Novel theory about radiosurgery's action mechanisms on trigeminal ganglion for idiopathic trigeminal neuralgia: Role of the satellite glial cells.

Background: There are many theories about the cause of trigeminal neuralgia (TN). None of them satisfactorily explains how demyelination alone through the ephaptic mechanism can contribute to the development of the TN crisis. The main characteristic of TN pain is its dynamic nature, which is difficult to explain based only on anatomical findings.

Gamma knife radiosurgery on the trigeminal ganglion for idiopathic trigeminal neuralgia: Results and review of the literature.

Background: In the present study, we evaluate the results of gamma knife surgery (GKS) for the treatment of trigeminal neuralgia (TN) using the trigeminal ganglion (TG') and the adjacent fibers of trigeminal nerve as a target.

Methods: From February 2013 to July 2017, we treated 30 cases of TN with GKS. In this group, all patients had an idiopathic typical TN.

Gamma knife radiosurgery to the trigeminal ganglion for treatment of trigeminal neuralgia secondary to vertebrobasilar ectasia.

Background: We report the result obtained using Gamma knife stereotactic radiosurgery on the trigeminal ganglion (TG) in a patient with trigeminal neuralgia (TN) secondary to vertebrobasilar ectasia (VBE).

Case Description: Retrospective review of medical records corresponding to one patient with VBE-related trigeminal pain treated with radiosurgery. Because of the impossibility of visualization of the entry zone or the path of trigeminal nerve through the pontine cistern, we proceeded with stereotactic radiosurgery directed to the TG.

Radioprotective effects of the 21-aminosteroid U-74389G for stereotactic radiosurgery.

Objective: Future improvements in the results of stereotactic radiosurgery will be related to better patient selection, dose planning, radiosensitization of the target, and, possibly, protection of the brain surrounding the target. 21-Aminosteroids may provide protection against brain radiation injury by inhibition of lipid peroxidation and a selective action on vascular endothelium. We hypothesized that the 21-aminosteroid U-74389G would reduce radiosurgery-related brain injury without attenuating the target volume response.

Endoscopic transsphenoidal resection of a large chordoma in the posterior fossa.

Encouraged by an experience with endoscopic transsphenoidal pituitary surgery, an endoscopic transsphenoidal technique was applied in a patient with a large chordoma in the posterior fossa. The patient was a 40-year-old man with a two-year history of progressive ataxia, a memory disorder and emotional instability. A magnetic resonance (MR) scan of the brain revealed a midline posterior fossa mass measuring 4 cm in diameter located between the clivus and the brainstem.

Early outcomes after stereotactic radiosurgery for growing pilocytic astrocytomas in children.

To examine the role of stereotactic radiosurgery in the adjuvant management of children with growing and unresectable deep-seated pilocytic astrocytomas, we reviewed our experience in 9 patients. The tumors were located in the dorsolateral pons (n = 2), midbrain (n = 1, cerebellar peduncle (n = 2), thalamus (n = 1), temporal lobe (n = 1), hypothalamus (n = 1), and caudate nucleus (n = 1). The mean tumor diameter was 16 mm (range, 11-25 mm).

Endoscopic transsphenoidal resection of a large chordoma in the posterior fossa. Case report.

The authors report their encouraging experience using an endoscopic technique for transsphenoidal surgery in a patient with a large chordoma in the posterior fossa. The patient was a 40-year-old man with a 2-year history of progressive ataxia, a memory disorder, and emotional instability. A magnetic resonance (MR) image of the brain revealed a midline posterior fossa mass measuring 4 cm in diameter located between the clivus and the brainstem.

Radiosurgery: its role in brain metastasis management.

Stereotactic radiosurgery is effective in controlling brain metastasis at presentation and those that recur after radiotherapy. It is the treatment of choice for most patients with small solitary brain metastasis by virtue of its low morbidity, high-effectiveness, and cost.

Radiosurgery and fractionated radiation therapy: comparison of different techniques in an in vivo rat glioma model.

To identify histological changes and effects on survival in rats harboring C6 gliomas, the authors compared radiosurgery to different fractionated radiation therapy regimens including doses of calculated biological equivalence. Rats were randomized to control (54 animals) or treatment groups after implantation of C6 glioma cells into the right frontal brain region. At 14 days, treated rats underwent stereotactic radiosurgery (35 Gy to tumor margin; 22 animals), whole-brain radiation therapy (WBRT) (20 Gy in five fractions; 18 animals), radiosurgery plus WBRT (13 animals), hemibrain radiation therapy (85 Gy in 10 fractions; 16 animals) or single-fraction hemibrain irradiation (35 Gy; 10 animals).

Survival after stereotactic biopsy and irradiation of cerebral nonanaplastic, nonpilocytic astrocytoma.

The authors investigated the outcome of stereotactic biopsy and radiotherapy in 35 consecutive adult patients with nonanaplastic, nonpilocytic astrocytomas who were diagnosed between 1982 and 1992. The median patient age at presentation was 32 years. All received fractionated external-beam radiation therapy (median dose 56 Gy) as the initial management strategy.

Brain astrocytomas: biopsy, then irradiation.

We believe that every patient who has clinical symptoms and neurodiagnostic imaging signs suggesting a low-grade glial neoplasm should undergo early diagnosis and treatment. Observation is not warranted for a tumor that has a median survival of 5 years. The value of cytoreductive surgery for many patients has yet to be proven.

Cerebral radioprotective effects of high-dose pentobarbital evaluated in an animal radiosurgery model.

Because pentobarbital has been shown to reduce cerebral toxicity to single-fraction whole brain irradiation in a rat model, we sought to evaluate its cerebral radioprotective effects for stereotactic radiosurgery. We hypothesized that concurrent high-dose pentobarbital anaesthesia (50 mg kg-1) during irradiation could delay or prevent the onset of radiation necrosis within the radiosurgical volume. Six rats were placed in pentobarbital or control groups, irradiated, and then evaluated at different intervals (60, 100, 150, 365 days; total = 48 animals studied).

Stereotactic radiosurgery for cerebral metastatic melanoma.

To determine local tumor control rates and survival of patients with melanoma metastases to the brain, the authors reviewed the results of 23 consecutive patients with a total of 32 tumors (19 patients had a solitary tumor and four had multiple tumors) who underwent adjuvant stereotactic radiosurgery. Tumor locations included the cerebral hemisphere (24 cases), brain stem (four cases), basal ganglia (two cases), and cerebellum (two cases). Fifteen patients had associated cranial symptomatology and eight had incidental metastases.

Radiosurgery for vascular malformations of the brain stem.

The challenges associated with microsurgery of vascular malformations located in the midbrain, pons and medulla have promoted the development of alternative therapeutic techniques. To assess the efficacy and safety of radiosurgery in the management of brain stem vascular malformations we reviewed our 5-year experience in 50 patients evaluated between 4 and 51 months (mean, 25 months) after radiosurgery. Twenty-eight patients (56%) underwent gamma unit radiosurgery for symptomatic arteriovenous malformations (AVMs), and 22 patients (44%) for angiographically occult vascular malformations (AOVMs).