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A Bonafe

Publications and source records attributed to A Bonafe.

At least 19 recordsLinked to original sources
PubMed2006

[Can multislice helical computed tomography replace conventional angiography in the diagnosis of non traumatic subarachnoid hemorrhage?].

AIM OF THE STUDY: To evaluate the reliability of CT angiography in the diagnosis of non traumatic subarachnoid hemorrhage. MATERIALS AND METHODS: We prospectively studied 57 patients presenting with non traumatic subarachnoid hemorrhage. In all cases, CT angiography of the circle of Willis was performed, followed by conventional angiography. We compared the results of both techniques, with conventional angiography considered as the gold standard. RESULTS: The specificity of CT angiography for diagnosing intracranial aneurysms was 100% with sensitivity and negative predictive values of 86% and 65% respectively. The aneurysms that were not diagnosed on CT angiography were located on the supra-cavernous internal carotid artery and their size was less than 5mm. Futhermore CT angiography failed to diagnose the other causes of subarachnoid hemorrhage. CONCLUSION: CT angiography can be considered as a first line imaging technique for diagnosis of non traumatic subarachnoid hemorrhage. However, conventional angiography including three dimensional acquisitions must be performed for all cases where the cause of hemorrhage remains undiagnosed at CT angiography.

Cerebral Angiography↗
PubMed2002

Selective endovascular treatment of intracranial aneurysms using micrus microcoils: preliminary results in a series of 78 patients.

PURPOSE: To determine the safety and reliability of a new platinum microcoil (Micrus), in the treatment of intracranial aneurysms. PATIENTS AND METHODS: Seventy-eight patients (28 male and 50 female patients; age range, 28-83 years; mean age, 44 years) with 80 intracranial aneurysms were treated in 10 centers in Belgium and France. All aneurysms were smaller than 15 mm. Nine aneurysms (11%) were located in the posterior circulation and 71 (89%) in the anterior. Fifty aneurysms (63%) were ruptured and 30 (37%) unruptured. Micrus microcoil is a new platinum coil. It is electrically detached with a time of detachment close to 5 seconds. RESULTS: The degree of occlusion of the aneurysm was classified as total in 49 aneurysms (61%), subtotal in 28 cases (35%) and incomplete in 3 cases (4%). Technical complications were encountered in 10 patients (13%) including parent artery occlusion and thromboembolism (4 cases), coil migration (2 cases) and non-detachment of the coil (2 cases). The immediate morbidity rate was 1.3% and mortality rate 1.3%. CONCLUSION: Micrus microcoils are effective and safe in the selective treatment of ruptured and unruptured intracranial aneurysms. Spherical microcoils are helpful to create a good basket in the aneurysmal sac at the beginning of treatment.

Adult↗
PubMed2001

Vestibular schwannomas: correlations between magnetic resonance imaging and histopathologic appearance.

BACKGROUND: The indication for surgery of vestibular schwannomas (VS) remains controversial and depends on several factors. The ability to predict their patterns of growth would allow better surgical planning. This growth may depend on tumoral proliferation but also depends on dystrophic changes. OBJECTIVE: The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in predicting the evolution of VS. For this purpose, the authors attempted (1) to compare the MRI appearance of VS with its histopathologic features, (2) to correlate the MRI appearance of VS and its histopathologic features with its size, and (3) to evaluate the index of proliferation (IP) of each VS. PATIENTS AND METHODS: Thirty VS were studied with MRI before surgery. The VS were measured and classified as homogeneous, heterogeneous, and cystic. After surgery, IP was evaluated with immunohistochemical study using MIB-1 monoclonal antibody, and compared with tumor size. Pathologic studies evaluated the prevalence of Antoni type A and type B tissue, the amount of fibrosis, and the presence of siderin-loaded macrophages, xanthomatous cells, and cysts. RESULTS: The IP was low (0.2%-2.2%) and was not correlated with VS size. On MRI, 13 VS were homogeneous, 12 heterogeneous, and 5 cystic. The 13 homogeneous VS were smaller and were predominantly made of Antoni type A tissue. The 12 heterogeneous and 5 cystic VS were larger and were predominantly made of Antoni type B/mixed tissue. Heterogeneous and cystic VS showed significantly more hemosiderin deposits. There was a significant relation between the amount of hemosiderin deposits and the mean size of VS. Microscopic cysts were observed only in VS with cystic MRI appearance. Fibrosis was present in all tumors regardless of their size and MRI appearance. CONCLUSION: A heterogeneous MRI aspect (correlated with larger mean size) not only is related to the ratio of type A to type B tissue but also is caused by other pathologic changes, mainly hemosiderin deposits and cystic formation. Increasing tumor size probably depends less on IP than on dystrophic changes (hemosiderin, cysts) and/or on the presence of type B tissue.

Adolescent↗
PubMed2000

Magnetic resonance imaging stereotactic target localization for deep brain stimulation in dystonic children.

OBJECT: The actual distortion present in a given series of magnetic resonance (MR) images is difficult to establish. The purpose of this study was to validate an MR imaging-based methodology for stereotactic targeting of the internal globus pallidus during electrode implantation in children in whom general anesthesia had been induced. METHODS: Twelve children (mean follow up 1 year) suffering from generalized dystonia were treated with deep brain stimulation by using a head frame and MR imaging. To analyze the influence of distortions at every step of the procedure, the geometrical characteristics of the frame were first controlled using the localizer as a phantom. Then pre- and postoperative coordinates of fixed anatomical landmarks and electrode positions, both determined with the head frame in place, were statistically compared. No significant difference was observed between theoretical and measured dimensions of the localizer (Student's t-test, ¿t¿ > 2.2 for 12 patients) in the x, y, and z directions. No significant differences were observed (Wilcoxon paired-sample test) between the following: 1) pre- and postoperative coordinates of the anterior commissure (AC) (deltax = 0.3+/-0.29 mm and deltay = 0.34+/-0.32 mm) and posterior commissure (PC) (deltax = 0.15+/-0.18 mm and deltay = 0.34+/-0.25 mm); 2) pre- and postoperative AC-PC distance (deltaL = 0.33+/-0.22 mm); and 3) preoperative target and final electrode position coordinates (deltax = 0.24+/-0.22 mm; deltay = 0.19+/-0.16 mm). CONCLUSIONS: In the authors' center, MR imaging distortions did not induce detectable errors during stereotactic surgery in dystonic children. Target localization and electrode implantation could be achieved using MR imaging alone after induction of general anesthesia. The remarkable postoperative improvement in these patients confirmed the accuracy of the procedure (Burke-Marsden-Fahn Dystonia Rating Scale score delta = -83.8%).

Adolescent↗
PubMed1999

Relationship between cochleovestibular disorders in hemifacial spasm and neurovascular compression.

OBJECTIVE: To investigate the evolution of cochleovestibular symptoms before, during, and after microvascular decompression (MVD) of the facial nerve in hemifacial spasm. STUDY DESIGN: Prospective study in patients with hemifacial spasm. Among our 13 patients who underwent MVD of the facial nerve from 1995 to 1997, 6 had associated cochleovestibular disorders confirmed by neurotologic tests. RESULTS: In four of these patients, a concomitant compression of the eighth and facial nerves was found at surgery. Preoperative magnetic resonance angiography studies had shown three cases of this double neurovascular compression. Intraoperative auditory brainstem response monitoring showed that interposition of Teflon between vessel and facial nerve was highly critical to the auditory function. Auditory brainstem response monitoring was used to guide the surgeon during this critical phase. Surgery improved at least one cochleovestibular symptom in each patient. CONCLUSIONS: The authors propose two pathophysiologic hypotheses. First, the concomitant facial and cochleo-vestibular symptoms may be due to a hyperactivity of both the facial and vestibular nuclei. According to theories about cryptogenic hemifacial spasm, the origin of this hyperactivity could be an ectopic excitation focus. However, the two nerves may have different sites of ectopic excitation. According to the second hypothesis, a pulsatile compression of the facial nerve may be transmitted to the eighth nerve. This could take place even if only the facial nerve is in contact with a vascular loop.

Aged↗
PubMed1998

Pre-operative and per-operative factors conditioning long-term facial nerve function in vestibular schwannoma surgery through translabyrinthine approach.

Facial nerve function was evaluated in 103 patients, after vestibular schwannoma removal through the translabyrinthine approach. The mean follow-up was 43 months (minimum six months). Grade I facial function was achieved in 100 per cent of stage I schwannomata compared with 36 per cent of stage IV schwannomata. Grade I or II facial function was found in 78 per cent of homogeneous schwannomata, compared with 48 per cent of heterogeneous schwannomata. Facial function was preserved in 89 per cent of cases, if the angle between the internal auditory canal and the schwannoma was > 66 degrees, compared with 54 per cent if the angle was < 66 degrees. There was 82 per cent of normal facial function when the nerve appeared normal after tumour removal, compared with 18 per cent when the nerve was traumatized. When the ratio (stimulation threshold at the internal auditory canal/stimulation threshold at brainstem) was < 2, post-operative facial function was preserved in 87 per cent of cases, compared with 13 per cent when the ratio was > 2.

Adolescent↗
PubMed1998

[Cochleovestibular disorders associated with hemifacial spasm: an outcome after microvascular decompression of the facial nerve].

Twelve patients underwent microvascular decompression by retrosigmoid approach to relieve severe hemifacial spasm. The surgery was done under intraoperative monitoring of the auditory function. Assessment at Day 2, Day 10, 2 months and 6 months after the operation found that the surgery had resulted in 9 recoveries, 3 improvements and 1 failure. Brain stem auditory evoked potentials monitoring showed that the interposition of Teflon between the vascular loop and the facial nerve is a critical stage for the auditory function. Six of the twelve patients were also complaining of cochleo-vestibular disorders: vertigo and tinnitus, or hearing loss and tinnitus, or vertigo alone. The surgery improved at least one of these cochleo-vestibular symptoms in each one of the patients. There was one hearing improvement, vertigo disappeared in three cases out of four, and tinnitus disappeared in four cases out of five. The possibility of a concomitant compression of cochleo-vestibular and facial nerve was investigated using cochleovestibular tests, radiological data and intra-operative findings.

Aged↗
PubMed1996

[The contribution of "time-of-flight" MRI-angiography in the study of neurovascular interactions (hemifacial spasm and trigeminal neuralgia)].

The purpose of this study was to investigate capabilities of Magnetic Resonance Angiography (MRA) in delineating neurovascular compression which has emerged as the most frequent etiology in cases of Hemi-Facial Spasm and Trigeminal Neuralgia. MR investigations were carried out at 1.5 t unit (Magnetom Vision, Siemens). The examination consisted of 3D time-of-flight MRA (3d TOF) protocol, with a FISP sequence (Fast Imaging Steady Precession) and magnetization transfer. Imaging parameters were; TR 39 ms, TE 7 ms; MX 256-512; FOV 210-210 mm. Time acquisition is 10 mm 30 s. The axially acquired angiographic slices were reformatted with a multiplanar reconstruction program (MPR) along and across the plane of facial and trigeminal nerves. Then millimetric raw data images were postprocessed with a maximum intensity projection (MIP) technique. 58 patients presented either with hemifacial spasm (36 cases, 16 women, 20 men, mean age: 58.5 y) or trigeminal neuralgia (22 cases, 13 women, 8 men, mean age: 51 y) were compared with 17 patients (9 women, 8 men, mean age: 57.5 y) as references. MRA with MIP and MPR techniques reliably demonstrates neurovascular compression at the root entry zone (REZ), and allows recognition of the implicated vascular loop in 34 the cases of hemifacial spasm investigated. Raw data were post-processed in an axially oblique plane parallel to the acoustico-facial bundle and secondarily reconstructed in coronally obliques views. These reconstructed images clearly delineate the cross-compression of the emerging facial nerve. The neurovascular conflict was related to an arterial loop from the postero-inferior cerebellar artery (PICA, 21 cases, 61%) and the antero-inferior cerebellar artery (AICA, 8 cases, 23%). Vertebral artery is implicated in conflicts in 5 cases. In 2 cases MRA exploration was negative. In HFS group distance between Vth nerve emergency and neuro vascular contact was measured and compared with control group; there is a significative difference (p < 0.01). In case of trigeminal neuralgia, MRA demonstrates neurovascular compression at the root entry zone of the Vth nerve of 16 patients. In theses cases, oblique and coronally reconstructed images are crucial in demonstrating neurovascular contacts. The vessel implicated in conflict is always the superior cerebellar artery (SCA). A supero-medial loop of the superior cerebellar artery was depicted in these 16 cases. Although 3 patients had negative MRA and MR studies, a case of compression of the origin of the Vth nerve by a enlarged draining vein in a case of brainstem arterio-venous malformation, a petrous apex meningioma was incidentally discovered and thoroughly investigated with gadolinium T1 weighted sequences and 1 demyelinating plaques located along the intraaxial course of the Vth nerve were noticed. In control group on 34 explanations only there are only 4 contacts between Vth nerve and SCA. MRA with a 3D-TOF FISP sequence allows recognition of neurovascular conflicts in case of hemifacial spasm and trigeminal neuralgia while MIP helps to characterize the implicated vessel. Sources images need to be carefully assessed in order to depict unsuspected pathology.

Adolescent↗
PubMed1993

[Cerebral arteritis, carotid thrombosis and rubella: relation or coincidence?].

A 10 year-old boy presented with an acute transitory right hemiparesis with aphasia. On CT-scan there was a left temporal low density. The cerebral angiography showed a total obstruction of the left terminal internal carotid with a "beading" of the posterior cerebral artery on the same side. Blood serologies and the presence of specific IgM in the cerebrospinal fluid gave evidence for recent rubella. An other arteriogram after a follow-up of 3 months showed a persistent obstruction of the internal carotid but a disappearance of the cerebral posterior artery abnormalities.

Carotid Artery Thrombosis↗
PubMed1993

[Histiocytosis X of the petrous pyramid in adults. X-ray computed tomographic and MRI aspects].

Two cases are reported of histiocytosis X in young adults, both confined to the petrous bone. In one case the clinical signs were those of a progressive facial palsy, developing over 3 years; the other case had pulsatile tinnitus with clear otorrhoea and symptoms of vestibular deficiency. Computed tomography showed extensive bone destruction by a soft-tissue density process which enhanced strongly after iodinated contrast injection. Magnetic resonance imaging (T1 weighted sequences before and after intravenous gadolinium injection) confirmed the presence of a mass lesion in the petrous bone with contrast medium uptake which showed cystic areas within it: it also showed the absence of extension through the dura mater by the intracranial component which remained extradural. It confirmed the patency of arteries and veins, so enabling a differentiation to be made between histiocytosis X and advanced glomus tumours.

Adolescent↗
PubMed1992

[Dissection of the sylvian artery with resulting aneurysm in a 6 years old child].

BACKGROUND: Dissection of the walls of the cervical and cerebral arteries is rare in childhood. CASE REPORT: A 6 year-old girl suddenly suffered a loss of consciousness followed by a generalized tonic-clonic seizure 90 min after a non-traumatic fall. At admission, she had a massive right hemiplegia with aphasia. The CSF was not hemorrhagic. A CT-scan performed at H3 without infusion of radiopaque contrast material was normal, but a second CT-scan on day 4 showed a low density in the low area of the middle cerebral artery. An arteriogram taken on day 6 showed that the wall of the proximal part of this artery was irregular, with a discrete additive imaging. The child was treated with IV heparin for 3 weeks, then with aspirin. All investigations for the possible cause of thrombosis (protein C and S, antithrombin III, homocystinuria, etc...) were negative. Two further arteriograms, the last after a follow-up of 16 months, showed progressive disappearance of the wall irregularities and replacement of the additive imaging by a large aneurysm, suggesting a dissection. The hemiplegia persists under prolonged aspirin therapy. CONCLUSION: This case shows that dissection may occur in childhood without any apparent cause. It can result in the development of an aneurysm, a complication which is more frequent following dissection of the cervical rather the cerebral arteries.

Aortic Dissection↗
PubMed1989

Long term effects of continuous subcutaneous infusion of the somatostatin analog octreotide in the treatment of acromegaly.

The marked pituitary tumor shrinkage achieved by continuous sc infusion (CSI) of the long-acting somatostatin analog octreotide in one acromegalic patient led us to treat 16 other acromegalic patients for up to 24 months by CSI. This therapy, given in doses ranging from 100-600 micrograms/day, resulted in normalization of the mean daily serum GH (mGH) and insulin-like growth factor I levels in 9 of the 17 patients (53%). In 7 patients, mean daily serum GH decreased but not to normal; 3 of these patients had hyperprolactinemia which was not influenced by octreotide. One patient was completely unresponsive. In contrast to the biochemical results, 80% of the patients had marked clinical improvement. Side-effects consisted of slightly impaired carbohydrate tolerance in 2 patients and cholelithiasis in 2 patients. Pituitary tumor size decreased in only 3 patients; in 1 of them visual field defects disappeared rapidly. These results suggest that octreotide treatment may prove beneficial before surgery in patients with macroadenomas, although its efficacy varies widely. Potential responsivity can usually be determined by a short course (24 h) of CSI of octreotide.

Acromegaly↗