correlation with brain tumor and migraine, as example of arteriovenous malformation or angioma, migraine associated with meningioma is very rare. In arteriovenous malformation, pathophysiology of migraine is unclear, but induction of circulatory disturbance in the distribution of the posterior cerebral, posterior communicating and basilar artery is supposed. And then a space occupying lesion in the occipital lobe is possible to cause in the circulatory disturbance of the posterior cerebral and basilar artery. In the diagnosis of migraine, we should consider its relation to brain tumors, such as meningioma.     

The clinical assessment of attachment in children under five

Dural arteriovenous malformations (AVMs) are considered to be acquired lesions that develop secondary to venous obstruction, which sometimes happens in head trauma. However, there has been a report of an anterior cranial fossa dural AVM that occurred independently of a history of head trauma, and there has been speculation that these malformations are congenital. The authors recount their experience with a patient who had an anterior cranial fossa dural AVM that was discovered incidentally. The lesion was fed by the bilateral anterior ethmoidal arteries and drained into the superior sagittal sinus via frontal cortical veins. The patient had a history of severe head trauma that had occurred 30 years earlier. This is the first case report in which a previous head trauma is strongly believed to be the cause of an anterior cranial fossa dural AVM. The authors postulate that anterior cranial fossa dural AVMs can develop secondary to a head trauma.     

Histopathological aspects of dural arteriovenous fistulas in the transverse-sigmoid sinus region in nine patients

OBJECTIVE: In recent years, dural arteriovenous fistulas (DAVFs) have been primarily thought to be acquired lesions, formed after sinus thrombosis. The pathogenesis of DAVF, however, is still controversial. We have studied histopathological aspects of DAVFs in resected specimens obtained from nine patients, to obtain clues to the pathogenesis of DAVFs. METHODS: Histological comparison was made among nine DAVF cases and five control cases without venous sinus disease. In addition, the relationship between the clinical course and histological aspects was investigated. RESULTS: The essential abnormality found was a connection between the dural arteries and the dural veins within the venous sinus wall, through small vessels averaging approximately 30 microns in diameter. By using several staining methods, we confirmed that the vessels were part of the venous system; we named these dilated venules "crack-like vessels." CONCLUSIONS: The development of abnormal communications between dural arteries and dural veins (crack-like vessels) is regarded as the essential part of the pathogenesis of DAVFs, and sinus thrombus is not thought to be an essential lesion of DAVFs. It might be postulated that sinus hypertension caused by stenocclusive disease of the venous sinuses triggers the development of fistulous connections between arteries and veins in the dural wall, which may result in increasingly dilated venules and the formation of DAVFs.     

Epidural hematomas in the posterior cranial fossa

A review of 89 cases of posterior fossa epidural hematoma (PFEDH) is presented. The mortality rate was 17.9%. In 44 cases (49.4%) there were associated intracranial hematomas. In 30 cases the hematoma was localized within the boundary of the foramen magnum and the transverse and sigmoid sinuses ("pure" PFEDH). In 59 cases the hematoma extended beyond the sinuses to the occipital area ("mixed" PFEDH). In the pure PFEDHs, the bleeder could be identified in only six cases and in five cases the source was a bleeding transverse sinus. The bleeders disclosed in the mixed PFEDHs were a torn transverse sinus in 28 cases, a meningeal artery in three cases, and a bony fracture in three cases. The possibility of a PFEDH should be kept in mind when evaluating patients who have suffered an occipital blow resulting in a frontal or temporal hematoma. In our series, patients with the pure PFEDHs with no associated intracranial hematomas had the best prognoses. Nine patients developed a PFEDH after surgery for a supratentorial hematoma. In 14 cases the PFEDH was treated at the subacute or chronic stage. All but one patient survived with a good recovery. Children generally had better prognoses.     

Posterior fossa decompression without duraplasty in infants and young children for treatment of Chiari malformation and achondroplasia

Some children with Chiari malformation and achondroplasia require posterior fossa decompression that typically includes expansion of the dural tube with duraplasty. Infants and young children, however, may have a more distensible dura mater than do older patients. Furthermore, the structures that compress the hindbrain of young patients may be the bone and abnormally thickened atlantooccipital membrane, i.e., dural band, rather than the dura mater. We have treated 7 children who had Chiari malformation or achondroplasia with posterior fossa decompression without duraplasty. All children were symptomatic; 3 had Chiari-I malformations, 2 Chiari-II malformations, and 2 achondroplasia. The age range was 3 months to 2.5 years (mean 15.1 months). The exent of tonsillar herniation and other hindbrain anomalies was assessed on preoperative magnetic resonance imaging. The infants with Chiari-II malformations underwent cervical laminectomies, whereas the other young children with Chiari-I malformations or achondroplasia underwent suboccipital craniectomy as well as cervical laminectomy. In Chiari malformation, the dural band was divided; in achondroplasia, there was no identifiable dural band. Following bony decompression and division of the identifiable dural band, immediate expansion of the stenotic region with visible cerebrospinal fluid space posterior to the neural elements could be ascertained by intraoperative ultrasonography. During a follow-up period ranging from 4.5 months to 4 years (mean 22 months), all patients made improvements in their symptoms, 3 having complete resolution of their symptoms. This preliminary experience indicates that in children 2 years of age or younger, posterior fossa bony decompression without duraplasty can be effective treatment for Chiari malformations or achondroplasia.     

Successful management of a giant spinal arteriovenous malformation with multiple communications between primitive arterial and venous structures by embolization: report of a case

A 47-year-old woman was admitted to our hospital with a giant spinal arteriovenous malformation (AVM) causing heart failure and thoracic myelopathy. Angiography revealed that the spinal AVM had multiple feeding vessels branching from the 5th through 12th intercostal arteries. The drainage vein flowed to the azygos vein and superior vena cava. The AVM destroyed the 7th thoracic vertebra. The cardiac output was 16.7l/min and the shunt ratio was 64% before treatment. Embolization with cyanoacrylate was performed because the operation was considered to be associated with a significant risk of paraplegia and organ ischemia. The cardiac output decreased to 11.6l/min and the shunt ratio was reduced to 32%. After embolization the patient demonstrated no symptoms of either heart failure or sensory deficits. During embolization, provocative tests using sodium amytal and lidocaine with magnetic stimulation were also performed. The above findings suggest that provocative tests and magnetic stimulation are useful to predict paraplegia, which could result from embolization while, in addition, embolization is considered to be a useful treatment for multiple shunt and nidus in this region.     

Future shock and medical research*

The AA. report 9 cases of arteriovenous angiomata in the posterior cranial fossa with chronic evolution: in 8 of these the diagnosis was made before a subarachnoid haemorrhagic episode precipitated the symptomatology. Angiomata in the posterior cranial fossa are detected less often than sopratentorial angiomata, and the possible reasons of this are considered. During the last 11 years in the Neurosurgical Institute of the University of Padua the incidence was 23%, one of the highest reported in literature. The clinical diagnostic criteria of angioma in the posterior cranial fossa with chronic evolution are also discussed. The importance of a fluctuating development of the symptomatology is emphasised with an almost constant association of signs of pyramidal and cerebellar involvement, as well as the differential diagnostic problems with multiple sclerosis. In six of the cases the malformation was so extensive to make it impossible to determine afferences and drainages, so that a surgical operation could not be carried out. This finding seemed rather peculiar, owing to the relatively poor simptomatology, mainly if compared with smaller supratentorial malformations. It appears from the literature that angiomata in the posterior cranial fossa including those found at autopsy are as common as the supratentorial ones; this would suggest that many of these lesions are not diagnosed in life.     

First record of host defence peptides in tadpoles. The magnificent tree frog Litoria splendida

We treated a 73-year-old man with a dural arteriovenous fistula (AVF) with cortical venous drainage of the left mastoid region using transarterial embolization of the middle meningeal and occipital arteries with n-butyl 2-cyanoacrylate (NBCA). The patient's clinical symptoms improved dramatically. Three months after the procedure, follow-up CT showed resolution of white matter edema and follow-up angiograms showed no evidence of a recurrent AVF. This report indicates that dural AVFs without sinus drainage can be cured solely with transarterial NBCA embolization.     

Radical resection of meningiomas and arteriovenous fistulas involving critical dural sinus segments: experience with intraoperative sinus pressure monitoring and elective sinus reconstruction in 10 patients

OBJECTIVE: Radical resection of meningiomas and dural arteriovenous fistulas involving functional major dural sinuses entails the risk of intracranial hypertension and venous infarction. Surgical reconstruction of dural sinuses and bridging veins increases the spectrum of dural sinus conditions that can be treated by complete resection, but indications for venous reconstructions and associated risks are still not well defined. We report our experience with sinus reconstruction based on the intraoperative assessment of collateral venous flow. METHODS: Radical resection of meningiomas (n = 5) or dural arteriovenous fistulas (n = 5) involving critical segments of dural sinuses was performed in 10 patients. All but two patients were suffering from recurrent disease after incomplete treatment. Tolerance of sinus occlusion was assessed intraoperatively by measuring stump pressure in the superior sagittal sinus during test clamping of the involved sinus segment. RESULTS: In five patients, the results of pressure monitoring suggested that occlusion of the sinus might not be tolerated. In two other patients, major bridging veins entered the diseased segment. In these patients, the resected sinus segment was reconstructed and bridging veins were reinserted as far as possible. Postoperative graft occlusion occurred in two patients. One patient who was managed without reconstruction sustained a transient postoperative neurological deficit resulting from venous congestion in the vein of Labbé. Postoperative imaging confirmed total elimination of the pathological process in all 10 patients. There was no recurrence of disease during follow-up periods of up to 8 years. CONCLUSION: The monitoring of sinus pressure, together with the possible reconstruction of the diseased sinus, allows complete surgical treatment of dural sinus abnormalities and involves acceptable risk.     

Overattendance at primary care: a study of psychosocial factors]

We compared MRI studies of the sellar area and embryological and adult histological studies of the cavernous sinuses and pituitary fossa. MRI studies were performed in 50 normal subjects with coronal sections using a fast inversion-recovery sequence to demonstrate the dural walls of the cavernous sinus and pituitary fossa. With this sequence, dura mater appears as a high-signal linear structure. The lateral and superior walls of the cavernous sinus was easily identified on all studies, but demonstration of a dural wall separating the cavernous sinus from the pituitary fossa was not possible. These results correlated well with embryological and adult histological studies obtained from 14 specimens. The absence of a strong separation between the pituitary fossa and the cavernous sinus explains the high incidence of extension of pituitary tumours to the cavernous sinuses and vice versa.     

Medullomyoblastoma. A rare cerebellar tumour in children

Seven patients between the ages of 3 and 24 years were admitted to our hospital in the last 28 years who had a histological diagnosis of medullomyoblastoma. These patients presented with classic symptoms of a posterior fossa midline mass associated with evidence of raised ICP. A CT scan in each patient revealed a uniformly high-attenuating tumour in the posterior fossa with gross hydrocephalus. In all seven patients a ventriculoperitoneal shunt was placed prior to definitive surgery. Radical tumour excision was carried out in all cases 3-5 days after CSF diversion. The histological diagnosis was made on H&E-stained slides. In two cases each, the tumour tissue was subjected to electron microscopy and immunohistochemical studies. Six of the seven patients survived the operation. One patient died 21 days after surgery as a result of shunt block and shunt infection. All surviving patients received cranial and spinal radiation 2-4 weeks after surgery, and also chemotherapy. The cranial radiation dose ranged from 4500 to 5000 rad, while the spinal radiation dose was limited to 1500 rad. Patients were followed up carefully. Three patients died within 6 months, and the remaining three between 2.5 and 3 years after surgery. None of the patients in our study survived longer than 3 years. One patient had developed paraplegia. This study highlights the details of an uncommon entity and reports the largest collection of such cases in the literature.     

Persistent feeding arteries to angiographically completely embolized arteriovenous malformation demonstrated by intraoperative color-flow Doppler testing: report of two cases

Two cases of arteriovenous malformation (AVM) treated preoperatively by endovascular embolization that appeared to be completely occluded after embolization are presented. Seven and 12 days later, respectively, these patients underwent resection of their AVM. At the time of surgery, intraoperative color-flow Doppler studies revealed persistent feeding arteries to an active residual nidus of the AVM. The significance of this finding is presented in light of previous published literature.     

Occurrence of severe vasospasm following intraventricular hemorrhage from an arteriovenous malformation. Report of two cases

The authors present two rare cases of severe cerebral vasospasm following the rupture of arteriovenous malformations (AVMs). Computerized tomography revealed intracerebral hemorrhage in the thalamus in one case and in the putamen in the other, both accompanied by cast formation of intraventricular clots without radiological evidence of subarachnoid hemorrhage. Initial angiograms showed arterial narrowing of the bilateral internal carotid arteries in the supraclinoid portion but failed to demonstrate an arteriovenous shunt. Subsequent angiograms clearly demonstrated the existence of an AVM. Radiological features and possible mechanisms are discussed.     

Non-Hodgkin lymphoma of the central skull base: MR manifestations

OBJECTIVE: The aim of this study was to demonstrate the MR characteristics of non-Hodgkin lymphoma of the skull base to help in the differential diagnosis of this neoplasm from other conditions. MATERIALS AND METHODS: MR of five patients, 7-64 years old, with pathologically proved lymphomas of the skull base were reviewed. Three cases had primary skull base lesions involving the sphenoid bone and the cavernous sinus. One case with a nasal cavity lesion involving the skull base and one with a relapsing skull base lesion of previously treated tonsillar lymphoma were included. RESULTS: The lesions had signal intensities that were similar to that of gray matter of brain on both T1- and T2-weighted imaging. Bilateral cavernous sinuses were involved with encasement of internal carotid arteries in every case. Postcontrast MR showed homogeneous enhancement of the tumor with dural infiltration along the planum sphenoidale, clivus, or tentorium. The clivus was destroyed or replaced by tumors in adult cases but in two children the clivus was preserved with intact sphenooccipital synchondrosis. In one case the tumor extended to the extracranial portion through the jugular foramen. CONCLUSION: The MR findings of a permeative lesion of the skull base, invasion of the cavernous sinus without arterial narrowing, infiltration along the dural surface, and an iso- or hypointensity with brain on T2-weighted imaging should suggest lymphoma.