Biomedical subjects
Publications and source records attributed to L Pierot.
Vertebral arteriovenous fistulae in patients with neurofibromatosis 1 (von Recklinghausen's disease) are rare. The mechanism of their formation is unclear. The vascular anatomy, which may be simple or complex has important implications for planning treatment. We describe two cases and review the literature.
Eclampsia is defined as the development of convulsion and/or coma during pregnancy. Physiopathology remains unclear. We report a case of eclampsia and review the literature. CT, MR and angiographic findings are described. Value of various techniques is discussed.
Fifteen patients with Sjögren's syndrome without clinical evidence of central nervous system disease were studied by MRI. Signal abnormalities were observed in 9 (60%). They were always visible on T2-weighted images as small punctate areas of high signal in the basal ganglia and the white matter of the cerebral hemispheres. Abnormalities were less frequently seen on T1-weighted images. Enlargement of cerebral sulci was observed in 6 cases. The specificity and significance of these abnormalities are discussed.
Dural arteriovenous fistula and sinus thrombosis are sometimes associated. The relationship between these two conditions remains unclear. Thrombophlebitis of the dural sinus may induce a dural fistula. Conversely, thrombophlebitis is sometimes observed in the course of dural fistulas. We report five cases of dural arteriovenous fistulas associated with sinus thrombosis. In three cases, the angiographic and pathological data indicated the responsibility of thrombosis in the occurrence of the fistula. In the others two cases, thrombophlebitis and fistula were simultaneously diagnosed by angiography. However, in one of these cases, the clinical data showed that the fistula probably was a causative factor in the occurrence of thrombophlebitis.
In a patient with dural carotid-cavernous fistula supplied by meningeal branches of both internal and external carotid arteries, particulate embolization of the meningeal branches of only the external carotid artery failed to cure the fistula. Subsequent radiation therapy achieved clinical and anatomical cure of the lesion.
Direct arteriovenous fistulae supplied by the external carotid artery are unusual. Rarely, congenital fistulae have been described involving the head and neck. We describe the first case of congenital internal maxillary arteriovenous fistula in a child. Balloon embolization is currently considered the method of choice for treatment of direct arteriovenous fistula.
Endoarterial embolization is now the treatment of choice for traumatic carotid-cavernous fistulas. However, traumatic or surgical occlusion of the carotid artery, or special cases such as unilateral double carotid-cavernous fistula, can make the transarterial approach hazardous or impossible. In such cases transvenous embolization can be an alternative treatment, although it is sometimes difficult or impossible to perform. Three cases of direct traumatic carotid-cavernous fistula and their treatments are described. In the first case, unilateral double carotid-cavernous fistula was treated with detachable balloons. In the second case, the fistula had previously been treated by trapping; percutaneous angioplasty was performed with subsequent plastic embolization of the fistula. In the third case, transarterial and transvenous approaches were impossible, and the patient was cured by combining a surgical procedure and an interventional technique.
Leuko-araiosis is an unspecific radiologic sign, seen with CT scan or with MRI. It can be found as well in normal elderly persons as in pathological conditions. For the sake of clarity, CT scan and MRI images have to be distinguished. CT leuko-araiosis is linked with vascular risk factors and with age. The situation is more complex for MRI leuko-araiosis (likely on account of the higher sensitivity of MRI). Some images (caps and rims), frequently seen in normal, even young, individuals, are more frequent in aging. On the contrary, abnormal images at a distance from the ventricle are more difficult to interpret. Some of them are due to pathological well defined conditions (small infarcts, Binswanger's disease, cysts, plaques). Others may be secondary to remote pathologies (such as infarcts). Others are due to little specific conditions, such as perivascular dilatations ('état criblé' due to brain vasogenic edema, or to brain atrophy whatever its cause, and more frequently seen in the elderly). Other changes, such as incomplete infarction or myelin pallor with gliosis, have been described. At last, in some cases, no clearcut pathological lesion could be found. Leuko-araiosis may be present in primary degenerative dementia of the Alzheimer type, but it is neither necessary nor sufficient to establish the diagnosis of Alzheimer's disease, and it does not seem more frequent than in elderly controls. The mechanism of leuko-araiosis in Alzheimer's disease is likely multifactorial (for example, cerebral atrophy, amyloid angiopathy, associated hypertensive arteriolosclerosis could be involved). The relationship between leuko-araiosis, myelin pallor and white matter atrophy is poorly understood, and remains to be studied.
Fifty-one patients with intracerebral stenosing arteriopathy were studied by computerized tomography (CT), magnetic resonance imaging (MRI) and cerebral arteriography. Clinical symptoms were varied, included impaired cognitive functions, progressive neurological deficit, headache and vomiting, and were sometimes not suggestives of the diagnosis. CT scans of the brain were normal in 25 percent of the cases or they were not probative because of various and non-specific abnormalities (hypodensity of various types or haemorrhagic hyperdensity). MRI always showed abnormalities but in many cases the lesions observed on T2-weighted images consisted of non-specific focal areas of high-intensity signal in the white matter. High-intensity signals in both white matter and cortex seemed to be more suggestive of the diagnosis. In this as in other studies, arteriography therefore remains the reference examination for stenosing arteriopathies. Inflammatory, infectious and atheromatous processes are the main causes of these arterial lesions. The aetiological value of radiological examinations is poor, and in most cases the morphology and distribution of the lesions does not point to any specific origin. However, herpes zoster arteritis usually affects the proximal segments of the anterior and middle cerebral arteries and spares the carotid siphon.
The authors report the CT and MR findings of a rare benign primary choroid plexus papilloma developed in the CPA with invasion of the neighboring structures, apparently the first description of such a case. Differential diagnosis with other CPA tumors is discussed. Papillomas should be considered among the vascular, calcified enhancing masses of the CPA even in adulthood.
The MRI findings in a 6-year-old boy with an astrocytoma of the mesancephalon are reported. A ventriculocisternostomy had been performed in order to reduce the hydrocephalus. At the site of the ventriculocisternostomy, the T2-weighted images showed a low signal in the anterior part of the third ventricle, the interpeduncular and the pontine cistern. This was attributed to CSF flow void. We conclude that MRI can provide information about the precise location and normal functioning of a ventriculocisternostomy.
The densities of D1- and D2-type dopamine receptors were measured with [3H]SCH23390 and [3H]spiperone, in the caudate nucleus and putamen of a large series of patients with Parkinson's disease or progressive supranuclear palsy, in relation to markers of dopaminergic and cholinergic innervation of the striatum ([3H]dihydrotetrabenazine binding and choline acetyltransferase activity). Correlations were sought between these parameters and clinical characteristics of the patients (abnormal involuntary movements, dementia, confusional syndrome or treatment). In Parkinson's disease, the densities of both types of receptors were unchanged, whereas in PSP, the density of D2, but not D1-type dopamine receptors, was decreased in the caudate nucleus and the putamen. No correlations between the biochemical and clinical data were found.
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Neurenteric cysts are rare congenital lesions that may cause spinal cord compression. Two cases are reported emphasizing the value of magnetic resonance imaging without and with contrast medium (Gd-DTPA) administration.
PURPOSE: To describe the clinical presentation, angioarchitecture, and risks and problems of therapy in patients with dural arteriovenous malformations of the posterior fossa draining into subarachnoid veins. PATIENTS AND METHODS: Twelve patients with dural arteriovenous malformations of the posterior fossa draining into subarachnoid veins were studied. RESULTS: These fistulas often presented with intracranial hemorrhage (eight cases) and myelopathy (two cases). They were located in the tentorium (six cases) or at the skull base (six cases). The arterial supply was provided by branches of the external carotid artery (nine cases), by the posterior meningeal branch of the vertebral artery (nine cases), and by the meningohypophyseal trunk (three cases). The fistulas drained directly into a cortical vein (six cases) or into a venous lake (six cases). In two cases, perimedullary draining veins were observed. The treatment modalities were endovascular embolization alone (two cases), surgery alone (five cases), and embolization followed by surgery (three cases). Despite the treatment, four patients died; in two cases, intracranial hemorrhage recurred. CONCLUSIONS: Subtotal occlusion of a fistula by surgery or embolization alone is not protective against further complications, especially hemorrhage. The goal of treatment is to achieve a rapid and complete anatomical cure; combined endovascular and neurosurgical treatment seems to be the therapeutic choice.
In a patient with palatal myoclonus, MR imaging demonstrated bilateral hyperintense lesions in the ventral part of the medulla. Microscopic examination of the inferior olives showed gliosis, enlargement and vacuolation of the neurons, and demyelinization.
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