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Biomedical subjects

Philippe Demaerel

Publications and source records attributed to Philippe Demaerel.

At least 19 recordsLinked to original sources
PubMed2006

Magnetic resonance imaging of spinal cord trauma: a pictorial essay.

Assessing a patient with clinical signs of acute spinal cord trauma is an emergency. A radiological work-up is crucial in determining management, and magnetic resonance imaging (MRI) is the modality of choice. It should therefore be performed immediately, preferably within 3 hours, even when plain radiography does not show an abnormality. By choosing an appropriate imaging protocol, it is possible to assess the spinal cord, joints, muscles, ligaments and bone marrow of the spine. Moreover, early MRI findings assist in determining functional prognosis. A major limitation to early MRI is that the examination is usually restricted to stable trauma patients because of the difficulties in monitoring ventilated patients during scanning. However, when an anaesthesiologist with experience in MRI and MR-compatible monitoring equipment is available, even these patients can be safely examined. MRI is also indicated for the evaluation of patients with late complications and sequelae following spinal cord trauma, since many of these chronic lesions are potentially treatable.

Emergencies↗
PubMed2006

Lhermitte-Duclos disease: 11C-methionine positron emission tomography data in 4 patients.

BACKGROUND: Lhermitte-Duclos disease is a cerebellar lesion, characterized by an overgrowth of cerebellar ganglion cells, which replace granular cells and Purkinje cells. Lhermitte-Duclos disease may be a manifestation of Cowden syndrome (multiple hamartoma-neoplasia syndrome). The nature of LDD, whether neoplastic, dysplastic, or hamartomatous, is still not exactly understood. Metabolic imaging of the amino acid metabolism using PET could be useful for noninvasive characterization of these lesions. METHODS: To define the Meth-PET imaging characteristics of these lesions, we undertook a Meth-PET study in 4 patients with LDD after obtaining informed consent. All 4 patients had clinical signs of Cowden syndrome. In 2, the diagnosis was made with MRI; in 2, it was confirmed histologically. RESULTS: Using Meth-PET, the cerebellar lesions had a high methionine uptake, except in the subtotally resected lesion. The uptake of the lesions was markedly higher than that of the contralateral normal regions. The mean L/C ratio was 2.07. CONCLUSION: 11C-methionine positron emission tomography visualizes the lesion of Lhermitte-Duclos disease as a high uptake area. This amino acid hypermetabolism may be related to the slow growth of the lesions, and is an argument to suggest that patients with LDD should be followed up carefully to detect progression of the cerebellar lesion.

Adult↗
PubMed2006

Ictal perfusion patterns associated with single MRI-visible focal dysplastic lesions: implications for the noninvasive delineation of the epileptogenic zone.

BACKGROUND: Invasive electroencephalogram (EEG) studies are often considered necessary to localize the epileptogenic zone in partial epilepsies associated with focal dysplastic lesions (FDL). Our aim was to evaluate the relationships between subtraction ictal SPECT coregistered with magnetic resonance imaging (MRI) (SISCOM) hyperperfusion clusters and MRI-visible FDL, and to establish a preliminary algorithm for a noninvasive presurgical evaluation protocol for MRI-visible FDLs in patients with refractory epilepsy. METHODS: Fifteen consecutive patients with refractory partial epilepsy and a single MRI-visible FDL underwent a noninvasive presurgical evaluation including SISCOM. Each hyperperfusion cluster was visually analyzed, automatically quantitated, and its distance form the lesion as outlined on the MRI was measured. In patients who underwent surgery, the volumes of resected brain tissue containing the FDL, the SISCOM hyperperfusion cluster, and surrounding regions were assessed on postoperative MRI and correlated with surgical outcome. RESULTS: Fourteen of the 15 patients (93%) showed SISCOM hyperperfusion overlapping with the FDL. The FDL was detected only after reevaluation of the MRI guided by the ictal SPECT in 7 of the 15 patients (47%). Four distinct hyperperfusion patterns were observed, representing different degrees of seizure propagation. Nine patients have been operated on. Five have been seizure-free since surgery and one since a reoperation. The degree of resection of the MRI-visible FDL was the major determinant of surgical outcome. Full resection of the SISCOM hyperperfusion cluster was not required to render a patient seizure-free. CONCLUSION: Detailed analysis of SISCOM hyperperfusion patterns is a promising tool to detect subtle FDL on MRI and to establish the epileptic nature of these lesions noninvasively. Overlap between the SISCOM hyperperfusion cluster and MRI-visible FDL in a noninvasive presurgical evaluation with concordant data may suffice to proceed to epilepsy surgery aimed at removing the MRI-visible FDL and the part of the hyperperfusion cluster within and immediately surrounding the FDL.

Adult↗
PubMed2005

Magnetic resonance imaging study of the level of termination of the conus medullaris and the thecal sac: influence of age and gender.

STUDY DESIGN: Sequential study of magnetic resonance imaging (MRI) of the spine for assessing the level of termination of the conus medullaris (CMT) and thecal sac (TST). OBJECTIVES: To determine the variation in CMT and the TST as a function of age and gender in an adult population without spinal deformity and to investigate the relationship between CMT and TST. SUMMARY OF BACKGROUND DATA: It is generally accepted that the conus medullaris terminates in the lower third of L1; however, a wide range of values has been reported in cadaver studies as well as in MRI studies during life. There have been only a few reports on the influence of gender on the CMT, and the influence of age has not been studied at all. There have been few studies on the range of termination of the thecal sac, and the influence of age and gender remain unexplored. METHODS: We reviewed the 3-mm sagittal MR images of 635 patients, including 297 women and 338 men, with a mean age of 49.43 years. The CMT and TST were located in relation to spinal levels and assigned numerical values ranging from 0 to 13. Parametric and nonparametric statistical tests were used for the data analysis. RESULTS: Mean CMT was at the level of the middle third of L1. The range span extended from the lower third of Th11 to the upper third of L3. The CMT displayed a small but significant positive correlation with age and with gender. Mean TST was at the level of the upper third of S2. The range extended from the lower third of L3 to the upper third of S5. The TST was not affected by gender, but age had an effect on TST. CONCLUSIONS: The CMT and TST displayed a wide range of values in our study. We detected small but systematic influences of gender and age on CMT and of age on TST, as well as a positive correlation between CMT and TST. These effects are small in amplitude, but they met all the criteria for statistical significance and have practical value for clinicians, as well as theoretical value for the medical and biologic community.

Adolescent↗
PubMed2005

Comparison of gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for enhanced MR imaging of brain and spine tumours in children.

BACKGROUND: Gadobenate dimeglumine (Gd-BOPTA) demonstrates superior enhancement of brain tumours in adult patients than Gd-DTPA. OBJECTIVE: To determine whether Gd-BOPTA has advantages over Gd-DTPA for enhanced MR imaging of paediatric brain and spine tumours. MATERIALS AND METHODS: Sixty-three subjects, aged 6 months to 16 years, who were enrolled in a prospective, fully blinded, randomized parallel-group phase III clinical trial, received 0.1 mmol/kg doses of either Gd-BOPTA (n=29) or Gd-DTPA (n=34). The MR images were acquired before and within 10 min of contrast agent injection. The primary objective was to compare the difference from pre-dose to post-dose lesion visualization between Gd-BOPTA and Gd-DTPA. Lesion visualization was determined as the sum of individual scores for three criteria of lesion morphological characteristics (lesion border delineation, internal morphology, and contrast enhancement), each assessed qualitatively using 4-point scales. Quantitative evaluation compared changes in lesion-to-background (LBR) and contrast-to-noise (CNR) ratios and per cent enhancement. Monitoring for adverse events and evaluation of vital signs and laboratory values was performed. RESULTS: Pre-dose to post-dose changes in lesion visualization were significantly better for Gd-BOPTA for both lesion level (2.68+/-2.17 vs. 1.05+/-1.90, P=0.0106) and patient level (2.55+/-2.18 vs. 1.14+/-1.68, P=0.0079) comparisons. The mean pre-dose to post-dose change in CNR was greater for Gd-BOPTA (9.13+/-15.36) than Gd-DTPA (2.18+/-9.90), but the difference was only marginally significant (P=0.0779; 95% CI: -0.553, 14.454) because of wide variations of signal intensity between lesions. Similar findings were obtained for LBR and per cent enhancement. No differences between the agents were noted in terms of safety parameters. CONCLUSIONS: At an equivalent dose Gd-BOPTA is significantly better than Gd-DTPA for visualization of enhancing CNS tumours in paediatric patients.

Adolescent↗
PubMed2005

Long-term survival in a child with a brain stem dermoid cyst.

BACKGROUND: Brain stem dermoid cysts are very rare lesions, and in most, the outcome has been very poor. Because of the dangers of dissecting the cyst wall away from the brain stem parenchyma, some authors have advocated not to attempt a radical resection. METHODS: We describe a child in whom the brain stem dermoid cyst recurred rapidly after a conservative approach. We therefore attempted a radical removal. RESULTS: During surgery, the almost complete resection of the cyst wall was not very difficult, leading to an apparent cure after 4 years. CONCLUSION: In exceptional cases, it may be possible to remove a brain stem dermoid cyst without prohibitive morbidity and with long-term cure.

Brain Stem Neoplasms↗
PubMed2005

Cytokeratin-positive meningeal peripheral PNET/Ewing's sarcoma of the cervical spinal cord: diagnostic value of genetic analysis.

Peripheral primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES) of the central nervous system is extremely rare and should be differentiated from central PNET and other small blue round cell tumors. We describe a case of a meningeal peripheral PNET/ES of the spinal cord in an 11-year-old boy. Immunohistochemically, the small blue round cell tumor showed expression of epithelial markers and of CD99, thus posing an important differential diagnostic problem with a poorly differentiated synovial sarcoma. Fluorescence in situ hybridization revealed rearrangement of the EWS gene, as seen in peripheral PNET/ES. Peripheral PNET/ES does occur in the central nervous system, but its diagnosis can be extremely difficult on morphologic and immunohistochemical grounds alone. Genetic analysis plays a key role in its distinction from other small blue round cell tumors.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Magnetic resonance angiography in suspected cerebral vasculitis.

The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion "more than two stenoses in at least two separate vascular distributions" to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen.

Adult↗
PubMed2004

Langerhans cell histiocytosis of the cervical spine: a single institution experience in four patients.

When Langerhans cell histiocytosis (LCH) occurs at critical sites, such as in the cervical spine, there is a substantial risk for morbidity. Therefore, reports on clinical experiences with those patients remain important. We summarize the history of four patients with unifocal LCH at the cervical spine. All four patients received a biopsy to prove the histopathological diagnosis of LCH by demonstration of CD1a+cells. They were treated with oral prednisolone. All patients recovered completely and kept a normal function of the cervical spine. No reactivation of the disease occurred with an observation time of 3.4-7.3 years. This report contributes to the clinical experience for the treatment of LCH at critical sites.

Adolescent↗
PubMed2004

Transient local response and persistent tumor control in a child with recurrent malignant glioma: treatment with combination therapy including dendritic cell therapy. Case report.

Treatment of malignant glioma is difficult and discouraging. Even after resection and maximal adjuvant therapy, the prognosis remains poor. The authors sought a novel form of treatment, such as stimulating the patient's own immune response against the tumor, and developed a protocol of tumor vaccination in which autologous dendritic cells (DCs) were used in patients with recurrent malignant glioma. A 4-year-old girl was treated by means of biopsy sampling and radiotherapy for a rolandic low-grade glioma. Ten years later, a Grade III recurrence was discovered and treated with subtotal resection, interstitial radiation, six courses of oral temozolomide, and 12 courses of oral VP 16. At the end of the chemotherapy cycle, a new rapidly growing recurrence was diagnosed. A macroscopically complete resection was performed. Afterward, the girl was vaccinated with autologous DCs that had been pulsed ex vivo with the homogenate of the resection specimen. She received six vaccines in total. The efficacy of immunization was checked by a positive delayed-type hypersensitivity skin reaction after the second injection. After the fifth vaccine, a transient contrast enhancement without mass effect was visualized on magnetic resonance imaging. Simultaneously, positron emission tomography imaging revealed a transient increase of metabolic activity around the resection cavity, but the metabolic uptake ratio remained below 1.8. The patient's disease is still in complete remission 24 months after the last surgery. She is clinically well with minor and stable left hemiparesis. This case report illustrates the potential of vaccination with DCs loaded with crude tumor homogenate as adjuvant therapy to induce prolonged tumor control of malignant glioma and the objective noninvasively monitored immune response against infiltrating tumor cells.

Astrocytoma↗
PubMed2004

Dural arteriovenous fistula as a late complication of upper cervical spine fracture. Case report.

The authors report an unusual case of a dural arteriovenous fistula (DAVF) in the cervical spine after a C1-2 fracture. The patient presented with a delayed epidural hematoma and quadriparesis. The DAVF was successfully treated by coil embolization and the patient made a full recovery. The possibility of a DAVF as a late complication of an upper cervical spine fracture should be considered when a patient presents with a spinal epidural hematoma.

Adult↗
PubMed2004

Partial rhombencephalosynapsis.

We describe an infant in whom partial rhombencephalosynapsis was diagnosed by using MR imaging. The anterior vermis and nodulus were normally developed, but part of the posterior vermis was deficient. There was partial fusion of the hemispheres in the inferior part of the cerebellum. Partial rhombencephalosynapsis is described for the first time, and our findings support the recent embryologic observations.

Abnormalities, Multiple↗
PubMed2003

D,L-3-hydroxybutyrate treatment of multiple acyl-CoA dehydrogenase deficiency (MADD).

Cardiomyopathy and leukodystrophy are life-threatening complications of multiple acyl-CoA dehydrogenase deficiency (MADD). A 2-year-old boy with this disorder developed rapidly progressive leukodystrophy resulting in complete paralysis within 4 months. Within a week of starting sodium-D,L-3-hydroxybutyrate he had improved. After 2 years, neurological function returned, including walking independently, with progressive improvement of brain MRI. Two additional infants with MADD developed life-threatening cardiomyopathy unresponsive to conventional treatment. On sodium-D,L-3-hydroxybutyrate treatment their cardiac contractility showed progressive and sustained improvement. D,L-3-hydroxybutyrate is a therapeutic option for cerebral and cardiac complications in severe fatty acid oxidation defects.

3-Hydroxybutyric Acid↗
PubMed2003

Accuracy of diffusion-weighted MR imaging in the diagnosis of sporadic Creutzfeldt-Jakob disease.

The definitive diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) is based on brain autopsy. The 14-3-3 analysis in the CSF is considered a highly sensitive and specific procedure. Sensitivity, specificity and accuracy of EEG, the 14-3-3 assay and MR imaging in 12 patients referred for suspected sCJD were calculated. We suggest that diffusion-weighted MR imaging (DWI) should be included in the array of diagnostic tests because of the 100 % sensitivity and specificity.

Aged↗
PubMed2003

Segmental spinal cord hypoplasia and meningocele with preservation of medullary function: case report.

BACKGROUND: In very rare dysraphic cases, it is not clear whether the primary abnormalities are in the neural elements, or in the bony elements. CASE DESCRIPTION: We describe a case of segmental hypoplasia of the spinal cord, with absent nerve roots in the afflicted segments, and associated meningocele and vertebral abnormalities. We illustrate the arguments for and against the classification of this lesion either as an atypical case of myelomeningocele (MMC) or as a mild case of segmental spinal dysgenesis (SSD). CONCLUSIONS: Possibly, in this exceptional case, the primary defect is in the neural tissue like in more usual cases of MMC and not in the spine, like in segmental spinal dysgenesis.

Child↗