Basal ganglia dysfunction in OCD: subthalamic neuronal activity correlates with symptoms severity and predicts high-frequency stimulation efficacy

Functional and connectivity changes in corticostriatal systems have been reported in the brains of patients with obsessive–compulsive disorder (OCD); however, the relationship between basal ganglia activity and OCD severity has never been adequately established. We recently showed that deep brain stimulation of the subthalamic nucleus (STN), a central basal ganglia nucleus, improves OCD. Here, single-unit subthalamic neuronal activity was analysed in 12 OCD patients, in relation to the severity of obsessions and compulsions and response to STN stimulation, and compared with that obtained in 12 patients with Parkinson's disease (PD). STN neurons in OCD patients had lower discharge frequency than those in PD patients, with a similar proportion of burst-type activity (69 vs 67%). Oscillatory activity was present in 46 and 68% of neurons in OCD and PD patients, respectively, predominantly in the low-frequency band (1–8 Hz). In OCD patients, the bursty and oscillatory subthalamic neuronal activity was mainly located in the associative–limbic part. Both OCD severity and clinical improvement following STN stimulation were related to the STN neuronal activity. In patients with the most severe OCD, STN neurons exhibited bursts with shorter duration and interburst interval, but higher intraburst frequency, and more oscillations in the low-frequency bands. In patients with best clinical outcome with STN stimulation, STN neurons displayed higher mean discharge, burst and intraburst frequencies, and lower interburst interval. These findings are consistent with the hypothesis of a dysfunction in the associative–limbic subdivision of the basal ganglia circuitry in OCD's pathophysiology

Mechanisms and therapeutic applications of electromagnetic therapy in Parkinson's disease

© 2015 Vadalà et al. Electromagnetic therapy is a non-invasive and safe approach for the management of several pathological conditions including neurodegenerative diseases. Parkinson's disease is a neurodegenerative pathology caused by abnormal degeneration of dopaminergic neurons in the ventral tegmental area and substantia nigra pars compacta in the midbrain resulting in damage to the basal ganglia. Electromagnetic therapy has been extensively used in the clinical setting in the form of transcranial magnetic stimulation, repetitive transcranial magnetic stimulation, high-frequency transcranial magnetic stimulation and pulsed electromagnetic field therapy which can also be used in the domestic setting. In this review, we discuss the mechanisms and therapeutic applications of electromagnetic therapy to alleviate motor and non-motor deficits that characterize Parkinson's disease

Analysis of shared common genetic risk between amyotrophic lateral sclerosis and epilepsy

Because hyper-excitability has been shown to be a shared pathophysiological mechanism, we used the latest and largest genome-wide studies in amyotrophic lateral sclerosis (n = 36,052) and epilepsy (n = 38,349) to determine genetic overlap between these conditions. First, we showed no significant genetic correlation, also when binned on minor allele frequency. Second, we confirmed the absence of polygenic overlap using genomic risk score analysis. Finally, we did not identify pleiotropic variants in meta-analyses of the 2 diseases. Our findings indicate that amyotrophic lateral sclerosis and epilepsy do not share common genetic risk, showing that hyper-excitability in both disorders has distinct origins

Patient with perinatal brain injury dystonia treated by deep brain stimulation: Management during pregnancy

International audienc

Symptomatic cervical myelopathy due to general dystonia: Case report and review of the literature

International audienc

Headache changes prior to aneurysmal rupture: A symptom of unruptured aneurysm?

International audienceBACKGROUND AND OBJECTIVES:The symptomatic status of unruptured aneurysms has to be looked for. The objective of this retrospective case-control study was to identify the headache semiologic characteristics of symptomatic aneurysms during the 3 months prior to patient admission.PATIENTS AND METHODS:The case cohort was composed of 40 consecutive patients admitted for the treatment of a ruptured intracranial aneurysm (IA) and able to answer a standardized questionnaire by the same neurologist. This cohort was matched with a control cohort of 40 patients operated on for a degenerative lumbar pathology. This questionnaire, using the criteria for headache characteristics according to the International Headache Society (IHS) enabled us to classify headaches during the previous 3 months prior to the rupture (study period) and during the year prior to the period studied (reference period) in both cohorts. Headache status was considered as unstable if there were modifications of semiologic headache characteristics, thunderclap headaches or de novo headaches, or on the contrary stable.RESULTS:During the status period, chronic headaches were reported by 31 patients (77.5%) in the studied cohort and 35 (87.5%) in the control cohort. During the study period, the cephalagia status was stable in 19 patients (47.5%) versus 35 patients (87.5%) in the control cohort (P<0.001). Modifications of chronic headaches were present in 11 patients (35.5%) in the studied cohort versus 4 patients (11.4%) in the control cohort (P=0.04). Thunderclap headaches were present in 7 patients (17.5%) in the studied cohort but none in the control cohort (P=0.006).DISCUSSION:Modifications of headaches semiologic characteristics during the 3 previous months were significantly more frequent in the studied cohort. This modification could be a sign of IA instability

Management and outcome of cerebral venous thrombosis after head trauma: A case series

International audienc

Impact of deep brain stimulation on pharyngo-esophageal motility: a randomized cross-over study

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Stimulation of the subthalamic nucleus in Parkinson's disease: a 5 year follow up

Background: The short term benefits of bilateral stimulation of the subthalamic nucleus (STN) in patients with advanced levodopa responsive Parkinson's disease (PD) are well documented, but long term benefits are still uncertain. Objectives: This study provides a 5 year follow up of PD patients treated with stimulation of the STN. Methods: Thirty seven consecutive patients with PD treated with bilateral STN stimulation were assessed prospectively 6, 24, and 60 months after neurosurgery. Parkinsonian motor disability was evaluated with and without levodopa treatment, with and without bilateral STN stimulation. Neuropsychological and mood assessments included the Mattis Dementia Rating Scale, the frontal score, and the Montgomery-Asberg Depression Rating Scale (MADRS). Results: No severe peri- or immediate postoperative side effects were observed. Six patients died and one was lost to follow up. Five years after neurosurgery: (i) activity of daily living (Unified Parkinson Disease Rating Scale (UPDRS) II) was improved by stimulation of the STN by 40% ("off" drug) and 60% ("on" drug); (ii) parkinsonian motor disability (UPDRS III) was improved by 54% ("off" drug) and 73% ("on" drug); (iii) the severity of levodopa related motor complications was decreased by 67% and the levodopa daily doses were reduced by 58%. The MADRS was unchanged, but cognitive performance declined significantly. Persisting adverse effects included eyelid opening apraxia, weight gain, addiction to levodopa treatment, hypomania and disinhibition, depression, dysarthria, dyskinesias, and apathy. Conclusions: Despite moderate motor and cognitive decline, probably due to disease progression, the marked improvement in motor function observed postoperatively was sustained 5 years after neurosurgery