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Biomedical subjects

J P Nguyen

Publications and source records attributed to J P Nguyen.

At least 19 recordsLinked to original sources
PubMed1996

Improvement of severe postural cerebellar tremor in multiple sclerosis by chronic thalamic stimulation.

Tremor can be particularly disabling in patients with multiple sclerosis (MS) and is mildly improved by drug treatment. The efficiency of stereotactic thalamotomy has been reported in a small number of patients but was counterbalanced by severe postoperative complications. Stimulation of the thalamic ventral intermediate nucleus, which is a less aggressive surgical method, is efficient in essential and in parkinsonian tremors. We report here the results of thalamic stimulation in 13 patients with MS with tremor. All patients were subjected to clinical examination, videorecording, and quantification of the functional disability before surgery and 3 months postoperatively. The surgical intervention was well tolerated in all cases. A clear improvement of the tremor was observed in 69.2% of the patients. Functional improvement was more varied and depended on the severity of tremor and coexistence of other neurological symptoms. Of the eight most severely affected patients, seven recovered the possibility to easily catch an object and use it. The results indicate that thalamic stimulation may be useful in the treatment of severe postural cerebellar tremor in MS.

Adult↗
PubMed1996

Long-term outcome of unilaterally transplanted parkinsonian patients. I. Clinical approach.

Five patients with Parkinson's disease, unilaterally transplanted with foetal mesencephalic cells into putamen (n=1) or putamen and caudate (n=4), were followed throughout a period of 15-36 months after surgery, according to the recommendations of the core assessment programme for intracerebral transplantations (CAPIT). All these patients exhibited an increase in the fluorodopa uptake in the grafted putamen, which was most significant in the first and last patient of the series. Long-term bilateral improvement of skilled hand movements was observed, starting between the third and sixth month after grafting, and confirmed by the statistical analysis of CAPIT timed tests. A mild to moderate effect on the amount of 'off' time and 'on-off' fluctuations was observed, whereas, apart from one case, no other clear effect on gait, walking and speech was found. One patient included in the study, already suffering slight cognitive impairment, clearly exhibited progression of a dementia process after surgery. Daily living activities were clearly improved in only one of the other four patients. At the end of the study period, all patients needed L-dopa therapy at a similar or higher dose than before grafting, but, in most of them, other dopaminergic drugs were reduced or stopped. All patients exhibited bilateral dyskinesias before grafting that were greatly decreased in intensity a few months after surgery. Delayed asymmetrical dyskinesias, occurring on the side displaying the better motor improvement, i.e. contralateral to the graft, were observed in three patients. These results suggest that neural transplants may influence two central mechanisms involved in motor function and the onset of dyskinesias. These effects are likely to occur through complex interactions with the post-synaptic dopaminergic receptors. The occurrence of dyskinesias might simply reflect increased presynaptic storage and release of dopamine. Alternatively, it might, in part, represent some other long-term deleterious effect of the graft. Since PET-scan data indicate that the reinnervation obtained is sub-optimal, it will be of interest to obtain a larger and denser reinnervation of the host striatum and to try, thereafter, to reduce the dose of L-dopa.

Aged↗
PubMed1996

Percutaneous endoscopic treatment of suprasellar arachnoid cysts: ventriculocystostomy or ventriculocystocisternostomy? Technical note.

The use of an endoscope in the treatment of suprasellar arachnoid cysts provides an opening of the upper and lower cyst walls, thereby allowing the surgeon to perform a ventriculocystostomy (VC) or a ventriculocystocisternostomy (VCC). To discover which procedure is appropriate, magnetic resonance (MR)-imaged cerebrospinal fluid (CSF) flow dynamics in two patients were analyzed, one having undergone a VC and the other a VCC using a rigid endoscope. Magnetic resonance imaging studies were performed before and after treatment, with long-term follow-up periods (18 months and 2 years). The two patients were reoperated on during the follow-up period because of slight headache recurrence in one case and MR-imaged CSF flow dynamics modifications in the other. In each case surgery confirmed the CSF flow dynamics modifications appearing on MR imaging. In both cases, long-term MR imaging follow-up studies showed a secondary closing of the upper wall orifice. After VCC, however, the lower communication between the cyst and the cisterns remained functional. The secondary closure of the upper orifice may be explained as follows: when opened, the upper wall becomes unnecessary and tends to return to a normal shape, leading to a secondary closure. The patent sylvian aqueduct aids the phenomenon, as observed after ventriculostomy when the aqueduct is secondarily functional. The simplicity of the VCC performed using endoscopic control, which is the only procedure to allow the opening in the cyst's lower wall to remain patent, leads the authors to advocate this technique in the treatment of suprasellar arachnoid cysts.

Adult↗
PubMed1994

[Neurosurgical endoscopy. Diagnostic and therapeutic indications].

An historical review of neurosurgical endoscopy is evocated. The characteristics of the endoscopic material are discussed: flexible or rigid?, length?, diameter?, irrigation?, free-hand manipulation or fixed arm? A rigid neurosurgical endoscope (STORZ) is described which characteristics are the following: 5 mm/3.7 mm ovale diameter, working length of 21 cm (allowing its use under stereotactic conditions), 5F working channel and articulated arm for solid immobilization in the desired position. All the indications of endoscopy are described and illustrated with a series of 48 patients. Indications for diagnosis are rare and summarised in exceptional help for conventional surgery. 80% of the usual indications of endoscopy were represented by third ventriculostomy. The endoscopic guidance brings safety and allows an increasing of the ventriculostomy's indications. Endoscopic fenestrations of arachnoid cyst are described with a particular interest on suprasellar cysts. The other indications are rare: unilateral hydrocephalus, biopsies of intraventricular tumors, puncture of colloid cysts.

Brain Diseases↗
PubMed1993

Thalamic stimulation and proximal tremor. A specific target in the nucleus ventrointermedius thalami.

The severe proximal cerebellar postural tremor (also called action or intention or hyperkinetic tremor) is barely influenced by thalamotomy or stimulation of the thalamus at the classic target in the lower part of the nucleus ventrointermedius thalami (VIM). In four patients with a severe postural distal and proximal tremor, an electrode fitted with four points of contact was introduced within the entire height of the VIM. In each patient, stimulation of the lower part of the VIM was most effective in the distal component of the tremor, whereas its proximal component was specifically reduced by stimulation of its upper part. These results indicate that (1) proximal postural tremors can be as much affected by stimulation of the VIM as distal tremors, (2) there is a somatotopy in the VIM that is similar to that in the nucleus ventralis posterolateralis thalami, and (3) it is possible with this technique to adjust the VIM stimulation site so as to obtain the maximum efficacy according to the locale of the tremor.

Adolescent↗
PubMed1993

Pseudotumoral neuro-Behçet's disease.

Pseudotumoral presentation of Neuro-Behçet's disease has been described before. The diagnosis may be difficult obtain in patients without mucosal, cutaneous, and ocular signs. We report the observation of a young patient suffering from a right hemiparesis with computed-tomographic (CT) features suggestive of a thalamocapsular expanding lesion. Histologic study of brain biopsy tissue ruled out a tumor but did not show any specific diagnosis. The patient improved with steroid therapy.

Adult↗
PubMed1992

A technique for stereotactic aspiration of deep intracerebral hematomas under computed tomographic control using a new device.

A new device, modified from the Nucleotome (Surgical Dynamics, Alameda, CA), was used for stereotactic aspiration of deep brain hematomas. Real-time monitoring by computed tomography allows a very safe procedure, and the risk of aspirating the surrounding brain is avoided. The technique was applied in 13 cases of deep brain hematomas. The intraoperative computed tomographic scan demonstrated that the mass effect was always immediately improved. Aspiration was stopped when the midline shift disappeared or was dramatically reduced. For most of the cases, a total aspiration of the hematoma was not needed (mean value of the aspiration rate of 71, 5%). No rebleeding and no complication related to the technique was observed. This technique was easily performed in emergency conditions.

Activities of Daily Living↗
PubMed1992

Multiple vertebral hemangiomas with neurological signs. Case report.

A case of multiple vertebral hemangiomas with progressive neurological deficit is presented. Successful treatment was accomplished using preoperative embolization, palliative surgical decompression, and postoperative radiation therapy. The patient has remained asymptomatic for 6 years. The authors review the role of current imaging modalities and options for therapeutic intervention. Preoperative embolization, palliative surgical decompression, and postoperative radiotherapy appear to provide a satisfactory outcome in patients with multiple hemangiomas and may represent an effective alternative to more aggressive surgical intervention.

Adult↗
PubMed1991

[Anesthesia for thalamic stimulations: value of flumazenil].

Five cases are reported of peroperative awakening in order to obtain patient cooperation during stereotaxic procedures. General anaesthesia was induced with 0.25 mg.kg-1 midazolam, 1.5 to 2 micrograms.kg-1 fentanyl, and 0.1 mg.kg-1 vecuronium. Maintenance was obtained with isoflurane, nitrous oxide, and small doses of fentanyl. Isoflurane inhalation was discontinued 30 to 40 min before the time of awakening required by surgery. Once expiratory isoflurane concentration reached a level less than or equal to 0.1%, nitrous oxide administration was stopped, and 0.5 mg flumazenil administered. After surgical checking, on the fully awake patient of the efficiency of thalamic stimulation and the lack of any motor deficit, anaesthesia was deepened again, with either isoflurane or a non benzodiazepine intravenous agent. All five patients recovered rapidly and calmly.

Adult↗
PubMed1991

[Intracerebral hematoma surgically treated under x-ray computed tomography with Backlund's needle. A series of 15 cases].

15 cases of supratentorial intracerebral hematomas (12 cases of primary hematomas and 3 post-traumatic cases) were operated under C.T. scan control, using the screw and suction technique (Backlund's needle). 10 cases of primary hematomas were operated early, before the 24th hour. The patients were selected for intervention on the following criteria: 1) Patients aged less than 70 years old; 2) initial Glasgow coma scale between 6 and 10; 3) cases with involvement of the mesencephalon by the hematoma were excluded. In the 3 cases of post-traumatic hematomas, intervention was decided in reference to the clinical course. The volume of the hematomas ranged from 40 to 160 cc. Putaminal or thalamic hematomas were observed in 9 cases. The percentage of aspirated hematoma volume ranged from 50 to 91%, the average being 70.5%. Dramatic improvement of the consciousness was observed in all cases. Improvement of the motor deficit was incomplete, for the most part. 1 patient rebled and 1 patient died (6.6% mortality). In 26% of the cases (4 patients) the development of a brain oedema, in the surrounding of the residual hematoma site, was observed during the post operative follow up. There was no post operative infection. Intervention under direct C.T. control allows an accurate guidance of the needle. Efficacity of the evacuation is attested by an immediate improvement of the mass effect on C.T. scan. Under C.T. control the risk to aspirate the adjacent brain is avoided. The technique proposed here has been easily performed in emergency condition.

Adult↗
PubMed1990

[Optimal length of antibiotic therapy in aspirated cerebral abscess].

Between 1983 and 1988, 22 patients with brain abscess were admitted to our neurosurgery department; 2 patients deeply comatose on admission and who died on the first day were excluded from this study. Treatment consisted of needle aspiration of the abscess and antibacterial therapy initially using a broad-spectrum antibiotic later replaced, in all cases, by an antibiotic found to be active in vitro against the organism(s) isolated. The portal of entry was eradicated as early as possible. The duration of antibiotic therapy was determined according to the changes observed on computerized tomography images classified as cavitary, nodular, hypodense or normal. Nodular images were taken as reflecting an inflammatory state in the healing process, and hypodense images as sequelae, so that antibiotics were withdrawn in patients with such images. Altogether, 62 per cent of the patients received antibiotics for 60 days and 95 per cent for 90 days. There was no recurrence. In some patients with deep or, chiefly, multiple abscesses, treatment was pursued. In any case, antibiotics should not be given for more than 90 days if the initial treatment has proved effective, since cure is achieved in 45 to 60 days on average.

Anti-Bacterial Agents↗
PubMed1990

[Correlations between anatomy and computerized tomography findings in transtentorial cerebral herniation].

The diagnosis of transtentorial brain herniation has long relied on encephalography, then arteriography. Computerized tomography (CT) is a safer method which permits a more precise and earlier visualization of temporal and central herniations and herniation of the culmen cerebelli, which are the three varieties of transtentorial herniation. In an attempt to evaluate the reliability of CT images of herniation, the authors have conducted a study of anatomy-CT correlations, using autopsy specimens of brains with these three types of transtentorial herniation. Temporal herniation was well studied, irrespective of the CT reference plane. Direct visualization of temporal uncus herniation and filling of the homolateral perimesencephalic cistern was regularly obtained. Central herniation was better visualized when the occipito-temporal was used as reference. The disappearance of perimesencephalic cisterns on CT sections through the widest part of the tentorial incisura is the best element of diagnosis. Herniation of the culmen is easily studied on the conventional orbito-meatal plane. Provided CT scans are performed with the technique they recommend, the authors consider that this examination is reliable for the diagnosis of transtentorial herniation. Some variations in the anatomy of the incisura may explain why the clinical consequences of herniation are varied. CT perfectly shows the configuration of this notch and therefore may be helpful in predicting the prognosis.

Brain↗
PubMed1989

[The role of surgery and low molecular weight heparin in the treatment of cerebral venous thrombosis. Apropos of 2 cases].

For one case of thrombosis of sinus sagittalis superior joint haemorrhagic cerebral softening necessitates surgical draining of haemorrhagic focus grown to a true intracranial haematoma; for the another case direct low molecular weight heparin treatment obtained a mere evolution. Authors are of the opinion that early low molecular weight heparin treatment is able to avoid massive haemorrhage.

Adult↗
PubMed1989

[Radiotherapy of vertebral hemangioma with neurologic complications].

The interest of radiotherapy in the treatment of compressive vertebral hemangiomas (H.V.C.) is discussed from a literature review. Recent advances in imaging permit to precisely define the target-volume. The dose of 35 grays with standard fractioning affords optimal results on H.V.C. with no risk of spinal cord damage.

Hemangioma↗
PubMed1989

[Vertebral hemangioma with neurologic signs. Therapeutic results. Survey of the French Society of Neurosurgery].

45 cases of vertebral hemangiomas with neurologic involvement are reported. This series corresponds to the french experience between 1969 to 1988 (series of the "Société Française de Neuro-Chirurgie" (S.F.N.)). In this report, the therapeutic results are detailed. 16 patients were treated by a simple laminectomy, 6 by laminectomy associated with radiotherapy, 4 by radiotherapy alone. In 9 patients, a large removal of the hemangioma was performed by mean of a lamino-arthrectomy (7 cases) or a corporectomy (2 cases). 7 patients were treated by embolization or vertebroplasty. Both techniques were used alone or in association with surgery or radiotherapy. 3 patients had no therapy. Results of the S.F.N. series demonstrated that 75.5% of the patients had a long term favorable clinical course. 13.4% of the patients were not improved. Mortality was of 11.1%. The mean follow up time was of 51.6 months. Recurrence was encountered in 13 cases. It was mainly observed in the first two years. In cases of total involvement of the vertebrae by hemangioma, laminectomy associated with radiotherapy was the best mean of therapy: 93% of recovery without recurrence. Treatment of body localization appeared to be difficult. Corporectomy could be unefficient if a complete removal of the hemangioma could not be performed. In contrast, posterior arch localization was successfully treated by a simple laminectomy without radiotherapy, even in cases of incomplete removal of the hemangioma: all such cases (10 cases) had a complete recovery without recurrence.

Combined Modality Therapy↗
PubMed1989

Anatomy-computerized tomography correlations in transtentorial brain herniation.

The diagnosis of transtentorial brain herniation has long relied on encephalography, then arteriography. Computerized tomography (CT) is a safer method which permits a more precise and earlier visualization of temporal and central herniations and herniation of the culmen cerebelli, which are the three varieties of transtentorial herniation. In an attempt to evaluate the reliability of CT images of herniation, the authors have conducted a study of anatomy-CT correlations, using autopsy specimens of brains with these three types of transtentorial herniation. Temporal herniation was well studied, irrespective of the CT reference plane. Direct visualization of temporal uncus herniation and filling of the homolateral perimesencephalic cistern was regularly obtained. Central herniation was better visualized when the occipito-temporal plane was used as reference. The disappearance of perimesencephalic cisterns on CT sections through the widest part of the tentorial incisura is the best element of diagnosis. Herniation of the culmen is easily studied on the conventional orbito-meatal plane. Provided CT scans are performed with the technique they recommend, the authors consider that this examination is reliable for the diagnosis of transtentorial herniation. Some variations in the anatomy of the incisura may explain why the clinical consequences of herniation are varied. CT perfectly shows the configuration of this notch and therefore may be helpful in predicting the prognosis.

Autopsy↗
PubMed1989

[Vertebral hemangioma with neurologic signs. Clinical presentation, results of a survey by the French Society of Neurosurgery].

45 cases of vertebral hemangiomas with neurologic involvement are reported. This series corresponds to the french experience between 1969 and 1988 (series of the "Société Française de Neurochirurgie" (S.F.N.)). In this report the clinical presentation and the results of the radiological examination are detailed. Local vertebral pain was present in half of the cases. The neurological symptoms were related to spinal cord compression in 33/45 of the patients and to radicular suffering in the other cases. Evolution of the neurological symptoms appeared to be slow: the mean evolution time before diagnosis was of 10 months. Hemangioma involved the thoracic column in 73% of the cases. Neurologic symptoms was due to a diffuse narrowing of the spinal canal in 28.8% of the cases, to a local bony expansion in 60% of the cases. Hemangioma was found to involve the whole vertebra in 44.4% of the cases, the vertebral body alone in 24.4% of the cases and the posterior arch alone in 22.2% of the cases. An incomplete involvement of both vertebral body and posterior arch was found in 6.6% of the cases. 2.2% of the cases corresponded to pure epidural hemangioma. Preoperative diagnosis was established in 58% of the patients. In these cases, the diagnosis was based on standard radiography and CT datas. Results of the S.F.N. serie are compared with those of the main series of the literature.

Adolescent↗