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Biomedical subjects

J Chiras

Publications and source records attributed to J Chiras.

At least 55 records · Page 3Linked to original sources
PubMed1999

[The persistence of a spheno-occipital synchondrosis in an adult].

The postnatal development of the central skull base is a complex process: at least 25 separate ossification centers are assimilated in the maturing sphenoid and occipital bones. Some synchondroses may only be partially fused and persist during adulthood. We report the case of a 30-year-old man with a penetrating trauma of the central skull base. Skull computed tomography demonstrated a rare anatomic variant: incomplete fusion of the spheno-occipital synchondrosis. Knowledge of the normal skull base development and of its variants may prove helpful in differentiating a post-traumatic injury from a normal variant.

Adult↗
PubMed1999

Cross-sectional anatomy of the facial nerve.

The length and complexity of the anatomical course of the facial nerve explains the difficulty of its accurate morphologic evaluation. CT and MR appear to be complementary techniques to precisely depict the nerve from its pontine origin to the parotid gland. Anatomical variations exist in length or thickness of all intrapetrous segments or as frequent dehiscences which can lead to false positive results or at the opposite falsely negative diagnoses. Close relations with the antero-inferior cerebellar artery in the intracisternal and intracanalicular segments must be known. Gadolinium enhancement is usual in the fallopian canal with variable intensity and thickness and should be differentiated from pathological enhancement. Finally the intrapetrous course of the chorda tympani can be precisely displayed on CT in the intra-osseous canal and in the middle ear near the ossicles.

Anatomy, Cross-Sectional↗
PubMed1999

[Vertebro-epidural lumbosacral vascular malformations. An unusual cause of lumbo-sciatic pain].

Sciatica is most commonly caused by nerve root compression secondary to herniated disk. Rarely, it can be due to a lumbosacral vascular malformation. We present five cases with such a malformation, presenting as a chronic lumboradiculagia. The patients were explored with computed tomography, MRI and selective spinal angiography. Polymorphic anatomic and hemodynamic aspect of these cases are reported: 1. One vertebral hemangioma with epidural extension; 2. Three purely epidural malformations: a) one epidural cavernous hemangioma, b) one epidural arteriovenous malformation, c) one epidural varix; 3. One paravertebral arteriovenous fistula with epidural venous drainage. Diagnosis of these rare malformations may be difficult. A multiplanar cross-sectional magnetic resonance and computed tomography scan with contrast enhancement can show characteristic abnormalities and may assist in recognition these malformations. Selective spinal angiography confirms the diagnosis, allows to classify the malformation and is required to evaluate endovascular therapeutic possibilities.

Adolescent↗
PubMed1998

Acetabulum malignancies: technique and impact on pain of percutaneous injection of acrylic surgical cement.

The aim of our study was to describe the technique of percutaneous injection of acrylic surgical cement into acetabulum malignancies [percutaneous acetabuloplasty (PCA)] and determine its efficiency in relieving pain. Eighteen patients (8 men, 10 women; aged 40-81 years) with painful acetabular malignancies (18 lesions; 17 metastases, 1 multifocal bone sarcoma) were treated with PCA. Procedures were done using lateral approach with fluoroscopic guidance. The 18 procedures were evaluated and resulted in 4 (22 %) total improvement, 7 (39 %) clear improvement, 4 (22 %) moderate improvement, 1 (6 %) no improvement, and 2 (11 %) worsening in keeping with a cement leak in contact with the sciatic nerve and a leak towards the joint. Follow-up ranged from 2 to 48 months (average 9.4 months). We observed 2 cases of recurrence of pain at 6 and 39 months, both in keeping with local tumoral progression. PCA of malignancies is a minimally invasive and low-cost procedure that provides immediate and long-term pain relief.

Acetabulum↗
PubMed1998

Imaging findings of central nervous system neuroepithelial cysts.

Neuroepithelial cysts are rare and mostly asymptomatic cerebrospinal fluid (CSF)-like cysts. We describe herein the imaging findings in five patients with neuroepithelial cysts. Two cases of proven and three of presumed neuroepithelial cysts are presented. Three of five are located in the thalamus, a location which is not characteristic for neuroepithelial cysts. In the case of incidental finding of asymptomatic neuroepithelial cyst, clinical and radiological follow-up is indicated and surgical intervention is not necessarily warranted.

Adult↗
PubMed1998

Dural arteriovenous fistulas as a cause of intracranial hypertension due to impairment of cranial venous outflow.

OBJECTIVES: A retrospective study was carried out on 13 patients with intracranial dural arteriovenous fistulas (DAVFs) who presented with isolated or associated signs of intracranial hypertension. METHODS: Nine patients presented with symptoms of intracranial hypertension at the time of diagnosis. Ocular fundoscopy available in 12 patients showed bilateral papilloedema in eight and optic disk atrophy in four. Clinical evolution was particularly noticeable in five patients because of chronic (two patients) or acute (after lumbar shunting or puncture: three patients, one death) tonsillar herniation. RESULTS: Two patients had a type I fistula (drainage into a sinus, with a normal antegrade flow direction). The remaining 11 had type II fistulas (drainage into a sinus, with abnormal retrograde venous drainage into sinuses or cortical veins). Stenosis or thrombosis of the sinus(es) distal to the fistula was present in five patients. The cerebral venous drainage was abnormal in all patients. CONCLUSION: Type II (and some type I) DAVFs may present as isolated intracranial hypertension mimicking benign intracranial hypertension. Normal cerebral angiography should be added as a fifth criterion of benign intracranial hypertension. The cerebral venous drainage pattern must be carefully studied by contralateral carotid and vertebral artery injections to correctly evaluate the impairment of the cerebral venous outflow. Lumbar CSF diversion (puncture or shunting) may induce acute tonsillar herniation and should be avoided absolutely. DAVF may induce intracranial hypertension, which has a poor long term prognosis and may lead to an important loss of visual acuity and chronic tonsillar herniation. Consequently, patients with intracranial hypertension must be treated, even aggressively, to obliterate the fistula or at least to reduce the arterial flow and to restore a normal cerebral venous drainage. The endovascular treatment may associate arterial or transvenous embolisation and/or surgery. Patients in whom the fistula is not obliterated after an endovascular therapeutic procedure, need continuous clinical and angiographical follow up.

Adult↗
PubMed1998

[Intracranial dural arteriovenous fistula with perimedullary venous drainage].

Two cases of intracranial dural arterio-venous fistula (DAVF) with perimedullary venous drainage are reported. In both cases, MRI T2-weighted (T2W) images showed an hypersignal within the cervical cord with sparing of the thoracic cord. In one case perimedullary vessels were demonstrated on T1W images after gadolinium i.v. administration. A complete spinal angiogram did not show evidence of fistula but demonstrated the lack of opacification of the conus medullaris venous drainage. Cerebral angiogram demonstrated in the first case a foramen magnum DAVF and in the second case a petrous apex DAVF. Hypersignal limited to the cervical cord at MRI on T2W images remain exceptionnal in case of intracranial DAVF with perimedullary venous drainage. When neurological symptoms are suggestive, post gadolinium T1W sequences should be conducted, followed by selective spinal angiogram. If normal venous drainage is not objectivated (e.g. opacification of radiculo-medullary veins on the late phase), cerebral angiogram should be done to rule out an intracranial DAVF.

Aged↗
PubMed1998

[Percutaneous vertebroplasty of the cervico-thoracic junction using an anterior route. Technique and results. Report of nine cases].

Percutaneous vertebroplasty using fluoroscopy is a well known technique. Visualization of the posterior wall of the vertebra is mandatory. Good assessment of this part of the vertebra is usually difficult at the cervico-thoracic junction. We propose an original method to obtain adequate visualization of the posterior wall, avoiding the shoulders superposition. Using this technique, we performed twelve vertebroplasties in nine patients (one angioma and eleven metastatic lesions). Clinical outcome was good for all patients, even a total filling of the vertebra body by the cement was obtained in only eight cases on twelve. No clinical complication was observed.

Cervical Vertebrae↗
PubMed1997

High-intensity lesion on T1-weighted MR images in neurofibromatosis type 1: a case of premalignant lesion.

We report a patient with NF1, who was followed up because of an optic glioma and one enhancing lesion presumed to be a pilocytic astrocytoma. T1- and T2-weighted MR images showed also a hyperintense periventricular lesion with no enhancement and no mass effect, of an unsuspected nature. Three years later a glioblastoma multiforme developed at the site of this preceding lesion.

Adult↗
PubMed1997

Long-term changes in intracranial dural arteriovenous fistulae leading to worsening in the type of venous drainage.

We review seven patients with intracranial dural arteriovenous fistulae (ICDAVF), each altering the initial type of venous drainage to one with a higher grading during long-term follow-up. Five were discovered due to symptoms of intracranial hypertension, two due to changes in tinnitus and one case following subarachnoid haemorrhage. In five cases, cortical venous drainage developed during the follow-up period. Three different mechanisms were observed: stenosis or thrombosis in the draining veins in 4 cases: increased arterial flow in 2; and the appearance o a new fistula site or extension of the initial shunt in 2. Type I and type II a fistulae which are not completely cured, require both close clinical observation and Doppler examinations in the follow-up period. Any charge in the clinical pictures indicates a repeat angiogram. Stenosis of the venous drain-age, forecasting later worsening in the venous outlet, requires more thorough angiographic follow-up.

Adult↗
PubMed1997

Cranial MRI findings in myotonic dystrophy.

MRI was performed in 13 patients with the adult form of myotonic dystrophy (MD) and compared with that of sex- and age-matched normal controls. There was some cerebral atrophy in the patients and marked thickening of the skull in three of them, associated with ossification of the falx cerebri in two. We found high-signal areas on T2-weighted images in the white matter in 9 (70%) of the patients; five showed high-signal areas in the subcortical white matter of the temporal lobes. These findings were associated with intellectual impairment in only one patient, who had a history of a difficult birth and temporal lobe epilepsy.

Adult↗
PubMed1997

Contrast enhancement of the facial nerve on MRI: normal or pathological?

We prospectively analysed the normal contrast-enhanced MRI features of the facial nerve and determined criteria for pathological contrast enhancement. We studied 31 patients with clinically normal facial nerves with T1-weighted images before and after contrast medium. The intensity, thickness and right-left symmetry of enhancement were assessed in each segment and correlated with MRI features observed in abnormal facial nerves. Enhancement along at least one segment of the facial nerve was seen in 98% of cases, but only within the facial canal: labyrinthine segment: 78.2%; geniculate ganglion: 96.9%; tympanic: 88.4%; mastoid: 66.6%. Marked (+2) to intense (+3) enhancement was seen in the labyrinthine segment in 17.4%, the geniculate ganglion in 36.3%, and the tympanic (25.6%) and mastoid (7.1%) segments, whereas intense enhancement was only seen in the geniculate ganglion (6%) and the tympanic segment (11.6%). A right-left asymmetry was noted in 69% of cases. No correlation was found between enhancement and the thickness of the nerve. No enhancement of the eighth nerve was seen. We suggest three criteria for pathological enhancement: enhancement outside the facial canal; extension of enhancement to the eighth nerve; and intense enhancement in the labyrinthine and/or mastoid segments.

Adolescent↗
PubMed1997

[Percutaneous vertebral surgery. Technics and indications].

Percutaneous vertebroplasty is a technique of interventional radiology, which allows to fulfill pathologic vertebral body with acrylic cement. This method is used to strengthen the vertebral body and reduce pain in some diseases involving the vertebra. Main indications are spine angiomas, metastases and osteoporosis. The vertebroplasty is realised under neuroleptanalgesia for cervical spine antero lateral way is used. For thoracic or lumbar vertebra, the way of approach is usually transpedicular; but in some cases, this approach is not possible: osteolysis of the pedicle, surgical osteosynthesis; in such cases, a postero lateral approach is realized. Technical incidents are not rare, but are usually asymptomatic. More frequent are venous filling with cement; the veins involved can be intra spinal (vertebral plexus) or paraspinal. Instead of this frequency pulmonary embolism in direct relation with the vertebroplasty where not reported. Extravasation in intervertebral disk or soft tissue can also be observed. This last incident can be in relation with the way of the needle or with a cortical rupture. Local complications are rare: rate of neurological deficit or infection is under 0.5%. Radicular pain is observed in 3.7% of cases. These complications are in close relation with the radiological involvement of the vertebra: cortical disruption, heterogeneous Lysis of the vertebral body. The frequency of complications is 1.3% in osteoporosis, 2.5% in spine angiomas and 10% in metastatic disease. Indications concern lesion involving the vertebral body: symptomatic spine angiomas; painful osteoporotic fractures after medical treatment or in patients with a high risk of decubitus complications; in metastatic disease, vertebroplasty is a way to consolidate the vertebral body and release pain. It can be usefull in recurrent pain after chemotherapy and/or radiotherapy, and also in unstable vertebra to obtain a stabilization before radiotherapic or chemotherapic treatment isolated or in combination with surgical osteosynthesis.

Acrylic Resins↗
PubMed1997

[The nasopharynx and deep spaces of the face: anatomy and applications to pathology].

Deep facial spaces are anatomically delineated by the layers of deep cervical fascia. They are located between the skull base and the hyoid bone. Each space contains specific anatomic structures, which can be responsible for specific pathologic processes. Deep facial spaces can be divided in two medial odd spaces (pharyngeal mucosal and retropharyngeal spaces), and in three lateral even spaces (retrostylian, prestylian, and masticator spaces). The dividing of these core tissues are useful for the analysis of the lesions found in this area. CT scan and MRI (with axial and coronal views) provide precise analysis. The main lesions are: -medially, adenoidal hyperplasias and squamous cell carcinomas (pharyngeal mucosal space), adenopathies and abscess (retropharyngeal space). -laterally, salivary tumors (prestylian space), adenopathies, schwannomas and paragangliomas (retrostylian space). Masticator space (and especially pterygopalatine fossa) is an important way of communication and is often involved by the extension of locoregional pathologic processes.

Adenoids↗