The moderating effect of perceived punishment on the relationship between the Dark Triad and corruption

The present study aimed to investigate the moderating effect of perceived punishment on the relationship between the Dark Triad personality traits and corruption in Brazil (N = 118) and the United Kingdom (N = 130). Participants answered the Dark Triad Dirty Dozen Scale, as well as measures of corruption and perceived punishment. It was found that punishment predicts corruption in both countries. Regarding the Dark Triad traits, a relationship between Machiavellianism and corruption was identified in Brazil and the United Kingdom, although an interaction with punishment was identified only in Brazil. Moreover, psychopathy had no relationship with corruption or punishment in either country. A direct relationship was found only in Brazil on narcissism, although the interaction term was significant in both countries. In general, it was identified that perceived punishment and the dark triad traits contribute to the understanding of corruption, despite some differences in the results between Brazil and the United Kingdom.

O presente estudo tem como objetivo investigar o papel moderador da percepção de punição na relação entre Tríade Sombria da personalidade e corrupção no Brasil (N = 118) e no Reino Unido (N = 130). Participantes responderam à Escala Dark Triad Dirty Dozen, bem como a medidas de corrupção e percepção de punição. Foi encontrado que a punição prediz a corrupção em ambos os países. Em relação à Tríade Sombria, o relacionamento entre maquiavelismo e corrupção foi identificado no Brasil e no Reino Unido, embora a interação com a punição tenha sido identificada apenas no Brasil. Adicionalmente, a psicopatia não teve relação com a corrupção ou com a punição em nenhum dos países. Um efeito direto do narcisismo foi encontrado apenas no Brasil, apesar do termo de interação ter sido significativo em ambos os países. De forma geral, foi identificado que a percepção de punição e a tríade sombria contribuíram com a compreensão da corrupção, apesar de algumas diferenças nos resultados entre Brasil e Reino Unido.

El presente estudio tuvo como objetivo investigar el efecto moderador del castigo percibido sobre la relación entre los rasgos de personalidad de la tríada oscura y la corrupción en Brasil (N = 118) y en el Reino Unido (N = 130). Los participantes respondieron a la Escala de la Docena Sucia de la Triada Oscura, así como a medidas de corrupción y castigo percibido. Se encontró que el castigo predice la corrupción en ambos países. En cuanto a los rasgos de la tríada oscura, se identificó una relación entre el maquiavelismo y la corrupción en Brasil y en el Reino Unido, aunque se identificó una interacción con el castigo solo en Brasil. Además, la psicopatía no tuvo relación con la corrupción o el castigo en ninguno de los dos países. Se encontró una relación directa solo en Brasil con el narcisismo, aunque la interacción fue significativa en ambos países. En general, se identificó que el castigo percibido y los rasgos de la tríada oscura contribuyen a la comprensión de la corrupción, a pesar de algunas diferencias en los resultados entre Brasil y el Reino Unido.

Physical activity and long COVID: findings from the Prospective Study About Mental and Physical Health in Adults cohort.

OBJECTIVES: The study investigated the longitudinal association between physical activity and the risk of long COVID in patients who recovered from COVID-19 infection. STUDY DESIGN: We analyzed longitudinal data of the Prospective Study About Mental and Physical Health cohort, a prospective cohort study with adults living in Southern Brazil. METHODS: Participants responded to an online, self-administered questionnaire in June 2020 (wave 1) and June 2022 (wave 4). Only participants who self-reported a positive test for COVID-19 were included. Physical activity was assessed before (wave 1, retrospectively) and during the pandemic (wave 1). Long COVID was assessed in wave 4 and defined as any post-COVID-19 symptoms that persisted for at least 3 months after infection. RESULTS: A total of 237 participants (75.1% women; mean age [standard deviation]: 37.1 [12.3]) were included in this study. The prevalence of physical inactivity in baseline was 71.7%, whereas 76.4% were classified with long COVID in wave 4. In the multivariate analysis, physical activity during the pandemic was associated with a reduced likelihood of long COVID (prevalence ratio [PR]: 0.83; 95% confidence interval [CI]: 0.69-0.99) and a reduced duration of long COVID symptoms (odds ratio: 0.44; 95% CI: 0.26-0.75). Participants who remained physically active from before to during the pandemic were less likely to report long COVID (PR: 0.74; 95% CI: 0.58-0.95), fatigue (PR: 0.49; 95% CI: 0.32-0.76), neurological complications (PR: 0.47; 95% CI: 0.27-0.80), cough (PR: 0.40; 95% CI: 0.22-0.71), and loss of sense of smell or taste (PR: 0.43; 95% CI: 0.21-0.87) as symptom-specific long COVID. CONCLUSION: Physical activity practice was associated with reduced risk of long COVID in adults.

Depression and anxiety symptoms remained elevated after 10 months of the COVID-19 pandemic in southern Brazil: findings from the PAMPA cohort.

OBJECTIVES: This study aimed to examine the changes in depression and anxiety symptoms among Brazilian adults over 10 months of the COVID-19 pandemic. STUDY DESIGN/METHODS: The present study used data from wave 1 (June/July 2020) and wave 2 (December 2020/January 2021) of the Prospective Study About Mental and Physical Health (PAMPA) Cohort, a state-level, ambispective longitudinal study with adults from southern Brazil. The frequency of anxiety and depressive symptoms was assessed using the Hospital Anxiety and Depression Scale. Anxiety and depressive symptoms before social distancing were retrospectively assessed during wave 1. RESULTS: Most of the 674 participants were classified as non-symptomatic for depressive (85.0%) and anxiety symptoms (73.2%) before the COVID-19 pandemic. At wave 1, there were increases in symptoms of depression (7.6% [95% confidence interval [CI]: 7.2%, 8.1%]) and anxiety (9.1% [95% CI: 8.6%, 9.5%]). These decreased at wave 2 (depression: 6.9% [95% CI: 6.5%, 7.2%]; anxiety: 7.4% [95% CI: 7.1%, 7.8%]) although they were still elevated compared with pre-COVID (depression: 4.5% [95% CI: 4.2%, 4.8%]; anxiety: 5.8% [95% CI: 5.5%, 6.1%]). Adults living alone (b = 0.44 [95% CI: 0.07, 0.82]) had a faster trajectory in anxiety symptoms than their counterparts. Cohort members who were living alone (b = 0.24 [95% CI: 0.06, 0.42]) and with diagnosed chronic disease (0.32 [95% CI: 0.18, 0.46]) had a faster increase in depressive symptoms than their respective counterparts. Participants aged ≥60 years showed a slower trajectory of depressive (b = -0.46 [95% CI: -0.73, -0.18]) and anxiety (b = -0.61 [95% CI: -1.20, -0.02) symptoms. CONCLUSIONS: During 10 months of COVID-19, anxiety and depression symptoms improved but were still higher than before COVID-19.

Association between specific types of physical activity during the COVID-19 pandemic and the risk of subjective memory decline: findings from the PAMPA Cohort.

OBJECTIVES: This study aimed to identify the effects of different physical activities practised during the time period when COVID-19 social distancing measures were in place on the risk of subjective memory decline in adults. STUDY DESIGN: Retrospective cohort study. METHODS: Data from the Prospective Study about Mental and Physical Health (PAMPA), a state-level (Rio Grande do Sul, Brazil), online-based cohort study, were analysed. Respondents were asked to rate their memory before COVID-19 social distancing measures were implemented (retrospectively) and on the day that the survey was completed. Subjective memory decline was defined as a perceived worsening of memory function during COVID-19 social distancing compared with the pre-pandemic period. The types of physical activity practised before and during COVID-19 social distancing measures were assessed. RESULTS: Data from 2319 adults were included. Out-of-home endurance, muscle strengthening, combined endurance and muscle strengthening, and stretching activities reduced the risk of subjective memory decline during the pandemic. In terms of physical activities practised at home, only muscle strengthening did not protect against subjective memory decline. Participants who sustained any type of physical activity at home during the COVID-19 pandemic showed a reduced risk for subjective memory decline. CONCLUSIONS: Physical activity, regardless of the type of activity and location performed, during the time period when COVID-19 social distancing measures were in place can mitigate the effects of the pandemic on subjective memory decline.

Sharp increase in depression and anxiety among Brazilian adults during the COVID-19 pandemic: findings from the PAMPA cohort.

OBJECTIVES: We aimed to compare the prevalence of depression and anxiety symptoms before and during the pandemic and identify factors associated with aggravated mental health symptoms. STUDY DESIGN: Retrospective cohort study. METHODS: We identified the proportion of normal, mild, moderate, and severe symptoms of depression and anxiety before and during the social distancing restrictions in adults from southern Brazil. An online, self-administered questionnaire was delivered for residents within the state of Rio Grande do Sul. Depressive and anxiety symptoms were examined by the Hospital Anxiety and Depression Scale. RESULTS: Most of the participants (n = 2314) aged between 31 and 59 years (54.2%), were women (76.6%), White (90.6%) with a university degree (66.6%). Moderate-to-severe symptoms of depression and anxiety were reported in 3.9% and 4.5% of participants, respectively, before COVID-19. During the pandemic (June-July, 2020), these proportions increased to 29.1% (6.6-fold increase) and 37.8% (7.4-fold increase), respectively. Higher rates of depressive and anxiety symptoms were observed among women, those aged 18-30 years, diagnosed with chronic disease and participants who had their income negatively affected by social restrictions. Remaining active or becoming physically active during social distancing restrictions reduced the probability of aggravated mental health disorders. CONCLUSIONS: Depressive and anxiety symptoms had a 6.6- and 7.4-fold increase since the COVID-19 pandemic. Public policies such as physical activity promotion and strategies to reduce the economic strain caused by this pandemic are urgently needed to mitigate the impact of the pandemic on mental health.

[Diet and lifesyle of a cohort of primary school children]. / Abitudini alimentari e comportamentali di una coorte di bambini della scuola primaria.

INTRODUCTION: The obesity is the disease of the new millennium, because it affects about 300 million people in the world, and especially it has a high prevalence in children. Obesity is a significant risk factor for cardiovascular disease, diabetes mellitus type II, hypertension, problems of adaptation and relationship with other, lower self-esteem and depression. AIMS: The objective of our study is to identify children at risk of overweight/obesity in order to primary prevention. We have organized meetings with children, families and school's members where we discussed the results of our investigation about the importance of healthy diet and lifestyle. PATIENTS-METHODS: The study was carried out on 545 children (282F, 263M), age 6.-10 years, of two primary schools in Catanzaro, from 2008 to 2010. The valuation parameters were: gender, age, weight, height, blood pressure and waist circumference. To children were also administered a questionnaire about dietary habits and lifestyle. STATISTICAL ANALYSIS: Fisher's test. RESULTS: We had that 62% of children was normal weight, 27% overweight, 11% obese. A particularly relevant datum is that the percentage of overweight-obese boys of 8 and 9 years old was higher (56%) than that of normal weight. We found cases of hypertension only in obese children. 98% of obese, 80% of overweight and 24% of normal weight children had a high waist circumference. We did not find differences in food quality among normal weight and overweight/obese children. Instead, we found significant differences in behavior between children: 90% of obese, 64% of overweight and 53% of normal weight children passed more than 2 hours in the afternoon watching television, playing computer and video games. 70% of normal weight, 82% of overweight and 95% of obese children practiced physical activity. DISCUSSION/CONCLUSION: Our study shows a alarming fact about the increase of the obesity in children. In particular the most important problem is that this condition could predispose to cardio-metabolic, endocrine, respiratory, musculoskeletal and psychological consequence. So it is important that everybody who lives with children, especially parents and school's members, educates children to have healthy lifestyles. These attentions may slow the worryng epidemic of obesity.

Correlation between otitis media and dental malocclusion in children.

AIM: To determine the possible correlation between otitis media and dental malocclusion in children. METHODS: Fifty subjects (26 males and 24 females; mean age: 7.8 +/- 1 years) were assessed: 25 patients, with otitis media formed the study group, while 25 healthy subjects formed the control group. An otolaryngological examination and dental cast measurements were performed in order to evaluate adenoids, tonsils and dental relationships, respectively. RESULTS: A significant correlation (p<0.05) was found between otitis media and enlargement of adenoids (13 patients, 52% in the study group) and tonsils (11 patients, 44% in the study group). Furthermore, a significant predominance (p<0.05) of posterior crossbite was found in the study group (19 children, 76%), in comparison to the control group (4 children, 16%). No correlation between otitis media and overjet, overbite, Angle Class relationship, or inadequate oral habits were found. CONCLUSIONS: Posterior cross-bite and adenoids-tonsils enlargement are factors significantly associated with otitis media in children.

Intercomparison of magnetic field measurements near MV/LV transformer substations: methodological planning and results.

Within the framework of Environmental Agencies system's activities, coordinated by ISPRA (superior institute for environmental protection and research), a comparison among measurements was designed and accomplished, in order to go into depth on the matter of measurement problems and to evaluate magnetic field at power frequencies. These measurements have been taken near medium voltage /low voltage transformer substation. This project was developed with the contribution of several experts who belong to different Regional Agencies. In three of these regions, substations having specific international standard characteristics were chosen; then a measurement and data analysis protocol was arranged. Data analysis showed a good level of coherence among results obtained by different laboratories. However, a range of problems emerged, either during the protocol predisposition and definition of the data analysis procedure or during the execution of measures and data reprocessing, because of the spatial and temporal variability of magnetic field. These problems represent elements of particular interest in determining a correct measurement methodology, whose purpose is the comparison with limits of exposure, attention values and quality targets.

Modulation of beta oscillations in the subthalamic area during action observation in Parkinson's disease.

Mapping observed actions into the onlooker's motor system seems to provide the neurofunctional mechanisms for action understanding. Subthalamic nucleus (STN) local field potential (LFP) recordings in patients with movement disorders disclosed that network oscillations in the beta range are involved in conveying motor and non-motor information across the cortico-basal ganglia-thalamo-cortical loop. This evidence, together with the existence of connections between the STN and cortical areas active during observation of actions performed by other people, suggests that the STN oscillatory activity in specific frequency bands could encode not only motor information, but also information related to action observation. To test this hypothesis we directly recorded STN oscillations through electrodes for deep brain stimulation in patients with Parkinson's disease during observation of actions and of static objects. We found selective action-related oscillatory modulations in two functionally distinct beta bands: whereas low-beta oscillations (10-18 Hz) selectively desynchronized only during action-observation, high-beta oscillations (20-30 Hz) synchronized both during the observation of action and action-related objects. Low-beta modulations are therefore specific to action observation and high-beta modulations are related to the action scene. Our findings show that in the basal ganglia there are functional changes spreading to the action environment, probably presetting the motor system in relation to the motor context and suggesting that the dynamics of beta oscillations can contribute to action understanding mechanisms.

[PC use in university students]. / Indagine sull'utilizzo del videoterminale in studenti universitari.

This study was aimed at investigating features related to PC use and prevalence of musculoskeletal symptoms among university students. A cross-sectional study was carried out among 98 university students. A questionnaire was used to collect data on personal characteristics, PC use and symptoms prevalence. Mean duration of daily PC use was 8,3 (DS 1,9) hours. The prevalences of neck, hand/wrist and shoulder pain in the previous month were 76%, 69% and 56% respectively. The findings of the present study suggest the needing of specific ergonomic training in university students.

Gender-related differences in the human subthalamic area: a local field potential study.

The objective of this study was to investigate the possible existence of gender-related neurophysiological differences in the oscillatory activity of the human subthalamic area. To this end, we recorded local field potentials (LFPs) after neurosurgical procedures for deep brain stimulation (DBS) in 24 patients (12 males and 12 females) with Parkinson's disease. LFP recordings at rest before levodopa medication (19 nuclei from 11 female patients and 16 nuclei from ten male patients) showed significantly higher power in the alpha/low-beta band (8-12 Hz, P<0.01; 13-20 Hz, P=0.03) in females than in males. After levodopa medication (ten nuclei from six female patients and 11 nuclei from seven male patients), the power in the high-gamma band (60-90 Hz) and of the 300 Hz rhythm was significantly higher in females than in males (high-gamma, P=0.007; 300 Hz, P=0.002). These findings show that functional gender-related differences in the central nervous system involve the human subthalamic area (STN) and its response to levodopa in Parkinson's disease. Gender-related neurophysiological differences may be important for understanding gender-specific features of neurodegenerative disorders and should be considered when interpreting LFP data from the human basal ganglia.

Subthalamic oscillatory activities at beta or higher frequency do not change after high-frequency DBS in Parkinson's disease.

This study aimed to assess whether changes in the patterns of local field potential (LFP) oscillations of the subthalamic nucleus (STN) underlie to the clinical improvement within 60 s after turning off subthalamic DBS. We studied by spectral analysis the STN LFPs recorded in 13 nuclei from 7 patients with Parkinson's disease before and immediately after unilateral high-frequency (130 Hz) stimulation of the same nucleus, when the clinical benefit of DBS was unchanged. The results were compared with LFP data previously reported [A. Priori, G. Foffani, A. Pesenti, F. Tamma, A.M. Bianchi, M. Pellegrini et al., Rhythm-specific pharmacological modulation of subthalamic activity in Parkinson's disease. Exp. Neurol. 189 (2004) 369-379]--namely 13 STN from 9 parkinsonian patients recorded before and after levodopa administration--which were used as a control. Before DBS, in the 'off' clinical state after overnight withdrawal of dopaminergic therapy, the STN spectrum did not significantly differ from the control nuclei, showing prominent activity at beta frequencies (13-20 and 20-35 Hz). After DBS (10-15 min) of the STN, the recorded nuclei significantly differed from the control, failing to show significant changes either in the beta bands or at higher frequencies (60-90 and 250-350 Hz). The patterns of subthalamic LFP oscillations after DBS therefore differ from those after dopaminergic medication. These results suggest (1) that subthalamic LFP modulations are not the epiphenomenon of peripheral motor improvement and (2) that the transitory clinical efficacy maintained after discontinuation of subthalamic DBS is not associated with local modulation of LFP activity at beta or higher frequencies within the STN.

Physiological recordings from electrodes implanted in the basal ganglia for deep brain stimulation in Parkinson's disease. the relevance of fast subthalamic rhythms.

Deep brain stimulation electrodes implanted in the subthalamic nucleus of patients with Parkinson's disease allow electrophysiological recordings from the human basal ganglia. Subthalamic local field potential recordings revealed the presence of multiple rhythms, from the classical EEG frequency range (<50 Hz), to surprisingly high frequencies (70 Hz and 300 Hz). Fast rhythms are particularly attractive because of their likely interaction with the excitatory mechanisms of action of deep brain stimulation. Here we investigated whether the two rhythms at 70 Hz and at 300 Hz represent distinct modes of operation, and therefore different targets, within the subthalamic nucleus. We retrospectively analyzed the dataset we used to describe the 300 Hz rhythm (Foffani, Priori et al., Brain 126: 2153-2163, 2003) searching for significant 70 Hz oscillations after levodopa administration. Whereas (as previously reported) 300 Hz activity was a consistent feature in the dataset, significant 70 Hz activity was observed in only 2 of 11 nuclei. Therefore, 70 Hz oscillations are not a necessary condition for the presence of 300 Hz oscillations. The two rhythms probably arise from different mechanisms, reflecting different functional and/or spatial aspects of subthalamic pathophysiology. Fast subthalamic oscillations could be exploited for intra-operative electrophysiological monitoring of the subthalamic nucleus, post-operative confirmation of electrode placement and patient-specific 'reglage' of the electrical parameters for chronic deep brain stimulation.

Altered subthalamo-pallidal synchronisation in parkinsonian dyskinesias.

The aim of this work was to study the role of subthalamo-pallidal synchronisation in the pathophysiology of dyskinesias. We recorded local field potentials (LFPs) in a patient with Parkinson's disease and left surgery induced dyskinesias with double, bilateral deep brain stimulation electrode implants in the subthalamic nucleus (STN) and the globus pallidus internus (GPi). Synchronisation was studied through coherence analysis. In the nuclei contralateral to the dyskinetic side of the body there was decreased STN-GPi coherence in the high beta range (20-30 Hz) and an enhanced coherence at low frequencies (<10 Hz). Despite the possible limitations arising from single-case observations, our findings suggest that parkinsonian dyskinesias are related to altered synchronisation between different structures of the basal ganglia. Firing abnormalities within individual basal ganglia nuclei are probably not enough to account for the complex balance between hypokinetic and hyperkinetic symptoms in human parkinsonian dyskinesias and altered interactions between nuclei should also be considered.

Long term effects of bilateral subthalamic nucleus stimulation on cognitive function, mood, and behaviour in Parkinson's disease.

BACKGROUND: Long term effects of subthalamic nucleus (STN) stimulation on cognition, mood, and behaviour are unknown. OBJECTIVE: This study evaluated the cognitive, mood, and behavioural effects of bilateral subthalamic nucleus deep brain stimulation (STN DBS) in patients with Parkinson's disease (PD) followed up for three years. METHODS: A consecutive series of 77 PD patients was assessed before, one, and three years after surgery. Mean (SD) age at surgery was 55 (8). Seven patients died or were lost for follow up. Neuropsychological assessment included a global cognitive scale, memory, and frontal tests. Depression was evaluated using the Beck depression inventory. Assessment of thought disorders and apathy was based on the unified Parkinson's disease rating scale. Reports of the behavioural changes are mainly based on interviews done by the same neuropsychologist at each follow up. RESULTS: Only two cognitive variables worsened (category fluency, total score of fluency). Age was a predictor of decline in executive functions. Depression improved whereas apathy and thought disorders worsened. Major behavioural changes were two transient aggressive impulsive episodes, one suicide, four suicide attempts, one permanent apathy, one transient severe depression, four psychoses (one permanent), and five hypomania (one permanent). CONCLUSIONS: Comparing baseline, one year, and three year postoperative assessments, STN stimulation did not lead to global cognitive deterioration. Apathy scores mildly increased. Depression scores mildly improved. Behavioural changes were comparatively rare and mostly transient. Single case reports show the major synergistic effects of both medication and stimulation on mood and behaviour, illustrating the importance of a correct postoperative management.

The subthalamic nucleus in Parkinson's disease: power spectral density analysis of neural intraoperative signals.

To test a new tool for the neurophysiological identification of the human subthalamic nucleus (STN) during stereotactic surgery for the implantation of deep-brain-stimulation (DBS) electrodes, we analysed off-line the intraoperative signals recorded from patients with Parkinson's disease. We estimated the power spectral density (PSD) along each penetration track (8 patients, 13 sides) and determined the spatial correlation of the PSD with the target location estimated from neuroimaging procedures ("anatomical target"), and with the final target location derived from standard intraoperative neurophysiological procedures for STN localization ("clinical target"). At each step we recorded the 'on-line' signal for 120 seconds; because the PSD was estimated by calculating the periodogram for 6-second epochs of neural signal, we had 20 epochs at each step. When the electrode track crossed the STN, the PSD in the 0.25-2.5 kHz band increased, peaking on average <0.5 mm cranial to the clinical target and 1.00+/-1.51 mm caudal to the anatomical target. When the track was outside the nucleus, the PSD remained unchanged. Even on recordings with low signal-to-noise ratio, off-line PSD analysis of neural signals showed a good correspondence with the target indicated by the surgical team. On-line intraoperative estimation of the PSD may be a simple, reliable, rapid and complementary approach to electrophysiological monitoring during STN surgery for Parkinson's disease.

Multiple sequential image-fusion and direct MRI localisation of the subthalamic nucleus for deep brain stimulation.

AIM: Deep brain stimulation (DBS) is the treatment of choice for advanced Parkinson's disease. The target co-ordinates are traditionally calculated in relation to the intercommissural distance. Anterior (AC) and posterior commissures (PC) may be visualised by the means of ventriculography, CT or MRI. METHODS: We have studied the efficacy of direct visualisation of the subthalamic-red nucleus complex on MRI, the advantage of fusion of stereotactic CT and MR images (Multiple Sequences Image Fusion - MuSIF). These methods are combined with double check of indirect calculation of the target co-ordinates based on AC-PC line, as well as the corrispondence to the stereotactic electronic atlas. RESULTS: Subthalamic nucleus (STN) was well recognisable in fused images in all 22 sides. At 3 months from surgery it was possible to reduce 76% of L-dopa equivalent daily dose. Dyskine-sias reduced to 50% and motor fluctuation up to 45%. CONCLUSION: In our experience MuSIF offers very high rate of accuracy in calculation of target co-ordinates. Direct visualisation of STN in MR and MuSIF are reliable and facilitate the accuracy of identification of target co-ordinates. Intraoperative neurophysiological recording increases the accuracy of microelectrode position.

Do intraoperative microrecordings improve subthalamic nucleus targeting in stereotactic neurosurgery for Parkinson's disease?

AIM: The clinical importance of intraoperative microrecordings for subthalamic nucleus (STN) localization in neurosurgical practice remains a matter of debate in the various groups. METHODS: To investigate their usefulness in localizing the STN, we retrospectively evaluated how intraoperative microelectrode recordings changed the targeting of the STN estimated only on intraoperative stimulation and neuroanatomic targeting procedures. For neuroradiologic targeting of the nucleus we used a TC-MRI fusion algorithm and direct visualization of the STN. Besides standard microrecordings we also analyzed the power spectral density (PSD) pattern of physiological signals along the track and its neuroanatomic and clinical correlations. RESULTS: In our series of 12 patients with Parkinson's disease undergoing surgery for implantation of deep-brain stimulation (DBS) electrodes in the STN we found that in 25% (1/4) of patients, microrecordings determined the choice of the optimal track. In all the tracks analyzed the PSD peak coincided with the point selected for the final electrode implantation on the basis of the standard procedure for intraoperative monitoring based on both microstimulation and recordings. CONCLUSION: Intraoperative microrecordings are of determinant importance for accurate STN localization and are essential for optimal results in neurosurgical practice. PSD analysis is a simple and quick quantitative signal descriptor that will probably provide even more precise, simple and rapid tool for intraoperative neurophysiological localization of the STN.

300-Hz subthalamic oscillations in Parkinson's disease.

Despite several studies and models, much remains unclear about how the human basal ganglia operate. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for complicated Parkinson's disease, but how DBS acts also remains unknown. The clinical benefit of DBS at frequencies >100 Hz suggests the possible importance of neural rhythms operating at frequencies higher than the range normally considered for basal ganglia processing (<100 Hz). The electrodes implanted for DBS also offer the opportunity to record neural activity from the human basal ganglia. This study aimed to assess whether oscillations at frequencies >100 Hz operate in the human STN. While recording local field potentials from the STN of nine patients with Parkinson's disease through DBS electrodes, we found a dopamine- and movement-dependent 300-Hz rhythm. At rest, and in the absence of dopaminergic medication, in most cases (eight out of 11 nuclei) the 100-1000 Hz band showed no consistent rhythm. Levodopa administration elicited (or markedly increased) a 300-Hz rhythm at rest [(mean +/- SD) central frequency: 319 +/- 33 Hz; bandwidth: 72 +/- 21 Hz; power increase (after medication - before medication)/before medication: 1.30 +/- 1.25; n = 11, P = 0.00098]. The 300-Hz rhythm was also increased by apomorphine, but not by orphenadrine. The 300-Hz rhythm was modulated by voluntary movement. Before levodopa administration, movement-related power increase in the 300-Hz rhythm was variably present in different subjects, whereas after levodopa it became a robust phenomenon [before 0.014 +/- 0.014 arbitrary units (AU), after 0.178 +/- 0.339 AU; n = 8, P = 0.0078]. The dopamine-dependent 300-Hz rhythm probably reflects a bistable compound nuclear activity and supports high-resolution information processing in the basal ganglia circuit. An absent 300-Hz subthalamic rhythm could be a pathophysiological clue in Parkinson's disease. The 300-Hz rhythm also provides the rationale for an excitatory--and not only inhibitory--interpretation of DBS mechanism of action in humans.