A multiinstitutional study was conducted to evaluate the technique, dose-selection parameters, and results of gamma knife stereotactic radiosurgery in the management of trigeminal neuralgia. Fifty patients at five centers underwent radio-surgery performed with a single 4-mm isocenter targeted at the nerve root entry zone. Thirty-two patients had undergone prior surgery, and the mean number of procedures that had been performed was 2.8 (range 1-7). The target dose of the radiosurgery used in the current study varied from 60 to 90 Gy. The median follow-up period after radiosurgery was 18 months (range 11-36 months). Twenty-nine patients (58%) responded with excellent control (pain free), 18 (36%) obtained good control (50%-90% relief), and three (6%) experienced treatment failure. The median time to pain relief was 1 month (range 1 day-6.7 months). Responses remained consistent for up to 3 years postradiosurgery in all cases except three (6%) in which the patients had pain recurrence at 5, 7, and 10 months. At 2 years, 54% of patients were pain free and 88% had 50% to 100% relief. A maximum radiosurgical dose of 70 Gy or greater was associated with a significantly greater chance of complete pain relief (72% vs. 9%, p = 0.0003). Three patients (6%) developed increased facial paresthesia after radiosurgery, which resolved totally in one case and improved in another. No patient developed other deficits or deafferentation pain. The proximal trigeminal nerve and root entry zone, which is well defined on magnetic resonance imaging, is an appropriate anatomical target for radiosurgery. Radiosurgery using the gamma unit is an additional effective surgical approach for the management of medically or surgically refractory trigeminal neuralgia. A longer-term follow-up review is warranted.

According to most existing literature, the absence of an MRI lesion is generally associated with poorer prognosis in resective epilepsy surgery. Delineation of the epileptogenic zone (EZ) by intracranial recording is usually required but is perceived to be more difficult in 'MRI negative' cases. Most previous studies have used subdural recording and there is relatively less published data on stereoelectroencephalography (SEEG). The objective of this study was to report the experience of our group in using SEEG in presurgical evaluation, comparing its effectiveness in normal and lesional MRI cases. One hundred consecutive patients undergoing SEEG for presurgical assessment were studied. Forty-three patients out of one hundred (43%) had normal MRI and 57 (57%) had lesional MRI. Successful localization was achieved with no difference between these two groups, in 41/43 (95%) normal MRI and in 55/57 (96%) lesional MRI cases (P = 1.00). Surgery was proposed in 84/100 patients and contraindicated in 16/100 with no significant difference between lesional and MRI-negative groups (P > 0.05). At 1 year follow-up, 11/20 (55%) of those having undergone cortectomy in the MRI-negative group and 21/40 (53%) in the lesional MRI group were entirely seizure free (P > 0.05) and these proportions were maintained at 2 years follow-up. Significant improvement in seizure control (ILAE outcome groups 1-4) was achieved in >90% cases with no difference between groups (P > 0.05). Of MRI-negative cases that underwent surgery, 10/23 (43%) had focal cortical dysplasia. This series showed that SEEG was equally effective in the presurgical evaluation of MRI-negative and lesional epilepsies.

In Parkinson's disease, dopamine dysregulation syndrome (DDS) is characterized by severe dopamine addiction and behavioral disorders such as manic psychosis, hypersexuality, pathological gambling, and mood swings. Here, we describe the case of 2 young parkinsonian patients suffering from disabling motor fluctuations and dyskinesia associated with severe DDS. In addition to alleviating the motor disability in both patients, subthalamic nucleus (STN) deep brain stimulation greatly reduced the behavioral disorders as well as completely abolished the addiction to dopaminergic treatment. Dopaminergic addiction in patients with Parkinson's disease, therefore, does not constitute an obstacle to high-frequency STN stimulation, and this treatment may even cure the addiction.