[Treatment of choroid melanoma by Gamma-Knife radiosurgery]. / Traitement du mélanome choroïdien par radiochirurgie Gamma-Knife.

Conservative treatment of uveal melanomas by Gamma Knife Radiosurgery is based on the use of cross fire technique with 201 Cobalt60 sources. A following of 13 months is available for the first case operated by Gamma-Knife Surgery in France. Technical baselines and one year preliminary results are reported. The diagnosis of uveal melanoma T3NOMO was established by converging results of clinical examination, angiography and echography. The definition of the target was based on stereotactic MRT examination. We delivered a dose of 50 Gys to the marginal isodose (50%). Today, one year after treatment the tumor decreased, the visual function was preserved. There were no side effect or complication.

Effect of the Gamma Knife on trigeminal neuralgia.

The Gamma Knife radiosurgical treatment of 20 patients suffering from trigeminal neuralgia is reported. Eleven patients received radiosurgical treatment with the goal of pain relief. Six had secondary trigeminal neuralgia due to AVM, large cavernous sinus and petrous bone meningiomas, trigeminal neurinoma, or chordoma; 5 others had essential trigeminal neuralgia. Radiosurgical treatment was considered only after the failure of conventional medical and surgical treatment. For the other 9 patients, the control of the tumor was the main objective (four acoustic and one trigeminal neurinoma, one petroclival chordoma, and three tumors of the cavernous sinus: one hemangiopericytoma, one metastasis, one meningioma). We have not been using this method for sufficient time to evaluate long-term results. However, we believe that a large majority of our patients benefited greatly from this technique with a rapid clinical improvement, which is a reflection of the relevance of the chosen target.

First selective amygdalohippocampal radiosurgery for 'mesial temporal lobe epilepsy'.

All the well-documented radiosurgery of epilepsy cases are secondary epilepsies with space-occupying lesions. These results have prompted the idea of testing radiosurgery as a new way of treating epilepsy without space-occupying lesions. We have treated 4 patients with 'mesial temporal lobe epilepsy'. The preoperative evaluation programme was one we usually perform for patients selected for microsurgery of epilepsy. We report the baselines of this treatment, the radiosurgical protocol details, and preliminary results for the first patient treated (follow-up 16 months). Since treatment, the patient has been seizure free, but it is too soon to draw long-term conclusions about the efficiency of the radiosurgery of epilepsy. Morphological (MRI) and functional (PET scan) changes are discussed in relation to our technical choices. Our amygdaloentorhinohippocampal target has been selectively injured.

Correlation between cytogenetic and histopathological findings in 75 human meningiomas.

The correlations between cytogenetic and histopathological findings were analyzed in 75 human meningiomas. The tumors were classified according to increasing degrees of anaplasia into three grades: Grade I, benign; Grade II, atypical; Grade III, anaplastic. In 45 tumors of Grade I (benign), we more often observed a normal karyotype or monosomy 22. In 23 tumors of Grade II (atypical), we observed karyotypes with structural and/or numerical abnormalities with the presence of telomeric associations in 8 of them. These last tumors were fibroblastic. In seven Grade III tumors (anaplastic), we also observed complex abnormalities, and in one case, we observed telomeric associations. Our observations show that complex chromosome abnormalities and telomeric associations are observed in tumors that histologically display a certain degree of anaplasia. It is possible that the result of histopathological and cytogenetic correlations might represent a prognostic factor in meningiomas.

[Nociceptive flexion reflex of the leg. Use after surgical treatment of herniated disk]. / Réflexe nociceptif de flexion de la jambe. Utilisation après intervention chirurgicale pour hernie discale.

In patients suffering from acute sciatica due to herniated disk Lasegue's manoeuvre inhibits the leg flexion nociceptive reflex (RIII reflex) in either the ipsilateral or the contralateral limb. This is thought to be due what is called "diffuse noxious inhibitor control" modulating the activity of a group of convergent spinal neurons. The purpose of this study was to determine whether surgical resection of the herniated disk in patients suffering from sciatica might relieve this so-called "counter-irritation". Among 10 patients whose sciatica resulted from herniated disk, the decrease in amplitude of the RIII response observed when Lasegue's manoeuvre is applied disappeared in 7 patients, 6 to 8 days after surgical resection of the herniated disk. These results suggest that this test might be a useful tool for postoperative prediction of radicular compression.

Hemangiopericytomas of the spinal canal. Report of four cases and review of literature.

The Authors report four cases of spinal hemangiopericytomas. The diagnosis has been ascertained by electron microscopy. Despite the malignant nature, the association of surgery and radiotherapy is interesting in that it prolongs the survival rate. Clinical, neuroradiological, microscopic and ultrastructural features of intraspinal hemangiopericytomas are evaluated in the light of the review of the relevant literature.

Long-term follow-up after stereotaxic basal ganglia surgery in parkinsonism. A neuroanatomical study of a case showing unusual postural disorders.

A 60-year-old man who had Parkinson's disease for 25 years became unable to maintain the upright position of the trunk while standing or walking. Because of a loss of postural fixation, his trunk sank forward until his back was horizontal. Fifteen years before, a bifocal implantation of radioactive yttrium-90 had been performed by a stereotaxic procedure at the level of the globus pallidus (GP) and the ventrolateral thalamus, respectively on the right side. A second operation, 2 years later, had been made by electrocoagulation in the left ventrolateral thalamus. Postmortem examination showed the following features (a) neuronal cell loss in the pigmented nuclei of the brainstem with intracellular Lewy bodies and gliosis. These data corresponded with the usual pathology of idiopathic Parkinson's disease; (b) surgical lesions resulting from the previous stereotaxic operations in the right GP and the ventrolateral thalamus on both sides and (c) neuronal cell loss without gliosis in the right GP that was evident in regions spared by the surgical lesion. Moreover, these degenerative changes were particularly seen in the left GP, which was surgically unlesioned. The ansa lenticularis was demyelinated on both sides. These data might be consistent with a retrograde degenerative process affecting the pallidothalamic projections. Beside the role of the neuronal cell loss affecting the pars compacta of the substantia nigra (SN) in akinesia, the role of the lesions affecting the G.P. in the genesis of postural disorders is suggested.

[Stereotaxic guidance in open surgery of the brain]. / Guidage stéréotaxique de certaines interventions à crâne ouvert.

The authors describe the technique used to precisely locate, before surgical ablation, small superficial or deep seated intracerebral lesions. When they are superficial, a burrhole is placed above the lesional site, that is reconstructed by superimposing the CT image onto a plain film radiogram taken during stereotaxy. Deep seated lesions are localized by inserting a guide under stereotaxy, prior to open surgery, which will lead the neurosurgeon without error from the cortex to the lesion. 37 observations are reported where this technique lead to a greatly simplified intervention with minimal cortical damage.

Stereotactic biopsy and treatment of brain stem lesions: combined study of 33 cases (Bologna-Marseille).

Intraaxial brain stem tumours are rarely treated by open surgical technique. In Bologna and Marseille, 23 and 10 stereotactic biopsies respectively were performed in patients with brain stem mass lesions. The mortality due to biopsy was 3% (1 pat.); while the morbidity was temporary in 6 cases (18%) and permanent in one patient (3%). The approach to the brain stem was via a frontal burr hole. 7 times, after biopsy and histological diagnosis, radioisotope implant of the neoplasm was performed with 125I (iodine). From the histological diagnoses of the lesions the following was found: only 40% of the young patients had highly malignant tumours; 83% of the adults had neoplasms (not all of the malignant type), while 17% of the verified lesions were non-neoplastic. Since a diagnosis of the lesion nature is impossible with current neuroradiological means, the authors noting a variety of masses found in their experience, emphasize the importance of stereotactic biopsy, as a scarcely invasive method to give a precise diagnosis and a possible treatment.

[Prevention of risk in stereotaxic biopsy of various tumors of the pineal region. Apropos of 3 cases]. / De la prévention des risques de la biopsie stéréotaxique de certaines tumeurs de la région pinéale. A propos de 3 observations.

During the last ten years, the authors have performed 750 stereotactic biopsies with 6 deaths. In 3 cases, the lesion was a pinealoblastoma, with comparable symptomatology and CT scan image. Safety measures are discussed.

[Modern imaging and stereotaxy]. / Imagerie moderne et stéréotaxie.

The authors present their technique of utilization in stereotaxic neurosurgery of CT and IRM documents realized in standard condition. Besides, they present an original apparatus that allows to combine the advantages of Leksell and Talairach's stereotaxic system.

[Results of percutaneous selective thermocoagulation of Gasser's ganglion in essential facial neuralgia. Synthesis of results obtained in 939 treated patients]. / Résultats de la thermo-coagulation percutanée sélective du ganglion de Gasser dans la névralgie faciale essentielle. Synthèse des résultats obtenus chez 939 patients traités.

The authors report the late results of thermocoagulation of the gasserian ganglion in 939 patients operated by 3 different neurosurgical teams, (Bologna, Bordeaux, Marseille). It has been assessed that the results are comparable among the 3 teams and that percutaneous selective thermocoagulation represents a simple and low-risk technique with a high rate of efficacity.

Long-term results of conventional surgical treatment for epilepsy. Delayed recurrence after a period of 10 years.

The results of the surgical treatment of epilepsy were studied in 44 patients 10 or more years after operation. Thirty-seven patients underwent operation only once; these patients were observed 11-26 years postoperatively. Seven patients had a recurrence within 5 years after operation and required a second operation; these patients were observed 11-17 years after the second operation. Recovery persisted for 15-27 years in 32 patients. There was a recurrence in 12 cases 11-19 years after operation. With one exception, these recurrences were satisfactorily treated medically.

Comparative study of the posterior red nucleus in baboons and gibbons.

The posterior red nucleus (PRN) was studied in two species of primates by the technique of retrograde degeneration of rubrospinal cells following transection of the spinal cord at different levels. The form of the PRN was reconstructed for both a quadruped monkey (baboon) and an anthropoid with erect posture (gibbon). The PRN contains polymorphic cells characterized by their very chromophilic and granular Nissl substance. These neurons vary in diameter from 25 micrometer to 70 micrometer. Some of them give rise to the rubrospinal tract. Baboon: The approximately 1,300 rubrospinal cells in this species are divided into two equal groups, one related to the contralateral forelimb, with axons ending between the second cervical and third thoracic segment, and the other related to the contralateral hindlimb, projecting caudally beyond T3. Following a high cervical lesion, nondegenerated cells of similar description remain throughout the nucleus. A significantly large group of these cells occurs medially and may be the source of fibers ending in the brain stem or cerebellum. Gibbon: In this species, the number of rubrospinal cells controlling the hindlimb is less than half that found in the baboon. This reduction in the gibbon is much greater for medium-sized cells, but is also significant for the giant cells. These results obtained from primates are compared with those reported for the cat. A possible function for the PRN in the control of limb movements is discussed from the viewpoint of phylogeny.

[The role of stereotaxic biopsy in the therapeutic approach to malignant gliomas (author's transl)]. / Place de la biopsie en condition stéréotaxique dans la tactique thérapeutique des gliomes malins.

Analysis of 770 biopsies of intra-cerebral neoplasms under stereotaxic conditions and performed in Bordeaux, Rennes and Marseilles. The study emphasized the relative benign nature of this examination (1% deaths, 1.4 % severe sequellae) bearing in mind the severity of the underlying disease. In a very large number of cases (from 7 to 38% according to Schools) the diagnosis made before biopsy was fundamentally altered by this examination. The quasi-certitude of the nature of the lesion, and the possible facilitation of surgery by the precision of the lesional topography, and finally the possibility of a therapeutic gesture of evacuation in certain cases, is felt to justify intra-cranial biopsy performed under stereotaxic conditions.

Indications and ethical considerations of deep brain stimulation.

Electrical impulses through chronically implanted electrodes in the human brain are used today in the relief of chronic crippling pain, motor movement disorders and behavior disturbances. A great number of reports from animal studies and several descriptions of the results produced by human stimulation seem to suggest that pain can often be adequately controlled. However, the perspectives of such methods raise many ethical problems and ask for caution. Nervous tissue damage after long-term stimulation, biochemical modifications, electrode migration and long-term follow-up of its clinical value are still under study and are the factors which might limit for the time being the indications. A restrictive role for this procedure is advocated for: 1. cases of chronic facial pain, 2. cases of chronic pain in other locations where other neurosurgical operations have failed and where the patient is not too young and is not suffering from pain of benign origin.