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Biomedical subjects

S Blond

Publications and source records attributed to S Blond.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Novel possibilities for treatment of parkinsonian tremor and other abnormal movements by stimulation of the nucleus ventralis intermedius thalami].

Chronic thalamic stereotactic stimulation has been performed in 22 patients with disabling tremor and poor response to drug therapy: 17 parkinsonian tremors and 5 essential tremors. Our first results are presented with a mean follow-up of 26 months. Parkinsonian tremors 17 = complete disappearance: 12, clear improvement: 5. Essential tremors 5 = complete disappearance: 3, clear improvement: 1, failure 1 cured by thalamotomy. Choreic or ballistic dyskinesias 7 = complete disappearance: 5, clear improvements: 2. Dystonic dyskinesias 3 = complete disappearance: 2, failure: 1. This new stereotactic procedure permits to control easily not only tremor but also L-Dopa induced dyskinesias: choreic or ballistic dyskinesias and biphasic dystonic dyskinesias. The place of this surgical treatment among the other therapeutic possibilities is discussed.

Electric Stimulation Therapy↗
PubMed1992

[Neuropsychological evaluation before and after thalamic stimulation in 9 patients with Parkinson disease].

Chronic thalamic-VIM stimulation was performed in 9 parkinsonian patients with disabling tremor and poor response to drugs. Neuropsychological assessment was performed before and after deep brain electrode implantation and stimulation. Mild cognitive disorders were observed prior to thalamic implantation. Neuropsychological testing failed to show intellectual function worsening after implantation and stimulation. We conclude that thalamic stimulation could be an appropriate treatment of untractable tremor as this could provide less neuropsychological side-effects than thalamotomy, especially in Parkinson's disease.

Aged↗
PubMed1991

The stereotactic approach to brain stem lesions: a follow-up of 29 cases.

Stereotactic biopsy is the safest and most reliable method for the histological diagnosis of intraaxial brain stem lesions. The definitive pathological diagnosis permits the selection of adequate therapy. No operative and/or adjuvant therapy must be proposed without a previous histological diagnosis. This approach avoids the complication of inappropriate therapy and provides valuable prognostic information.

Adolescent↗
PubMed1991

Thalamic stimulation for the treatment of tremor and other movement disorders.

Thalamic stimulation for the treatment of tremor and other motor movement disorders is attractive in view of the fact that it is a non-destructive procedure. With the experience of 26 cases indications can be defined. The method is an alternative for treatment of tremor only when thalamotomy carries a high risk of complications. Not only is the cost a limiting factor but also repeated operations for replacing the neuro-pacemaker and thus the risk of infection have to be taken in consideration.

Brain Damage, Chronic↗
PubMed1991

[Thalamocapsular metastasis of muco-epidermoid adenocarcinoma of the parotid gland].

A 58 years woman with muco-epidermitis carcinoma of the left parotid gland treated by parotidectomy and external radiation developed seven years later a left hemianopsia and moria related to thalamo-capsulo-lenticular lesions. Three stereotactic biopsies were performed. Neuropathological examination confirmed a secondary lesion of carcinoma with the same histological features than primary lesion of the parotid. Due to the metastasis location treatment consisted in external radiotherapy guided by stereotactic coordinates.

Adenocarcinoma↗
PubMed1991

[Chronic sciatalgia caused by sensitive deafferentiation following surgery for lumbar disk hernia: clinical and therapeutic aspects. Apropos of 110 patients].

Sensitive deafferentation is a well recognized entity which has changed the therapeutic approach of some kinds of chronic post operative sciatalgia. It mainly occurs related with a long story of radicular pain and the responsibility of so-called epidural fibrosis has to be discussed. The case records of 110 consecutive patients with deafferentation sciatalgia were reviewed and the clinical data precised: chronic and lasting burning pain with acute nightly paroxysms and sensitive alterations at objective examination. Neuroradiological explorations eliminated the possibility of recurrent disc herniation and neurophysiological tests assessed the chronic radicular suffering and the degree of lemniscal degeneration. After medical treatment (analgesic drugs with central tropism), a strict clinical assessment of pain intensity allowed optimal choice of the technique of neurostimulation: transcutaneous electrical stimulation (51 patients) and/or spinal cord stimulation (59 patients). The efficacy of transcutaneous stimulation (40 excellent and good results) was most often related to its continuous utilisation with a short post-effect. Its side-effects and the frequency of multiradicular involvement lead to spinal cord stimulation. With a mean follow-up period of 37 months, the pain relief was considered as excellent in 51.5%, good in 38% and poor in 8.5% of the patients. One patient had a negative test and was not definitively implanted. Another case failed to respond to stimulation. The clinical and technical complication of the method are reported.

Adult↗
PubMed1990

[Stereotaxic radiosurgery:methods and indications in the treatment of cerebral arteriovenous malformations].

After Leksell and Steiner's pioneering experience with the use of the gamma units, another technically different system has been developed, using a linear accelerator. It's a very precise stereotactic radiosurgical approach which allows to deliver the necessary dose of radiation to the target volume while sparing the surrounding structures from potentially dangerous levels of radiation. This hyperselective irradiation is a new and complementary method of treatment of arteriovenous malformations located in central or functionally critical areas of the brain. The aim is to obtain a progressive and total obliteration of the lesion. The place of radiosurgery is obviously reserved for the patients who do not seem able to profit from the benefits of open surgery and/or embolization techniques.

Dose-Response Relationship, Radiation↗
PubMed1990

[Rhythmical myoclonus and tremor at rest disclosing mesencephalic metastasis].

We report a case in which rhythmical myoclonus and tremor at rest revealed a thalamo-subthalamic metastasis from a bronchial carcinoma. Tremor of the upper limbs and face (4 Hz) disappeared with sustained posture and action. A cogwheel phenomenon, hypotonia and disorders of automatic and voluntary movements were also present. Surface electromyographic recordings showed a rhythmical, synchronous activity of the biceps brachialis and triceps muscles at rest. Pathology disclosed lesions of the red nucleus and neighbouring area and severe compression of the substantia nigra which were likely to be the cause of the signs and symptoms.

Adenocarcinoma↗
PubMed1990

[Cellular kinetics of cerebral glioma: study of the proliferative activity using monoclonal antibody Ki 67. Apropos of 60 cases].

The monoclonal antibody Ki 67 is able to detect a nuclear antigen expressed by proliferating cells during the cellular cycle (phase G1, G2, S and M). It is used as a marker of the proliferative activity of 60 cerebral gliomas including 41 biopsied under stereotaxic conditions. The immunocytochemical study performed with the peroxidase antiperoxidase technique on crushed and smeared fresh tumors, permit to define a nuclear marking index for each tumor. The index Ki 67 is correlated with the degree of tumor malignancy. The maximum values are found in astrocytomas IV (20%) and malignant ependymomas (18%), with a mean index at 11% in the 25 high-grade gliomas and 1.7% in low-grade gliomas. The minimum values are observed in pilocytic astrocytomas and low-grade oligodendrogliomas. Marked variations of the index Ki 67 are found in homogeneous tumor classes regrouping tumors of identical nature and grade: grade IV astrocytomas (5 to 20%), grade III astrocytomas (8 to 18%). These marking differences reflect the heterogeneous nature of the proliferative activity of morphologically similar gliomas. The nuclear marking index with antibody Ki 67 complements the findings of the standard histological examination of cerebral gliomas. This is an additional diagnostic mean to evaluate the proliferative potential and the prognosis of these tumors.

Antibodies, Monoclonal↗
PubMed1989

[Intracerebroventricular morphine therapy. Apropos of 79 patients].

The authors report their experience in the treatment of 79 patients suffering from intractable cancer pain with intra-cerebro-ventricular morphine. They obtain a long-lasting analgesia (34.2 hours at the beginning of treatment and 27.9 hours at the end; mean follow-up of 65 days) with a very low daily morphine consumption. The results obtained, good and very good in 95% of the cases, could be explained by patients' selection criteria and quality of the follow-up (prospective sheet given to the patients, regular phone calls and consultations in the pain clinic). The authors discuss the indications of this technique in relation with other neurosurgical procedures, taking into account the neurophysiological mechanism of action of morphine.

Female↗
PubMed1988

[Stereotaxic approach in extensive lesions of the septum-fornix-callosal region. Apropos of 14 cases].

Stereotactic approach of anterior midline lesions which involve the septum-fornix-callosal region is a logical alternative to open surgery as a first choice. It contributes to know anatomical relations--particularly vascular and ventricular--of the lesion; it provides an accurate neuro-pathological diagnosis, with grading and spatial configuration of the lesion, and therapy in some cases. In other cases, it is a guide for appropriate therapeutic choice.

Adolescent↗
PubMed1988

[Stereotaxic diagnosis and treatment of colloid cysts of the 3d ventricle. Apropos of 7 cases].

The clinical and anatomical results of the treatment of 7 colloid cysts of third ventricle by stereotaxic aspiration are reported. A history of increased intracranial pressure was reported in all patients (4 females aged of 12, 16, 28, 38 years; 3 males aged of 36, 54, 59 years). A ventricular shunting device has been inserted in 4 patients. Pre-operative clinical findings were: signs of increased intracranial pressure (1 case), isolated memory disturbances (3 cases); motor weakness, memory disturbances and psychomotor slowness (2 cases); 1 of the 2 last cases had also thymic disturbances. Clinical examination was normal in 1 patient. CT-Scan revealed 5 hyperdense lesions, 3 with slight enhancement; 1 hypodensity encircled by an hyperdense ring without enhancement, 1 not enhancing isohypodensity. 6 colloid cysts were between the Foramens of Monro, 1 in the posterior third ventricle. Cyst volume ranged from 1.8 to 6.3 cc. (m: 3.4). Biventricular hydrocephalus was present in all but 1 patient. Stereotaxic aspiration of the cyst performed according to Talairach's system resulted in a release of C.S.F. circulation in all cases. 3 colloid cysts were aspirated completely, 4 were reduced to 3%, 11%, 12%, 33% of the initial volume. Post-operatively 2 patients presented with a transient meningeal reaction, 1 with a transient "myoclonic" syndrome. In 1 "completely aspirated" case a control CT-Scan showed, 5 years later, a small hyperdensity corresponding to 4% of the initial cyst volume. All patients lead a normal and useful life (Follow-up: 8-78 months, m: 45). Neurological examination is normal in 6 cases and shows a pre-existent facial asymmetry in 1. Ours results suggest that stereotaxic investigation should be the first safe procedure in order to achieve both diagnosis and treatment of colloid cysts of third ventricle.

Adolescent↗
PubMed1987

Serial stereotactic biopsies and CT scan in gliomas: correlative study in 100 astrocytomas, oligo-astrocytomas and oligodendrocytomas.

Histologic features of 100 supra-tentorial astrocytomas, oligodendrogliomas and oligo-astrocytomas obtained from serial stereotactic biopsies were compared with the corresponding CT scans. Topographic comparisons provided by visualization of the biopsy trajectories on post-biopsy CT scans were available in 24 cases. Areas of contrast enhancement and low attenuation were compared with the histologic grade of malignancy, tumor delimitation and structural type. The latter was determined as follows: Type I-solid tumor tissue without significant peripheral isolated tumor cells; Type II-solid tumor tissue associated with peripheral isolated tumor cells; Type III-isolated tumor cells only. There was a strong correlation between areas of contrast enhancement and tumor microvascularity. In addition, contrast enhancement occurred only in the solid tumor tissue component of the neoplasm. This correlation accounted for the relationship observed between CT images and the structural type of glioma. Contrast enhancement was constant in structural type I gliomas, inconstant in structural type II, and absent in structural type III. No correlation was found between malignancy and contrast enhancement. Contrast enhancement occurred in all grades of malignancy but was a constant feature of grade 4 gliomas. The volume of the tumors could not be reliably determined from CT images alone. Areas of low attenuation on contrast CT scans could correspond to either peritumoral edema or to edematous parenchyma infiltrated by isolated tumor cells. Serial stereotactic biopsies combined with calculations based on the CT scan provided a more precise definition of the tumor volume and identification of structural type. Such classification may prove useful in prospective analysis of various modes of therapy.

Adolescent↗
PubMed1987

Partly native epitopes are already present on early intermediates in the folding of tryptophan synthase.

Two monoclonal antibodies directed against the native beta 2 subunit of Escherichia coli tryptophan synthase [L-serine hydro-lyase (adding indoleglycerol-phosphate), EC 4.2.1.20], one recognizing the C-terminal F1 domain and the other the N-terminal F2 domain, were used to detect immunoreactive intermediates in the folding of the protein. For that purpose, the association of the monoclonal antibodies with either the beta 2 subunit or its isolated domains was studied by using fluorescence energy transfer between tryptophan residues of the antibodies and a dansyl group covalently linked to the antigen. It is shown that the association of both monoclonal antibodies with the antigen occurs within a few seconds after initiation of the renaturation, whereas complete refolding of the beta 2 subunit requires several minutes under the same experimental conditions. Thus, immunoreactive intermediates appear to be formed at an early stage of the folding process. While the isolated F1 domain alone is able to rapidly refold into a conformational intermediate already well recognized by the anti-native-beta 2 antibody, it cannot, in the absence of the F2 domain, reach its native conformation. However, its association with the anti-native-beta 2 antibody induces a structural change of F1 that brings it closer to the conformation it normally adopts when interacting with F2 inside the native beta 2 subunit.

Antibodies, Monoclonal↗
PubMed1987

Stereotactic aspiration of colloid cysts of the third ventricle. Preliminary report.

From January, 1979, to July, 1986, 10 patients (6 females, 4 males; 12-59 years, mean 37) with colloid cysts of the third ventricle were treated by stereotactic aspiration (Talairach's method). Five cysts have been completely aspirated. The mean residual volume of the other 5 was 19% of the initial volume. Clinical symptoms completely cleared in all but one patient. The advantages of the procedure are discussed.

Adolescent↗
PubMed1987

[Value of bifocal stereotaxic destruction in case of dyskinesia in patients with a motor deficit of cerebral origin].

Authors report a study concerning 12 dyskinetic patients with cerebral palsy. The clinical pre-operative examination shows that many signs and symptoms are associated: volitional and postural dyskinesia, athetosis and dystonia, pyramidal deficit and spasticity. Talairach's stereotactic methodology has been used for bifocal (VPL thalamic nucleus and internal pallidum) Yttrium 90 implantation. After stereotactic bifocal lesions, involuntary movements have been reduced in 45.5% of cases and have disappeared in 27% of cases. Impairment of previous motor deficit has been observed in 3% of cases; volitional and postural dyskinesia seems to be the most curable symptomatology. Clinical results in athetoid involuntary movements and dystonia are less rewarding. Because of important anatomical modifications often observed cerebral palsy patients, the authors stress the interest of individual acute neurophysiological study and discuss about the stereotactic targets and the modalities of destruction. They insist upon the necessity of rigorous selection of indications based on acute clinical examination in the perspective of improvement of global functional capacities.

Adolescent↗