[Role of radiosurgery in the management of intracranial cavernomas. Review of the literature]

From a review of the literature dealing with radiosurgery of cavernous malformations, we have analyzed its impact on hemorrhagic risk, epilepsy, histological modifications, morbidity and potential indications of treatment. Radiosurgery could significantly reduce the hemorrhagic risk, in a selected population with a high risk of hemorrhage, after an interval of about 2 years, but cannot provide protection against rebleeding. As for epilepsy related to the lesion, a significant reduction of seizures has been observed in certain cases, with better control in case of recent evolution and simple seizures linked to the site of the vascular malformation. Histologic lesions are vascular fibrosis, fibrinoid necrosis and ferrugination, without good correlation with results of CT scan or MRI. Morbidity of radiosurgery seems higher compared to other diseases with similar doses and target volumes. The rate of transient complications was about 25%, with permanent sequelae in 5 to 10% of patients. This would be due to a radiosensitizing effect of the hemosiderin halo around the lesion. Radiosurgery can be proposed for non-surgical lesions with a high risk of hemorrhage, nevertheless the superiority of the technique over conservative treatment has to be proven. Without long-term prospective studies, the efficiency of RS for cavernomas remains questionable and subject to debate. New imaging methods proving the obstruction of the cavernous malformation are needed.

Radiotherapy of pituitary adenomas: state of the art

Pituitary adenomas represent approximately 12% of intracranial tumors. They are defined as tumors that are functional or nonfunctional and invasive or noninvasive. Therapeutic strategies rely on surgery, medical treatment, and radiotherapy depending on histology. Neither the role of external radiotherapy nor the technique to be used are firmly established. Nonfunctioning adenomas must be operated on to relieve the compression. Prolactin-secreting adenomas are first treated with dopamine agonists, and GH-secreting adenomas are first treated by surgery if excising the complete tumor is possible; otherwise medical treatment is started. The first-line treatment of ACTH-secreting adenomas is surgery; however, in many cases, insufficient control of either secretion or tumoral volume leads to consideration of irradiation. Complications of conventional radiotherapy are well known and fractionated stereotactic radiotherapy appears to be as safe as radiosurgery. The volume to irradiate is still difficult to define, and this parameter can influence the technique chosen for treatment. Because the indications of radiotherapy are still debated, irradiation of pituitary adenomas must be decided by the complete team of endocrinologists, neurosurgeons, radiologists and radiotherapists.

Dérivation du liquide cérébrospinal avec valve: ses conséquences sur la biomécanique de l'oreille interne chez les patients atteints d'hydrocéphalie chronique de l'adulte

BACKGROUND AND PURPOSE

Patients suffering from hydrocephalus are often treated by the surgical placement of a shunt, directing the excess of cerebrospinal fluid towards another body compartment. However, the degree of clinical improvement is variable and the dynamics of cerebrospinal fluid pressure in shunted hydrocephalus is poorly understood. A recently developed noninvasive technique makes it possible to follow pressure variations: it is based on otoacoustic emissions, sounds naturally emitted by the cochlea and routinely detected in audiology. When cerebrospinal fluid pressure changes, emissions undergo a phase shift while crossing the oval window. The goal of this work is to study how this shift is affected by shunt placement.

METHOD

Otoacoustic emissions were recorded repeatedly in 22 adult patients who suffered from chronic hydrocephalus. Their phase shifts were measured, in sitting and recumbent positions, before and after surgical placement of a ventriculo-peritoneal shunt (Sophysa SM8).

RESULTS

Postural shift in normal subjects is a phase lead, and this outcome was found in 17 of 22 patients preoperatively. After shunt placement, the postural effect became a phase lag in 18 patients of 20. In a given posture, sitting or recumbent, phase shifts changed from pre to postoperative measurements in a systematic manner.

CONCLUSION

Otoacoustic emissions respond in a characteristic way to posture changes in normal adults, and having received a shunt for chronic hydrocephalus reverses the effect, presumably in relation to the existence of a "vacuum" in the inner ear.

Indications thérapeutiques des cavernomes du système nerveux central

We describe the therapeutic indications for central nervous system cavernomas based on three criteria: 1) Single and multiple lesions: indications are the same, considering that in multiple lesions, one location can be symptomatic; 2) locations: indications are easy to define for exophytic cavernomas close to the hemisphere, brain stem or cerebellum pial surface, or to the ventricular ependyma; 3) symptomatic and non symptomatic presentations: usually, symptomatic forms require surgery except deep lesions located in functional zones distant from the ependyma or the pia matter, unless life prognosis is compromised. Treatment of a symptomatic forms remains debatable, opinion being divided between therapeutic abstention and surgery (in case of cavernomas close to the pia matter or the ependyma). Scientific data strongly support surgical indication for lesions presenting with epilepsy specially when drug-resistant; 4) natural history: prevention against hemorrhage is an argument in favor of surgery for the lesions located in non functional zones or where the risk of bleeding is higher, especially in the brain stem. Discrepancy in the risk of bleeding reported in the literature tends to temper this attitude. Radiosurgery is exceptionally reserved for technically inoperable cavernomas. Partial protection for two years can be expected. Epileptic seizures decrease but few prospective randomised studies are available. The rate of complication appears to be higher than in other affections.

Analyse d'une série de cavernomes du système nerveux central: 39 cas non opérés, 39 cas opérés et un cas décédé

Cavernomas are vascular malformations frequently localized in the central nervous system. Debate remains open concerning proper treatment. We reviewed a series of cavernomas in order to collect information concerning the natural history. This retrospective study concerned 79 patients seen over a 15-year period. The epidemiologic, clinical, radiological, therapeutic and follow-up data were analyzed. The cavernomas were encephalic (including brain stem and cerebellum) in 74 patients, and in the spinal cord in 5 patients. Average age was 40.08 years, without sex predominance. The most frequent clinical sign was a focal neurological deficit. The cavernoma was solitary in 71 patients. The subtentorial localization was most frequent (44 cases). Bleeding was observed in 31 patients giving a hemorrhagic risk of 0.013%/patient/year. One patient died at admission, 39 were operated and surgical abstention with clinical and radiological follow up was decided for 39 patients (no bleeding in 64.2%). The course in these patients was marked by bleeding in six during 29.5 months follow-up of (rate of hemorrhagic risk 6.27%/patient/year). These results are not in total agreement with the literature. They demonstrate the difficulties for an exact evaluation of the hemorrhagic risk in cavernomas of the central nervous system. So, it is very important to meticulously discuss surgical indications.

Interleukin-6 gene amplification and shortened survival in glioblastoma patients

Interleukin-6 (IL-6) is known to promote tumour growth and survival. We evaluated IL-6 gene amplification in tumours from 53 glioma patients using fluorescence in situ hybridisation. Amplification events were detected only in glioblastomas (15 out of 36 cases), the most malignant tumours, and were significantly associated with decreased patient survival.

Pneumonia can cause 111Indium octreotide uptake

An 18-year-old woman underwent an (111)In octreotide scan for evaluation of a possible insulinoma. This showed mildly increased radiopharmaceutical uptake involving the right lung base. The patient reported a productive cough for 5 days before the octreotide scan. A chest radiograph was taken, which showed increased airspace opacification in the right lower lobe, corresponding to the uptake seen on the octreotide scan. After a course of oral antibiotics, the patient's chest symptoms improved and the radiograph opacification resolved, confirming the diagnosis of community-acquired pneumonia. This case stresses the need to correlate scan results with the patient's presentation and symptoms to avoid false-positive data.

[The future of pediatric intensive care]

Paediatric intensive care is born 40 years ago. It has been shown that admission of critically ill children in intensive care (ICU) where no paediatric intensivists worked increased significantly the mortality and the length of stay. The recognition of Paediatric Intensive Care (PICU) does not exist in Belgium and children are admitted in both adult and paediatric intensive care units. It is mandatory to recognise the PICU specificity and the usefulness of a fellowship in paediatric intensive care. Development of molecular biology and genetics will permit in the near future to understand reversible and irreversible cellular processes of the majority of problems responsible for mortality in critical care and to allow the development of new diagnostic and therapeutic techniques. Rapid development of information will permit the creation of multicenter databases including all PICU's data. The final goal is an intelligent tool for making decision process. Telemedecine is born which permits a virtual consultation of the patient. Technological progress must not impair the wellbeing of the child and its family. The PICU of the future must be "parents admitted". PICU profile is progressively changing, the way of taking care of the critically ill child and its family is also changing and improving. An ethical reflexion among the health care providers' team and a dialogue with parents will blossom.

Place de la radiochirurgie dans le traitement des oligodendrogliomes

Radiosurgery of oligodendrogliomas is not specific. It must be integrated into the overall treatment scheme for gliomas which remains to be strictly defined. Nevertheless, empirically, and in light of the limited constraints for the patient and the encouraging radiological and clinical benefits, radiosurgical teams usually propose this technique in the event of recurrence of malignant gliomas, as a second line treatment. Exceptionally radiation can be used for some small benign gliomas which could not be treated by open surgery and accurately defined radiologically. Radiosurgery can achieve local control of the lesion, mostly transitionally, with 15 to 18 Gy at the reference isodose. One of the key problems is the definition of the glioma boundaries. Despite progress in neuroimaging techniques most the limits of malignant forms are still not accessible. In routine practice, the nodular area, considered as the most active on MRI, i.e. the contrast enhanced area, is accepted as the target. Its widest dimension must be about 35-40 mm. Only patients with minimal disability can benefit from radiosurgery. Optimization of the target definition (in particular the most active zone) and prospective randomized studies should be helpful in clarifying indications for this technique.

[Spontaneous intrasphenoidal encephalocele. Report of two cases revealed by rhinorrhea]

We report two cases of spontaneous anteromedial temporo-sphenoidal meningo-encephalocele. The first patient was a 67-year-old man with a history of treated epiglotic cancer 6 years ago, was referred to us for CSF rhinorrhea. Lateral sphenoidal CSF fistula was confirmed by CT cisternography. Four lumbar taps were performed and rhinorrhea stopped for 2 years. At relapse of rhinorrhea, the patient was operated on via a subtemporal approach. The dural defect was filled by an intradural patch of pericranium. Four years later patient showed no evidence of cerebrospinal fluid leakage. The second patient was a 54-year-old woman referred to us after a one year history of CSF rhinorrhea. CT cisternography confirmed lateral sphenoidal CSF fistula. The patient was operated on via a subtemporal approach. The dural defect was filled by a patch of pericranium. Three years later the patient had no evidence of cerebrospinal fluid leakage. Twenty-one cases of anteromedial temporosphenoidal meningo-encephaloceles have been reported in the literature. They probably are of a developmental origin. Some cases have been successfully treated via a transsphenoidal route. However surgical failures related to this approach can be due to the lack of control of the lateral recess of the sphenoid sinus. Therefore, the frontotemporal approach seems more adequate but the transphenoidal endoscopic approach will probably be used in the future.

Clinical implications of quantitative real-time RT-PCR analysis of hTERT gene expression in human gliomas

The presence of telomerase activity in a glioma may be a predictor of its malignant potential. Activation of telomerase is regulated at the transcriptional level of the human telomerase reverse transcriptase (hTERT). Here, we evaluated whether the amount of hTERT mRNA provides a molecular marker of glioma malignancy that would have clinical utility. We used a real-time RT-PCR to assess the number of hTERT transcripts in primary tumour samples derived from 70 glioma patients. Results were standardised by quantifying the number of ABL transcripts as internal control and expressed as hTERT/ABL ratio. The percentage of patients with detectable hTERT mRNA markedly increased with enhanced malignancy: low-grade gliomas expressed hTERT in one out of 14 cases (7.1%), anaplastic gliomas in four out of 13 cases (30.8%) and glioblastoma multiforme (GBM) tumours in 30 out of 43 cases (69.8%). The mean hTERT/ABL ratio was significantly higher in GBMs than in non-GBMs. Subdividing hTERT/ABL ratios as low (< pr = 25%) and high (>25%), we found that the overall survival among hTERT-positive GBMs was significantly worse in high hTERT expressors than in low hTERT expressors (P=0.0082). We conclude that the amount of hTERT mRNA may represent a diagnostic and prognostic indicator for GBM patients.

Experimental verification of quadrupole-dipole interference in spin-resolved photoionization

We have measured the spin polarization of Xe (4p)(-1) photoelectrons after ionization with circularly polarized light at photon energies close to the ionization threshold where a resonant enhancement of quadrupole transitions has recently been predicted. At a reaction angle of 90 degrees a nonvanishing longitudinal spin polarization component of about 4% clearly indicates a quadrupole contribution to the photoexcitation. This is the first experimental evidence for the influence of nondipole transitions on the photoionization process at excitation energies much below 1 keV in an observable other than the intensity angular distribution.

Slow pressure waves in the cranial enclosure

Slowly varying pressure oscillations in the cranial enclosure are well known, especially intracranial pressure waves as best described by the pioneering works of Janny and Lundberg. Nevertheless, in spite of over twenty five years research on intracranial pressure waves, their origin and regulation remain unclear but are often considered only as pathological. Our aim was to review data on these phenomena to clarify their biological status and the role that they could play in the management of patients suffering from such intracranial neurosurgical diseases as intracranial hypertension, severe head injury, and hydrocephalus. It appears that these pressure waves reveal important information on the function of the cerebral vasculature and as such have significance for influencing intracranial compliance. Pressure waves are also closely associated with autoregulation, in particular dynamic autoregulation. It seems evident that they are not only pathophysiological but also physiological, linked with other biological parameters such as the neurovegetative cardiovascular system, breathing, and sleeping. This study shows that it is not only important to continue to explore these slow waves, but also the methods of analysis in order to more fully clarify their clinical significance.

Design of thoracolumbosacral orthosis (TLSO) braces using CT/MR

The field of orthotics has gained scientific attention over the last few years. Its objective is to correct, adjust, or modify the operation of human limbs, joints, or muscles. Thoracolumbosacral orthosis (TLSO) braces are used by scoliosis and postoperative patients who need back correction and/or support. The anatomic dimensions for TLSO braces have been acquired mainly by casting the patient. Casting is a time-proven method for obtaining surface geometry, but it can be inconvenient in certain situations. For example, casting might not be suitable for postoperative and trauma patients owing to the risk of further injury. Such prohibitive cases can still be handled safely by X-ray CT or MR scanning. This article presents an alternative method for data acquisition of TLSO patients' anatomic dimensions using CT/MRI. The experimental results show the method to be statistically accurate, efficient, and feasible compared with the conventional casting method.

Asymmetry in photoelectron emission from chiral molecules induced by circularly polarized light

In photoionization of free, unoriented chiral molecules with circularly polarized radiation, a significant circular dichroism, i.e., an asymmetry in the forward-backward electron emission, has been observed in the photoelectron angular distribution. This leads also to an asymmetry in the momentum transfer to the photoions. The spectra for the left- and right-handed enantiomers of bromocamphor exhibit asymmetries up to several percent which vary as a function of orbital binding energy. This enantioselective effect can similarly occur for biomolecules with handedness, like amino acids, and may thus be a contributing factor related to the origin of the terrestrial biomolecular homochirality.

[Neurological outcome of 152 surgical patients with spinal metastasis]

BACKGROUND AND PURPOSE

The aim of this study is to evaluate retrospectively the benefit of the surgical spinal decompression in 152 patients with spinal metastasis.

METHODS

Based on clinical notes and GP inquiry, we determined the actuarial survival curve, and assessed the pain level one month post-operatively and the motor, the sensory and sphincter distrurbances three months after surgery.

RESULTS

Thoraco-lumbar lesions were usually treated using a posterior approach, with a laminectomy and if necessary an osteosynthesis. Cervical lesions were treated with an anterior approach, i.e. a corporectomy and a methylmetacrylate stabilization. Sixty eight percent of patients (103/152) had pre or postoperative radiotherapy. After the surgical decompression for a spinal metastasis, our study demonstrated an improvement in sensory status (31 % of the patients), in motor ability (56 %), in sphincter function (51 %), and a decrease in the pain intensity in 47 % of the patients. Among 83 patients who could not walk on admission (grade A, B and C of Frankel), 52 % recovered a gait function 3 months post operatively. The best benefit after surgery concerned grade C patients, of which 71 % recovered the gait function. Two percent of the patients had postoperative worsening of their motor strength. No operative mortality was noted, and the postoperative mortality rate was 3 % at 7 days and 9 % at 30 days. The analysis of the actuarial survival curve demonstrated a mean follow up of 3.7 years. The mean survival time was 12 months with 25 % of patients surviving 2 years.

CONCLUSION

Surgical decompression is effective in relieving neurological symptoms from spinal metastasis. In our experience a complete motor deficit does not seem to be a good surgical indication because of the lack of postoperative improvement.

Prediction of "intent", "discrepancy with intent", and "discrepancy with nonintent" for the patient with chronic pain to return to work after treatment at a pain facility

OBJECTIVE

We previously determined that "intent" to return to work post pain facility treatment is the strongest predictor for actual return to work. The purposes of the present study were the following: to identify variables predicting "intent"; to predict membership in the "discrepant with intent" group [those chronic pain patients (CPPs) who do intend to return to work but do not]; and to predict membership in the "discrepant with nonintent" group (those CPPs who do not intend to return to work but do).

DESIGN

A total of 128 CPPs completed a series of rating scales and yes/no questions relating to their preinjury job perceptions and a question relating to "intent" to return to the same type of preinjury job post-pain facility treatment. These CPPs were part of a grant study for prediction of return to work, and therefore their work status was determined at 1, 3, 6, 12, 18, 24, and 30 months posttreatment. Preinjury job perceptions and other demographic variables were utilized using stepwise discriminant analysis to identify variables predicting "intent" and predicting membership in the "discrepant with intent" and "discrepant with nonintent" groups.

SETTING

Pain facility (multidisciplinary pain center).

PATIENTS

Consecutive low back pain CPPs, mean age 41.66+/-9.54 years, with the most frequent highest educational status being high school completion (54.7%) and 60.2% being worker compensation CPPs.

RESULTS

"Intent" was predicted by (in decreasing order of probability) postinjury job availability variables, job characteristic variables, and a litigation variable. "Discrepant with intent" was predicted by (in decreasing order of probability) for the 1-month follow-up time point, postinjury job availability variables, pain variables, a litigation variable, and a function perception variable, and for the final follow-up time point, pain variables only. "Discrepant with nonintent" was predicted by (in order of decreasing probability) for the 1-month follow-up time point, a job availability variable, a demographic variable, and a functional perception variable, and for the final follow-up time point a pain variable and a job availability variable. The percentage of CPPs correctly classified by each of these analyses was as follows: "intent" 81.25%, "discrepant with intent" 87.01% (at 1-month follow-up) and 74.03% (final follow-up), "discrepant with nonintent" 92.16% (at 1-month follow-up) and 75.00% (final follow-up).

CONCLUSIONS

CPPs intentions of returning to their preinjury jobs are mainly determined by job availability and job characteristic variables but surprisingly not by pain variables. However, the results with "discrepant with intent" and "discrepant with nonintent" groups indicate that actual return to work is determined by an interaction between job availability variables and pain variables with pain variables predominating for long-term outcome.