[Benign vertebral osteoblastoma. Report of 6 cases]. / L'ostéoblastome bénin vertébral. A propos de 6 observations.

We present six cases of benign spinal osteoblastoma. This localization of this uncommon benign bone tumor occurring in young subjects is rare. The patients were explored with radiotomography, computed tomography, myelography and medullo-spinal angiography. These benign tumors may appear radiographically as pure bone lysis mimicking malignancy. The size of these tumors often leads to widening search for extension, particularly in recurrent, aggressive, multifocal forms which require wide resection, and sometimes total vertebrectomy. Medullo-spinal angiography can confirm the vascular involvement of the tumor nidus and is require to identify arteries supplying the spinal canal which would modify operative strategy.

[Intracranial dural fistula with spinal cord venous drainage. Apropos of 2 cases]. / Les fistules durales intracrâniennes a drainage veineux périmédullaire. A propos de deux observations.

The authors report 2 new cases of intracranial dural fistula draining into spinal veins. Comparisons with 19 other published cases showed that dural fistulae of the spine share common features with intracranial fistulae. The first case concerned a 78-year old woman presenting with a thoraco-lumbar myelopathy which proceeded by increasingly severe bouts and ended within 6 months in a flaccid sensorimotor paraplegia with urinary incontinence. Paraclinical examinations consisted of MRI, myelography and spinal as well as cerebral arteriography. MRI and thoraco-lumbar myelography displayed marks of dilated retrospinal vessels. Spinal arteriography showed no arteriovenous malformation, but the venous return of Adamkiewicz artery was not visible. Diagnosis was made by cerebral arteriography which demonstrated an intracranial arteriovenous fistula in the occipital region, draining into the posterior spinal vein. Treatment was endovascular and consisted of embolization by micro-coils, but clinical improvement was mediocre. Six months later, as the clinical picture was getting worse a second arteriography was performed. It showed recanalization of the fistula which was embolized again, using both coils and particles. No improvement in spinal cord deficit was observed. The second case was that of a 42-year old man presenting with paraparesis, tetrapyramidal syndrome, sensory deficit at T9, peribuccal dysaesthesias and genito-urinary sphincteral disorders, all gradually getting worse. The paraclinical exploration was the same as in the first case. MRI and myelography showed retrospinal vascular impressions. Spinal arteriography was normal, except for the lack of venous return of Adamkiewicz artery. Cerebral arteriography detected an intracranial dural arteriovenous fistula in the occipital region, draining into the anterior and posterior spinal veins. Treatment was surgical, consisting of exclusion of the arteriovenous fistula. Partial clinical improvement was noted. These two cases, compared with those of the literature, shared a number of features with spinal dural arteriovenous fistulae: they occur in middle-aged and predominantly male patients, and the clinical signs of ascending myelopathy are caused by the same physiopathological mechanism of spinal vein hyperpressure. Lesions of the medulla oblongata or the cervical spinal cord are found only in intracranial arteriovenous fistulae draining into spinal veins. Diagnosis is based on data provided by myelography (impressions of dilated and sinous vessels) and MRI (low-intensity perispinal signals, widening of the conus medullaris with high-intensity centrospinal signal); spinal cord angiography only shows a lack of venous return of Adamkiewicz artery without any other abnormality, whereas cerebral arteriography confirmed the diagnosis of intracranial dural arteriovenous fistula draining into spinal veins.

[Endovascular treatment of iatrogenic false aneurysm in the right subclavian pit. Apropos of a case]. / Traitement endovasculaire d'un faux anévrysme iatrogène du creux sus-claviculaire droit. A propos d'un cas.

The authors report about one case of false aneurysm in the right subclavicular pit, which developed after iterative venous punctures in a 67-year-old woman. Surgery was excluded, and an endovascular treatment was decided, with an approach of the lesion by direct puncture in this case and the insertion of an inflatable balloon.

Relationship between levodopa-independent symptoms and central atrophy evaluated by magnetic resonance imaging in Parkinson's disease.

Thirty patients with Parkinson's disease were studied for the purpose of investigation relations between motor symptoms and cerebral atrophy evaluated by magnetic resonance imaging (MRI). Axial symptoms (gait disorder, postural instability and difficulty in arising from a chair), assessed at the time of maximum clinical improvement, were significantly correlated with frontal atrophy, while no correlation was found between the basal parkinsonian disability score and cerebral atrophy. It is suggested that frontal atrophy observed by MRI is linked with axial motor symptoms resulting from non-dopaminergic lesions. The origin of this atrophy is unknown.

[Bone density in idiopathic hypercalciuria in men. Study by dual photon absorptiometry, X-ray computed tomography and histomorphometry]. / La densité osseuse dans l'hypercalciurie idiopathique chez l'homme. Etude par absorptiométrie biphotonique, tomodensitométrie et histomorphométrie.

Lumbar bone mineral density (BMD) of the L3 vertebra was evaluated by double photon absorptiometry or tomodensitometry (TDM) in 55 hypercalciuric individuals in two separate studies. In the first, in a department of nephrology, 29 lithiasis patients were studied by TDM of L3. By this technique, trabecular density was 75 +/- 23% of normal. It was lower in the 17 patients in whom hypercalciuria persisted after calcium restriction (66 +/- 15% of normal and below the "fracture threshold" in 9 cases) than in the 12 patients in whom it disappeared after the prescription of such a diet (88 +/- 26%, below the "fracture threshold" in 3 cases), this difference being significant (p less than 0.01). In another 26 patients, seen in a department of rheumatology, three of whom had osteoporosis with vertebral fracture, density was measured in 21 cases by double photon absorptiometry (mean Z score -1.9 +/- 1.0) and in 5 cases by TDM (mean BMD of L3 69 +/- 21% of normal). Mean iliac trabecular volume, measured in 8 cases only, was 70 +/- 25% of normal and was below the "fracture threshold" in 3 cases. Comparison of the two study groups was not possible because of differences in recruitment and methods of investigation. These two studies nevertheless show the existence of significant vertebral bone rarefaction during hypercalciuria in the young man. Confirmed and quantified in patients in whom the metabolic disturbance was discovered as a result of radiological abnormalities, this quantitative abnormality was also seen in patients in whom hypercalciurie was found because of renal lithiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-dimensional reconstruction in routine computerized tomography of the skull and spine. Experience based on 161 cases.

Three-dimensional (3D) reconstruction in routine computerized tomography (CT) presupposes that the referring clinicians are motivated, software programs are of good quality, a second working console is available and manipulations are made by experienced persons. Maxillofacial surgery is the main, conventional indication, but the method is also used to plan the surgical treatment of craniofacial malformations and that of injuries and tumours. 3D reconstruction cannot replace a thorough analysis of the acquisition sections since its spatial definition is not as good as theirs. Without competing with pure research-work, a number of applications remain in the realm of speculative imaging, but it cannot be denied that 3D reconstruction has an interesting potential for teaching.

Osteoid osteoma of the spine: radiological aspects and value of arteriography. Four cases.

The authors present four cases of osteoid osteoma of the spine and review the usual clinical and paraclinical data leading to its diagnosis. The value of radionuclide bone scanning is emphasized: it supersedes the often disappointing radio-tomography and guides computerized tomography which, with modern scanners, virtually always demonstrates the lesion and locates it with accuracy. In the author's experience, spinal and spinal cord arteriography plays an important role: it identifies the radiculospinal vessels preoperatively and provides additional aetiological arguments based on the usual hypervascularity of osteoid osteomas and on the pain induced by injection of the feeding vessels. Data from the literature concerning the vascularization of the nidus suggest that treatment by embolization alone can be envisaged but must be demonstrated.

Apparently isolated, spontaneous haematomas of the brain stem. Seven cases explored by CT and MRI.

The authors present seven cases of apparently isolated spontaneous haematomas of the brain stem detected by computerized tomography (CT). Magnetic resonance imaging (MRI) was performed in all patients, and in three of these on two occasions at different stages of the lesion. Changes in MRI signal according to the moment this examination was carried out (acute, subacute or chronic stage) are described. In two of three patients operated upon the haematoma was found to be due to an occult vascular malformation.

Spinal metastases of carotid paraganglioma. One case and review of the literature.

Paragangliomas of the carotid body are uncommon tumours usually regarded as benign or locally malignant. Metastasis occurs in 5 to 25% of the cases, involving mainly the liver, lung and bones. A case of carotid body tumour without histological evidence of malignancy but with local invasion and, subsequently, multiple spinal metastases is reported. Since the histological prognosis of the initial tumour is impossible to make in most cases, the authors underline the importance of signs of local invasion which is predictive of metastasis and requires regular monitoring with radionuclide bone scanning and MRI.

[MRI of the cervical spine. Creation of a surface coil. Technical and clinical results]. / IRM du rachis cervical. Réalisation d'une antenne de surface. Résultats techniques et cliniques.

Cervical myelopathy represents a good indication for study by Magnetic Resonance Imaging (MRI). The MRI examination may be performed without hospitalisation and without any pain or risk for the patient. It often gives sufficient information to decide whether to proceed with surgical intervention, after imaging on standard plain films and ever before cervical myelography. An efficient study of the cervical spinal cord requires special surface coils adapted to this region. We have developed a surface coil, working as a receiver, inductively coupled, tuned and matched all at once, and easy to use. The concave form of this coil has been studied so as to be comfortable for all patients. It can be directly connected to our Thomson CGR machines (Magniscan 5000). In continuous routine use for 6 months, without any problems, it has been found to be very reliable. We present here some results on different types of myelopathy and discuss methodological aspects concerning the choice of acquisition parameters in the examinations. The simplicity of its realisation and the low cost leads us to believe that it will be possible to construct other surface coils convenient on many other parts of the body.

Magnetic resonance imaging and the "one-and-a-half" syndrome: a case report.

A patient is described who had magnetic resonance imaging (MRI) findings of a left paramedian pontine ischemic stroke. It was associated with right motor sensory and left cerebellar dysfunction and the "one-and-a-half" syndrome of Fisher.

[Segmentation of the lumbar radicular canal]. / La segmentation du défilé radiculaire lombaire.

The lumbar CT horizontal sections identification requires three levels to be defined of each vertebra: The arthropedicular level (upper third) describes an (omega) at the back with its dense bone structures. At each side of the canal is the upper part of the lateral recess, the narrowest and therefore the most threatened part of the nerve root passage. The isthmopedicular level (middle third) describes a complete bone ring around the vertebral canal. On this non articular level, the congenital dysplasia is most clearly observed. The subpedicular level (lower third) with its muscular surrounding, shows a floral outline. A fourth level, intervertebral or discal, is added. It is very similar to the last one and of course is the most common point of disco-radicular conflict. Each level appears to be specific, both by the silhouette outlined by the ligament and bone structures and by the relationship which they have with the meninges. Each of them has its own pathology which precisely directs the surgical approach.