Exploring clinical outcomes in patients with idiopathic/inherited isolated generalized dystonia and stimulation of the subthalamic region.

BACKGROUND: Deep Brain Stimulation (DBS) is an established treatment option for refractory dystonia, but the improvement among the patients is variable. OBJECTIVE: To describe the outcomes of DBS of the subthalamic region (STN) in dystonic patients and to determine whether the volume of tissue activated (VTA) inside the STN or the structural connectivity between the area stimulated and different regions of the brain are associated with dystonia improvement. METHODS: The response to DBS was measured by the Burke-Fahn-Marsden Dystonia Rating Scale (BFM) before and 7 months after surgery in patients with generalized isolated dystonia of inherited/idiopathic etiology. The sum of the two overlapping STN volumes from both hemispheres was correlated with the change in BFM scores to assess whether the area stimulated inside the STN affects the clinical outcome. Structural connectivity estimates between the VTA (of each patient) and different brain regions were computed using a normative connectome taken from healthy subjects. RESULTS: Five patients were included. The baseline BFM motor and disability subscores were 78.30 ± 13.55 (62.00-98.00) and 20.60 ± 7.80 (13.00-32.00), respectively. Patients improved dystonic symptoms, though differently. No relationships were found between the VTA inside the STN and the BFM improvement after surgery (p = 0.463). However, the connectivity between the VTA and the cerebellum structurally correlated with dystonia improvement (p = 0.003). CONCLUSIONS: These data suggest that the volume of the stimulated STN does not explain the variance in outcomes in dystonia. Still, the connectivity pattern between the region stimulated and the cerebellum is linked to outcomes of patients.

ANTECEDENTES: A estimulação cerebral profunda (ECP) é um tratamento estabelecido para distonias refratárias. Porém, a melhora dos pacientes é variável. OBJETIVO: O objetivo do estudo foi descrever os desfechos da ECP da região do núcleo subtalâmico (NST) e determinar se o volume de tecido ativado (VTA) dentro do NST ou se a conectividade estrutural entre a área estimulada e diferentes regiões cerebrais estão associadas a melhora da distonia. MéTODOS: A resposta da ECP em pacientes com distonia generalizada isolada de etiologia hereditária/idiopática foi mensurada pela escala de Burke-Fahr-Marsden Dystonia Rating Scale (BFM) antes e 7 meses após a cirurgia. A soma dos volumes do NST nos dois hemisférios foi correlacionada com a melhora nos escores do BFM para avaliar se a área estimulada dentro do NST afeta o desfecho clínico. A conectividade estrutural estimada entre o VTA de cada paciente e as diferentes regiões cerebrais foram computadas usando um conectoma normativo retirado de indivíduos saudáveis. RESULTADOS: Cinco pacientes com idade de 40,00 ± 7,30 anos foram incluídos. O BFM motor e de incapacidade basal eram de 78,30 ± 13,55 (62,00­98,00) e 20,60 ± 7,80 (13,00­32,00), respectivamente. Os pacientes melhoraram com a cirurgia, mas com variabilidade. Não houve relação entre o VTA dentro do NST e a melhora do BFM após a cirurgia (p = 0.463). Entretanto, a conectividade estrutural entre o VTA e o cerebelo correlacionaram com a melhora da distonia (p = 0.003). CONCLUSãO: Os dados sugerem que o VTA dentro do NST não explica a variabilidade do desfecho clínico na distonia. Porém, o padrão de conectividade entre a região estimulada e o cerebelo foi relacionada com o desfecho dos pacientes.

Exploring clinical outcomes in patients with idiopathic/inherited isolated generalized dystonia and stimulation of the subthalamic region / Explorando os desfechos clínicos em pacientes com distonia idiopática/hereditária generalizada isolada submetidos a estimulação da região subtalâmica

Abstract Background Deep Brain Stimulation (DBS) is an established treatment option for refractory dystonia, but the improvement among the patients is variable. Objective To describe the outcomes of DBS of the subthalamic region (STN) in dystonic patients and to determine whether the volume of tissue activated (VTA) inside the STN or the structural connectivity between the area stimulated and different regions of the brain are associated with dystonia improvement. Methods The response to DBS was measured by the Burke-Fahn-Marsden Dystonia Rating Scale (BFM) before and 7 months after surgery in patients with generalized isolated dystonia of inherited/idiopathic etiology. The sum of the two overlapping STN volumes from both hemispheres was correlated with the change in BFM scores to assess whether the area stimulated inside the STN affects the clinical outcome. Structural connectivity estimates between the VTA (of each patient) and different brain regions were computed using a normative connectome taken from healthy subjects. Results Five patients were included. The baseline BFM motor and disability subscores were 78.30 ± 13.55 (62.00-98.00) and 20.60 ± 7.80 (13.00-32.00), respectively. Patients improved dystonic symptoms, though differently. No relationships were found between the VTA inside the STN and the BFM improvement after surgery (p = 0.463). However, the connectivity between the VTA and the cerebellum structurally correlated with dystonia improvement (p = 0.003). Conclusions These data suggest that the volume of the stimulated STN does not explain the variance in outcomes in dystonia. Still, the connectivity pattern between the region stimulated and the cerebellum is linked to outcomes of patients.

Resumo Antecedentes A estimulação cerebral profunda (ECP) é um tratamento estabelecido para distonias refratárias. Porém, a melhora dos pacientes é variável. Objetivo O objetivo do estudo foi descrever os desfechos da ECP da região do núcleo subtalâmico (NST) e determinar se o volume de tecido ativado (VTA) dentro do NST ou se a conectividade estrutural entre a área estimulada e diferentes regiões cerebrais estão associadas a melhora da distonia. Métodos A resposta da ECP em pacientes com distonia generalizada isolada de etiologia hereditária/idiopática foi mensurada pela escala de Burke-Fahr-Marsden Dystonia Rating Scale (BFM) antes e 7 meses após a cirurgia. A soma dos volumes do NST nos dois hemisférios foi correlacionada com a melhora nos escores do BFM para avaliar se a área estimulada dentro do NST afeta o desfecho clínico. A conectividade estrutural estimada entre o VTA de cada paciente e as diferentes regiões cerebrais foram computadas usando um conectoma normativo retirado de indivíduos saudáveis. Resultados Cinco pacientes com idade de 40,00 ± 7,30 anos foram incluídos. O BFM motor e de incapacidade basal eram de 78,30 ± 13,55 (62,00-98,00) e 20,60 ± 7,80 (13,00-32,00), respectivamente. Os pacientes melhoraram com a cirurgia, mas com variabilidade. Não houve relação entre o VTA dentro do NST e a melhora do BFM após a cirurgia (p = 0.463). Entretanto, a conectividade estrutural entre o VTA e o cerebelo correlacionaram com a melhora da distonia (p = 0.003). Conclusão Os dados sugerem que o VTA dentro do NST não explica a variabilidade do desfecho clínico na distonia. Porém, o padrão de conectividade entre a região estimulada e o cerebelo foi relacionada com o desfecho dos pacientes.

Subthalamic low beta bursts differ in Parkinson's disease phenotypes.

OBJECTIVE: Parkinson's disease (PD) patients may be categorized into tremor-dominant (TD) and postural-instability and gait disorder (PIGD) motor phenotypes, but the dynamical aspects of subthalamic nucleus local field potentials (STN-LFP) and the neural correlates of this phenotypical classification remain unclear. METHODS: 35 STN-LFP (20 PIGD and 15 TD) were investigated through continuous wavelet transform and machine-learning-based methods. The beta oscillation - the main band associated with motor impairment in PD - dynamics was characterized through beta burst parameters across phenotypes and burst intervals under specific proposed criteria for optimal burst threshold definition. RESULTS: Low-frequency (13-22 Hz) beta burst probability was the best predictor for PD phenotypes (75% accuracy). PIGD patients presented higher average burst duration (p = 0.018), while TD patients exhibited higher burst probability (p = 0.014). Categorization into shorter and longer than 400 ms bursts led to significant interaction between burst length categories and the phenotypes (p < 0.050) as revealed by mixed-effects models. Long burst durations and short bursts probability positively correlated, respectively, with rigidity-bradykinesia (p = 0.029) and tremor (p = 0.038) scores. CONCLUSIONS: Subthalamic low-frequency beta bursts differed between TD and PIGD phenotypes and correlated with motor symptoms. SIGNIFICANCE: These findings improve the PD phenotypes' electrophysiological characterization and may define new criteria for adaptive deep brain stimulation.

Should the Globus Pallidus Targeting Be Refined in Dystonia?

BACKGROUND AND STUDY AIMS: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is a highly effective therapy for primary generalized and focal dystonias, but therapeutic success is compromised by a nonresponder rate of up to 20%. Variability in electrode placement and in tissue stimulated inside the GPi may explain in part different outcomes among patients. Refinement of the target within the pallidal area could be helpful for surgery planning and clinical outcomes. The objective of this study was to discuss current and potential methodological (somatotopy, neuroimaging, and neurophysiology) aspects that might assist neurosurgical targeting of the GPi, aiming to treat generalized or focal dystonia. METHODS: We selected published studies by searching electronic databases and scanning the reference lists for articles that examined the anatomical and electrophysiologic aspects of the GPi in patients with idiopathic/inherited dystonia who underwent functional neurosurgical procedures. RESULTS: The sensorimotor sector of the GPi was the best target to treat dystonic symptoms, and was localized at its lateral posteroventral portion. The effective volume of tissue activated (VTA) to treat dystonia had a mean volume of 153 mm3 in the posterior GPi area. Initial tractography studies evaluated the close relation between the electrode localization and pallidothalamic tract to control dystonic symptoms.Regarding the somatotopy, the more ventral, lateral, and posterior areas of the GPi are associated with orofacial and cervical representation. In contrast, the more dorsal, medial, and anterior areas are associated with the lower limbs; between those areas, there is the representation of the upper limb. Excessive pallidal synchronization has a peak at the theta band of 3 to 8 Hz, which might be responsible for generating dystonic symptoms. CONCLUSIONS: Somatotopy assessment of posteroventral GPi contributes to target-specific GPi sectors related to segmental body symptoms. Tractography delineates GPi output pathways that might guide electrode implants, and electrophysiology might assist in pointing out areas of excessive theta synchronization. Finally, the identification of oscillatory electrophysiologic features that correlate with symptoms might enable closed-loop approaches in the future.

Neurocircuitry of Deep Brain Stimulation for Obsessive-Compulsive Disorder as Revealed by Tractography: A Systematic Review.

Objective: Deep brain stimulation (DBS) was proposed in 1999 to treat refractory obsessive-compulsive disorder (OCD). Despite the accumulated experience over more than two decades, 30-40% of patients fail to respond to this procedure. One potential reason to explain why some patients do not improve in the postoperative period is that DBS might not have engaged structural therapeutic networks that are crucial to a favorable outcome in non-responders. This article reviews magnetic resonance imaging diffusion studies (DTI-MRI), analyzing neural networks likely modulated by DBS in OCD patients and their corresponding clinical outcome. Methods: We used a systematic review process to search for studies published from 2005 to 2020 in six electronic databases. Search terms included obsessive-compulsive disorder, deep brain stimulation, diffusion-weighted imaging, diffusion tensor imaging, diffusion tractography, tractography, connectome, diffusion analyses, and white matter. No restriction was made concerning the surgical target, DTI-MRI technique and the method of data processing. Results: Eight studies published in the last 15 years were fully assessed. Most of them used 3 Tesla DTI-MRI, and different methods of data acquisition and processing. There was no consensus on potential structures and networks underlying DBS effects. Most studies stimulated the ventral anterior limb of the internal capsule (ALIC)/nucleus accumbens. However, the contribution of different white matter pathways that run through the ALIC for the effects of DBS remains elusive. Moreover, the improvement of cognitive and affective symptoms in OCD patients probably relies on electric modulation of distinct networks. Conclusion: Though, tractography is a valuable tool to understand neural circuits, the effects of modulating different fiber tracts in OCD are still unclear. Future advances on image acquisition and data processing and a larger number of studies are still required for the understanding of the role of tractography-based targeting and to clarify the importance of different tracts for the mechanisms of DBS.

Fields of Forel Brain Stimulation Improves Levodopa-Unresponsive Gait and Balance Disorders in Parkinson's Disease.

BACKGROUND: Gait and balance disturbance are challenging symptoms in advanced Parkinson's disease (PD). Anatomic and clinical data suggest that the fields of Forel may be a potential surgical target to treat these symptoms. OBJECTIVE: To test whether bilateral stimulation centered at the fields of Forel improves levodopa unresponsive freezing of gait (FOG), balance problems, postural instability, and falls in PD. METHODS: A total of 13 patients with levodopa-unresponsive gait disturbance (Hoehn and Yahr stage ≥3) were included. Patients were evaluated before (on-medication condition) and 1 yr after surgery (on-medication-on-stimulation condition). Motor symptoms and quality of life were assessed with the Unified Parkinson's Disease Rating scale (UPDRS III) and Quality of Life scale (PDQ-39). Clinical and instrumented analyses assessed gait, balance, postural instability, and falls. RESULTS: Surgery improved balance by 43% (95% confidence interval [CI]: 21.2-36.4 to 35.2-47.1; P = .0012), reduced FOG by 35% (95% CI: 15.1-20.3 to 8.1-15.3; P = .0021), and the monthly number of falls by 82.2% (95% CI: 2.2-6.9 to -0.2-1.7; P = .0039). Anticipatory postural adjustments, velocity to turn, and postural sway measurements also improved 1 yr after deep brain stimulation (DBS). UPDRS III motor scores were reduced by 27.2% postoperatively (95% CI: 42.6-54.3 to 30.2-40.5; P < .0001). Quality of life improved 27.5% (95% CI: 34.6-48.8 to 22.4-37.9; P = .0100). CONCLUSION: Our results suggest that DBS of the fields of Forel improved motor symptoms in PD, as well as the FOG, falls, balance, postural instability, and quality of life.

Subthalamic Nucleus Deep Brain Stimulation Lessens Acquired Dystonia: Report of Two Patients and Systematic Review of Published Cases.

INTRODUCTION: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an efficient treatment of primary dystonia. Few studies have reported the effect of STN-DBS on secondary or acquired dystonia. METHODS: We reported 2 patients with acquired dystonia treated by subthalamic DBS and followed up for 24 months, besides providing a systematic review and meta-analysis of published series. RESULTS/CONCLUSIONS: Both patients had thalamic vascular or autoimmune lesions within the ventral and the pulvinar nuclei. A reduction of 67.2% on the Burke-Fahn-Marsden Dystonia Rating Scale and 90% improvement in disability scores were shown in the first patient, while the second patient showed a lower reduction in both dystonia symptoms (28.6%) and disability scores (44%). Both patients had a significant mean improvement in the quality of life (62.5% in the first and 57.9% in the second) and were free of drugs postoperatively. A systematic review showed a mean follow-up of 13 months in 19 patients, including our 2 patients. The review showed a significant Burke-Fahn-Marsden Dystonia Scale (BFMDRS) score median reduction of 19 points (52.4%; confidence interval [CI]: 11.0-25.0) and a significant median reduction of 6 points in disability scores (44.5%; 95% CI: 4.0-14.0), thereby improving quality of life. Age at surgery was inversely correlated with postoperative improvement (r = 0.63; p = 0.039). Hemidystonia had a nonsignificant better improvement than generalized dystonia (55.3 vs. 43.5%; p = 0.4433). No association between etiology and postoperative improvement and no serious complications were found. Although few data reported so far, subthalamic DBS is likely efficient for acquired dystonia.

Spectral characteristics of subthalamic nucleus local field potentials in Parkinson's disease: Phenotype and movement matter.

Parkinson's disease (PD) is clinically heterogeneous across patients and may be classified in three motor phenotypes: tremor dominant (TD), postural instability and gait disorder (PIGD), and undetermined. Despite the significant clinical characterization of motor phenotypes, little is known about how electrophysiological data, particularly subthalamic nucleus local field potentials (STN-LFP), differ between TD and PIGD patients. This is relevant since increased STN-LFP bandpower at α-ß range (8-35 Hz) is considered a potential PD biomarker and, therefore, a critical setpoint to drive adaptive deep brain stimulation. Acknowledging STN-LFP differences between phenotypes, mainly in rest and movement states, would better fit DBS to clinical and motor demands. We studied this issue through spectral analyses on 35 STN-LFP in TD and PIGD patients during rest and movement. We demonstrated that higher ß2 activity (22-35 Hz) was observed in PIGD only during rest. Additionally, bandpower differences between rest and movement occurred at the α-ß range, but with different patterns as per phenotypes: movement-induced desynchronization concerned lower frequencies in TD (10-20 Hz) and higher frequencies in PIGD patients (21-28 Hz). Finally, when supervised learning algorithms were employed aiming to discriminate PD phenotypes based on STN-LFP bandpower features, movement information had improved the classification accuracy, achieving peak performances when TD and PIGD movement-induced desynchronization ranges were considered. These results suggest that STN-LFP ß-band encodes phenotype-movement dependent information in PD patients.

Stereotactic Lesion in the Forel's Field H: A 2-Years Prospective Open-Label Study on Motor and Nonmotor Symptoms, Neuropsychological Functions, and Quality of Life in Parkinson Disease.

BACKGROUND: Stereotactic lesion in the Forel's field H (campotomy) was proposed in 1963 to treat Parkinson disease (PD) symptoms. Despite its rationale, very few data on this approach have emerged. Additionally, no study has assessed its effects on nonmotor symptoms, neuropsychological functions and quality of life. OBJECTIVE: To provide a prospective 2-yr assessment of motor, nonmotor, neuropsychological and quality of life variables after unilateral campotomy. METHODS: Twelve PD patients were prospectively evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS), the Dyskinesia Rating Scale and the Parkinson's disease quality of life questionnaire (PDQ39) before campotomy, and after 6 and 24 mo. Nonmotor, neuropsychiatric, neuropsychological and quality of life variables were assessed. The impact of PD on global health was also rated. RESULTS: A significant reduction in contralateral rest tremor (65.7%, P < .001), rigidity (87.8%, P < .001), bradykinesia (68%, P < .001) and axial symptoms (24.2%, P < .05) in offmedication condition led to a 43.9% reduction in UPSDRS III scores 2 yr after campotomy (P < .001). Gait improved by 31.9% (P < .05) and walking time to cover 7 m was reduced by 43.2% (P < .05). Pain decreased by 33.4% (P < .01), while neuropsychiatric and neuropsychological functions did not change. Quality of life improved by 37.8% (P < .05), in line with a 46.7% reduction of disease impact on global health (P < .001). CONCLUSION: A significant 2-yr improvement of motor symptoms, gait performance and pain was obtained after unilateral campotomy without significant changes to cognition. Quality of life markedly improved in parallel with a significant reduction of PD burden on global health.

Targeting the hot spot in a patient with essential tremor and Parkinson's disease: Tractography matters.

INTRODUCTION: Thalamic ventralis intermedius deep brain stimulation (VIM-DBS) is generally effective in treating refractory tremor in Parkinson's disease (PD) and in essential tremor (ET), but some patients do not respond well due to side effects or from loss of the effect of stimulation over time. The caudal zona incerta (ZI) has emerged as a promising target in ET, and the effects of ZI-DBS on PD tremor are less studied. Here, we describe a rare situation in which both ET and PD coexist in a 72-year-old male referred for ZI-DBS due to refractory tremor. The aim of this study was to evaluate whether there was a difference in the area stimulated to improve each type of tremor and whether tractography could improve and predict motor outcome. METHODS: Two months after the surgery, in order to define which of the cathodes was the most effective towards improving the tremor and parkinsonian symptoms, a double-blinded, monopolar evaluation was conducted on both hemispheres separately. Once the best contact and parameters were defined, the volume of tissue activation (VTA) was represented spatially for each type of tremor and, finally, the image model was fused with the tractography. RESULTS: For both types of tremor, the hot spot stimulated region achieved the dentato-rubro-thalamic tract (DRTT) at the higher fiber density region. The DRTT fibers were asymmetrical between the right and left hemispheres. CONCLUSION: Regardless of the type of tremor, DRTT can be the most effective region for stimulation. Tractography should be considered when planning the surgical target since the DRTT is not always symmetrical, and the reconstruction of the VTA together with the tractography can greatly improve the DBS programming, and, probably, the patient's outcome to the stimulation.

Validation of the National Institute of Neurological Disorders and Stroke Criteria for Psychosis in Parkinson Disease.

OBJECTIVES: Parkinson disease (PD) psychosis is a condition associated with several negative outcomes. Despite its impact, there is a lack of validated diagnostic tools for this condition. In this study, we aim to verify the validity of the proposed NINDS criteria for PD psychosis and explore its possible applications in clinical practice. DESIGN, SETTINGS, PARTICIPANTS: We prospectively selected 104 subjects with idiopathic PD referred to a movement disorder clinic for a cross-sectional evaluation. MEASUREMENTS: A neurological evaluation confirmed idiopathic PD and classified PD psychosis according to the NINDS criteria. A psychiatrist then classified the subject according to DSM-IV-TR criteria for psychosis, considered the reference standard. We used Cohen's kappa (κ) to quantify reliability between methods. Finally, we designed models assigning a weighted score to each characteristic psychotic symptom from the NINDS criteria (criterion A), and plotted receiver operating curves for each model. RESULTS: Of the total sample, 52 (50%) met proposed criteria for NINDS PD psychosis and 16 (15.6%) met reference standard criteria. Inter-rater reliability showed only a fair agreement (κ = 0.30). By using a scoring approach for each NINDS criteria item and a cutoff total score for the diagnosis of PD psychosis, we significantly increased the agreement for diagnosis reliability (κ = 0.72), with sensitivity of 94% and specificity of 91%. CONCLUSIONS: Although the NINDS criteria had limited reliability for diagnosing PD psychosis, a scoring approach for symptoms showed good reliability, with sensitivity and specificity above 90%. This scoring approach may be an accurate tool for identifying patients with PD psychosis.

Lexical-retrieval and semantic memory in Parkinson's disease: The question of noun and verb dissociation.

The dissociation between the processing of verbs and nouns has been debated in light of the Embodied Cognition Theory (EC). The objective of this paper is to verify how action and verb processing deficits of PD patients are modulated by different tasks with different cognitive demands. Action and object lexical-semantic processing was evaluated in patients with Parkinson's Disease (PD) and cognitively healthy controls through three different tasks (verbal fluency, naming and semantic association). Compared to controls, PD patients presented worse performance in naming actions and in the two semantic association tasks (action/object). Action verbal fluency performance was significantly associated with PD severity whereas object semantic association deficits and noun verbal fluency scores were associated to lower scores in measures of global cognitive functioning. Our data suggest that semantic deficits are related to the type of cognitive processing and this is in the line with more flexible EC accounts.

Clinical Implications of the National Institute of Neurological Disorders and Stroke Criteria for Diagnosing Psychosis in Parkinson's Disease.

The effect of psychotic symptoms in Parkinson's disease (PD) is variable among patients, and different methods to assess psychosis may yield conflicting results. A sample of 102 patients with a diagnosis of idiopathic PD underwent neurological, psychiatric, and neuropsychological assessment. Participants were divided into three groups: those who met DSM criteria for psychotic disorder, those who had psychotic symptoms but did not meet DSM criteria, and those without any psychotic symptoms. The first group had significantly worse sleep and worse cognitive and psychopathological symptoms compared with the other two groups. Results suggested that patients meeting DSM criteria for psychotic disorder comprise a separate clinical category.

Evoked potentials to nociceptive stimuli delivered by CO2 or Nd:YAP lasers.

OBJECTIVE: This study compares the amplitude, latency, morphology, scalp topography and intracranial generators of laser-evoked potentials (LEPs) to CO(2) and Nd:YAP laser stimuli. METHODS: LEPs were assessed in 11 healthy subjects (6 men, mean age 39+/-10 years) using a 32-channel acquisition system. Laser stimuli were delivered on the dorsum of both hands (intensity slightly above pain threshold), and permitted to obtain lateralised (N1) and vertex components (N2-P2) with similar scalp distribution for both types of lasers. RESULTS: The N1-YAP had similar latencies but significantly higher amplitudes relative to N1-CO(2). The N2-P2 complex showed earlier latencies, higher amplitudes (N2) and more synchronised responses when using Nd:YAP stimulation. The distribution of intracranial generators assessed with source localization analyses (sLORETA) was similar for Nd:YAP and CO(2) lasers. The insular, opercular, and primary sensorimotor cortices were active during the N1 time-window, whereas the anterior midcingulate, supplementary motor areas and mid-anterior insulae were active concomitant to the N2-P2 complex. CONCLUSIONS: Earlier latencies and larger amplitudes recorded when using Nd:YAP pulses suggest a more synchronized nociceptive afferent volley with this type of laser. SIGNIFICANCE: This, together with its handy utilization due to optic fibre transmission, may favour the use of Nd:YAP lasers in clinical settings.

Pain influences hedonic assessment of visual inputs.

It is acknowledged that the emotional state created by visual inputs can modulate the way we feel pain; however, little is known about how acute pain influences the emotional assessment of what we see. In this study healthy subjects scored affective images while receiving painful or innocuous electrical shocks. Painful stimuli did not make unpleasant images more unpleasant, but rendered pleasant pictures significantly less pleasant. Brain responses to visual inputs (64-channels electroencephalogram) mirrored behavioural results, showing pain-induced effects in the orbitofrontal cortex, the subgenual portion of the cingulate gyrus, the anterior prefrontal and the temporal cortices, exclusively during presentation of pleasant images. In addition to this specific effect on pleasant pictures, pain also produced non-specific effects upon all categories of images, engaging cerebral areas associated with attention, alertness and motor preparation (middle-cingulate, supplemental motor, prefrontal cortex). Thus, pain appears to have a dual influence on visual processing: a non-specific effect related to orienting phenomena; and a more specific action exerted on supra-modal limbic areas involved in the production of affective states. The latter correlated with changes in the subjective appraisal of visual stimuli, and may underlie not only the change in their subjective assessment but also reactive processes aimed at coping with unpleasant contexts.

Emotional modulation of pain: is it the sensation or what we recall?

Emotions modulate pain perception, although the mechanisms underlying this phenomenon remain unclear. In this study, we show that intensity reports significantly increased when painful stimuli were concomitant to images showing human pain, whereas pictures with identical emotional values but without somatic content failed to modulate pain. Early somatosensory responses (<200 ms) remained unmodified by emotions. Conversely, late responses showed a significant enhancement associated with increased pain ratings, localized to the right prefrontal, right temporo-occipital junction, and right temporal pole. In contrast to selective attention, which enhances pain ratings by increasing sensory gain, emotions triggered by seeing other people's pain did not alter processing in SI-SII (primary and second somatosensory areas), but may have biased the transfer to, and the representation of pain in short-term memory buffers (prefrontal), as well as the affective assignment to this representation (temporal pole). Memory encoding and recall, rather than sensory processing, appear to be modulated by empathy with others' physical suffering.

Chiari type I presenting as left glossopharyngeal neuralgia with cardiac syncope.

Glossopharyngeal neuralgia is an uncommon craniofacial pain syndrome that is occasionally associated with cardiac syncope. However, we relate Chiari I syndrome as a cause of this clinical picture for the first time in the literature. The authors analyze the relevant literature and discuss the pathogenesis and treatment of associated syndromes. We describe the case of a 45-year-old female patient who presented with a 3-year history of left glossopharyngeal neuralgia with occasional dysphagia and episodes of syncope when eating or swallowing. The pain was not disseminated to the right side and was fairly well controlled by carbamazepine. The syncopal attacks had a duration of about 10 sec. Neurological examination elicited a faint dysphonia associated with paradoxical dysphagia. The cranial magnetic resonance imaging scan showed a bilateral herniation of the cerebellar tonsils through the foramen magnum, more evidently on the left side. The patient received a suboccipital craniectomy and resection of the posterior arch of C1. The dura mater was opened, and we found both tonsils displaced into the foramen magnum extending caudally toward the C1 level. Both tonsils were compressing the brainstem and especially the low cranial nerves bilaterally. The lower cranial nerves were compressed between the posterior inferior cerebellar artery (PICA) and the herniated cerebellar tonsil on both sides. Both PICAs were dissected by microsurgical technique and all the arachnoid adherences were cut. The left tonsil was resected by means of ultrasonic aspirator. Duraplasty was performed with the occipital pericranium. The paroxysmal pain attacks and the syncopal picture disappeared immediately after the operation. The patient was discharged on the 7th postoperative day. One year later, she was free of symptoms. This case provides clinical evidence of close connections between the glossopharyngeal and vagus nerves, which control visceral sensation; and compression of the IX and X nerves between the herniated tonsil and PICA or vertebral artery may cause an irritative sensory phenomenon, which is the origin of the algic sensation and the cardiac syncope by means of cross talk between the fibers of the same nerve.

Hemangiopericitoma meningeo: relato de 7 casos e revisäo de literatura / Meningeal hemangiopericytoma: report ou 7 cases and critical review of the literature

Os autores apresentam 7 casos de pacientes portadores de hemangiopericitomas meningeos (HPM), operados no Hospital das Clinicas da Universidade de Sao Paulo (HCFMUSP) de 1990 a 1997. Aspectos relativos ao quadro clinico, anatomia patologica e terapeutica sao discutidos, com enfase na necessidade de embolizacao pre-operatoria e na complementacao terapÛutica com radioterapia.