[Ineffectiveness of hyperbaric oxygen therapy in multiple sclerosis. A randomized placebo-controlled double-blind study]. / Inefficacité de l'oxygénothérapie hyperbare dans la sclérose en plaques. Essai randomisé contrôlé par placebo en double aveugle.

Seventeen patients with definite and progressive multiple sclerosis entered a double-blind randomized placebo-controlled therapeutic trial of hyperbaric oxygen (HBO). Exposure in monoplace chamber was 90 minutes long each time, 5 days a week, for 4 weeks. The treatment and placebo groups received 100% oxygen at 1.5 bar constant pressure or normal air at 0.1-0.2 bar, respectively. The clinical status of the patients in both groups were compared until one year after treatment. There was no benefit of HBO versus placebo according to the Kurtzke disability status scale. A lesser proportion of patients with deterioration of bowel/bladder function 12 months after therapy was the only benefit of HBO versus placebo according to Kurtzke functional systems scales. On the whole however, HBO is useless in the management of progressive forms of multiple sclerosis.

[Decision to limit or practise maximum therapeutic support in a neurosurgical intensive care unit]. / Décisions de limitation ou d'engagement thérapeutique maximal dans une unité de réanimation neurochirurgicale.

OBJECTIVE: To assess the respective rates of intensive care maximalization, limitation and withdrawal practice in a neurosurgical intensive care unit. STUDY DESIGN: Prospective clinical study. PATIENTS: All patients who died in the unit during the year 1994 were included in this study. METHODS: Demographic data and medical history of these patients were collected, and treatments during the last days and the 24 hours before death were reviewed. RESULTS: Among the 49 cases collected during the study period, 16 patients (33%) received full intensive therapy until their death. In 29 (59%), death was preceded by some limitation of treatment, and in 4 (8%) life-sustaining treatment (mechanical ventilation, vasopressor infusion) had not been undertaken. CONCLUSION: This prospective study confirmed the results of several previous surveys. The medical decision to limit or to discontinue treatments is rather frequent in intensive care units. This is an illegal practice in French legislation and code of professional ethics. Recommendations by representative French medical associations on the modalities of decision making on limitation of therapy would be welcome.

[Aseptic meningitis. Demonstration of bacterial DNA in cerebrospinal fluid by gene amplification]. / Méningites aseptiques. Mise en évidence dans le LCR d'ADN bactérien par amplification génique.

OBJECTIVE: To develop a diagnostic tool to recognize whether a postoperative meningitis occurring in neurosurgical patients is of bacteriological origin or not, in detecting in CSF bacterial DNA with the polymerase chain reaction (PCR) technique. STUDY DESIGN: Laboratory study. PATIENTS: Twenty-seven neurosurgical ICU patients associating, in the postoperative period, the CDC criteria of meningitis and a neutrophil polymorphonuclear count over 100 cells.mm-3 were allocated either into the MB+ group (n = 7) when their CSF culture was positive or in the MB- group (n = 20) when the culture was sterile. The CSF of 43 neurosurgical ICU patients without postoperative clinical and biological features of meningitis acted as controls. Sixteen specimens out of the 43 were inoculated with bacteria at a known concentration. METHODS: The CSF specimens of all patients were tested for the presence of eurcaryote DNA using the PCR technique. Beforehand its sensitivity had been assessed using the inoculated CSF of control group: a positive amplification at 20 cycles was equivalent to 10(5) CFU.mL-1 and a positive amplification at 25 cycles to 10(3) CFU.mL-1. RESULTS: In the 43 sterile control CSF specimens the amplification was negative in all at 20 cycles and in 42 at 25 cycles. In the 16 previously sterile control specimens supplemented with bacteria, as well as in the CSF of all 7 patients of MB+ group the amplification was positive at 20 and 25 cycles. In those of MB- group the amplification was negative in all at 20 cycles, but was positive in 19 out of 20 at 25 cycles. Southern blot with specific procaryote probes was positive with amplification products from CSF of MB+ and MB- groups and negative with control CSFs and human DNA. DISCUSSION: The presence of bacteria in CSF of patients sustaining a meningitis can be accurately detected through their DNA. Postoperative aseptic meningitides may have a bacterial origin. PCR can be used as a routine technique to provide a diagnosis of bacterial meningitis in less than 6 hours. Additionally specific oligonucleotides allow to identify the bacteria in less than 12 hours.

[Cerebrovascular reactivity to CO2 during general anesthesia maintained with either isoflurane-N2O or propofol-N2O. A comparative study by transcranial Doppler velocimetry]. / Réactivité vasculaire cérébrale au CO2 sous anesthésie générale entretenue par isoflurane-N2O ou propofol-N2O. Etude comparative par vélocimétrie Doppler transcrânienne.

OBJECTIVES: To compare, using transcranial doppler velocimetry (TDV), the cerebral blood flow velocity and CO2 reactivity during general anaesthesia maintained with either isoflurane-N2O-O2(IF) or propofol-N2O-O2 (PF) in adults with a normal brain. STUDY DESIGN: Nonrandomized controlled trial. PATIENTS: Forty ASA I patients (mean age 41 +/- 13 yrs, 15 F/35 M) undergoing surgery of the lumbar spine in prone position. The first 20 were allocated into the IF group and the subsequent 20 into the PF group. METHODS: General anaesthesia was induced with midazolam (0.05 mg.kg-1), phenoperidine (0.03 mg.kg-1), thiopentone (5 mg.kg-1), vecuronium (0.1 mg.kg-1) and maintained with N2O (50 vol %) and O2 (50 vol %) and either isoflurane (0.8 < Fet < 1 vol %) in IF group or propofol (6 mg.kg-1.h-1) in PF group. The vascular reactivity was assessed with velocimetry measurements (Angiodine DMS, with a probe transmitting a 2-MHz pulsed wave) of flow in the middle cerebral artery at a given PetCO2 (obtained by adjustments of VT) during systole (SV) and diastole (DV). Three measurements were made: at T1 (PetCO2 = 30 +/- 2 mmHg), at T2 (PetCO2 = 40 +/- 2) and at T3 (PetCO2 = 30 +/- 2 mmHg). RESULTS: In the IF group, VS increased by +32% at T2 (P = 0.006) with an increase of + 3.4 %/1 mmHg of PetCO2. Similarly, in the PF group VS increased by + 31 % at T2 (P < 0.0001) with an increase of 2.9 %/1 mmHg of PetCO2. In both groups the VS returned to baseline values at T3. In the IF group, VD increased by + 66% at T2 (P < 0.0001), with an increase of + 7%/1 mmHg of PetCO2. Similarly in the PF group, VD increased by + 61% (P < 0.0001) with an increase of + 5.7%/1 mmHg of PetCO2. In both groups the VD returned to baseline values at T3. CONCLUSIONS: During anaesthesia maintained with either isoflurane-N2O-O2 or propofol-N2O-O2, a change in PetCO2 results in similar changes in VS and VD. These anaesthetic agents preserve the cerebrovascular reactivity of the normal brain. The results of this study are in accordance with those obtained with other reference techniques in healthy volunteers. Transcranial doppler velocimetry can be a useful noninvasive tool of clinical research in neuroanaesthesia.

[Value of D(-) lactate determination for the fast diagnosis of meningitis after craniotomy. An initial study]. / Intérêt du dosage du D(-) lactate pour le diagnostic rapide de méningite après craniotomie. Etude préliminaire.

The early diagnosis of postoperative bacterial meningitis (BM) may be difficult. CSF cultures may remain sterile. Clinical features and routine laboratory data often fail to give an evidence. As early antibiotic therapy is essential in such patients, a rapid diagnosis is required. Different authors proposed the D(-) isomer of lactic acid as an early and effective marker of infection in the body fluids (including CSF). D(-) lactate is produced by bacteriae and fungi; L(+) lactate may be produced also by human tissues in anaerobic situations. We conducted a prospective study in a neurosurgical intensive care unit to evaluate this technique for the diagnosis of meningitis following craniotomy. Fifty-four patients were included, 40 in group A (not infected or infected out of the CNS), 4 in group B (suspected BM), 10 in group C (BM with positive CSF cultures). No patient suffered from septicemia, haemodynamic or ventilatory instability, nor metabolic disorder. Clinical data, CSF and blood samples (cytology, conventional biochemistry, D(-) and L(+) lactate, bacteriology) were collected at inclusion and, in group B and C patients, at day 2, 5 and at clinical recovery. D(-) lactate measurements were performed with an enzymatic method adaptated from a Boehringer Mannheim kit (for determination in foodstuff). Statistics were based on the comparison of group A vs C patients. D(-) and L(+) lactate concentrations in the CSF were significantly higher in group C patients, and blood concentrations were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

[General anesthesia during neurosurgery in sitting position]. / Anesthésie générale en neuro-chirurgie au cours des interventions en position assise

Sitting position during surgery of the posterior fossa is very convenient for the neurosurgeon but can be dangerous, specially concerning the risk of air-embolism. We discuss the major problems of this special position, and the modifications of respiratory and hemodynamic functions from our experience on 84 cases. We study the monitoring of these patients during surgery, with special emphasis on prevention and detection of air-embolism with the capnograph. With the protocol suggested we can avoid major risk in this position.

[Indications of planned sedation following intracranial neurosurgery. Prospective study of decisional criteria]. / Indications d'une sédation délibérée après neurochirurgie intracrânienne. Etude prospective de critères décisionnels.

General Anaesthesia (GA) is usually stopped early after intracranial surgery. An impaired neurological status or surgical difficulties may lead to sedate some patients (pts) in the intensive care unit (ICU). The aims of the study were to establish and to evaluate predictive criteria for post- operative sedation. In one group (G1), GA and mechanical ventilation (MV) were discontinued early after surgery and pts stayed at least 12 h. in the ICU. In the other group (G2), sedation and MV were prolonged 24 h., until a clinical and scannographic evaluation. Thereafter, sedation was discontinued or prolonged according to both surgical and anesthetic considerations. These criteria were established according to the literature and to local practices. Before surgery, they depended on clinical status, radiological data and etiology; during surgery, on surgical and medical semiology and difficulties or incidents during the procedure. Adult pts undergoing intracranial surgery under GA were consecutively included in a 6 months prospective study. Patients suffering acute head trauma, pre operative coma (Glasgow CS < 8) or extraneurologic disease (responsible for delayed MV weaning) were not included. Sedation was performed with midazolamR (.05-.15 mg.kg-1.h-1) + phenoperidineR without myorelaxation. The ideal level of sedation was established as defined by Boeke. One hundred and ninety five pts (80 f; 49 +/- 15y-o) were included (G1 = 130, G2 = 65). Surgical indications were: malignant tumor = 61, meningioma = 50, vascular disease = 53, other = 31. ICU stay lasted 5.6 +/- 8 d and MV 3.7 +/- 7 d.(ABSTRACT TRUNCATED AT 250 WORDS)

[Reliability of the results of the ultrasonic hemodynamic recording (Doppler effect) in the diagnosis of cerebral ishemic ischemia of carotid origin]. / Fiabilité des résultats du bilan hémodynamique ultrasonographique (effet Doppler) dans le diagnostic de l'ischémie cérébrale d'origine carotidienne.

The Doppler ultrasound diagnosis of carotid artery stenosis (asymetrical systolic and diastolic flows; elevated resistance index: ratio of flow pulse amplitude to systolic and diastolic values; flow reversal in the ophtalmic artery) is compared, in 52 patients, to the clinical, angiographic (40 patients) an surgical findings and to the peroperative measure of intra-arterial pressure and flow (30 patients). Its reliability is proved as a guide for angiographic exploration and for postoperative watching, but it is restricted to great vessels (cervical carotid artery) and is unable to detect ulcerated plate without stenosis.

[Complications related to the seated position of the aged patient in neurosurgery]. / Complications liées à la position assise chez le sujet âgé en neurochirurgie.

The advantages of the sitting position for neurosurgery of the posterior fossa are evident and universally admitted. However, respiratory and haemodynamic consequences make this position uncommon and even exceptional for the old patient whose existing physiological cardiovascular and pulmonary disturbances may result in greater risks. In this study, the complications observed during and after surgery in twenty-two patients over 65 years are analysed. These patients underwent functional neurosurgical procedures in sitting position. According to the results, old age does not appear to be an absolute contra-indication of the sitting position for this type of surgery.

[Preoperative treatment of arterial spasm and preparation of the patient for surgery of intracranial aneurysm]. / Traitement pré-opératoire du spasme artériel et préparation du malade à l'intervention chirurgicale pour cure d'anévrisme intracranien.

In spite of various clinical status and timing in surgical treatment of ruptured intracranial aneurysm, some general rules can be put in practice at the preoperative period. Rebleeding prevention by sedation and bedrest seems better than antifibrinolytic therapy which can induce delayed ischemic syndrome and/or hydrocephalus. Most important of treatment regimen appears to be a good hemodynamic stability with hypervolemic hemodilution and hydroelectrolytic control for compensating hyponatremia. Calcium blockers precociously given can be discussed in case of high ICP.

Hyperbaric oxygenation for severe head injuries. Preliminary results of a controlled study.

60 patients were included in a prospective study to evaluate the effectiveness of hyperbaric oxygenation (OHP) as a treatment of head injury coma. They were assigned to nine subgroups according to age, level of consciousness and eventual neurosurgical procedure, and then selected randomly for OHP or standard therapy. OHP was administered in one or several series of daily exposure at 2.5 ATA. However, the OHP therapy protocol was to be interrupted in 11 cases developing pulmonary, hyperoxic, or infectious complications. Overall mortality and mean duration of coma in survivors were not different in both groups, indicating that OHP was either ineffective or too intermittently applicated. Analysis of results in subgroups revealed that, in one subgroup (18 patients), the rate of recovered consciousness at 1 month was significantly higher when OHP was used. These patients were under 30 and had a brain stem contusion without supratentorial mass lesion. The view is defended that, besides its toxic action on the normal nervous tissue, OHP can counteract edema and ischemia in the zones of brain injuries.