[What sedation for prevention and treatment secondary brain insult?]. / Quelle sédation pour la prévention et le traitement de l'agression cérébrale secondaire ?

The aim of sedation and analgesia is to prevent secondary brain insult. The goals of sedation are the prevention and treatment of intracranial hypertension and systemic disorders. In such situation, the use of sedative and analgesic therapy should respect the rate of cerebral blood flow/cerebral oxygen consumption coupling while preserving cerebral perfusion pressure and decreasing the intracranial pressure. This treatment should have an analgesic and myorelaxing action with short and predictable time of action. The optimal agent with all these characteristics does not exist, but the combination of several pharmacological compounds may reach this goal. Benzodiazepines are the most frequently agents used. In most of cases they are associated with analgesics like opioids or ketamine. Opioids are the basis of analgesia because they do not produce brain haemodynamic alterations if arterial pressure is maintained. Ketamine, which use in this indication is matter of debate, has the advantage to maintain haemodynamics. Ketamine has no side effects on brain haemodynamics when used in combination with propofol or midazolam. Because of their side effects on haemodynamics and immune response, barbituric are no longer used as long term sedative agents. However, they are still recommended in cases of refractory intracranial hypertension. Propofol remains the optimal sedative agent because of its short duration action although its use is restricted because it is an expensive drug. Its use is recommended for short time sedation with or without opioids. The use of neuromuscular blockers should be focused on the patients with an intracranial hypertension refractory to standard treatment. The presence of brain damage in patients makes difficult to assess the level of sedation. One should avoid over sedation, which increases morbidity by prolongation of the duration of mechanical ventilation.

[Value of retrolabyrinthine approach for surgical resection of meningiomas inserted around the lateral sinus between the transverse and sigmoid parts]. / Avantages de l'abord rétro-labyrinthique pour l'exérèse des méningiomes insérés au pourtour du coude du sinus latéral.

PURPOSE: To describe the retrolabyrinthine approach for the resection of 9 meningiomas inserted around the lateral sinus between the transverse and sigmoid parts, to discuss the value of this approach compared to the retrosigmoid approach for resection of meningioma in this localization and to review the literature. METHODS: Retrospective study. Between 1988 and 2002, 9 patients (8 female, mean age 50 years) underwent surgery via the retrolabyrinthine approach for resection of meningiomas inserted around the lateral sinus between the transverse and sigmoid parts. RESULTS: Resection was total (8 Simpson I and 1 Simpson II) in all patients. In the early postoperative course, one patient was treated for meningitidis with an LCR leak and one patient present a temporary paresis of the vagus nerve. Mean follow-up was 5 years (6 months-10 years). All patients continued their pre-treatment occupation after surgery. No recurrence was observed. CONCLUSION: Two approaches can be used for resection of meningiomas in this localization. The retrosigmoid approach is a common neurosurgical approach exposure of the cerobellopontine angle. It is practised by most neurosurgeons. Via this approach, the cerebellar lobe must be pushed back so the arteries feeding the tumor are in the operative field at the end of the procedure. For numerous authors the operative field is too narrow. On the other hand, the retrolabyrinthine approach described in 1972 by Hitselberger and Pulec allows exposure of feeding arteries during the first steps of operation, an easier resection of meningioma insertion and better control of the lateral sinus. This approach can be enlarged to the retrosigmoid or the subtemporal anatomic region.

[Epidural intracranial hematomas: practical issues revealed by management of 100 recent cases]. / Hématomes intra-crâniens extra-duraux: à propos de 100 cas récents. Notre expérience et considérations pratiques.

We present a retrospective study on the management of 100 patients who presented epidural hematoma over a four-year period. Our goal was to provide an update on management of this injury. Computed tomography was performed because of the clinical presentation. Results provided information on the type of injury and appropriate treatment. A three-phase clinical progression was observed in only 6% of the patients. Despite state-of-the-art management, mortality remained high in these brain-injured patients (21%). No progress appears to have been achieved in the last ten years. This paradoxical fact probably results from the enhanced severity observed in our patients, who often suffered from associated intracranial injuries as well as multiple trauma (thoracic, abdominal trauma). Analysis study of the results confirms an improvement in mortality among patients with isolated epidural hematoma (6.6%), but great concern remains about the high mortality among patients with associated intracranial lesions (33.3%) or multiple trauma (32%).

[Extradural hematoma of the posterior fossa]. / Hématome extradural de la fosse postérieure.

Extradural hematoma of the posterior fossa (EDHPF) is considered to be a rare complication of head injuries. In early reports, diagnosis was made only at the time of autopsy. Today, CT scanning prompts early diagnosis leading to better outcome. We report 20 consecutive patients observed over the last ten years who underwent surgery for EDHPF. This localization was found in 14,3% of all trauma patients operated for extradural hematoma. In our experience, EDHPF occurs in young adults with a clear male predominance. Vehicle accidents are the most frequent mechanism of injury. The main clinical presentation is subacute onset of signs (50% of our cases). Postoperative outcome was favorable in 19 of our patients (95%). We propose mandatory CT scanning that may have to be repeated as needed, to prevent delay in diagnosis and decision for surgery. Surgical removal of the EDHPF must be carried out as soon as possible as this is the only way to reduce morbidity and mortality.

[Subperiosteal hematoma of the orbit. Three cases]. / Hématome sub-périosté de l'orbite.

Orbital subdural hematoma should be considered in victims of head and face trauma with signs of exophthalmia. Early diagnosis and treatment, consisting of decompression, is mandatory to avoid long-term functional complications.

[Tuberculous abscess of the cerebellum. Apropos of a case]. / Abcès tuberculeux du cervelet. A propos d'un cas.

A 22-year-old Asian man developed intracranial hypertension with a 38 degrees C fever. Two months earlier, he had undergone surgery and medical treatment for tuberculous otomastoiditis and pulmonary tuberculosis. The CT scan revealed multiple tuberculous abscesses of the cerebellum. Histological, microbiological and biological proof of diagnosis was obtained. We advocate surgical treatment of intracranial tuberculous abscesses associated with antituberculosis chemotherapy for 18 months. The earlier the treatment, the better the prognosis. This pathology must be kept in mind when treating patients from countries with a high endemic rate of tuberculosis and suffering from immunodeficiency syndrome.

Central neurocytoma: 2 case reports and review of the literature.

Central neurocytoma is a rare benign tumor of the central nervous system occuring in young adults and typically located in the ventricles. The tumor is composed of small round cells with neuronal differentiation and has a favourable prognosis. We report two cases of giant central neurocytomas with a triventricular extension in two young women. The first case concerned a 26 years old righthanded woman in whom an intraventricular mass was discovered, after a car accident with head trauma. Skull radiography showed an enlargment of the sella turcica. A CT scan performed in order to examine the pituitary gland revealed a voluminous and heterogenous intraventricular tumor with calcification. The second case concerned a 26 years old righthanded woman, presenting with a 4 Glasgow Coma Scale Score preceded by an acute onset of headache with projectile vomiting. A CT scan performed in emergency revealed a voluminous intraventricular mass with significant hydrocephalus. We review the different pathological and topographical patterns of previously published neurocytomas and discuss surgical management, effectiveness of radiation therapy and biological behavior.