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Biomedical subjects

R Ethier

Publications and source records attributed to R Ethier.

At least 19 recordsLinked to original sources

Conservative therapy of atlantoaxial osteomyelitis. A case report.

STUDY DESIGN: A rare case of C1-C2 vertebral osteomyelitis treated conservatively is described. The radiologic findings as well as the follow-up evaluation are reported. OBJECTIVE: To increase knowledge about the pathogenesis and treatment of vertebral osteomyelitis in the high cervical region. SUMMARY OF BACKGROUND DATA: This is one of the first cases reported of successful conservative treatment of osteomyelitis at this level. METHODS: In a 58-year-old man with lumbar staphylococcal infection, a subsequent cervical infection developed. Because the lumbar spondylitis was treated promptly, the cervical osteomyelitis was treated at a very early stage of development. RESULTS: Operative decompression is the treatment most often used in osteomyelitis at the C1-C2 level. This is an extremely unusual circumstance in which early treatment of the infection negated the need for surgery. CONCLUSION: Conservative treatment of osteomyelitis at the C1-C2 level can be efficacious in the correct setting.

Atlanto-Axial Joint↗

The negative angiogram in subarachnoid haemorrhage.

Our purpose was to review the incidence of negative cerebral panangiography in acute nontraumatic subarachnoid haemorrhage (SAH); to document the amount and distribution of subarachnoid blood on CT and determine its relationship to findings on repeat angiography; and to study the outcome of these patients from the time of presentation to hospital discharge. From 1983 to 1992, 295 patients underwent cerebral angiography for acute SAH at our institution. The CT, angiographic and MRI findings and clinical course of patients with initially negative angiograms were reviewed retrospectively. The overall incidence of negative cerebral panangiography was 31% (92/295). An aneurysm was disclosed on a second angiogram in 4 cases, and on a third angiogram in 1, giving a total false negative rate of 5%. In 55% of cases, only a small amount of SAH was present on CT. The distribution of the subarachnoid blood was nonspecific and resembled the pattern seen in aneurysmal SAH. Ninety-four percent of the patients presented in Hunt-Hess grades I and II. The complications of conservative treatment were few: a rebleed rate of 4%, delayed cerebral ischemia in 4%, cerebral infarcts in 8% and hydrocephalus requiring shunting in 3%. On discharge, 93% of patients had recovered completely and the others were left with moderate disability. There were two deaths related to massive rebleeding. Patients with perimesencephalic SAH (35%) fared particularly well; none developed complications during their hospital stay and repeat angiograms never revealed an underlying aneurysm. In such cases, further angiographic investigations do not seem warranted.

Angiography, Digital Subtraction↗

The role of computed tomographic angiography in the assessment of intracranial vascular disease.

Both technical and clinical implications of three-dimensional computed tomographic angiography in the evaluation of intracranial circulation, and in particular cerebral aneurysms, are presented. Three-dimensional computed tomographic angiography allows excellent visualization of the aneurysm, its neck, and its relationship with the parent artery and important adjacent bony structures. This technique has a major role in the evaluation of difficult aneurysms. In addition, advantages and disadvantages are discussed in comparison with more conventional techniques such as magnetic resonance imaging, magnetic resonance angiography, and digital subtraction angiography. Three-dimensional computed tomographic angiography will continue to develop with the advent of more rapid computed tomography scanners, playing a key role in the investigation and screening of patients with a family history of cerebral aneurysms.

Brain↗

Cerebral vein thrombosis due to hereditary antithrombin III deficiency.

Cerebral vein thrombosis, also called superior sagittal sinus thrombosis, is a well recognized clinical and radiologic entity associated with a variety of medical disorders. We report a patient with fatal cerebral vein thrombosis following myelography, in whom the cause was familial antithrombin III (AT3) deficiency. Unsuspected AT3 deficiency should be considered in cases of unexplained cerebral venous thromboses.

Adult↗

Extension of a cerebellar cystic astrocytoma into the cervical canal, demonstrated by magnetic resonance imaging.

One characteristic feature of ependymomas of the fourth ventricle is a tendency to extend through the foramina, specifically the foramina of Luschka and Magendie, the foramen magnum and the aqueduct of Sylvius. The authors report a case of pilocytic astrocytoma of the cerebellum that mimicked such extension into the upper cervical canal. This finding was revealed by magnetic resonance imaging and confirmed at surgery.

Astrocytoma↗

Multiple occult vascular malformations of the brain and spinal cord: MRI diagnosis.

We report a patient with multiple angiographically occult vascular malformations in the brain and spine. Magnetic resonance imaging showed multiple lesions in brain and spine with hypointense areas on both T1 and T2-weighted images. These hypointense areas are usually secondary to hemosiderin deposits consistent with remote bleeding in the lesions. We conclude that when magnetic resonance reveals an intraspinal lesion with signal intensity characteristics consistent with a vascular malformation, an examination of the brain should be performed to rule out associated intracranial lesions. The finding of multiple lesions in the brain with identical signal intensity characteristics reinforces the diagnosis of vascular malformation.

Brain↗

Hydrocephalus and prominence of the choroid plexus: an unusual computed tomographic presentation of cerebral toxoplasmosis in AIDS.

Toxoplasmosis is a frequent cause of infection of the central nervous system (CNS) in patients with acquired immunodeficiency syndrome. Computed tomography (CT) usually shows solitary or multiple parenchymal lesions, which are most often located in the cortex, the juxtacortical white matter and the basal ganglia. The authors describe a 30-year-old immunocompromised Haitian woman with pathologically proven CNS toxoplasmosis who presented with hydrocephalus and prominence of the choroid plexus; there was no evidence of focal parenchymal lesions in contrast-enhanced CT scans. An autopsy revealed diffuse destruction of the ependyma of the lateral, the third and the fourth ventricles. Necrosis was evident, and the periventricular tissues and the choroid plexus were infiltrated with neutrophils and macrophages. Pseudocysts of Toxoplasma were identified near the ventricular surface.

Acquired Immunodeficiency Syndrome↗

Hippocampal sclerosis in temporal lobe epilepsy demonstrated by magnetic resonance imaging.

The value of magnetic resonance imaging in the detection of hippocampal sclerosis has been controversial. We studied 10 patients aged 22.5 +/- 6.0 years with intractable temporal lobe epilepsy selected because of a history of a prolonged childhood convulsion, which is characteristic of a group of patients in whom hippocampal sclerosis is a constant finding. All 10 patients showed reduction in size of one hippocampus associated with increased signal intensity on T2-weighted magnetic resonance images. These changes were reliably detected on coronal spin-echo images, perpendicular to the long axis of the hippocampus. Appreciation of the normal imaging anatomy of the hippocampus allowed correct interpretation of the relative changes in signal intensities of the hippocampus and adjacent temporal horn on sequential echo images. The side of the abnormal hippocampus on magnetic resonance imaging accorded with the electroencephalographic localization in all 10 patients, and with the lateralization of the early convulsions in all 6 patients where this was known. Temporal lobectomy was performed in all 10 patients. Hippocampal sclerosis was confirmed in the 3 patients in whom hippocampal tissue was available for histological examination. The value of this technique was reinforced by the excellent postoperative results, with 80% being seizure free at a mean follow-up time of 33 +/- 4 months.

Adolescent↗

Percutaneous aspiration biopsy in cervical spine lytic lesions. Indications and technique.

We describe the technique and the results of the percutaneous aspiration biopsy (PAB) in a series of 9 patients presenting with neck pain and different degrees of myelopathy, in whom the cervical spine X-ray demonstrated lytic lesions of unknown origin. PAB is a useful, relatively safe technique, and leads to histological diagnosis between metastatic and inflammatory processes. Furthermore, in inflammatory lesions with negative hemoculture. PAB may help in detecting the micro-organism responsible and therefore allow a better antibiotic treatment.

Adult↗

Neuronal migration disorders: a contribution of modern neuroimaging to the etiologic diagnosis of epilepsy.

Computed tomography and magnetic resonance imaging enable the identification of neuronal migration disorders during life. Several specific syndromes have been identified and early diagnosis of previously unrecognized entities is now possible. We report 51 patients with imaging. Thirty-two had a single widespread cortical dysplastic lesion. Twenty-eight had focal corticectomies. From a pathological standpoint, these encompassed focal cortical dysplasia (14 cases) and forme fruste of tuberous sclerosis (10 cases). These two groups of patients were indistinguishable from the clinical and radiological standpoint. In only two was the MRI examination normal. In addition, there were 10 with bilateral perisylvian dysplasia, four with diffuse cortical dysplasia or the "double cortex" syndrome, three with hemimegalencephaly, one with megalencephaly, and one with nodular neuronal heterotopia. The electroclinical and imaging findings led to the development of specific surgical strategies for the alleviation of the intractable seizures in each of these radiologically-defined syndromes.

Adolescent↗

Spinal cord distraction: an in vitro study of length, tension, and tissue pressure.

Since the Scoliosis Research Society released a report on cord injury related to Harrington rod instrumentation for scoliosis, little has been published on the pathophysiology of this disorder. Dolan et al. (4) described diminished cord blood flow associated with spinal distraction in a cat model, but failed to demonstrate its cause. In this article, we describe a series of in vitro experiments performed on dog and sheep cadaver spinal cords. Controlled distractive forces were applied to spinal cords while monitoring both cord interstitial pressure and cord elongation. A close (Ravg = 0.986) correlation was noted between applied tensile forces and cord interstitial pressure. At 1,000-g loads, the average tissue pressure obtained was 29.5 cm H2O, ranging from 17 to 47 cm H2O. However, it was noted that the cord demonstrated nonlinear tensile elastic properties that appeared exponential in the range examined. These properties are consistent with those described for collagen-containing compounds. We conclude that spinal cord distraction is capable of generating cord tissue pressures that could cause a spinal cord compartment syndrome and thereby seriously impair spinal cord blood flow causing spinal cord injury.

Animals↗

Multiple intracerebral cavernous angiomas.

Eight patients (seven women and one man) with multiple intracerebral cavernous angiomas (cavernomas), also known as angiomatosis cerebri, were examined with high-field magnetic resonance imaging (MRI). Although previous articles have referred to such cases, a series similar to the one reported here has apparently not been described in the radiology literature. The patients presented with seizures, progressive neurologic deficit or cerebral hemorrhage. In all eight cases the multiplicity of the lesions was an incidental finding in the magnetic resonance images. The MRI appearance of the cavernomas, although characteristic, is similar to that of other angiographically occult intracranial vascular malformations, in particular thrombosed arteriovenous malformations and mixed vascular malformations, as well as that of hemorrhagic metastases. Additional criteria, such as the absence of edema, the presence of calcifications and the temporal evolution of the cavernomas on serial scans, should allow cavernomas to be differentiated from hemorrhagic metastases. The exquisite sensitivity in detecting angiomatosis cerebri and the ability to show the evolution of internal hemorrhage in individual lesions make MRI the method of choice for diagnosing and following this condition.

Adolescent↗

Magnetic resonance imaging of hypothalamic hamartomas causing gelastic epilepsy.

Hypothalamic hamartomas may cause a peculiar epileptic syndrome characterized by seizures of laughter and precocious puberty. Four mentally handicapped patients suffering from gelastic epilepsy were referred to our institution for investigation; three of them also presented with precocious puberty. In all four cases magnetic resonance imaging (MRI) revealed a space-occupying lesion of the hypothalamus that was considered to be a hamartoma. Biopsies were not performed. Hamartomas appear isodense in plain computed tomography scans, and they do not enhance. Such lesions display an isointense signal in T1-weighted magnetic resonance images and a hyperintense signal in proton density and T2-weighted images. MRI is the procedure of choice for detecting such lesions at the base of the brain.

Adolescent↗

[Angiolipoma of the central nervous system].

Angiolipomas of the central nervous system are rare tumors (37 cases in the literature) and are mostly located in the spine (95%), rarely in the skull. When they are intraspinal, these masses are extradural in more than 90% of the cases. Angiolipomas are benign tumors containing vascular and mature adipose elements. The clinical symptomatology is non specific, but computed tomography and mostly MRI provide a precise diagnosis. With 2 additional cases and a review of the literature, we define the main characteristics of these tumors.

Adult↗