Biomedical subjects
Publications and source records attributed to J Chiras.
Adult brain tumors comprise a remarkably diverse group of histologic varieties; the potential of CT and MRI for diagnosing presence of tumors of the brain and evaluating their extension is well recognized. A precise radiologic diagnosis can be often made as for as extra-axial tumors are concerned. On the contrary this is often more difficult for intraparenchymal tumors.
OBJECTIVE: To determine which brain structures are involved in symptomatic unilateral dystonia caused by localized cerebral infarction. DESIGN: Three-dimensional T1-weighted magnetic resonance imaging sequence and stereotactic analysis were used to analyze the topography of the lesions. Stereotactic localization of thalamic lesions was conducted according to the atlas of Hassler with a Voxtool software (Advantage Windows Workstation, General Electric, Milwaukee, Wis) workstation system. PATIENTS: Eight patients with hemidystonia, segmental dystonia, or focal dystonia were selected from among 51 consecutive patients (between January 1988 and May 1993) with symptomatic unilateral dystonia. RESULTS: Patients had dystonic spasms (n=4) or myoclonic dystonia (n=4). Lesions associated with dystonic spasms were located in the striatopallidal complex, and those with myoclonic dystonia were in the thalamus contralateral to the dystonia. Lesions of the striatopallidal complex involved the putamen posterior to the anterior commissure in all patients and extended variably into the dorsolateral part of the caudate nucleus, the posterior limb of the internal capsule, or the lateral segment of the globus pallidus. These lesions were centered in the "sensorimotor" part of the striatopallidal complex, with a trend toward a somatotopical distribution. Lesions of the thalamus were located in the ventral intermediate and ventral caudal nuclei, while the ventral oral anterior and posterior nuclei (which receive pallidal efferents) were largely spared. CONCLUSIONS: These results suggest that striatopallidal and thalamic dystonia may have different pathophysiologic bases.
For the non-operable malignant glioma patients, prognosis remains poor, with a survival of 8 months for the glioblastomas (G), and 15 months for anaplastic astrocytomas (AA). 27 histologic proven malignant gliomas (17 AA and 10 G) were treated between April 1991 and June 1992. Median age was 48 years. The therapeutic protocol consisted of three courses of intra arterial chemotherapy (IAC) with ACNU, at intervals of six weeks, and a localised 60 Gy radiotherapy between the first and the second IAC course. 72 courses of IAC were delivered (2.4 per patient). Response rate was 51.8%. Median survival (MS) was 13 months, with a survival rate of 28% at 24 months. For the AA, MS was 21 months, with a survival rate of 37% at 24 months. For the G, median survival was 10 months. Responders were 65% for AA, 30% for G. Non responders all died before 24 months had relapsed with a MS of 9 months. 54% of responding patients had a 2 years survival. Toxicity were acceptable with 7% of haematological toxicity and partial loss of visual acuity in 11% of the case. No chronic neurological sequellae were noted. We compare theses results with two previous trials, concerning inoperable patients, treated by association of radiotherapy and systemic chemotherapy. Survival seems to be equivalent with HeCNU and with this treatment, but toxicity decrease with ACNU. Early radiotherapy does not increase complications. This treatment can be used for patients with inoperable malignant gliomas.
A case of posttraumatic compressive subarachnoid cyst of the thoracic spine studied by MR myelography, and myelo-CT is reported. This cyst was surgically confirmed and treated by shunting.
We report two cases of acrylic vertebroplasty in symptomatic cervical vertebral haemangiomas. In both cases significant improvement of symptoms was rapid. One patient was able to return to work.
Neurological complications are rare in trichinosis. We report a case with marked hypereosinophilia in which MRI showed multiple small subacute cortical infarcts with Gd-DTPA enhancement.
A failed embolisation of a spinal dural arteriovenous fistula (AVF), because a pedicular injection has not reached the initial venous compartment, must be identified immediately, to allow prompt surgery and thus avoid clinical deterioration. The purpose of our study was to determine the role of CT in confirming a complete cure just after embolisation with N-butyl cyanoacrylate (NBCA). Seven patients embolised for spinal dural AVFs with perimedullary venous drainage had an immediate postembolisation CT scan. In six patients a complete cure was achieved, with a normal postembolisation angiogram in five cases. Just after injection of NBCA, we were unable to determine on plain films whether or not the glue had reached the draining vein in six of seven cases. The postembolisation CT showed various patterns: in two cured patients, the glue was visible in the inner surface of the dura mater and therefore on the venous side. In five cases, the glue was approaching the dura mater around the cord or seemed to reach its surface: in the four patients cured, the glue column was 7-18 mm high, whereas it was less than 2 mm high in the patient with angiographic proof of recurrent fistula. The follow-up angiogram remains the only way to confirm a durable cure. We suggest that immediate postembolisation CT may help in assessing endovascular treatment of spinal dural AVFs.
The case of a 42 year old man with headache, blurred vision, and diplopia allowed the description of a particular form of cerebral lacunae-that is, expanding lacunae. Brain MRI showed hydrocephalus and multiple lesions in the thalamomesencephalic region. The radiological features of these lesions were similar to the histological brain coronal section of a case reported in 1983 in which expanding lacunae were related to a dilatation of the perivascular spaces and a focal segmental necrotising angiitis. The role of the lymphatic drainage of the brain is discussed to explain the dilatation of the perivascular spaces. The hypothesis of a hydrodynamic factor being responsible for the expanding character of the lacunae was suggested by the location of the lesions and the influence of various clinical events on the symptomatology.
PURPOSE: To determine the efficacy of percutaneous vertebroplasty in treating spinal metastases that result in pain or instability. MATERIALS AND METHODS: Thirty-seven patients (20 men, 17 women; aged 33-86 years) underwent 52 percutaneous injections of surgical cement into a vertebra (vertebroplasty) with fluoroscopic guidance in 40 procedures. Vertebroplasty was performed for analgesia in 29 procedures, stabilization of the vertebral column in five procedures, and both in six procedures. RESULTS: Twenty-four of the 33 procedures performed for analgesia that were evaluated resulted in clear improvement; seven, moderate improvement; and two, no improvement. Improvement was stable in 73% of patients at 6 months. In the procedure performed for stabilization, no displacement of treated vertebrae was observed (mean follow-up, 13 months). Three patients had transient radiculopathy due to cement extrusion, and two patients had transient difficulty in swallowing. CONCLUSION: Vertebroplasty of metastases is a minimally invasive procedure that provides immediate and long-term pain relief and contributes to spinal stabilization.
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MR imaging of the brain, particularly with high field MR imagers, may demonstrate signal abnormalities consistent with deposits of iron or other paramagnetic substances in extrapyramidal disorders. The diagnosis of Parkinson's disease and progressive supranuclear palsy can be made on clinical grounds in most of the cases and MR signs are of little help in the diagnosis of these diseases. In patients with parkinsonian disorders poorly responding to therapy, MR imaging may be useful in demonstrating signal abnormalities in the putamen that may help to establish the diagnosis of striatonigral degeneration (component of multiple system atrophy) with a poorer prognosis than Parkinson's disease. Finally, MR imaging may be useful in the exclusion of other disease processes.
OBJECTIVES: To point out the usefulness and effication of endovascular treatment of arteriovenous fistulae complicating the insertion of central venous catheter. MATERIAL AND METHOD: Retrospective study of 7 cases treated between 1983 and 1993. The central venous catheterization had involved the right internal jugular vein in 5 cases and the right subclavian vein in 2 cases. RESULTS: Isolated endovascular therapy was performed in 5 cases. Surgery was necessary in 1 case to remove an hematoma. In another case, occlusion of a large AVF was performed during intraoperative endovascular temporary occlusion of the AVF. The choice of the occluding agent was primarily dictated by the hemodynamic and anatomical conditions (releasable balloons, coils). Vertebro-vertebral fistulae (3 cases) could be treated with patency of this vessel. No complications were encountered. CONCLUSION: Endovascular approach is a reliable and safe method to perform occlusion of post catheter AVF.
Vertebroplasty is a new therapeutic method which by way of filling with acrylic cement in the vertebral body gives a stabilization of the vertebra and an antalgic effect in painful lesions involving the spine. Main indications consist of spine angiomas, metastases and osteoporotic fractures involving the vertebral body. In most patients, vertebroplasty gives a very good and durable antalgic effect as in cases of angiomas or metastases as in post-therapeutic sequellae in malignant hematosarcomas. In osteoporotic fractures, antalgic effect is obtained very rapidly, but the follow-up is actually insufficient to evaluate the long term benefit.
Magnetic resonance based volumetric measures of hippocampal formation, amygdala (A), caudate nucleus (CN), normalised for total intracranial volume (TIV), were analysed in relation to measures of cognitive deterioration and specific features of memory functions in 18 patients with probable Alzheimer's disease. Neuropsychological examination included the mini mental state examination (MMSE), the Mattis dementia rating scale (DRS), tests of executive functions, assessment of language abilities and praxis, the Wechsler memory scale (WMS), the California verbal learning test (CVLT) and the Grober and Buschke test. The volume of the hippocampal formation (HF/TIV) was correlated with specific memory variables: memory quotient and paired associates of the WMS; intrusions and discriminability at recognition for the Grober and Buschke test. By contrast, except for intrusions, no correlations were found between memory variables and the volume of amygdala (A/TIV). No correlations were found between the volume of caudate nuclei (CN/TIV) and any neuropsychological score. The volume of the hippocampal formation was therefore selectively related to quantitative and qualitative aspects of memory performance in patients with probable Alzheimer's disease.
PURPOSE: To review the symptoms and progression of dural arteriovenous fistulas (AVFs) and correlate the findings with various angiographic patterns. MATERIALS AND METHODS: Patterns of venous drainage allowed classification of dural AVFs into five types: type I, located in the main sinus, with antegrade flow; type II, in the main sinus, with reflux into the sinus (IIa), cortical veins (IIb), or both (IIa + b); type III, with direct cortical venous drainage without venous ectasia; type IV, with direct cortical venous drainage with venous ectasia; and type V, with spinal venous drainage. RESULTS: Type I dural AVFs had a benign course. In type II, reflux into the sinus induced intracranial hypertension in 20% of cases, and reflux into cortical veins induced hemorrhage in 10%. Hemorrhage was present in 40% of cases of type III dural AVFs and 65% of type IV. Type V produced progressive myelopathy in 50% of cases. CONCLUSION: This classification provides useful data for determination of the risk with each dural AVF and enables decision-making about the appropriate therapy.
Cerebral toxoplasmosis remains the most frequent etiology of cerebral masses in AIDS. In most cases, the disclosure of multiple enhanced masses is suggestive of diagnosis of toxoplasmosis and leads to undertake presumptive therapy. Sometimes, the pattern is less suggestive, and the possibility of primary cerebral lymphoma (PCL) is a diagnostic dilemma, because this is a short term life-threatening lesion in the absence of an undelayed fitting therapy. However, apart from the periventricular form of PCL, where directly proceeding to biopsy should be suggested, there is no distinctive pattern of PCL. The most reliable features in distinguishing between PCL and toxoplasmosis are: solitary lesion, homogeneous enhancement of a lesion whose diameter is larger than 2 cm, situation in deep periventricular white matter and limited edema and mass effect. The presence of haemorrhagic foci in the lesion, if there is no steroid therapy is rather indicative of toxoplasmosis. The lack of enhancement on enhanced CT-scan does not allow to eliminate cerebral toxoplasmosis, and indicate MR examination, or empiric antitoxoplasmic treatment. The radiologic follow-up depends on clinical response and on initial pattern. The criteria of response to antitoxoplasmic treatment are: the decrease in volume or number of lesions, the decrease of edematous reaction and mass effect (if no steroid was administered). If the lesion was initially equivocal, the lack of growth in a 8-day delay is a criterion for toxoplasmosis, just as the occurring of haemorrhage in the lesions (if there is no steroid-therapy).
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