Results of surgery for lumbar spinal stenosis in patients aged 80 years or more. A retrospective study of thirty-four cases.

As life expectancy increases and spinal imaging techniques improve, surgery is being increasingly viewed as a therapeutic alternative for symptomatic lumbar spinal stenosis in patients older than 80 years. Thirty-four patients (21 men and 13 women) who had surgery for lumbar spinal stenosis in our department between 1979 and 1994 were studied retrospectively. The most common initial symptoms were walking-related disorders (n = 29) and sciatica or femoral neuralgia (n = 34). All 34 patients underwent laminectomy at one or more levels. Ten patients also had a herniated disk. There were no deaths and only two patients had serious complications (persistent foot drop in one and left-sided hemiplegia in the other). Results were evaluated immediately after surgery and after three and 12 months. The overall result on pain and walking-related disorders was good in 53% of cases, acceptable in 32%, and poor in 15%. Our data suggest that surgery is a reasonable alternative in symptomatic elderly patients who are in good general health. Satisfactory results can be obtained although disabling complications can occur.

[Transpetrosal approaches to the clivus. Surgical anatomy, challenges and limitations]. / Les voies trans-pétreuses dans l'accès au clivus. Anatomie chirurgicale, prétentions et limites.

Radical excision of skull base tumors is a real challenge for neurosurgeons. The need to preserve the nerves and the vessels in the area lead us to use lateral approaches, if the lesion lies lateral to the cavernous portion of the carotid artery and behind the petrous apex. Lateral approaches are classified into two groups: ventrolateral approaches (in front of the cochlea) and dorsolateral approaches (with or without resection of the bony labyrinth). The three surgical approaches studied were the subtemporal preauricular infratemporal, the subtemporal anterior transpetrosal, and the combined supra and infratentorial presigmoid approach. The approaches were performed on adult cadaver heads fixed in formolin. The technique, the exposure, the modifications and extensions, as well as the problems of reconstruction are discussed.

[Epidural hematoma. Myth and reality, based on 3 exemplary cases]. / L'hématome extra-dural. Mythes et réalités à propos de 3 observations exemplaires.

The acute epidural hematoma is a real surgical emergency with a good outcome if the operation is performed in reasonable delays. In 1994, too many young patients eventually died or were left with major disabilities, because of an unacceptable and almost always avoidable loss of time. We do emphasize some rules which have to be followed to avoid catastrophic events.

[Malignant astrocytoma of the cerebellum. Apropos of 10 cases. Review of the literature]. / Astrocytomes malins du cervelet. A propos de dix cas. Revue de la littérature.

While reviewing a series of 138 cerebellar tumors operated upon between 1978 and 1991, the authors could only find 2 glioblastomas and 8 anaplastic astrocytomas, occurring in 4 children (3 to 14 years old) and 6 adults (23 to 48 years old). These 10 cases represent 2% of the all malignant gliomas population observed during the same period of time. Clinically speaking, nothing makes these tumors different from other cerebellar ones. However, with an heterogenous image and an irregular contrast enhancement, the CT (scan) appearance can lead to the diagnosis. 7 lesions develop within the cerebellar vermis (vermis cerebelli) and 3 develop within the cerebellar hemisphere. Total surgical resection is performed in 9 cases and subtotal resection in 1 case (because of the extension to the floor of the fourth ventricle). Adjunctive radiotherapy on their posterior cranial fossa is achieved in 8 cases. The 2 patients with a glioblastoma present with a recurrence of their tumor at 15 months and 6 years respectively, and eventually died. Out of the patients with an anaplastic astrocytoma, 4 are still alive without recurrence and with a median follow-up of 7 years. The pathogenesis of such lesions is discussed. An aggressive therapeutic management is suggested because of the possible prolonged survival rate.

Autoantibodies against H- and M-subunits of neurofilaments are induced by PC12 cell grafts or lesions into different sites of rat brain.

Since autoantibodies against neurofilaments (NF) were frequently found in neurodegenerative disorders, this work is an attempt to investigate whether the same phenomenon occurs after intracerebral grafting or lesioning. We have thus either grafted PC12 cells or injected culture medium alone into three sites of rat central nervous system (CNS): olfactory bulb (OB), olfactory anterior nucleus (OAN) and hippocampus (HC), all three sites being impaired in Alzheimer's disease. At day 15, rat sera were collected and tested against NF by western blotting. Sera from grafted rats recognized the H- and M-subunits of NF; we have then quantified the autoantibody response by using an ELISA technique. We show that, in all cases of grafts, the autoantibody response against NF significantly increased when compared to controls (normal rats without grafts or lesions) for total immunoglobulin (Ig) amount. In contrast, concerning the Ig isotypes, some differences appeared depending on the implantation site: for grafts into OB, the immune response was of both the IgG and IgM isotypes, into OAN it was mainly of the IgM isotype and into HC, the isotype of antibodies against NF was mostly IgG. In the case of lesions alone into OAN and HC, no significant enhancement of autoantibody response was observed; in contrast, lesions into OB induced an increase in autoantibody response against NF which significantly differed from controls for all Ig isotypes tested. These data point out the diversity of the autoantibody responses following lesions or grafts according to the rat brain areas.

Are the calcium antagonists really useful in cerebral aneurysmal surgery? A retrospective study.

From 1983 to 1990, 234 patients with one or several cerebral arterial aneurysms were surgically treated in our department. Since 1983, we have been performing surgery as early as possible. As soon as the subarachnoid hemorrhage diagnosis is confirmed by computed tomography (or if unconfirmed, by lumbar puncture), we assume that each patient may have an aneurysm. Between 1987 and 1990, 111 patients were treated by vascular volume expansion (maintenance of central venous pressure above 5 cm H2O with 4% albumin or Ringer-lactate or, if necessary, with 20% albumin), which we supplemented with calcium antagonists (nimodipine in 60 patients and nicardipine in 51 patients). Two months after being discharged, each patient is examined by a neurosurgeon and, on the same day, is subjected to a neuropsychological evaluation and a computed tomographic scan of the brain. A few months after this consultation, a working-position/family-activities questionnaire is issued to the patient. All of the results studied on the basis of postoperative mortality, second-month computed tomographic scan ischemia, neuropsychological evaluation, and return to work show no significant difference between the groups with or without calcium antagonists or between the nimodipine and nicardipine subgroups.

[Osteosarcoma of the sacrum. Apropos of a case in a 14 year-old girl]. / Ostéosarcome du sacrum. A propos d'une observation chez une adolescente de 14 ans.

The authors report a case of sacral osteosarcoma, which is a rare and dreaded tumor. Sciatica was the first manifestation. Patients with refractory sciatica and normal plain films and computed tomography studies of the lumbar spine should undergo magnetic resonance imaging to look for a sacral lesion.

Differential behaviour of PC12 cells grafted into rat hippocampus and striatum.

To investigate the mechanisms involved in graft survival, a rat cell line (PC12) that differentiates into sympathetic-like neurons by exposure to trophic factors has been grafted into rat striatum and hippocampus, two structures which differ in their amounts of trophic factors. Our results show that grafted PC12 cells behave differently depending on the area of implantation; they display a differentiated morphology in the hippocampus and proliferate as a tumor in the striatum. A qualitatively similar immunological reaction occurs in both structures, characterized by the invasion of T and B lymphocytes, macrophage-like cells and by the expression of major histocompatibility complex class I and II antigens around the graft.

[Metastases in the cauda equina in visceral cancers. Apropos of 2 cases]. / Les métastases de la queue de cheval des cancers viscéraux. A propos de deux cas.

Two new cases of cauda equina metastases from visceral cancers are reported. This diagnosis is only infrequently considered in patients with intra-dural lesions visualized by magnetic resonance imaging or saccoradiculography. The diagnosis is especially difficult in patients with no known primary cancer. Diagnosis rests on surgery during which only a biopsy is performed. Treatment is symptomatic and focuses on relieving pain. Prognosis is bleak.

[Are calcium channel blockers really useful in cerebral aneurysm surgery?]. / Les anticalciques sont-ils réellement utiles en chirurgie anévrysmale cérébrale?

Two retrospective series of early operated cerebral arterial aneurysms are compared. One series involves 74 patients treated from 1983 to 1987 by vascular volume expansion only. The other series involves 75 patients treated from 1987 to 1990 by vascular volume expansion associated by calcium antagonists (nimodipine or nicardipine). The conclusion is that in our experience, calcium antagonists do not improve the outcome (mortality, cognition findings and return to work) obtained by vascular volume expansion alone. Moreover they put forward that there is no difference between the patients treated by nimodipine and those treated by nicardipine.

[Calcificated necrotic inflammatory granuloma after intradiscal injection of triamcinolone hexacetonide]. / Granulome nécrotico-inflammatoire calcifié après nucléorthèse à l'hexacétonide de triamcinolone.

Recently, it has been demonstrated that symptomatic epidural calcifications represent a complication of intradiscal injection of triamcinolone hexacetonide (Hexatrione). Out of our three cases, pathological examination showed lesions of necrosis with granulomatous inflammatory reaction and bone metaplasia. Necrosis seems to be the primary cause of calcifications so we propose to call the lesion inflammatory and necrotic granuloma. The incidence of these granulomas is unknown. They are unpredictable and appear with a mean range of a year following the intradiscal injection. The treatment is surgery if they become symptomatic.

[Value of the neuropsychological evaluation in cerebral arterial aneurysms surgically treated]. / Intérêt du bilan neuropsychologique dans les anévrysmes artériels cérébraux opérés.

Early examination (3 months) of 81 patients, operated on for ruptured cerebral aneurysms, by neurosurgeons and neuropsychologists show significant differences between them both; the neuropsychological evaluation has the best predictive value as far as the outcome is concerned especially regarding the return to their initial job (69% after a year in this series). The outcome also depends on the age, the preoperative grade, and the professional qualification. The aneurysm location and the date of the operation are not so important. Early neuropsychological evaluation enable us to start a rehabilitation program for socio professional reinsertion and to improve the quality of life.

[Intracerebral graft of a line of chromaffin cells. Immunologic aspects and role of nerve growth factor in survival and differentiation of the graft]. / Greffe intra-cérébrale d'une lignée de cellules chromaffines: aspects immunologiques et röle du nerve growth factor dans la survie et la différenciation du greffon.

The efficiency of neuronal grafts is correlated with the differentiation of the grafted cells and the connections they establish with the host tissue. The prolonged survival of a chromaffin cell line (PC12) transplanted into an immunodepressed rat brain shows that neuronal differentiation is correlated with the amount of nerve growth factor (N.G.F.) present in the grafted structure. This result is in agreement with in vitro studies. The characterization of other factors that influence the differentiation of PC12 cells in culture could lead to an increase in the efficiency of intracerebral grafts of adrenal medulla cells in Parkinson's disease.

[Cerebral edema with hyperammonemia in valpromide poisoning. Manifestation in an adult, of a partial deficit in type I carbamylphosphate synthetase]. / Oedème cérébral avec hyperammoniémie au cours d'une intoxication par le valpromide. Révélation, chez un adulte, d'un déficit partiel en carbamylphosphate synthétase de type I.

A case of cerebral oedema developed during an apparently common attempted suicide with valpromide is reported. The most conspicuous biochemical abnormality was hyperammonaemia. The oedema proved refractory to the standard medical treatment of intracranial hypertension, and decompressive craniectomy was performed with only minor sequelae. The cerebral oedema cum hyperammonaemia syndrome led to the discovery, in this hitherto asymptomatic adult subject, of a 50 per cent deficiency in type a carbamyl phosphate synthetase liver activity. By completing such a deficiency, valproate may produce an extremely serious syndrome resembling the neonatal encephalopathy due to complete enzyme deficiencies in the urea cycle. All valpromide or valproate intoxications probably are cerebral oedemas with hyperammonaemia akin ti Reye's syndrome. All accidents of this type occurring during treatment or poisoning with valproate should be investigated for urea cycle enzyme abnormalities.