Angio-architecture of spinal cord arteriovenous shunts at presentation. Clinical correlations in adults and children. The Bicêtre experience on 155 consecutive patients seen between 1981-1999.

OBJECTIVE: To analyse possible relationships between the symptoms and signs created by intradural spinal cord arteriovenous shunts (SCAVSs) and their angio-architecture. METHODS: The clinical and radiological files of 155 patients, both adults and children, seen between 1981 and 1999 with a SCAVS were retrospectively reviewed. SCAVSs were divided into nidus type (small superficial or large intramedullary), and fistulas (micro (mAVFs)- or macrofistulas (MAVFs)). The angio-architectural points studied were arterial stenosis, proximal arterial aneurysm, distal arterial aneurysm, arteriovenous fistulas, pial venous drainage and/or reflux, venous ectasias, venous stenosis, venous thrombosis, false aneurysms. Correlations between architecture, location, age groups and symptoms and signs were made. FINDINGS: A male predominance was noted in both adults and children. Most of the lesions were located at the thoracic level, but hemorrhage occurred as the presenting event predominantly in cervical localizations. 30 patients (20 AVMs; 4 mAVFs, 6 MAVFs) were children. 5 of the 6 MAVFs found in children were associated with Hereditary Hemorrhagic Telengiectasia (HHT1). Twenty one children (70%) had bled. Spontaneous total or subtotal recovery was the rule in 15 of those who had bled (72%) but early recurrent hemorrhages occurred in 2. Among 125 adults 56 presented with hemorrhage (45%). The proportions of those who recovered spontaneously (71%) or rebled (3,6%) in the same year after the initial episode were very similar to children. All other adults presented with acute or progressive non-hemorrhagic episodes. There was no significant difference in the angio-architecture between hemorrhagic and non hemorrhagic SCAVS, except for that occurrence of pseudo-aneurysms. Hemorrhage in SCAVSs may not be exclusively due to haemodynamic factors. Venous congestion was responsible for progressive symptoms. Acute deficits unrelated to bleeds were due to intralesional thrombosis or hemodynamic changes. INTERPRETATION: The short term prognosis of hemorrhagic SCAVSs is good, and there is no need for emergency treatment. MRI delineates the cord and makes the diagnosis of the lesion but angiography remains the gold standard for analysis of the vasculature. The angio-architecture reflects the ageing of the lesion but there is not a precise correlation between angio-architecture and clinical symptoms, except for pseudoaneurysms which relate to the hemorrhagic portion of the lesion.

Visibility of the central canal on MRI.

The central canal of the spinal cord is present at birth and becomes progressively obliterated. Cadaver studies have shown that it may persist partially or completely. To our knowledge, this entity has not been described on MRI. We reviewed 794 MRI studies of the spinal cord, and found 12 patients (aged 14 to 65 years) who had an intramedullary cavity. The cavity was at the junction of the ventral 1/3 and dorsal 2/3 of the spinal cord, except at the level of the lumbar enlargement, where it was central. It was filiform in most cases, although sometimes fusiform (3 to 4 mm in diameter), and had regular contours. The cavity were thoracic in 69 % of cases. The clinical features were totally unrelated to the image, and there were no anatomical factors (Chiari malformation, dysraphism) predisposing to syringomyelia. The images were perfectly compatible with a persistent central canal, which we interpret as a variant of normal anatomy. Therefore it is important to regard these findings as normal, to avoid unnecessary treatment and follow-up.

CSF flow measurement in syringomyelia.

BACKGROUND AND PURPOSE: CSF circulation has been reported to represent a major factor in the pathophysiology of syringomyelia. Our purpose was to determine the CSF flow patterns in spinal cord cysts and in the subararachnoid space in patients with syringomyelia associated with Chiari I malformation and to evaluate the modifications of the flow resulting from surgery. METHODS: Eighteen patients with syringomyelia were examined with a 3D Fourier encoding velocity imaging technique. A prospectively gated 2D axial sequence with velocity encoding in the craniocaudal direction in the cervical region was set at a velocity of +/- 10 cm/s. Velocity measurements were performed in the larger portion of the cysts and, at the same cervical level, in the pericystic subarachnoid spaces. All patients underwent a surgical procedure involving dural opening followed by duroplasty. Pre- and postoperative velocity measurements of all patients were taken, with a mean follow-up of 10.2 months. We compared the velocity measurements with the morphology of the cysts and with the clinical data. Spinal subarachnoid spaces of 19 healthy subjects were also studied using the same technique. RESULTS: A pulsatile flow was observed in syrinx cavities and in the pericystic subarachnoid spaces (PCSS). Preoperative maximum systolic cyst velocities were higher than were diastolic velocities. A systolic velocity peak was well defined in all cases, first in the cyst and then in the PCSS. Higher systolic and diastolic cyst velocities are observed in large cysts and in patients with a poor clinical status. After surgery, a decrease in cyst volume (evaluated on the basis of the extension of the cyst and the compression of the PCSS) was observed in 13 patients. In the postoperative course, we noticed a decrease of systolic and diastolic cyst velocities and a parallel increase of systolic PCSS velocities. Diastolic cyst velocities correlated with the preoperative clinical status of the patients and, after surgery, in patients with a satisfactory foraminal enlargement evaluated on the basis of the visibility of the cisterna magna. CONCLUSION: CSF flow measurement constitutes a direct evaluation for the follow-up of patients with syringomyelic cysts. Diastolic and systolic cyst velocities can assist in the evaluation of the efficacy of surgery.

[Dynamic MRI in the evaluation of syringomyelic cysts]. / Apport de l'exploration vélocimétrique en IRM dans l'exploration des kystes syringomyéliques.

We report the results of a MR velocity study of the cerebrospinal fluid including 36 patients with syringomyelic cysts (25 with a foraminal syringomyelia, 7 with a post-traumatic cyst, 2 with a tumoral spinal cord cyst, 2 with a spinal arachnoiditis). Velocity measurements were performed in the cysts and in the pericystic subarachnoid spaces and compared with clinical data, evolutive pattern of the disease, cyst volume, degree of stenosis of the cranio-cervical junction (in patients with Chiari I) or of the spinal canal (in post-traumatic cases), and with the extension of the cyst (post-traumatic cases). Cyst velocities correlated in the pre operative course with the clinical status of the patients and with the volume of the cyst. Correlation with the degree of foraminal stenosis was uncertain and no correlation was found with the duration of the disease course. In the post-operative course cyst velocity decreased and velocity of the subarachnoid spaces increased. Onset of the systolic peak occurred sooner in the cyst than in the subarachnoid spaces. We believe that this point may be important in the pathogenesis of the disease. We consider that systolic and diastolic cyst velocities respectively greater than 2.3 cm/s and 1.5 cm/s in the post-operative course may characterize aggressive cysts. In the future comparison of velocity measurements in patients with Chiari I without syrinx and patients with Chiari I related syringomyelia may be helpful for a better understanding of the natural history of the syringomyelia.

[History, controversy and pathogenesis]. / Histoire, controverses et pathogénie.

In this paper, we discuss the historical and pathophysiological aspects of syringomyelia. Defined as fluid cavities extending beyond several segments within the spinal cord this pathological entity is a condition with many possible causes. Hindbrain herniation is the commonest foramen magnum abnormality associated with the so called "hindbrain related syringomyelia". A history of birth injury, a small posterior fossa, an arachnoid scarring of the basal cisterna, a segmentation abnormality of the superior cervical vertebrae, a hydrocephalus or arachnoid cyst of the posterior fossa are often present in this context. Previous theories of the origin and the mechanism of syringomyelia progression have been controversly proposed. Gardner and colleagues postulated that the primary event is the incomplete embryonic opening of the outlets of the fourth ventricle. The fluid arrived in the syrinx along the embryologically natural route down the central canal. Their hydrodynamic theory states that with each arterial pulse, the outflow of CSF is transmitted from the fourth ventricle down to the syrinx via the central canal. Most patients have patent fourth ventricle foramina and evidence of communication between the ventricle and the syrinx is rare. Williams then proposed his "cranio-spinal pressure dissociation theory". Significant pressure differential occur daily during activities that increase intrathoracic pressure such as sneezing, coughing and could be transmitted to the spinal fluid from the epidural spinal veins. The progression of the cavity is better understood and analyzed with dynamic MR imaging and quantitative analysis. The CSF flow from the cranial to the spinal subarachnoid space results from the expansile motion of the brain during the cardiac cycle. The progression of the cavity is based on pressure acting on the surface of the cord and does not require any communication of the fourth ventricle with the central canal and the syrinx. The origin of fluid cavity remain questionable. Aboulker but also Ball and Dayan pointed out the role of the perivascular spaces and the DREZ which are involved in the communication between the perimedullar CSF, the spinal cord extracellular spaces and the central canal. Other causes of syringomylia include acquired conditions which could be grouped under the heading of "non-hindbrain related syringomyelia". Arachnoid scarring is related in many case to spinal trauma or occurs after spinal meningitis, spinal intradural surgery, peridural anesthesia, subarachnoid hemorrhage. Rarely an extra medullary compression is discussed. The mechanism involved is here again an alteration of the CSF flow at the spinal level.

[Correlations between clinical deficits, motor and sensory evoked potentials and radiologic aspects of MRI in malformative syringomyelia. 27 Cases]. / Corrélations entre déficits cliniques, potentiels évoqués moteurs et sensitifs, et aspects radiologiques à l'IRM dans la syringomyélie malformative. A propos de 27 cas.

Twenty-seven patients (15 males, 12 females, age range: 16-66 years) were admitted for malformative syringomyelia diagnosed on MRI with measures of syrinx extending and transverse diameter. Posterior tibial somatosensory evoked potentials (PT SEP), median (M SEP), trigeminal (V3 SEP), brain stem auditory evoked potentials (BEAP), cortical and cervical motor evoked potentials (MEP) were correlated with clinical and radiological findings. SEP abnormalities were not correlated with the duration of symptoms. PT SEP proved to be more sensitive than M SEP. MEP abnormalities were very frequent (87% of the cases), even without clinical motor deficits. Trigeminal SEP were more sensitive than BEAP which were not related to the presence of associated cranio-vertebral abnormalities. We found no significative relationship between clinical and radiological results. Moreover, there was a positive relationship between electrophysiological and radiological results: abnormal trigeminal SEP were detected in 85% of the patients with high cervical syringomyelia. In all cases, trigeminal SEP and MEP should be done in association with M and PT SEP as both of them detect subclinical evidence of spinal cord dysfunction in syringomyelia.

Embolisation of Spinal Cord Arteriovenous Malformations with Glue through the Anterior Spinal Axis. Review of 20 Cases.

SUMMARY: We reviewed the clinical and morphological results of spinal cord arteriovenous malformations (SCAVMs) embolised with acrylic glue through the anterior spinal axis (ASA), and assessed the anatomical guidelines that should be followed to safely embolise the ASA. Twenty consecutive SCAVMS seen between 1982 and 1996 were reviewed. There were 15 lesions in the thoracolumbar cord and 5 in the cervical cord. Haemorrhage was the revealing symptom in 13 patients (65%). Embolisation through the ASA was done in 19 SCAVMs (2 with PVA particles in our early experience and 17 with Histoacryl(*)). One patient was not embolised because of a spastic reaction of the ASA that led to secondary subtotal thrombosis of the SCAVM without neurological deficit. The ASA was chosen as arterial approach to the AVM because it was the only feeder to the lesion (1 case) andlor because it was one of the accessible pedicles harbouring particular angioarchitectural weakness points. Vascular occlusion was always indicated and performed following precise anatomical analysis of the lesion and of the regional vascular disposition. In all cases embolisation of the ASA feeders to a SCAVM was performed under general anaesthesia, without any evoked potentials or provocative tests. However, 3/19 (16%) patients presented transient worsening of their clinical condition. Permanent morbidity occurred in 2/19 patients (11%): one patient cured from a cervical intramedullary AVM presents mainly a deltoid palsy, the other with a thoracic intramedullary AVM has worsened his paraparesis. At follow-up, 6/19 patients (32%) are neurologically normal and 10/19 (53%) have improved their neurological conditions and deficits. One patient embolised recently is currently stable but is expected to improve. No embolised patient bled or rebled during followup. Neurological symptoms recurred in one patient who had been stable for one year after his first embolisation. For an experienced interventional neuroradiology team, embolisation of SCAVMs through the ASA is feasible with acrylic glue with good clinical results. Proper analysis of the vascular architecture is mandatory to select the cases that can benefit from such approach.

[Intramedullary glioma. Postoperative MRI aspects]. / Gliomes intramédullaires aspects post-opératoires en IRM.

MRI is the standard exploration of intramedullary tumours. Following up the patients is of prime importance to detect and treat possible recurrences at an early stage. The purpose of this paper is to specify the postoperative MRI semiology of intraspinal gliomas. During the 1986-1992 period, 47 patients operated upon in the Bicêtre hospital for primary intraspinal tumours were followed up with high-field MR (1.5 Tesla, Signa, G.E.). The retrospective visual study was carried out by two neuro-radiologists. The patients' group consisted of 24 women and 23 men aged from 15 to 67 years (mean 38 years). The tumours treated were 29 ependymomas and 18 astrocytomas. Eighty-five MRI examinations were analysed. Most of them comprised at least two planes in T1 and T2-weighted spin echo sequences with gadolinium injection, then only T1-weighted spin echo sequences after gadolinium injection (0.1 mmol/kg). The mean postoperative follow up period in the 47 patients was 32 months (range 7 to 84 months). Contrast enhancement of the spinal cord was observed in 20 cases. In the 6 patients with recurrence (5 astrocytomas, 1 malignant ependymoma) there was a segmental increase of spinal cord volume with contrast enhancement after gadolinium injection. In 3 out of these 6 patients clinical deterioration appeared later than MRI semiology. In clinically stable patients neither enhancement nor increase in spinal cord size was found in 27 cases, and enhancement alone was noted in 12 cases. There was no reliable criterion in the analysis of post gadolinium signal enhancement that could be used to differentiate recurrence from cicatricial contrast enhancement.(ABSTRACT TRUNCATED AT 250 WORDS)

[MRI symptomatology of primary intraspinal cord gliomas]. / Sémiologie IRM des gliomes primitifs intra-médullaires.

MRI has now been recognized as the best technique for exploration of spinal tumours and, in particular, tumours within the spinal cord. Based on a retrospective study of 74 operated glial tumours, we are trying to define a specific semiology for intramedullary astrocytomas and ependymomas. Thirty-four cases were selected including 17 astrocytomas (7 low-grade, 10 high-grade) and 17 ependymomas (1 of which was grade III) for whom the pre-operative MRI examination was complete, with T1-weighted sequences without, then with gadolinium, and T2-weighted sequences. The examination was performed using a high-field and in most cases 1.5 Tesla machine. Analysis, correlated with operative data and pathology results, comprised on the one hand patients' distribution by age, sex and location of the tumour on the spinal cord, and on the other hand the MRI semiology concerning the sagittal and axial localization of the fleshy portion after gadolinium injection, the limits of the tumour, the homo- or heterogeneous character of its enhancement, the possible existence of stigmas of intra- or peritumoral chronic bleeding, and finally the presence or absence of associated cysts in the 34 exploitable cases. Some semiological differences were elicited between astrocytomas and ependymomas: the patient's age at the time of diagnosis was predominantly 0 to 20 for astrocytomas (astrocytomas 39%, ependymomas 4%), and the well-limited character of the fleshy portion of the tumour after gadolinium injection was found in 70% of ependymomas, 40% of high-grade astrocytomas and 14% of low-grade astrocytomas. The homogeneity of contrast enhancement in ependymomas has been classically defined, but it did not show in our series. Finally, it seems that high-grade astrocytomas are characterized by the rare presence of hemosiderin deposits (high-grade 20%, low-grade 57%, ependymomas 58%) and by the absence or reduced extension of overlying and underlying cysts.

Spinal Cord Arteriovenous Malformations in a Pediatric Population Children below 15 Years of Age The Place of Endovascular Management.

SUMMARY: Among a global group of 164 spinal arteriovenous shunts, a series of 16 spinal cord arteriovenous malformations (SCAVMs) were diagnosed in a pediatric population below 15 years of age. The majority of the lesions affected the male population; 6 were located in the cervical spine and 10 at the thoracolumbar level. Hemorrhage was the most frequent symptom encountered (63%). Half of the bleeds occurred only in the subarachnoid spaces. Neurological deficits (acute or progressive) revealed the SCAVM in 31 % of patients. The lesion was an incidental finding in one patient (6%). All the diagnoses (except one) were made by MRI. Selective angiography confirmed the diagnosis and identified the type of the lesion (nidus or fistula) and its angioarchitecture, stressing that the veins and their related features are the key point in the clinical eloquence of SCAVMs. All the treatments performed were endovascular; no patient was deemed a surgical candidate. Therapeutic abstention was decided in 37% of cases, mainly for anatomical reasons. All the patients in this group improved (50% being normal and 50% presenting slight non-handicapping deficits due to the initial accidents). Embolisation was indicated in 10 patients (63%) and was performed with fluid agents (histoacryl(*)) except in the first patient who had been treated with particles. Twelve percent of patients were cured (fistula), the remaining 88% having their lesion controlled to more than 50%. This partial treatment was always targetted towards the angioarchitectural weak points of the lesion. All patients improved after embolisation, 45% of them being neurologically normal. Follow-up in this group ranges from 1.5 to 13 Years. No complications occurred after embolisation. No bleed, rebleed or clinical worsening has occurred after endovascular treatment. The results in this series suggest that endovascular treatment (even partial but targetted) represents a safe and stable therapeutic alternative in the management of SCAVMs in this population.

[Intraspinal hemangioblastoma. Apropos of a recent series of 20 cases]. / Les hémangioblastomes intra-rachidiens. A propos d'une série récente de 20 cas.

This report deals with a series of 20 patients admitted for a spinal hemangioblastoma between 1970 and 1993, 18 of whom between 1978 and 1993. There are 8 men and 12 women and the onset of spinal symptoms is before the age of 50 years for 76% of the patients. Nineteen patients have an intra-dural tumor (extramedullary 15.5%, intramedullary 75% with 62.5% close to the dorsal surface, 37.5% partly out, none totally enclosed with spinal cord) and only one patient has an extra-dural tumor. Cysts are present in 70% of our cases. Two cases have been revealed by an hemorrhagic syndrome. Ten cases belong to a von Hippel-Lindau (vHL) disease. Nineteen patients were operated on, one patient died. Total resection of the tumor was performed in 17. Symptoms improved postoperatively in 8 patients, were inchanged in 6, and worsened temporary in 4. MRI with gadolinium is the best procedure for both the diagnosis and the follow-up. After surgery, the prognosis is very good for sporadic cases with a single spinal lesion whereas it is very poor in case of vHl disease. For these patients (50% of our cases), half of them died because of the evolution of multifocal lesions even if they were operated on several times. Thus, each patient should have a precise check-up (SNC and visceral lesions). The gene causing vHL disease located on the short arm of the chromosome 3 has just been characterized. This will help to elaborate a presymptomatic diagnosis and a better screening of the patients with the hope of a specific treatment.

[Magnetic resonance imaging of intraspinal hemangioblastoma]. / Imagerie par résonance magnétique des hémangioblastomes intra-rachidiens.

Magnetic resonance (MR) findings in 16 patients operated on 21 spinal cord hemangioblastomas were reviewed. Three of these patients had von Hippel-Lindau syndrome. 13 patients had Gadolinium-DTPA enhanced MR and 2 had dynamic sequences. Using Gd-DTPA makes the diagnosis of hemangioblastomas considerably easier compared to conventional non contrast MR. Findings are specific: a tumor nodule with, as a general rule, an extensive cyst formation; the nodule shows intense, earliness, homogeneous contrast enhancement as the cyst wall does not. In less typical cases, dynamic sequences may be useful in order to distinguish hemangioblastoma from other spinal cord tumor nodules. Today, MRI is the diagnostic modality of choice and angiography should not be used. MRI is also an excellent way to check the central nervous system and the visceral manifestations in a case of von Hippel-Lindau disease and to follow up the patients.

[Brain and spinal cord cavernoma. Value of MRI and review of the literature. Apropos of a case]. / Cavernomatose encéphalo-médullaire. Intérêt de l'IRM et revue de la littérature. A propos d'une observation.

MRI has transformed the diagnosis of cavernous hemangioma, a hamartoma that is most often located in the central nervous system. The appearance of this lesion is fairly characteristic with MRI. This technique has allowed distinguishing multiple forms. Encephalic sites are most frequent, with rare medullary sites, and double brain and cord locations are exceptional. Many cases of single or multiple brain involvement have now been reported. Series of medullary involvement are much less frequent and include few cases. Double sites in the brain and cord are exceptional. The authors present a case of cavernous hemangiomas of the central nervous system with multiple encephalic sites associated with a single medullary site confirmed by surgery.

Oblique transcorporeal approach to anteriorly located lesions in the cervical spinal canal.

The technique of obliquely drilling out the postero-lateral part of the cervical vertebral bodies is described. It uses the antero-lateral (retro carotico-jugular) approach to control and displace the vertebral artery postero-laterally and to expose the lateral aspect of the vertebral bodies. It provides, through a wide field and with minimal retraction of the carotid artery and the internal jugular vein, an extensive view of the anterior aspect of the spinal cord. It has already been used to treat 15 anterior lesions compressing the spinal cord including neurinomas and osteophytes.

Intracranial arterial aneurysms: a review of neurosurgical results.

The results of elective surgery for intracranial aneurysms are now excellent, with a 90% cure rate, but they do not reflect the overall results of treatment of aneurysmal pathology. Despite improvements in microsurgical techniques, these results remain disappointing (56.4% cured, 27.3% dead in the 1983 co-operative study, this is mainly due to the severity of the initial haemorrhage caused by rupture of the aneurysms, but also to the problems encountered in transferring patients, as quickly as possible, to a specialized surgical unit. Only an early care of symptomatic patients will improve these results by reducing the frequency of rebleeding and vasospasm. The most dangerous complications to which patients who survived the first haemorrhage are exposed.

[MRI of malformative syringomyelia. Descriptive and developmental aspect]. / IRM des syringomyélies malformatives. Aspect descriptif et évolutif.

132 cases of malformative syringomyelia have been studied at the C.I.E.R.M. (Interdepartmental Magnetic Resonance Center) of Bicêtre Hospital. The authors describe their technique for the exploration on the cord in case of suspected intramedullary cavitation, and emphasize the morphological and evolutive aspects of these abnormalities, whether they have been operated or not.

Jugular foramen arteriovenous shunt with subarachnoid hemorrhage.

The authors report the case of a 37-year-old man with an extracerebral arteriovenous fistula at the skull base, revealed by subarachnoid and intraventricular hemorrhage. The malformation was fed by the neuromeningeal trunk of the ascending pharyngeal artery and drained into left laterobulbar veins. Embolization with bucrylate was performed and occluded totally the shunting zone. A 1-year follow-up angiogram confirmed the good stability of the result, the patient being asymptomatic. This case emphasizes the quality of results that can be obtained with bucrylate in arterioverious fistulas presenting with hemorrhage. It confirms that the external carotid artery must be studied when dealing with intracranial hemorrhage. On the other hand, magnetic resonance imaging and angiography may depict vascular abnormalities but do not always indicate the shunting area, thus the pathologic type of the malformation.

Cystic schwannoma mimicking a brain stem tumor: MR features.

A case of cystic schwannoma that presented as an intraaxial lesion on CT is reported. Magnetic resonance was able to detect the extraaxial origin of the tumor.

Angiography in the investigation of spinal dural arteriovenous fistula. A protocol with application of the venous phase.

The authors present their protocol for spinal angiography in their investigation of dural arteriovenous fistula (DAVF). The protocol has been used in approximately 120 patients from 1983 to the present at Bicetre Hospital. The approach is based on the fact that venous congestion is responsible for the myelopathy of DAVF. If the venous phase of the spinal circulation is normal, this alone rules out DAVF as the cause of the patient's symptoms. If there is stasis in the spinal circulation, this is consistent with DAVF, and thus complete spinal angiography is necessary. Complete angiography includes the selective intercostal arteries, including the lateral sacrals, as well as the supply to the cervical cord and posterior fossa.