Motor cortex stimulation for chronic neuropathic pain: results of a double-blind randomized study.

Motor cortex stimulation via surgically implanted electrodes has been used as an off-label treatment for chronic neuropathic pain, but its efficacy has not been fully established. We aimed to objectively study the efficacy of motor cortex stimulation and characterize potential predictors of response. In this randomized, double-blind, sham-controlled, single centre trial, we recruited 18 patients with chronic neuropathic pain who did not adequately respond to conventional treatment and had a numerical pain rating scale (NRS) score ≥6. Patients were initially assigned to receive 3 months of active ('on') or sham ('off') stimulation in a double-blind cross-over phase. This was followed by a 3-month single-blind phase, and 6 months of open-label follow-up. A meaningful response in our trial was defined as a ≥30% or 2-point reduction in NRS scores during active stimulation. Using Bayesian statistics, we found a 41.4% probability of response towards on versus off motor cortex stimulation. The probability of improvement during active stimulation (double-blind, single-blind and open-label phases) compared to baseline was 47.2-68.5%. Thirty nine per cent of the patients were considered long-term responders, 71.4% of whom had facial pain, phantom limb pain or complex regional pain syndrome. In contrast, 72.7% of non-responders had either post-stroke pain or pain associated with brachial plexus avulsion. Thirty-nine per cent of patients had a substantial postoperative analgesic effect after electrode insertion in the absence of stimulation. Individuals with diagnoses associated with a good postoperative outcome or those who developed an insertional effect had a near 100% probability of response to motor cortex stimulation. In summary, we found that ∼40% of patients responded to motor cortex stimulation, particularly those who developed an insertional effect or had specific clinical conditions that seemed to predict an appropriate postoperative response.

Intraoperative dopamine release during globus pallidus internus stimulation in Parkinson's disease.

BACKGROUND: It is still unclear whether dopamine (DA) levels correlate with Parkinson's disease (PD) severity or play a role in the mechanisms of high-frequency stimulation (HFS). METHODS: We have used microdialysis to record pallidal DA in 5 patients with PD undergoing microelectrode-guided pallidotomy. RESULTS: We found that patients with more severe disease and, consequently, lower pallidal DA did poorly after pallidal lesions. In the operating room, 4 of 5 patients had a significant increase in DA levels during HFS (600%, on average). To test the hypothesis that DA was important for the effects of stimulation, we correlated the amelioration in rigidity observed in the operating room with pallidal DA release. Though rigidity was 56% better during stimulation, no correlation was found between such an improvement and DA release. CONCLUSIONS: These findings suggest that additional mechanisms not directly dependent on pallidal DA release may be involved in the clinical effects of HFS of the globus pallidus internus.

Quality of Life After Motor Cortex Stimulation: Clinical Results and Systematic Review of the Literature.

BACKGROUND: Motor cortex stimulation (MCS) is routinely used for the treatment of chronic neuropathic pain but its effect on quality of life remains uncertain. OBEJCTIVE: To systematically review the published literature on MCS and quality of life and report the effects of this therapy in a series of patients prospectively followed in our center. METHODS: The systematic literature review was conducted using the search words "motor cortex stimulation and pain and neurosurgery" and "motor cortex stimulation and pain and quality of life." Quality of life in our clinical trial was investigated in a series of 10 patients with chronic neuropathic pain prospectively followed for 12 mo after MCS. RESULTS: Two hundred eighteen nonreplicated articles were pooled for analysis. Of these, 6 described measures of quality of life in the pre- and postoperative period. In these studies, 64 patients with different clinical conditions associated with neuropathic pain were followed for 6 to 84 mo after MCS surgery. Improvement in quality of life ranged from 35% to 85%. In our clinical series, visual analog scale (VAS), SF-12 physical (PhysCS), and mental scores (MenCS) recorded 12 mo after MCS were improved by 60 ± 10% (P = .002), 50 ± 13% (P = .002), and 22 ± 6% (P = .01), respectively. No significant correlation was found between postoperative improvement in pain and either PhysCS (r = 0.18; P = .6) or MenCS (r = -0.24; P = .5). CONCLUSION: MCS improves quality of life in patients with chronic refractory neuropathic pain. Additional factors other than a simple analgesic effect may contribute to these results.

Reconstruction of reaching movement trajectories using electrocorticographic signals in humans.

In this study, we used electrocorticographic (ECoG) signals to extract the onset of arm movement as well as the velocity of the hand as a function of time. ECoG recordings were obtained from three individuals while they performed reaching tasks in the left, right and forward directions. The ECoG electrodes were placed over the motor cortex contralateral to the moving arm. Movement onset was detected from gamma activity with near perfect accuracy (> 98%), and a multiple linear regression model was used to predict the trajectory of the reaching task in three-dimensional space with an accuracy exceeding 85%. An adaptive selection of frequency bands was used for movement classification and prediction. This demonstrates the efficacy of developing a real-time brain-machine interface for arm movements with as few as eight ECoG electrodes.

Lateral hypothalamic activity indicates hunger and satiety states in humans.

Lateral hypothalamic area (LHA) local field potentials (LFPs) were recorded in a Prader-Willi patient undergoing deep brain stimulation (DBS) for obesity. During hunger, exposure to food-related cues induced an increase in beta/low-gamma activity. In contrast, recordings during satiety were marked by prominent alpha rhythms. Based on these findings, we have delivered alpha-frequency DBS prior to and during food intake. Despite reporting an early sensation of fullness, the patient continued to crave food. This suggests that the pattern of activity in LHA may indicate hunger/satiety states in humans but attest to the complexity of conducting neuromodulation studies in obesity.

Surgical variation of microvascular decompression for trigeminal neuralgia: A technical note and anatomical study.

BACKGROUND: In this article, the authors described their experience in microvascular decompression for trigeminal neuralgia. METHODS: The microvascular decompression technique used in the authors' institution is described in a step by step manner with some illustrative cases as well as a cadaver dissection to highlight the differences with other previously described techniques. RESULTS: Since 2013, 107 patients were operated in the Neurosurgery Division of the University of São Paulo using the described technique, with a shorter operative time and avoiding cerebellar retractor compared with classic techniques. CONCLUSION: Our modified microvascular decompression technique for trigeminal neuralgia can be used with safety and efficiency for treating trigeminal neuralgia.

Caudal Zona Incerta/VOP Radiofrequency Lesioning Guided by Combined Stereotactic MRI and Microelectrode Recording for Posttraumatic Midbrain Resting-Kinetic Tremor.

OBJECTIVE: Reporting the outcome of two patients who underwent unilateral ablative stereotactic surgery to treat pharmacologic resistant posttraumatic tremor (PTT). METHODS: We present two patients (31 and 47 years old) with refractory PTT severely affecting their quality of life. Under stereotactic guidance, refined by T2-weighted magnetic resonance imaging and double-channel multiunit microelectrode recording (MER), three sequential radiofrequency lesions were performed in the caudal zona incerta (cZi) up to the base of thalamus (VOP). Effects of cZi/VOP lesion were prospectively rated with a tremor rating scale. RESULTS: Both patients demonstrated intraoperative tremor suppression with sustained results up to 18 months follow-up, with improvement of 92% and 84%, respectively, on the tremor rating scale. Tremor improvement was associated with enhancement functionality and quality of life for the patients. The patients returned to their work after the procedure. No adverse effects were observed up to the last follow-up. CONCLUSION: Radiofrequency lesion of the cZi/VOP target was effective for posttraumatic tremor in both cases. The use of T2-weighted images and MER was found helpful in increasing the precision and safety of the procedure, because it leads the RF probe by relying on neighbor structures based on thalamus and subthalamic nucleus.

Surgical Treatment for Spasticity: Selective Dorsal Rhizotomy ­ Technique and Literature Review

Spasticity is amotor disorder that leads to a resistance to passive jointmovement. Cerebral palsy is the most important cause of spasticity and can be caused by several factors, including multiple gestations, alcoholism, infections, hemorrhages, drowning, and traumatic brain injuries, among others. There aremany scales that help tomeasure andmonitor the degree of impairment of these patients. The initial treatment should focus on the causal factor, such as tumors, inflammation, degenerative diseases, hydrocephalus, etc. Subsequently, the treatment of spastic musculature includes oral or intrathecal myorelaxants, spinal cord electrostimulation, neurotomies, Lissauer tract lesion, dentatotomy and selective dorsal rhizotomy. The latter is a safetechnique, possibleto beperformed inmost centers with neurosurgical support, and it is effective in the treatment of severe spasticity. In this article, the authors describe the surgical technique and conduct a review the literature.

Simultaneous bilateral stereotactic procedure for deep brain stimulation implants: a significant step for reducing operation time.

OBJECT Currently, bilateral procedures involve 2 sequential implants in each of the hemispheres. The present report demonstrates the feasibility of simultaneous bilateral procedures during the implantation of deep brain stimulation (DBS) leads. METHODS Fifty-seven patients with movement disorders underwent bilateral DBS implantation in the same study period. The authors compared the time required for the surgical implantation of deep brain electrodes in 2 randomly assigned groups. One group of 28 patients underwent traditional sequential electrode implantation, and the other 29 patients underwent simultaneous bilateral implantation. Clinical outcomes of the patients with Parkinson's disease (PD) who had undergone DBS implantation of the subthalamic nucleus using either of the 2 techniques were compared. RESULTS Overall, a reduction of 38.51% in total operating time for the simultaneous bilateral group (136.4 ± 20.93 minutes) as compared with that for the traditional consecutive approach (220.3 ± 27.58 minutes) was observed. Regarding clinical outcomes in the PD patients who underwent subthalamic nucleus DBS implantation, comparing the preoperative off-medication condition with the off-medication/on-stimulation condition 1 year after the surgery in both procedure groups, there was a mean 47.8% ± 9.5% improvement in the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) score in the simultaneous group, while the sequential group experienced 47.5% ± 15.8% improvement (p = 0.96). Moreover, a marked reduction in the levodopa-equivalent dose from preoperatively to postoperatively was similar in these 2 groups. The simultaneous bilateral procedure presented major advantages over the traditional sequential approach, with a shorter total operating time. CONCLUSIONS A simultaneous stereotactic approach significantly reduces the operation time in bilateral DBS procedures, resulting in decreased microrecording time, contributing to the optimization of functional stereotactic procedures.

Vitamin B12 deficiency in infancy as a cause of developmental regression.

Vitamin B12 deficiency can cause serious developmental regression, hypotonia and cerebral atrophy in infants. We report a 6-month-old infant, with insidious developmental regression and brain atrophy showed by CT scan, secondarily to vitamin B12 deficiency. His mother was a strict vegetarian and the patient was exclusively breastfed. The clinical symptoms and the brain CT were normalized after vitamin B12 administration.

Lesöes hipoatenuantes dos gânglios da base associadas a quadro pirâmido-extrapiramidal: relato dos casos de dois irmäos / Hypoattenuating lesions of the basal ganglio associated with pyramido-extrapyramidal features: report of the cases of 2 brothers

Säo relatados os casos de dois irmäos com tomografia computadorizada de crânio evidenciando lesöes hipoatenuantes dos gânglios da base. No caso 1 a anormalidade é de maior dimensäo, bilateral e associa-se a quadro neurológico em que as alteraçöes mais importantes säo: presença de posturas distônicas, principalmente nos membros inferiores e reflexos patelares exaltados, com clono de rótula bilateral. No caso 2 a alteraçäo tomográfica estava presente com localizaçäo semelhante, porém menor e somente à esquerda e o exame neurológico é normal apesar do relato de quedas freqüentes. Os autores discutem o diagnóstico diferencial do ponto de vista clínico e tomográfico

Avaliaçäo e acompanhamento audiológico após meningite bacteriana / Audiological assessment and follow-up post bacterial meningitis

A deficiência auditiva é uma das sequelas da meningite bacteriana que ocorre com maior frequência em crianças. Este estudo descreve o perfil audiológico (periférico e central) de crianças internadas com diagnóstico de meningite bacteriana. Nas 89 crianças que compareceram ao seguimento audiológico após a alta hospitalar e foram submetidas aos testes audiológicos, os resultados evidenciaram que 85,4 por cento apresentaram acuidade auditiva normal em ambas orelhas, 10,1 por cento apresentaram deficiência auditiva neurossensorial bilateral e 4,5 por cento apresentaram deficiência auditiva neurossensorial unilateral. Nos testes que avaliaram as habilidades de processamento auditivo, os resultados mostraram que 10 por cento dessas crianças apresentaram alterações no desempenho de localização auditiva e de reconhecimento de sentenças com mensagem competitiva ipsilateral.

Eating epilepsy

A epilepsia reflexa ao comer é uma rara de epilepsia reflexa. Um paciente de 24 anos com crises parciais complexas reflexas ao comer foi submetido a avaliaçöes clínica, neurológica neurorradiológica e eletrencefalográfica. O exame neurológico e a tomografia de crânio foram normais. Registros de EEG, incluindo menitorizaçäo vídeo-EEG durante a refeiçäo, mostraram presença de anormalidades focais relacionadas a ambos os lobos temporais, predominando à esquerda, e sincronia bilateral secundária, predominando em regiöes anteriores. Os achados ictais säo semelhantes à sincronia bilateral secundária interictal exceto por sua maior duraçäo. Monoterapias com PB, DPH e VPA näo surtiram efeito. Monoterapia com altas doses de CBZ trouxe bons resultados porém com controle incompleto das crises. Como grande número de fatores precipitantes estava potencialmente envolvido, näo foi possível determinar com precisäo a base fisiopatológica das crises reflexas neste caso

Avaliação auditiva de recém-nascidos gravemente enfermos através do método de emissões otoacústicas evocadas transientes (EOAT) e audiometria de tronco cerebral(BERA) / Auditory evaluation of critically sick newborns through evoked otoacustic emissions (EOAT) and auditory brain sten (BERA)

Objetivo: verificar a prevalência de deficiência auditiva em recém-nascidos (RN) que estiveram gravemente doentes, através de dois métodos - emissões otoacústicas evocadas transientes (EOAT) e audiometria de tronco cerebral (BERA)/ Objective: to verify the prevalence of hearing loss in critically sick newborns through evoked otoacustic potential emission (EOAT) and brainstem auditory evoked response test (BERA)...

Deficiência auditiva em recém-nascidos internados em unidade de terapia intensiva neonatal / Hearing loss in newborn admitted in intensive care unit

Objetivo: verificar a prevalência de deficiência auditiva em recém-nascidos internados em Unidade de Cuidados Intensivos Neonatais: avaliar os fatores de risco para a deficiência auditiva adquirida. Métodos: estudo de coorte prospectiva com 71 recém-nascidos, realizado no período de setembro de 2003 a março de 2004 / Objetive: to verify the prevalence of newborn hearing loss admitted in the Intensive Care Unit, to relate the risk factors with hearing loss. Methods: it was conducted a prospective cohort study with 71 newborns in the period of September 2003 until March 2004...

Coréia familiar benigna: relato de dois casos / Benign familial chorea: report of 2 cases

Säo apresentados dois casos (irmäs) de coréia familiar benigna. O estudo do heredograma mostra padräo compatível a herança autossômica dominante com penetrância incompleta. Discute-se o diagnóstico diferencial dessa doença e faz-se breve revisäo da literatura

A melatonina e o sono em criancas / Melatonin and sleep in children

A melatonina foi isolada e caracterizada como um hormonio produzido pela glandula pineal no final da decada de 50. A partir dai inumeros estudos trataram das funcoes da pineal e da melatonina, que surpreendentemente parece agir em praticamente todos os sistemas fisiologicos. Por ser sintetizada e secretada apenas durante o periodo de escuro, funciona como um sinalizador, para o meio interno, do dia e da noite. A producao de melatonina diminui com o envelhecimento. Devido a sua potente acao indutora de sono, a melatonina tem sido utilizada na terapeutica das perturbacoes do sono, principalmente nas insonias, nos transtornos decorrentes da mudanca de fusos horarios e nos trabalhadores com jornada noturna. Os estudos da melatonina nos disturbios do sono na infancia, sao ainda raros...