Biomedical subjects

J C Peragut

Publications and source records attributed to J C Peragut.

At least 19 recordsLinked to original sources

PubMed2002

[Gamma knife radiosurgery for the treatment of severe epilepsy].

The Gamma Knife radiosurgery is a neurosurgical approach having now demonstrated well its efficiency, its low morbidity and its comfort in the treatment of numerous neurosurgical disorders. These advantages of this type of intervention make it a method of great interest in functional neurosurgery and quite particularly in surgery of epilepsy. French experience is a pionner one in this domain. If for several years the positive evolution of the epilepsy associated to brain lesions had been noticed after the Gamma Knife radiosurgical treatment, the use of this approach in surgery of the epilepsy is systematically estimated since 1993. Data are today available concerning the surgical treatment of the epilepsies originating in temporomesiale area without occupying process, epilepsies associated to hypothalamic hamartomas and epilepsies associated to cavernous angiomas or to low grade gliomas. The quality of the epileptological result obtained in these various indications associated to a very reduced morbidity lets suppose that the Gamma Knife radiosurgery could indeed have tomorrow a place within the sample group of surgical approaches dedicated to the treatment of severe epilepsies. However, a larger number of treated patients and a more prolonged follow-up remains necessary to estimate in a more definitive way this approach.

Brain Diseases↗

PubMed2001

Long-term outcome after gamma knife surgery for secondary trigeminal neuralgia.

OBJECT: This study was directed to evaluate the potential role of gamma knife surgery (GKS) in the treatment of secondary trigeminal neuralgia (TN). The authors have identified three anatomicoclinical types of secondary TN requiring different radiosurgical approaches. METHODS: Pain control was retrospectively analyzed in a population of patients harboring tumors of the middle or posterior fossa that involved the trigeminal nerve pathway. This series included 53 patients (39 women and 14 men) treated using GKS between July 1992 and June 1997. The median follow-up period was 55 months. Treatment strategies differed according to lesion type, topography, and size, as well as visibility of the fifth cranial nerve in the prepontine cistern. Three different treatment groups were established. When the primary goal was treatment of the lesion (Group IV, 46 patients) we obtained pain cessation in 79.5% of cases. In some patients in whom GKS was not indicated for treatment of the lesion, TN was treated by targeting the fifth nerve directly in the prepontine cistern if visible (Group II, three patients) or in the part of the lesion including this nerve if the nerve root could not be identified (Group III, four patients). No deaths and no radiosurgically induced adverse effects were observed, but in two cases there was slight hypesthesia (Group IV). The neuropathic component of the facial pain appeared to be poorly sensitive to radiosurgery. At the last follow-up examination, six patients (13.3%) exhibited recurrent pain, which was complete in four cases (8.8%) and partial in two (4.4%). CONCLUSIONS: The results of GKS regarding facial pain control are very similar to those achieved by microsurgery according to series published in the literature. Nevertheless, the low rate of morbidity and the greater comfort afforded the patient render GKS safer and thus more attractive.

Adolescent↗

PubMed2001

[Gamma-knife radiosurgery for brainstem arteriovenous malformations. Preliminary results].

BACKGROUND AND PURPOSE: Microsurgical resection have the advantage to be immediately effective according to bleeding risk and is the reference treatment for cerebral arteriovenous malformations. For cerebral arteriovenous malformations located in the brainstem gamma-knife radiosurgery due to its low invasivity is classically a first line treatment. We reviewed the Marseilles experience to assess the efficacy and safety of gamma-knife radiosurgery for brain stem arteriovenous malformations. METHODS: We analyzed retrospectively data of 45 patients with an arteriovenous malformation located in the brain stem treated in Marseilles by gamma-knife radiosurgery by between 07/92 and 12/99. Mean age was 42 years, there were 5 children. Arteriovenous malformations were located in the pons or midbrain for the majority of the patients. Intraaxial lesion was found in 82% of patients. Hemorrhage prior to radiosurgery occurred in 75% of the patients. Gamma-knife procedure was the first treatment of the arteriovenous malformations for 29 patients (65%); previous surgery was performed in 34 patients (15%). Mean nidus volume was 550 mm(3) (32-14 196 mm(3)). Mean margin dose was of 23 Gy (range 15-30 Gy). Follow up was available for 25 patients (mean 18 months). RESULTS: One patient presented a transient worsening of his neurological status, and 2 patients developed a fixed deficit. Two patients underwent rebleeding at an interval of 12 to 36 months after the gamma-knife procedure. At last angiographic follow-up (13 patients), the obliteration rate was 82% of the arteriovenous malformations. A second procedure was proposed to a patient with only partial occlusion at 3 years. CONCLUSIONS: Gamma-knife radiosurgery can achieve good obliteration rate of brain stem arteriovenous malformations with low morbidity and may be a valuable first-choice therapy for such arteriovenous malformations. A larger population and longer follow up are mandatory in order to confirm these preliminary results.

Adolescent↗

PubMed2001

[Surgical removal of radio-induced lesions after radiosurgery of cerebral arteriovenous malformations].

Radioinduced lesions after radiosurgery of cerebral arteriovenous malformations may be associated with an increased signal on T2-weighted and gadolinium enhancement on T1-weighted MR images. They do not have necessarily a poor prognosis. These lesions are mostly asymptomatic. But in a few cases they can be associated with severe clinical symptoms which can become corticodependant or corticoresistant. We present the 5 cases of such cerebral arteriovenous malformations treated by radiosurgery, out of our series of 705 patients. The removal was easier than that of untreated cerebral arteriovenous malformations, and led to a complete recovery of symptoms and progressive decrease of imaging abnormalities. Such surgery should be proposed in case of symptomatic radioinduced lesions which fail to respond to steroids.

Adult↗

PubMed2000

Gamma knife radiosurgery as a primary treatment for prolactinomas.

OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

Humans↗

PubMed2000

The role of gamma knife surgery in the treatment of severe epilepsies.

There is a strong rationale for investigation of the role of gamma knife radiosurgery in the treatment of medically intractable epilepsy. To explore this potential application, the current outcome and morbidity associated with established microsurgical treatment, as well as the associated advantages and disadvantages of open surgery, are reviewed. The preliminary evidence in support of radiosurgical treatment and the recent experience with gamma knife treatment for epilepsy associated with mesial temporal sclerosis, cavernous angioma, and hypothalamic hamartoma or other lesions are presented. The strengths and limitations of this application are discussed, and the challenges facing both microsurgical and radiosurgical approaches are considered. Gamma knife surgery can be a main approach among others in the armamentarium of epilepsy surgery. Although the benefits of comfort and reduced invasivity can be clearly perceived, larger series and long-term follow up are still required in order to evaluate the future of this particular surgical approach.

Epilepsy↗

PubMed2000

[Neurofibromatosis type 2. Preliminary results of gamma knife radiosurgery of vestibular schwannomas].

BACKGROUND AND PURPOSE: The aim of this study was to assess tolerance and efficacy of gamma knife radiosurgery on vestibular schwannomas for patients affected with neurofibromatosis type 2. METHODS: Between July 1992 and December 1997, a gamma knife procedure was performed on 35 vestibular schwannomas affecting 27 patients (12 females and 15 males, mean age=27 years-old, range: 14-65). Fifteen of the patients were included in the Wishart subtype (severe form) and 12 patients in the Gardner subtype (mild form). This group of 27 patients represented 8,2% of the total group of vestibular schwannomas radiosurgically treated by our team. The mean tumor volume was 4,000 mm(3) (range: 400-14,400 mm(3)) and staging according to Koos classification was 9 stage 2 tumors (extension in the cerebellopontine angle), 19 stage 3 tumors (in contact with the brain stem or cerebellum) and 7 stage 4 tumors (compression of axial structures). The delivered mean marginal dose (50% isodose) was 13 Gy (range: 10-18 Gy). After the treatment, the mean clinical and radiological follow-up was 32 months (range: 6-70). RESULTS: Twenty six (74%) of the treated tumors were controlled by the treatment (15 stabilizations and 11 regressions of the tumor volume) at last follow-up. One microsurgical removal was required in a growing stage 4 tumor and in 2 cases of growing stage 3 tumors. Three post-radiosurgical facial nerve deficits (9%) were observed, 2 of them were transient. According to the Gardner and Robertson classification, classes I (good) and II (serviceable) hearing were preserved at last follow-up in 57% of the patients having the same hearing level prior to the gamma knife. CONCLUSIONS: Our experience confirms that tolerance of gamma knife radiosurgery compares favorably with microsurgery of bilateral vestibular schwannomas. This treatment should be restricted to small and medium growing tumors. Treatment strategy of neurofibromatosis type 2 patients should be planned by multidisciplinary experienced teams disposing of the whole armamentarium. A longer follow-up study is required to confirm the current results regarding the tumor control rate.

Adolescent↗

PubMed2000

[Synovial cyst of cervical spine].

The synovial cyst is a rare cause of cervical medullar compression. We report on one case of a 74-year-old man hospitalized for electric discharge in the limbs at neck extension. The MRI and CT-scan revealed a posterior extradural cystic lesion at the level of C5-C6. The surgical excision of the lesion resulted in completed recovery. The histological examination confirmed the diagnosis of a synovial cyst. Through this case and the review of the 9 reported cases in the literature, we discuss the etiopathogenesis, diagnosis and treatment of the lower cervical synovial cyst.

Aged↗

PubMed1999

Gamma knife surgery for mesial temporal lobe epilepsy.

PURPOSE: Gamma knife radiosurgery (GK) allows precise and complete destruction of chosen target structures containing healthy and/or pathologic cells, without significant concomitant or late radiation damage to adjacent tissues. All the well-documented radiosurgery of epilepsy cases are epilepsies associated with tumors or arteriovenous malformations (AVMs). Results prompted the idea to test radiosurgery as a new way of treating epilepsy without space-occupying lesions. METHODS: To evaluate this new method, we selected seven patients with drug-resistant "mesial temporal lobe epilepsy" (MTLE). The preoperative evaluation program was the one we usually perform for patients selected for microsurgery of TLE [video-EEG analysis of seizures, foramen ovale electrode recording, magnetic resonance imaging (MRI) positron emission tomography (PET) scan, neuropsychological testing]. In lieu of microsurgery, the amygdalohippocampectomy was performed by using GK radiosurgery. RESULTS: Morphologic (MRI) signs of destruction of the target took place at 9 months after GK surgery. Since the treatment day, the first patient has been seizure free. Seizure improvement came more gradually for the following patients, and complete cessation of seizures occurred around the tenth month (range, 8-15 months). MRI shows that the amygdaloentorhinohippocampal target was selectively injured. No significant side effect (except one case of homologous quadrantanopia) or morbidity and no mortality was observed. The current follow-up is 24-61 months, and all (but one) patients are seizure free. CONCLUSIONS: This initial experience proves clearly the short-to middle-term efficiency and safety of GK for MTLE surgery. These results need further confirmation of long-term efficiency, but the introduction of GK surgery into epilepsy surgery can reduce dramatically its invasiveness and morbidity.

Adult↗

PubMed1999

Early and delayed MR and PET changes after selective temporomesial radiosurgery in mesial temporal lobe epilepsy.

We report a patient with medically refractory mesial temporal lobe epilepsy treated by gamma knife radiosurgery. In lieu of a microsurgical procedure, an entorhinoamygdalohippocampectomy was performed with a gamma knife and low marginal doses (25 Gy). The clinical and imaging studies, including CT, MR imaging, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and long-term follow-up MR examinations, are reported. The patient has been seizure-free since the day of treatment, with no clinical complications. MR studies accurately depicted the effect on the target structures and the transient secondary changes around them. FDG-PET scans showed decreased metabolism after gamma knife surgery throughout the anteromesial part of the epileptogenic temporal lobe. This metabolic decrease was reversible in the lateral temporal cortex. Our case suggests that gamma knife surgery is a promising tool for use as a minimally invasive approach to the treatment of epilepsy.

Adult↗

PubMed1999

Radiosurgery for trigeminal neuralgia and epilepsy.

The role of Gamma Knife surgery in the field of functional surgery recently has evolved dramatically. For treatment of trigeminal neuralgia, Gamma Knife surgery is the least invasive procedure, with a low rate of hypesthesia. If a rate of complete relief similar to that of other surgical techniques could be achieved, this approach will become one of the main techniques used to treat the disease initially. The authors present their experience with a group of 16 patients with mesial temporal lobe epilepsy who have been treated successfully (15 completely seizure-free and 1 with rare, nondisabling seizures) without significant complication. After additional follow-up to demonstrate the absence of long-term consequences, this fascinating new approach could change epilepsy surgery practice dramatically.

Adult↗

PubMed1998

Gamma-knife surgery for secreting pituitary adenomas.

We report our preliminary results concerning 25 patients with secreting pituitary adenomas treated with stereotactic radiosurgery after partial transsphenoidal surgery and followed over a 6-36 month-period. Among the 15 acromegalic patients, a decrease of 65% in mean GH levels was achieved after 6 months and of 77% at 12 months after radiosurgery. Presently, only 3 patients (20%) are considered as in remission (mean GH and IGF1 level into the normal range). A decrease of 46% and 64% was observed at 6 and 12 months after radiosurgery in 4 patients with prolactinomas although no normalization of PRL levels occurred. Presently, 3/4 patients have individual PRL level slightly above the normal range. A normalization of Urinary Free Cortisol (UFC) was noticed in 4/6 (66%) patients with Cushing's disease within 6-12 months. No pituitary deficiency was noticed in this series with the exception of 4/25 patients (16%) who received subtotal or total pituitary irradiation for post-operative remnants of secreting adenomas poorly defined on MRI. One woman, who had undergone previously a conventional irradiation and presenting with a cavernous sinus adenoma reaching the optic nerve, developed an optic neuropathy. A second woman, with a cavernous sinus remnant, presented a cranial nerve palsy (VI) after the irradiation. We can conclude that radiosurgery using the Cobalt-60 Gamma-unit is, at least, as effective as conventional radiotherapy in the control of pituitary hormone hypersecretion from postoperative adenomas remnants with less adverse effects.

Acromegaly↗

PubMed1998

Preservation of hearing in acoustic neuromas treated by gamma knife surgery.

138 acoustic schwannomas were treated by Gamma Knife surgery from July 1992 to May 1994. Cases with neurofibromatosis were excluded because of differences in the patterns of growth and development of tumors in these cases. Hearing was evaluated by tonal and vocal audiometry and classified using the Gardner and Robertson score. 104 patients were observed at 3 years after treatment. Hearing studies, the relation of tumor volume to hearing, central and marginal dose, number of shots and preoperative brain-stem-evoked responses (BER) were all recorded. 70% of patients with normal hearing maintained a useful hearing, and 50% of patients with useful hearing maintained serviceable hearing. No correlation was found between hearing preservation and tumor volume, central and marginal dose and number of shots. Gamma Knife surgery seems to be superior to microsurgery with regard to preservation of useful hearing.

Audiometry↗

PubMed1998

Short-term endocrinological results after gamma knife surgery of pituitary adenomas.

We report our preliminary results after the radiosurgical treatment of 25 secreting pituitary adenomas with a mean follow-up of 20 months (range 6-36 months). Fifteen acromegalic patients showed a decrease of 65% in mean growth hormone (GH) levels after 6 months and of 77% after 12 months. Only 3 patients (20%) are considered to be in remission (mean GH and IGF1 level into the normal range). A decrease of prolactin (PRL) was noted in 46% and 64% at 6 and 12 months after radiosurgery in 4 patients with prolactinomas. There was no case of PRL normalizaion. At present 3/4 patients have individual PRL levels slightly above the normal range. A normalization of Urinary Free Cortisol (UFC) was noticed in 4/6 (66%) patients Cushing's disease within 6-12 months. Pituitary deficiency was noticed in this series in 4/25 patients (16%) who received subtotal or total pituitary irradiation for large postoperative remnants of secreting adenomas poorly defined on magnetic resonance imaging (MRI).

Acromegaly↗

PubMed1998

Effect of gamma knife on secondary trigeminal neuralgia.

The following study was conducted to evaluate the results of Gamma Knife stereotactic radiosurgery in the management of secondary trigeminal neuralgia. 53 patients suffering from secondary trigeminal neuralgia were studied and the results reported. We defined four therapeutic groups: group I correspond to essential trigeminal neuralgia. The primary aim was tumor control in group IV and pain cessation in group III and II (visualization of the fifth nerve root was possible in group II but not in group III). The target dose of the radiosurgery used in the current study varied from 20 to 40 Gy in group III and IV and from 70 to 90 Gy in group I and II. At short-term follow-up, 37 patients (74%) were pain-free, 9 patients (18%) were improved (50%-90% relief) and only 4 patients (8%) experienced treatment failure. Among the patients with early treatment success, 10 patients experienced a complete recurrence of pain in the four succeeding years, and 11 initially pain-free patients deteriorated to partial pain relief. The median time to pain relief was three months (range 1 day to 1 year). The mean follow-up was 32 months (range 7 to 60 months). No patient developed increased facial pain or deafferentation pain. Among the 53 patients, only two exhibit a slight facial hypesthesia and one patient described motor fasciculation related to Gamma Knife treatment. In our experience Gamma Knife surgery appears a safe and effective method for the treatment of secondary trigeminal neuralgia.

Adult↗

PubMed1996

Cauda equina paraganglioma with subsequent intracranial and intraspinal metastases.

A case of cauda equina paraganglioma is described; subsequent intracranial and intraspinal metastases occurred after partial resection and adjunctive radiotherapy. Cerebrospinal fluid dissemination is a rare complication of spinal paragangliomas. Factors predictive of this unusual biological behaviour are discussed.

Biomarkers, Tumor↗

PubMed1996

Adenosine and neuropathic pain.

Recent studies have reported the possibilities of relieving neuropathic pain by administering adenosine or its analogs. In order to determine if there exists a metabolic anomaly of this nucleoside in patients with neuropathic pain, circulating adenosine levels were compared in three patient groups. The first was composed of individuals suffering from neuropathic pain, the second of patients with nervous system lesions in the absence of pain, and the third was composed of patients suffering from pain resulting from excessive nociception. The adenosine blood levels of these patients were compared to those of a control group. Finally, adenosine in the cerebrospinal fluid (CSF) of some patients was also assayed. The results show that there are reduced levels of blood and CSF adenosine in patients with neuropathic pain. This adenosine deficiency could explain the potential therapeutic effects of administering adenosine or its analogs.

Adenosine↗

PubMed1996

Pineal region tumors and the role of stereotactic biopsy: review of the mortality, morbidity, and diagnostic rates in 370 cases.

OBJECTIVE: It is classically considered that the morbidity and mortality rates are greater for stereotactic biopsies of pineal region tumors, compared with tumors in other regions. However, to date, the number of cases studied in the literature has been insufficient to evaluate these parameters and compare them with the morbidity and mortality rates for stereotactic biopsies of tumors located elsewhere. METHODS: With the aim of evaluating these parameters, we reviewed 370 stereotactic biopsies of pineal region tumors, from 15 French neurosurgical centers. We statistically verified the absence of heterogeneity of the different French centers with regard to diagnostic, mortality, and morbidity rates. In contrast, statistical heterogeneity was clearly seen for the large stereotactic biopsy series (for all tumor locations) in the literature. RESULTS: The mortality rate was 1.3% (5 patients of 370), and 3 patients suffered severe neurological complications. This study is the first to clearly demonstrate that the mortality, morbidity, and diagnostic rates for stereotactic biopsies are not different in the pineal region. CONCLUSION: Our conclusion is that stereotactic biopsy must remain a main diagnostic modality for tumors of the pineal region.

Adolescent↗