Search

BackgroundReports on behavioural outcomes after subthalamic nucleus deep brain stimulation in Parkinson’s disease are controversial and limited to short-term data. Long-term observation in a large cohort allows a better counselling and management.MethodsTo determine whether a long-term treatment with subthalamic stimulation induces or reduces impulse control behaviours, neuropsychiatric fluctuations and apathy, 69 patients treated with subthalamic stimulation are prospectively and retrospectively assessed using Ardouin Scale of Behavior in Parkinson’s Disease before and after 3–10 years of stimulation.ResultsAt a mean follow-up of 6 years, all impulse control disorders and dopaminergic addiction were significantly decreased, apart from eating behaviour and hypersexuality. Neuropsychiatric fluctuations also significantly improved (ON euphoria: 38% of the patients before surgery and 1% after surgery, PConclusionsBilateral subthalamic nucleus stimulation was overall very effective in improving impulse control disorders and neuropsychiatric fluctuations in parkinsonian patients in the long term despite a counteracting frequent apathy. Transient episodes of impulse control disorders still occurred within the follow-up. These findings recommend a close follow-up in parkinsonian patients presenting with neuropsychiatric symptoms before deep brain stimulation surgery.Clinical trial registrationNCT01705418;Post-results.

Background Levodopa therapy in Parkinson9s disease (PD) is associated with non-motor complications resulting from sensitisation of the ventral striatum system. Recent studies showed an improvement in non-motor complications in PD patients with subthalamic stimulation. We hypothesised that ventral striatum desensitisation might contribute to this improvement. Methods Psychostimulant effects of levodopa were prospectively assessed in 36 PD patients with an acute levodopa challenge, before and 1 year after chronic subthalamic stimulation, using the Addiction Research Centre Inventory euphoria subscale. Postoperative evaluation was performed with the same dose of levodopa used in the preoperative assessment and after switching off stimulation. Preoperative and postoperative non-motor fluctuations in everyday life were investigated with the Ardouin Scale. Furthermore, in order to artificially reproduce non-motor fluctuations, a levodopa challenge keeping subthalamic stimulation on was performed to assess depression, anxiety and motivation before and after surgery under the different medication conditions. Results After 1 year of chronic subthalamic stimulation with 60.3% reduction in dopaminergic medication, the acute psychostimulant effects of levodopa were significantly reduced compared with preoperatively, as measured by the euphoria subscale (7.22±4.75 vs 4.75±5.68; p=0.0110). On chronic subthalamic stimulation and with markedly reduced dopaminergic medication, non-motor fluctuations were significantly improved. While off medication/on stimulation scores of depression and anxiety were improved, in the on medication/on stimulation condition the motivation score worsened. Conclusions Acute psychostimulant effects of levodopa (off stimulation) were significantly reduced 1 year after surgery. These findings are likely due to desensitisation of the ventral striatum, allowed by the reduction of dopaminergic treatment, and the replacement of pulsatile treatment with continuous subthalamic stimulation.

In reflex epilepsies, alteration of gamma oscillations may mediate transition between interictal and ictal states. Here we explored a patient having seizures triggered by syrup intake. From intracranial electroencephalography combined with functional magnetic resonance imaging, the overlap of the gustatory cortex and of the preictal and ictal onset zones, as defined by early gamma changes, motivated the successful resective surgery of the middle short gyrus of the right insula. This case provides a rare demonstration from human gamma activity that the route to seizure may be supported by the interplay between physiological and epileptogenic networks.

Before the introduction of high frequency stimulation of the subthalamic nucleus (STN), many disabled tremor dominant parkinsonian patients underwent lesioning or chronic electrical stimulation of the thalamus. We studied the effects of STN stimulation in patients with previous ventral intermediate nucleus (VIM) surgery whose motor state worsened. Fifteen parkinsonian patients were included in this study: nine with unilateral and two with bilateral VIM stimulation, three with unilateral thalamotomy, and one with both unilateral thalamotomy and contralateral VIM stimulation. The clinical evaluation consisted of a formal motor assessment using the Unified Parkinson's Disease Rating Scale (UPDRS) and neuropsychological tests encompassing a 50 point frontal scale, the Mattis Dementia Rating Scale, and the Beck Depression Inventory. The first surgical procedure was performed a mean (SD) of 8 (5) years after the onset of disease. STN implantation was carried out 10 (4) years later, and duration of follow up after beginning STN stimulation was 24 (20) months. The UPDRS motor score, tremor score, difficulties in performance of activities of daily living, and levodopa equivalent daily dose significantly decreased after STN stimulation. Neither axial symptoms nor neuropsychological status significantly worsened after the implantation of the STN electrodes. The parkinsonian motor state is greatly improved by bilateral STN stimulation even in patients with previous thalamic surgery, and STN stimulation is more effective than VIM stimulation in tremor dominant parkinsonian patients.