Subthalamic Neural Activity Patterns Anticipate Economic Risk Decisions in Gambling.

Economic decision-making is disrupted in individuals with gambling disorder, an addictive behavior observed in Parkinson's disease (PD) patients receiving dopaminergic therapy. The subthalamic nucleus (STN) is involved in the inhibition of impulsive behaviors; however, its role in impulse control disorders and addiction is still unclear. Here, we recorded STN local field potentials (LFPs) in PD patients with and without gambling disorder during an economic decision-making task. Reaction times analysis showed that for all patients, the decision whether to risk preceded task onset. We compared then for both groups the STN LFP preceding high- and low-risk economic decisions. We found that risk avoidance in gamblers correlated with larger STN LFP low-frequency (<12-Hz) fluctuations preceding task onset. In particular, the amplitude of low-frequency LFP fluctuations carried significant information about future decisions. Decisions of patients not affected by gambling disorder were instead not correlated with pretask STN LFP. Our results suggest that STN activity preceding task onset affects risk decisions by preemptively inhibiting attraction to high but unlikely rewards in favor of a long-term payoff.

Dental Care-Related Fear and Anxiety: Distress Tolerance as a Possible Mechanism.

Distress tolerance, the degree to which one is able to cope with and endure negative emotional states, has been broadly applied to understand and treat a variety of health (including behavioral) problems, but little is known about its role in oral health care and specifically dental care-related fear and anxiety, making it a novel construct in the oral health care literature. This cross-sectional study examined distress tolerance as a possible predictor of dental fear and anxiety among a sample of adults with and without diagnoses of dental phobia, investigated possible differences in levels of distress tolerance between adults with and without dental phobia, and determined possible associations between distress tolerance and fear of pain, anxiety sensitivity, and depression. Using 52 volunteers (n = 31, dental phobia group; n = 21, healthy comparison group), this investigation used self-report measures of distress tolerance, fear of pain, anxiety sensitivity, dental fear, and depression. The Anxiety Disorders Interview Schedule, a semi-structured interview, was used to assess for dental phobia and other psychological disorders. Distress tolerance significantly predicted dental fear and anxiety, even after controlling for age, sex, fear of pain, anxiety sensitivity, and depression. In addition, the dental phobia group had lower distress tolerance than the healthy comparison group. Distress tolerance was significantly associated with fear of pain, anxiety sensitivity, and depression. Findings indicate that low distress tolerance plays a unique and distinct role as a possible mechanism in the genesis of dental care-related fear and anxiety and phobia and may exacerbate the experience of other states, including fear of pain and anxiety sensitivity. Knowledge Transfer Statement: Results indicate that patients who have a lower ability to tolerate emotional and physical distress may have higher levels of dental care-related fear and anxiety and even dental phobia, as well as associated sequelae (e.g., avoidance of dental care). Treatment of highly fearful dental patients may helpfully include a focus on increasing distress tolerance.

Pallidal stimulation for acquired dystonia due to cerebral palsy: beyond 5 years.

BACKGROUND AND PURPOSE: There is increasing evidence that deep brain stimulation (DBS) of the globus pallidus internus (GPi) is effective in patients with idiopathic or inherited generalized dystonia. There is comparatively less experience about the effects of GPi DBS on acquired dystonia, particularly dystonia due to cerebral palsy (DCP). Clinical and demographic outcome predictors for DBS in dystonia syndromes are also poorly defined. Our aim was to examine the efficacy and safety of GPi DBS for the treatment of generalized DCP. METHODS: Fifteen patients with DCP up to 6.2 years after DBS surgery were studied. Only mild limb spasticity or mild static brain magnetic resonance imaging abnormalities were acceptable for inclusion. Dystonia severity and disability were assessed by the Burke-Fahn-Marsden dystonia rating scale (BFMDRS), and health-related quality of life was assessed by the Short Form General Health Survey (SF-36) scale. The amount of energy delivered was calculated, and adverse events and side effects were collected. RESULTS: At last follow-up, BFMDRS motor score improved on average by 49.5%, and the disability score improved by 30%. Health-related quality of life improved in most patients. Age at implant, age at onset and disease duration did not correlate to outcome, whilst higher pre-operative dystonia severity and occurrence of spasticity were associated with poorer outcome. The patients received a stable amount of energy after the first 2 years post-implant and throughout all the observation period. There were few serious adverse events or side effects. CONCLUSIONS: The outcome was encouraging in the majority of DCP patients, with a stable outlook and a good safety profile.

Impulse control behaviours in patients with Parkinson's disease after subthalamic deep brain stimulation: de novo cases and 3-year follow-up.

OBJECTIVE: To document the occurrence of impulse control behaviours (ICBs) in patients with Parkinson's disease after 3 years of continuous deep brain stimulation (DBS) of the subthalamic nucleus (STN). METHODS: Detailed neurological and ICB assessments were performed before STN DBS and up to 3 years after implant. RESULTS: 13 out of 56 patients (23.2%) had ICBs at baseline; they took higher doses of dopamine agonists (DAA). Three years after implant 11 had fully remitted with a 60.8% reduction of DAA medication; the remaining two, who had a similar medication reduction, had only compulsive eating, having recovered from hypersexuality. Six of the 43 patients without ICBs at baseline (14%) developed transient de novo ICBs after implant; none of them had ICBs at the 3-year observation. CONCLUSIONS: ICBs were abolished in patients 3 years after STN DBS and DAA dosages were lowered. New ICBs may occur after implant and are transient in most cases. Compulsive eating may be specifically related to STN stimulation.

Long-term outcome of subthalamic nucleus DBS in Parkinson's disease: from the advanced phase towards the late stage of the disease?

BACKGROUND: Deep Brain Stimulation of the Subthalamic Nucleus (STN-DBS) is an effective treatment for Parkinson's disease (PD), but only few studies investigated its long-term efficacy. Furthermore, little is known about the role of PD-subtype on STN-DBS long-term outcome. OBJECTIVE: To report the results of a long-term follow-up (mean 11 years, range 10-13) on 26 patients bilaterally implanted in two centres. METHODS: Patients were assessed preoperatively and 1, 5 and 11 years after the implant by the Unified Parkinson's Disease Rating Scale (UPDRS) and a battery of neuropsychological tests. Stimulation parameters, drugs dosages, non-motor symptoms and adverse events were also recorded. RESULTS: At 11 years, stimulation significantly improved the motor symptoms by 35.8%, as compared to the preoperative off-state. Motor complications were well controlled, with a 84.6% improvement of dyskinesias and a 65.8% improvement of motor fluctuations. Despite this, the UPDRS-II-on score worsened by 88.5%, mainly for the worsening of poorly levodopa-responsive symptoms. More than 70% of the patients performed in the normal range in most of the neuropsychological tests, despite the development of dementia in 22.7%. Age at disease onset, axial subscore in off-condition and presence of REM behaviour disorder at baseline were found to be associated with a higher risk of developing disability over time. CONCLUSIONS: Our study confirms the long-term safety and efficacy of STN-DBS in PD. Nevertheless, the functionality of patients worsens over time, mainly for the onset and progression of levodopa-resistant and non-motor symptoms. The role of PD-subtype seems to be relevant in the long-term outcome.

Use of social media by dental educators.

Social networking applications have become an established means of communication; applications that did not exist ten years ago are now used daily. Social media can be used for a myriad of reasons including instructional tools to supplement learning. This project was designed to assess the usage of social media applications by dental school faculty members and identify the types of accounts they prefer. Four hundred forty-three full-time dental and dental hygiene faculty members from five U.S. dental schools were invited to complete a twelve-item online survey regarding their social media usage. The response rate was 50 percent (n=221). Of the respondents, nearly half were dentists, and 62 percent were ≥51 years of age. Facebook was the most popular social network, reportedly used by 111 respondents. The most often reported frequency of use was weekly (20.4 percent, n=221); users indicated utilizing a network primarily for personal rather than professional purposes. However, 37 percent of the respondents reported not using any social media. The most frequently cited barriers to the use of social media were time (48 percent) and privacy concerns (48 percent). Although few would dispute the influence social media has on today's students, the suitability and appropriateness of social media technology and its integration into dental curricula require further evaluation.

fMRI study of brain activity elicited by oral parafunctional movements.

Parafunctional masticatory activity, such as the tooth clenching and grinding that is associated with bruxism, is encountered by clinicians in many disciplines, including dentistry, neurology and psychiatry. Despite this, little is known about the neurological basis for these activities. To identify the brain network engaged in such complex oromotor activity, functional magnetic resonance imaging (fMRI) was used to elucidate the brain activation patterns of 20 individuals (10 males and 10 females, mean s.d. age of 26.3+/-4.1 years) with (parafunctional, PFx group, 5M/5F) and without (normal functional, NFx group, 5 M/5F) self-reported parafunctional grinding and clenching habits during clenching and grinding tasks. Subject group classification was based on: (i) self-reported history, (ii) clinical examination, (iii) evaluation of dental casts and (iv) positive responses to the temporomandibular disorder (TMD) History Questionnaire [Dworkinand LeResche, Journal of Craniomandibular Disorders, (1992) 6:301]. While subjects performed these oromotor tasks, each wore a custom-designed oral appliance minimizing head motion during imaging. Mean per cent signal changes showed significant between group differences in motor cortical (supplementary motor area, sensorimotor cortex and rolandic operculum) and subcortical (caudate) regions. Supplementary motor area data suggest that motor planning and initiation, particularly during the act of clenching, are less prominent in individuals with oromotor parafunctional behaviours. The overall extent of activated areas was reduced in subjects with self-reported parafunctional masticatory activity compared with the controls. This study's methodology and findings provide an initial step in understanding the neurological basis of parafunctional masticatory activities that are relevant for therapeutic research applications of temporomandibular joint and muscle disorders and associated comorbidities.

Results by motor cortex stimulation in treatment of focal dystonia, Parkinson's disease and post-ictal spasticity. The experience of the Italian Study Group of the Italian Neurosurgical Society.

Extradural motor cortex stimulation has been employed in cases of Parkinson's disease (PD), fixed dystonia (FD) and spastic hemiparesis (SH) following cerebral stroke. Symptoms of PD are improved by EMCS: results were evaluated on the basis of the UPDRS and statistically analysed. In PD EMCS is less efficacious than bilateral subthalamic nucleus (STN) stimulation, but it may be safely employed in patients not eligible for deep brain stimulation (DBS). The most rewarding effect is the improvement, in severely affected patients, of posture and gait. FD, unresponsive to bilateral pallidal stimulation, has been relieved by EDMS. In SH reduction of spasticiy by EMCS allows improvement of the motor function.

Cognitive outcome 5 years after bilateral chronic stimulation of subthalamic nucleus in patients with Parkinson's disease.

AIM: To assess the long-term cognitive and behavioural outcome after bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) in patients affected by Parkinson's disease, with a 5-year follow-up after surgery. METHODS: 11 patients with Parkinson's disease treated by bilateral DBS of STN underwent cognitive and behavioural assessments before implantation, and 1 and 5 years after surgery. Postoperative cognitive assessments were carried out with stimulators turned on. RESULTS: A year after surgery, there was a marginally significant decline on a letter verbal fluency task (p = 0.045) and a significant improvement on Mini-Mental State Examination (p = 0.009). 5 years after surgery, a significant decline was observed on a letter verbal fluency task (p = 0.007) and an abstract reasoning task (p = 0.009), namely Raven's Progressive Matrices 1947. No significant postoperative change was observed on other cognitive variables. No patient developed dementia 5 years after surgery. A few days after the implantation, two patients developed transient manic symptoms with hypersexuality and one patient developed persistent apathy. CONCLUSION: The decline of verbal fluency observed 5 years after implantation for DBS in STN did not have a clinically meaningful effect on daily living activities in our patients with Parkinson's disease. As no patient developed global cognitive deterioration in our sample, these findings suggest that DBS of STN is associated with a low cognitive and behavioural morbidity over a 5-year follow-up, when selection criteria for neurosurgery are strict.

The PINK1 phenotype can be indistinguishable from idiopathic Parkinson disease.

Mutations in the PINK1 gene cause autosomal recessive parkinsonism characterized by early onset and a variable phenotypic presentation. A patient homozygous for the Ala168Pro mutation has been fully characterized clinically. Apart from onset at age 39 years and the excellent and sustained response to levodopa, all clinical and laboratory features, including SPECT and assessment of autonomic function, were indistinguishable from typical idiopathic Parkinson disease.

Bilateral high frequency subthalamic stimulation in Parkinson's disease: long-term neurological follow-up.

AIM: High frequency stimulation of the subthalamic nucleus (STN) is gaining recognition as a new symptomatic treatment for Parkinson's disease (PD). The first available long-term observations show the stability of the efficacy of this procedure in time. METHODS: Quadripolar leads were implanted bilaterally under stereotactic conditions in the STN of patients with advanced PD. High frequency stimulation was applied for 24 hours a day. Following implant, antiparkinsonian medication was reduced as much as possible and stimulation was gradually increased. The patients were evaluated in the practically defined "off" condition and in the "on" condition using the unified PD rating scale (UPDRS) and the Schwab & England scale. Neuropsychological testing was performed before and after the implant. Thirty-three patients were followed up for at least 3 months and 13 among them until 36 months. RESULTS: The patients had a mean age of 56.8+/-7.1 years and a mean disease duration of 13.8+/-5.5 years; they were followed-up for an average of 25.7+/-13.5 months. At the time of the last available visit, the stimulation amplitude was 2.47+/-0.40 V (the total energy delivered averaged 1.57+/-0.8 microW). The levodopa-equivalent daily dose was reduced by 56.2% (p<0.001). Parkinsonian features were improved in all patients, the greatest changes were seen for tremor, gait, bradykinesia and postural stability, then rigidity and limb akinesia. Compared with the pre-implant conditions, the UPDRS motor score in the "off" condition was improved by 51.6% at the time of the last visit (p<0.001), the UPDRS activities of daily living score was improved by 68.5% (p<0.001), the Schwab & England scale was improved by 196.8% (p<0.001). The neuropsychological data did not show significant changes. Night sleep improved in all patients, due to increased mobility at night. In almost all patients insomnia was resolved. All patients gained weight after surgery with an increase of 11.1% (p<0.001) compared to their pre-implant weight. The most common permanent side effects consisted in hypophonia and dysarthria, transient side effects were increased sexuality and mania, the most common side effects related to stimulation were ballic or choreic dyskinesias. The most common adverse event related to the surgical procedure was transient psychosis; unexplained switching-off of the stimulator was the most common device-related effect. CONCLUSION: This study extends our recently published 3-years FU series. It confirms again that symptomatic efficacy of STN stimulation is retained during the 2(nd) and 3(rd) years following the implant, without any obvious decay of efficacy or need for increase of energy delivered. Improvement of dyskinesias also persists and the procedure is well tolerated. Side effects and adverse events are sometimes severe, but can be managed in most cases. The improvement of daily living activities outweighs by far the motor benefit, indicating that the use of this procedure significantly improves the patients' lifestyle.

Cognitive and behavioural effects of chronic stimulation of the subthalamic nucleus in patients with Parkinson's disease.

OBJECTIVE: To investigate cognitive and behavioural effects of bilateral lead implants for high frequency stimulation (HFS) of the subthalamic nucleus in patients with Parkinson's disease; and to discriminate between HFS and the effects of surgical intervention on cognitive function by carrying out postoperative cognitive assessments with the stimulators turned on or off. METHODS: Motor, cognitive, behavioural, and functional assessments were undertaken in 20 patients with Parkinson's disease before implantation and then at three, six, and 12 months afterwards. Nine patients were also examined 18 months after surgery. Postoperative cognitive assessments were carried out with stimulators turned off at three and 18 months, and turned on at six and 12 months. RESULTS: Cognitive assessment showed a significant postoperative decline in performance on tasks of letter verbal fluency (across all postoperative assessments, but more pronounced at three months) and episodic verbal memory (only at three months, with stimulators off). At three, six, and 12 months after surgery, there was a significant improvement in the mini-mental state examination and in a task of executive function (modified Wisconsin card sorting test). On all postoperative assessments, there was an improvement in parkinsonian motor symptoms, quality of life, and activities of daily living while off antiparkinsonian drugs. A significant postoperative decrease in depressive and anxiety symptoms was observed across all assessments. Similar results were seen in the subgroup of nine patients with an 18 month follow up. Following implantation, three patients developed transient manic symptoms and one showed persistent psychic akinesia. CONCLUSIONS: Bilateral HFS of the subthalamic nucleus is a relatively safe procedure with respect to long term cognitive and behavioural morbidity, although individual variability in postoperative cognitive and behavioural outcome invites caution. Stimulation of the subthalamic nucleus does not per se appear to impair cognitive performance in patients with Parkinson's disease and may alleviate the postoperative decline in verbal fluency.

Long-term follow up of subthalamic nucleus stimulation in Parkinson's disease.

Twenty-two patients with PD received bilateral implants for high frequency stimulation of the subthalamic nucleus. The patients were treated for more than 1 year (up to 36 months). At the last visit, the Unified Parkinson Disease Rating Scale (UPDRS) motor score without medication improved by 50.2% (p < 0.001) and the UPDRS activities of daily living score improved by 68.4% (p < 0.001). The most common long-lasting adverse events were hypophonia and dysarthria; transient events were increased sexuality and mania. The surgical procedure induced transient intraoperative psychosis in seven patients.

Chronic subthalamic nucleus stimulation reduces medication requirements in Parkinson's disease.

OBJECTIVE: To reduce antiparkinsonian medication in parkinsonian patients with bilateral high frequency subthalamic nucleus (STN) stimulation. BACKGROUND: Parkinsonian syndromes are characterized by hyperactivity of the STN. Preliminary data indicate that functional inactivation of the STN may reduce the requirement for dopaminergic therapy in PD. METHODS: Bilateral quadripolar leads were implanted stereotactically in the STN of seven patients with advanced PD (mean age, 57.4 years; mean disease duration, 15.4 years). High-frequency stimulation was applied for 24 hours a day. Following implantation, antiparkinsonian medication was reduced to the minimum possible and stimulation was gradually increased. The patients were evaluated in the practically defined "off" and "on" conditions using the Unified Parkinson's Disease Rating Scale (UPDRS) and the Schwab & England scale. The average follow-up was 16.3+/-7.6 months. A battery of neuropsychological tests was applied before and 9 months after the implant. RESULTS: Parkinsonian features improved in all patients--the greatest change seen in rigidity, then tremor, followed by bradykinesia. Compared with the presurgical condition, off-drug UPDRS motor scores improved by 41.9% on the last visit (p = 0.0002), UPDRS activities of daily living (ADL) scores improved by 52.2% (p = 0.0002), and the Schwab & England scale score improved by 213% (p = 0.0002). The levodopa-equivalent daily dose was reduced by 65%. Night sleep improved in all patients due to increased mobility at night, and in five patients insomnia was resolved. All patients gained weight after surgery and their appetite increased. The mean weight gain at the last follow-up was 13% compared with before surgery. During the last visit, the stimulation amplitude was 2.9+/-0.5 V and the total energy delivered per patient averaged 2.7+/-1.4 W x10(-6). The results of patient self-assessment scales indicated a marked improvement in five patients and a moderate improvement in the other two. The neuropsychological data showed no changes. Side effects were mild and tolerable. In all cases, a tradeoff between the optimal voltage and the severity of side effects made it possible to control parkinsonian signs effectively. The most marked side effects directly related to STN stimulation consisted of ballistic or choreic dyskinesias of the neck and the limbs elicited by contralateral STN stimulation above a given threshold voltage, which varied depending on the individual. CONCLUSIONS: Parkinsonian signs can be controlled by bilateral high-frequency STN stimulation. The procedure is well tolerated. On-state dyskinesias were greatly reduced, probably due to the reduction of total antiparkinsonian medication. Bilateral high-frequency STN stimulation compensated for drug reduction and elicited dyskinesias, which differ from those observed following dopaminergic medication. ADL improved significantly, suggesting that some motor tasks performed during everyday chores, and that are not taken into account in the UPDRS motor score, also improved.