[Not Available]. / Résultats du traitement radiochirurgical Gamma Knife des malformations artério-veineuses cérébrales.

Gamma Knife treatments of arteriovenous malformations (AVM) are performed for about 40 years. This article presents the results of 123 patients treated for a brain AVM at the Gamma Knife Center ULB-Hôpital Erasme. Radiosurgical treatment is proposed following multidisciplinary discussion of the best therapeutic strategy based on specific parameters of the AVM. Gamma Knife irradiation was achieved for an AVM residue after endovascular embolization for 84% of patients, after microsurgery for 7% of patients, or after previous radiosurgical irradiation for 6% of patients. The whole volume of the nidus was irradiated in a single session for all patients. A mean margin dose of 22.3 Gy was delivered to the nidus, which had a mean volume of 3.3 cc. The maximum dose ranged from 30 Gy to 50 Gy (mean 44.1 Gy). All patients were prospectively followed after treatment with serial angio-MR and/or conventional angiography. A retrospective analysis shows complete obliteration of the AVM for 109 patients (89%) after 6 to 52 months (mean 32 months). For 14 patients the nidus was only partially obliterated from the radiosurgical procedure; for 9 patients a second irradiation was performed with subsequent complete occlusion of the AVM in all cases. So, 118 of 123 patients (96%) irradiated by Gamma Knife in 1 or 2 sessions were cured. Four patients bled after irradiation and before complete occlusion of the AVM, with neurological deficit for 2 patients. Transient neurological symptoms develop after treatment for 12 patients (10%), associated with postradic edema treated with corticoids. Permanent neurological worsening occurred in 5 patients (4%). Gamma Knife treatment of cerebral arteriovenous malformations is a highly efficient and low-risk therapy when used by a multidisciplinary team.

Posterior reversible encephalopathy syndrome as a revealing manifestation of Guillain-Barré syndrome.

We report a patient with a Guillain-Barré syndrome (GBS) revealed by a posterior reversible encephalopathy syndrome (PRES). The PRES is typically associated with bilateral parieto-occipital T2 and FLAIR hyperintense MRI lesions and observed in various etiologic conditions leading to acute arterial hypertension. PRES results from a breakdown of the circulatory autoregulation, many in the posterior cerebral territories. GBS can be considered as an independent risk factor of PRES, due to acute dysautonomia and pain with consecutive arterial hypertension, as well as to cytokine production changing capillary permability. Such patients with PRES-revealed GBS may be treated with intravenous immunoglobulin therapy only after exclusion of any ischemic or hemorrhagic cerebral complications, and after control of the blood pressure and of the encephalopathic signs and symptoms.

[Non-functioning pituitary adenoma: is there an interest to treat a residue after surgery?]. / Adénome hypophysaire non sécrétant: faut-il traiter un résidu après chirurgie?

Diagnosis of non-functioning pituitary adenoma is generally posted when there is a compression of the ophthalmic nerve or when a hypopituitarism occurred. Surgery will be the first treatment but complete removal can be achieved in less than 50% of the patients. In the great majority of the patients, there is a recurrence and a new treatment is proposed. The question is when we must treat a residue after surgery. We performed a retrospective study reviewing a series of 111 patients with a non-functioning pituitary adenoma. All patients had a pre- and post-operative MRI (1.5 T). A statistical analysis was done to determine the influence of the resection, the age of the patient on the recurrence. A complete removal was achieved for 45 patients and 11 of these present a recurrence. 39 patients out of 66 patients who had a partial removal presented also a recurrence. The mean age of the population is 53 years. The statistical analysis demonstrates that patients with a complete removal had less recurrence. Patient with an age below 60 years had more frequently a recurrence compared with older than 60 years old. In conclusion, treatment for non-functioning pituitary adenoma is a transsphenoidal approach surgery. A complete surgery must be the aim of the neurosurgeon. And when a residue is present, a secondary treatment must be given for patient with an age below 60 years old like radiosurgery or radiation therapy.