[Treatment of trigeminal neuralgia with radiosurgery]. / Traitement de la névralgie essentielle du trijumeau par radiochirurgie stéréotaxique.

Idiopathic trigeminal neuralgia is defined as brief paroxysms of pain limited to the facial distribution of the trigeminal nerve. Drug therapy is considered to be the first-line of treatment for trigeminal neuralgia. Unfortunately, medical treatment does not always provide satisfactory pain relief for 25% of the patients. Moreover, the relief provided by drug therapy generally decreases over time, and increased dosages of these medications are limited because of side effects. In this case, patients can be offered several surgical approaches, such as percutaneous techniques (thermocoagulation, microcompression, glycerol injection) or microvascular decompression in the cerebello-pontine angle (Gardner-Jannetta's technique). In this indication, stereotactic radiosurgery, driven by teams using Gamma Knife(®), has shown promising efficacy and tolerance to allow this treatment being truly part of trigeminal neuralgia treatment. Technological progresses now allow performing radiosurgery with ballistic and dosimetric processes optimized with stereotactic radiosurgery dedicated linear accelerators. This procedure supports frame implantation to guarantee targeting accuracy in accordance of elevated dose distribution. This article on trigeminal neuralgia treatment will review the different medical and surgical therapeutic options and specify the contemporary place of stereotactic radiosurgery in the light of its clinical results and tolerance aspects.

[Radiosurgery for brain arteriovenous malformations]. / Radiochirurgie stéréotaxique des malformations artérioveineuses cérébrales.

Radiosurgery as treatment for arteriovenous malformations has shown a good efficacy in reducing intracranial bleeding due to rupture. The choice of therapeutic modalities is based on evolutive risk and arteriovenous malformations volume, patient profile and risks stratification following therapeutic techniques (microsurgery, radiosurgery, embolization). Nidus size, arteriovenous malformations anatomical localization, prior embolization or bleeding, distributed dose are predictive factors for radiosurgery's good results and tolerance. This review article will highlight arteriovenous malformations radiosurgery indications and discuss recent irradiation alternatives for large arteriovenous malformation volumes.

[Stereotactic and diagnostic imaging in radiosurgery]. / Imagerie stéréotaxique et diagnostique en radiochirurgie.

Constant progress in medical imaging and particularly magnetic resonance imaging has profound impact in planning for stereotactic radiosurgery and radiotherapy. The purpose of this paper is to discuss the integration of medical imaging modalities in the planning process. Principles of generic algorithms to calculate stereotactic coordinates are treated for tomographic imaging and digital substraction angiography, and their accuracies are analyzed in a review of the literature. The algorithmic foundations and performance of automatic intermodality co-registration methods are developed. Finally, the MRI sequences useful in planning and follow-up are discussed and the role of MR angiographic sequences compared to conventional X-ray angiography in the particular case of the arteriovenous malformation planning.

Treatment of spasticity with intrathecal Baclofen administration: long-term follow-up, review of 40 patients.

STUDY DESIGN: Case series of a consecutive sample. Retrospective audit. OBJECTIVE: To analyze the long-term safety and efficacy of intrathecal baclofen (ITB), and technical incidents. SETTING: Neurosurgical and Physical Medicine Departments of two university hospitals in western France. METHODS: The medical records of 40 patients who underwent ITB pump placement for the treatment of severe chronic spasticity were reviewed. Patients were eligible independently of the origin of the spasticity (spinal cord origin 33, brain damage 8). They underwent a final assessment with clinical examination and questionnaire in 2001. Ashworth scale scores were assessed, patient satisfaction was rated on a visual analog scale (VAS), functional independence before and after treatment was classified as bed-ridden, wheelchair dependent or ambulant, and the frequency and nature of complications were noted. RESULTS: The average follow-up period was of 4 years. The average Ashworth score at the final assessment was 1.8+/-0.6. Average patients satisfaction was 7.4/10+/-2.21 on VAS. In all, 85% would have undergone the procedure again if they had to make the decision. In 85% of the cases the ambulation status was unchanged. Technical incidents occurred at least once in 37% of the patients (due to the catheter in 58% and to the pump in 42%). They included catheter disconnections (4), migration (4), kinks (3), obstruction (3), development of fibrosis (3), disconnection of pump reservoir (2), porosity of pump membrane (2), unexplained pump dysfunction (4) leakage, and subcutaneous collection (5). Severe pharmacological side effects requiring transfer to intensive care unit occurred in 12% of cases, 80% of which were directly related to pump refill procedures. CONCLUSION: ITB remained effective in the long term and patients were satisfied. Nevertheless, complications were frequent, involving mainly the catheters, which would require further technical improvements.

[Recurrent syncope and Chiari malformation]. / Syncopes itératives et malformation de Chiari.

Downward herniation of the cerebellar tonsils through the foramen magnum (Chiari I malformation) is usually revealed by head and neck pain, often associated with brain-stem or spinal cord disturbances. Syncopes are rarely reported and may be difficult to link to their cause when they occur alone. We report two cases with brief and repetitive syncopes revealing a Chiari I malformation. These manifestations may be attributed to transient compression of brain stem or vascular structures at the craniocervical junction, triggered by intracranial pressure increase, as they disappear after posterior fossa decompression.

[Multi-level traumatic lesions of the thoracic and lumbar spine. Value of the Cotrel-Dubousset instrumentation]. / Les lésions traumatiques pluriétagées du rachis thoracique et lombaire. Intérêt de l'instrumentation Cotrel-Dubousset.

Trauma of the spine involving several thoracic and lumbar vertebrae is rare (4 case in 250 spine operated in our unit from 1985 to 1990) and require difficult therapeutic decisions. The patients has one or more unstable fractures which could require 4 screw-plates that would be mechanically unsatisfactory, or an unstable fracture combined with other stable lesions requiring a mixed orthopaedic and surgical treatment that would lead to long term decubitus with a corset. The Cotrel-Dubousset system makes it possible to approach each lesion separately with segmentary instrumentation. Using different combinations of the implants we were able to obtain a construction which was both technically and mechanically satisfactory and allowed recovery of the sagittal spinal curvatures without external contention. A single operation treating all the different lesions was sufficient in 3 Frankel E patients, allowing them to return to their former activities in 3 to 6 months. The material was removed at about 20 months allowing good spinal mobility.

[Effects of Diprivan on cerebral blood flow, intracranial pressure and cerebral metabolism in head injured patients]. / Effets du Diprivan sur le débit sanguin cérébral, la pression intracrânienne et l'activité métabolique cérébrale chez le traumatisé crânien.

The effects of propofol on cerebral blood flow, intracranial pressure (ICP) and cerebral oxygen consumption (CMRO2) were assessed in ten severely head-injured patients undergoing surgery for limb fractures. The patients, aged between 15 and 40 years, were in deep coma, scored 6-7 on the Glasgow coma score. They were mechanically ventilated and sedated with 1 mg.h-1 phenoperidine. Anaesthesia was carried out with a 2 mg.kg-1 intravenous bolus of propofol, immediately followed by a 150 micrograms.kg-1.min-1 infusion, which lasted for a mean time of 41.4 +/- 7.3 min. Data were collected 5 min before any propofol was given, 15 min after the start of the infusion, and 15 min after its end. A radial artery cannula, a 7.5 Fr thermodilution flow-directed pulmonary arterial catheter, a cerebral intraventricular catheter and a catheter in the jugular venous bulb were used for this purpose. Carotid arterial injection of 133Xenon was used to determine regional cerebral blood flow (rCBF). Anaesthetic blood concentrations of propofol (3 to 5 micrograms.ml-1) were associated with a decrease in all the parameters studied: cerebral perfusion pressure, from 82 +/- 14 mmHg to 59 +/- 7 mmHg (p less than 0.001); rCBF, from 35 +/- 6 ml.100 g-1.min-1 to 26 +/- 5 ml.100 g-1.min-1 (p less than 0.01); ICP from 11.3 +/- 2.6 mmHg to 9.2 +/- 2.5 mmHg (p less than 0.001); CMRO2 from 1.63 +/- 0.38 mlO2 +/- 100 g-1.min-1 to 1.18 +/- 0.38 mlO2.100 g-1.min-1 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of propofol on cerebral hemodynamics and metabolism in patients with brain trauma.

The authors determined the effect of propofol on cerebral blood flow, intracranial pressure, and cerebral arteriovenous oxygen content difference in severely brain-injured patients during orthopedic treatment of fractures of the extremities. The Glasgow Coma Scale score was 6 or 7 at the time of the study. Data were collected in the operating room before and during (5 and 15 min) administration of propofol (2 mg/kg iv bolus immediately followed by a 150 micrograms.kg-1.min-1 infusion) before surgical stimulation. Propofol was infused during 41.4 +/- 7.3 min. After operation, the last set of measurements was made 15 min after propofol was stopped. The study was performed on 10 adults (age range, 15-40 yr) whose lungs were mechanically ventilated (air/O2) and who were sedated (phenoperidine, 1 mg/h), and was conducted using a radial artery cannula; a 7.5-Fr, thermodilution, flow-directed, pulmonary artery catheter; an intraventricular catheter; and a catheter in the jugular venous bulb. The 133xenon intra-internal carotid artery injection technique was used to determine regional cerebral blood flow (rCBF). Anesthetic blood concentration of propofol (3-5 micrograms/ml) was associated with decreases in cerebral perfusion pressure (CPP; from 82 +/- 14 to 59 +/- 7 mmHg; P less than 0.001), rCBF (from 35 +/- 6 to 26 +/- 5 ml.100 g-1.min-1; P less than 0.001), and intracranial pressure (ICP; from 11.3 +/- 2.6 to 9.2 +/- 2.5 mmHg; P less than 0.001). Cerebrovascular resistance and cerebral arteriovenous oxygen content difference were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of human hemispheric blood flow based on non invasive carotid blood flow measurements using the range-gated Doppler technique.

Common carotid blood flow (CCBF) was measured in 11 anesthetised patients without extracranial arterial disease (nine acute subarachnoid haemorrhages and two cases of head injury). The range-gated Doppler flowmeter with an adjustable range-gated time system and a double transducer probe was used to determine diameter, blood velocity, and blood flow of the common carotid artery. Values were, respectively, 5.9 +/- 1.1 mm, 13.8 +/- 6.1 cm . sec-1 and 387 +/- 183 cm3 . min-1. Mean cerebral blood flow (rCBF) measurements were simultaneously made by 133Xenon intra-arterial method, with a value of 22.28 +/- 5.96 ml . min-1 . 100 g. High correlation coefficient was found between CCBF and mean rCBF (r = 0.73, p less than 0.001). The range-gated Doppler flowmeter thus provides a non invasive and easily duplicated method for monitoring cerebral blood flow in anesthetized patients.