IRM interventionnelle : vers une neuronavigation en temps réel.
Martin, Didier ; Nguyen Khac, Minh-Tuan ; Scholtes, Félix et al
in Revue Médicale de Liège (2008), 63
La neuronavigation est un outil neurochirurgical qui peut être comparé au GPS. Elle sert à guider la procédure neurochirurgicale en visualisant les déplacements des instruments chirurgicaux sur les images ... [more ▼]
La neuronavigation est un outil neurochirurgical qui peut être comparé au GPS. Elle sert à guider la procédure neurochirurgicale en visualisant les déplacements des instruments chirurgicaux sur les images préopératoires. En augmentant la précision du geste, elle permet d’atteindre des lésions parfois très petites ou difficiles d’accès tout en réduisant la morbidité et en augmentant l’efficacité. Elle présente cependant un écueil majeur. L’image utilisée par le système de navigation est obtenue avant l’intervention et ne peut être corrigée durant celle-ci. En raison des modifications anatomiques inhérentes à l’opération (modification du volume du liquide céphalo-rachidien, résection de la tumeur,…), il apparaît progressivement une discordance entre la réalité chirurgicale et l’imagerie. Les informations pertinentes se périment ainsi peu à peu et la précision se perd. L’IRM interventionnelle est le moyen de réactualiser la neuronavigation par des images de haute définition. De plus, elle permet de réaliser des contrôles intra-opératoires de la qualité du geste chirurgical. [less ▲]Detailed reference viewed: 165 (3 ULg)
Rapid, postmortem 9.4 T MRI of spinal cord injury: correlation with histology and survival times.
Scholtes, Félix ; Phan-Ba, Rémy ; et al
in Journal of Neuroscience Methods (2008), 174(2), 157-67
High field magnetic resonance imaging (MRI) has been increasingly used to assess experimental spinal cord injury (SCI). In the present investigation, after partial spinal cord injury and excision of the ... [more ▼]
High field magnetic resonance imaging (MRI) has been increasingly used to assess experimental spinal cord injury (SCI). In the present investigation, after partial spinal cord injury and excision of the whole spine, pathological changes of the spinal cord were studied in spinal cord-spine blocks, from the acute to the chronic state (24 h to 5 months). Using proton density (PD) weighted imaging parameters at a magnetic field strength of 9.4 tesla (T), acquisition times ranging from <1 to 10 h per specimen were used. High in-plane pixel resolution (68 and 38 microm, respectively) was obtained, as well as high signal-to-noise ratio (SNR), which is important for optimal contrast settings. The quality of the resulting MR images was demonstrated by comparison with histology. The cord and the lesion were shown in their anatomical surroundings, detecting cord swelling in the acute phase (24 h to 1 week) and cord atrophy at the chronic stage. Haemorrhage was detected as hypo-intense signal. Oedema, necrosis and scarring were hyper-intense but could not be distinguished. Histology confirmed that the anatomical delimitation of the lesion extent by MRI was precise, both with high and moderate resolution. The present investigation thus demonstrates the precision of spinal cord MRI at different survival delays after compressive partial SCI and establishes efficient imaging parameters for postmortem PD MRI. [less ▲]Detailed reference viewed: 180 (13 ULg)
Surgical management of anterior cranial base fractures with cerebrospinal fluid fistulae: a single-institution experience.
; Scholtes, Félix ; et al
in Neurosurgery (2008), 62(2), 463-9469-71
OBJECTIVE: The management of cerebrospinal fluid (CSF) fistulae after anterior cranial base fracture remains a surgical challenge. We reviewed our results in the repair of CSF fistulae complicating ... [more ▼]
OBJECTIVE: The management of cerebrospinal fluid (CSF) fistulae after anterior cranial base fracture remains a surgical challenge. We reviewed our results in the repair of CSF fistulae complicating multiple anterior cranial base fractures via a combined intracranial extradural and intradural approach and describe a treatment algorithm derived from this experience. METHODS: We retrospectively reviewed the files of 209 patients with an anterior cranial base fracture complicated by a CSF fistula who were admitted between 1980 and 2003 to Liege State University Hospital. Among those patients, 109 had a persistent CSF leak or radiological signs of an unhealed dural tear. All underwent the same surgical procedure, with combined extradural and intradural closure of the dural tear. RESULTS: Of the 109 patients, 98 patients (90%) were cured after the first operation. Persistent postoperative CSF rhinorrhea occurred in 11 patients (10%), necessitating an early complementary surgery via a transsphenoidal approach (7 patients) or a second-look intracranial approach (4 patients). No postoperative neurological deterioration attributable to increasing frontocerebral edema occurred. During the mean follow-up period of 36 months, recurrence of CSF fistula was observed in five patients and required an additional surgical repair procedure. CONCLUSION: The closure of CSF fistulae after an anterior cranial base fracture via a combined intracranial extradural and intradural approach, which allows the visualization and repair of the entire anterior base, is safe and effective. It is essentially indicated for patients with extensive bone defects in the cranial base, multiple fractures of the ethmoid bone and the posterior wall of the frontal sinus, cranial nerve involvement, associated lesions necessitating surgery such as intracranial hematomas, and post-traumatic intracranial infection. Rhinorrhea caused by a precisely located small tear may be treated with endoscopy. [less ▲]Detailed reference viewed: 66 (1 ULg)
Acquired tonsillar herniation and syringomyelia after pleural effusion aspiration: case report.
Scholsem, Martin ; Scholtes, Félix ; Belachew, Shibeshih et al
in Neurosurgery (2008), 62(5), 1172-31173
OBJECTIVE: We present a case of brachial plexus avulsion and reconstructive surgery with cerebrospinal fluid leak between the cervical subarachnoid space and the pleural cavity responsible for tonsillar ... [more ▼]
OBJECTIVE: We present a case of brachial plexus avulsion and reconstructive surgery with cerebrospinal fluid leak between the cervical subarachnoid space and the pleural cavity responsible for tonsillar herniation and syringomyelia. CLINICAL PRESENTATION: A 17-year-old man presented with headaches when he was positioned upright, simultaneously with a persistent right pleural effusion for about 4 months after reconstructive surgery for a right brachial plexus avulsion. In addition, the headaches had worsened considerably after two aspirations of the pleural effusion. Magnetic resonance imaging (MRI) demonstrated signs of chronic intracranial hypotension and tonsillar herniation with a presyrinx cavity from vertebral level C1 to C7. None of those abnormalities were seen on the MRI scan obtained a few days after the initial trauma 7 months previously. Plexus brachial MRI confirmed the presence of a cerebrospinal fluid leak between the avulsed root of C8 and the pulmonary apex. INTERVENTION: The leak was treated by surgical closure of the dural tear of the C8 root. Postoperatively, the patient's headaches immediately resolved, and MRI 4 months later showed resolution of cerebellar tonsil herniation and regression of the syrinx. CONCLUSION: Resolution of acquired tonsillar herniation and syringomyelia can be achieved by closure of the dural tear responsible of the cerebrospinal fluid leak. [less ▲]Detailed reference viewed: 230 (17 ULg)
TGF-1 and TGF-2 expression after traumatic human spinal cord injury
; ; et al
in Spinal Cord (2008), 46
TGF-beta1 and TGF-beta2 expression after traumatic human spinal cord injury.Detailed reference viewed: 22 (0 ULg)
Table ronde : «Mort et résurrection de la moelle spinale».
Conference (2007, November 25)Detailed reference viewed: 2 (1 ULg)
Les lésions médullaires post-traumatiques : aspects fondamentaux.
Conference (2007, September 26)
State of the Art in Spinal Cord Injury – Research and Clinical Application
Conference (2007, September 06)Detailed reference viewed: 2 (0 ULg)
Growth-modulating molecules are associated with invading Schwann cells and not astrocytes in human traumatic spinal cord injury
; ; et al
in Brain (2007), 130(Part 4), 940-953
Despite considerable progress in recent years, the underlying mechanisms responsible for the failure of axonal regeneration after spinal cord injury (SCI) remain only partially understood. Experimental ... [more ▼]
Despite considerable progress in recent years, the underlying mechanisms responsible for the failure of axonal regeneration after spinal cord injury (SCI) remain only partially understood. Experimental data have demonstrated that a major impediment to the outgrowth of severed axons is the scar tissue that finally dominates the lesion site and, in severe injuries, is comprised of connective tissue and fluid-filled cysts, surrounded by a dense astroglial scar. Reactive astrocytes and infiltrating cells, such as fibroblasts, produce a dense extracellular matrix (ECM) that represents a physical and molecular barrier to axon regeneration. In the human situation, correlative data on the molecular composition of the scar tissue that forms following traumatic SCI is scarce. A detailed investigation on the expression of putative growth-inhibitory and growth-promoting molecules was therefore performed in samples of post-mortem human spinal cord, taken from patients who died following severe traumatic SCI. The lesion-induced scar could be subdivided into a Schwann cell dominated domain which contained large neuromas and a surrounding dense ECM, and a well delineated astroglial scar that isolated the Schwann cell/ECM rich territories from the intact spinal parenchyma. The axon growth-modulating molecules collagen IV, laminin and fibronectin were all present in the post-traumatic scar tissue. These molecules were almost exclusively found in the Schwann cell-rich domain which had an apparent growth-promoting effect on PNS axons. In the astrocytic domain, these molecules were restricted to blood vessel walls without a co-localization with the few regenerating CNS neurites located in this region. Taken together, these results favour the notion that it is the astroglial compartment that plays a dominant role in preventing CNS axon regeneration. The failure to demonstrate any collagen IV, laminin or fibronectin upregulation associated with the astroglial scar suggests that other molecules may play a more significant role in preventing axon regeneration following human SCI. [less ▲]Detailed reference viewed: 23 (0 ULg)
International Foundation for Research in Paraplegia
Conference (2007, February 20)Detailed reference viewed: 4 (0 ULg)
La pression intracrânienne normale et pathologique
Conference (2007, January 22)Detailed reference viewed: 9 (2 ULg)
Long-term follow-up reveals low toxicity of radiosurgery for vestibular schwannoma
; ; Seidel, Laurence et al
in Radiotherapy & Oncology (2007), 82(1), 83-89
AIM: The long-term effects of radiosurgery of vestibular schwannomas were investigated in a group of consecutively treated patients. METHODS AND MATERIALS: Between 1995 and 2001, 26 patients (median age ... [more ▼]
AIM: The long-term effects of radiosurgery of vestibular schwannomas were investigated in a group of consecutively treated patients. METHODS AND MATERIALS: Between 1995 and 2001, 26 patients (median age: 67, range: 30-82) with a vestibular schwannoma were treated by Linac-based stereotactic radiosurgery (SRS). The median follow-up was 49 months (16-85 months). Only progressive tumours were treated. The median size of tumours was 18 mm (range 9-30 mm). Before SRS, 11 patients had a useful hearing (Gardner-Robertson classes 1 and 2). Single doses of 10-14 Gy were prescribed at the 80% isodose at the tumour margin. The follow-up consisted of regular imaging with MRI the first 3-6 months after the intervention, followed by additional yearly MRIs, a hearing test and a neurological examination. RESULT: The 5-year-probability of tumour control (defined as stabilization or decrease in size) was 95%. Five-year-probability of preservation of hearing and facial nerve function was 96% and 100%, respectively. Hearing was preserved in 10 out of 11 patients who had a normal or useful hearing at the time of treatment. Mild and transient trigeminal toxicity occurred in 2 (8%) patients. It appeared to be significantly correlated to the dose used (p=0.044). However, only a tendency to significance could be demonstrated in the relationship between the two factors when using the Cox analysis (hazard ratio=1.7; 95% CI: 0.7-3.9; p=0.23). CONCLUSIONS: With the doses used, our study demonstrates that SRS provides an equivalent tumour control rate when compared to surgery, as well as on a long-term basis, an excellent preservation of the facial and the acoustic nerves. Although no permanent trigeminal toxicity was observed, our data confirm that doses below 14 Gy can avoid transient dysesthesias. [less ▲]Detailed reference viewed: 59 (2 ULg)
Matrix metalloproteinases and their inhibitors in human traumatic spinal cord injury.
; ; et al
in BMC Neurology (2007), 7
BACKGROUND: Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that degrade the extracellular matrix and other extracellular proteins. Studies in experimental animals ... [more ▼]
BACKGROUND: Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that degrade the extracellular matrix and other extracellular proteins. Studies in experimental animals demonstrate that MMPs play a number of roles in the detrimental as well as in the beneficial events after spinal cord injury (SCI). In the present correlative investigation, the expression pattern of several MMPs and their inhibitors has been investigated in the human spinal cord. METHODS: An immunohistochemical investigation in post mortem samples of control and lesioned human spinal cords was performed. All patients with traumatic SCI had been clinically diagnosed as having "complete" injuries and presented lesions of the maceration type. RESULTS: In the unlesioned human spinal cord, MMP and TIMP immunoreactivity was scarce. After traumatic SCI, a lesion-induced bi-phasic pattern of raised MMP-1 levels could be found with an early up-regulation in macrophages within the lesion epicentre and a later induction in peri-lesional activated astrocytes. There was an early and brief induction of MMP-2 at the lesion core in macrophages. MMP-9 and -12 expression peaked at 24 days after injury and both molecules were mostly expressed in macrophages at the lesion epicentre. Whereas MMP-9 levels rose progressively from 1 week to 3 weeks, there was an isolated peak of MMP-12 expression at 24 days. The post-traumatic distribution of the MMP inhibitors TIMP-1, -2 and -3 was limited. Only occasional TIMP immuno-positive macrophages could be detected at short survival times. The only clear induction was detected for TIMP-3 at survival times of 8 months and 1 year in peri-lesional activated astrocytes. CONCLUSION: The involvement of MMP-1, -2, -9 and -12 has been demonstrated in the post-traumatic events after human SCI. With an expression pattern corresponding largely to prior experimental studies, they were mainly expressed during the first weeks after injury and were most likely involved in the destructive inflammatory events of protein breakdown and phagocytosis carried out by infiltrating neutrophils and macrophages, as well as being involved in enhanced permeability of the blood spinal cord barrier. Similar to animal investigations, the strong induction of MMPs was not accompanied by an expression of their inhibitors, allowing these proteins to exert their effects in the lesioned spinal cord. [less ▲]Detailed reference viewed: 43 (3 ULg)
Intrasellar arachnoid cysts.
Dubuisson, Annie ; Stevenaert, Achille ; Martin, Didier et al
in Neurosurgery (2007), 61(3), 505-13513
OBJECTIVE: To evaluate the clinical, endocrinological, and radiological presentation of nine cases of surgically verified intrasellar arachnoid cysts and to discuss the physiopathological mechanisms of ... [more ▼]
OBJECTIVE: To evaluate the clinical, endocrinological, and radiological presentation of nine cases of surgically verified intrasellar arachnoid cysts and to discuss the physiopathological mechanisms of formation of these cysts. METHODS: Among 1540 patients presenting with pituitary lesions, nine presented with an intrasellar arachnoid cyst. Their charts were retrospectively reviewed. RESULTS: Presenting symptoms included headache (n = 2), visual symptoms (n = 3), menstrual irregularities (n = 2), rapid weight gain (n = 1), vertigo (n = 1), and/or confusion (n = 1). Two cysts were discovered incidentally. T1-weighted magnetic resonance imaging scans showed an intrasellar cystic lesion in all cases, with a huge suprasellar extension in six cases. The cyst was of the same intensity as the cerebrospinal fluid (CSF) in only two patients. A transsphenoidal approach allowed the transdural aspiration of fluid and injection of a water-soluble contrast agent under mild pressure. In three patients, the contrast infiltrated along the pituitary stalk toward the subarachnoid spaces; in the other patients, it remained in the intrasellar compartment. Cyst membranes were removed as completely as possible with fenestration toward the subarachnoid spaces in communicating cysts. In spite of tight packing of the sella and sphenoid sinus, CSF fistulae requiring reoperation developed in two patients. CONCLUSION: The clinical picture of an intrasellar arachnoid cyst resembles that of a nonfunctional pituitary adenoma. Magnetic resonance imaging scans typically show a cystic intrasellar lesion with suprasellar extension, containing isointense or, more often, hyperintense fluid on T1-weighted sequences. In spite of the risk of CSF fistulae, the preferred surgical approach is transsphenoidal. A physiopathological mechanism is proposed according to anatomic variations of the sellar diaphragma allowing penetration of subarachnoid spaces into the sellar compartment and their enlargement by a ball-valve mechanism. [less ▲]Detailed reference viewed: 209 (5 ULg)
Le cas clinique du mois. Le syndrome lissencephalique de Miller-Dieker.
Cremers, Julien ; ; Scholtes, Félix et al
in Revue Médicale de Liège (2007), 62(3), 139-43
We present the case of a 10-year-old boy who presents with a severe epilepsy resistant to medical treatment in the context of a Miller-Dieker syndrome. This patient underwent the implantation of a ... [more ▼]
We present the case of a 10-year-old boy who presents with a severe epilepsy resistant to medical treatment in the context of a Miller-Dieker syndrome. This patient underwent the implantation of a pneumogastric nerve stimulator. We describe the patient's clinical history and the main characteristics of lissencephaly syndrome. [less ▲]Detailed reference viewed: 167 (9 ULg)