Cortico-cerebellar connectivity underlying motor control in chronic post-stroke individuals.

The robust, reciprocal anatomical connections between the cerebellum and contralateral sensorimotor cerebral hemisphere underscores the strong physiological interdependence between these two regions in relation to human behavior. Previous studies have shown that damage to sensorimotor cortex can result in a lasting reduction of cerebellar metabolism, the magnitude of which has been linked to poor rehabilitative outcomes. A better understanding of movement-related cerebellar physiology as well as cortico-cerebellar coherence (CCC) in the chronic, post-stroke state may be key to developing novel neuromodulatory techniques that promote upper limb motor rehabilitation. As a part of the first in-human phase-I trial investigating the effects of deep brain stimulation of the cerebellar dentate nucleus (DN) on chronic, post-stroke motor rehabilitation, we collected invasive recordings from DN and scalp EEG in subjects (both sexes) with middle cerebral artery stroke during a visuo-motor tracking task. We investigated the excitability of ipsilesional cortex, DN and the their interaction as a function of motor impairment and performance. Our results indicate that 1) event-related oscillations in the ipsilesional cortex and DN were significantly correlated at movement onset in the low-ß band, with moderately and severely impaired subjects showing desynchronization and synchronization, respectively. 2) Significant CCC was observed during isometric 'hold' period in the low-ß band, which was critical for maintaining task accuracy. Our findings support a strong coupling between ipsilesional cortex and DN in the low-ß band during motor control across all impairment levels which encourages the exploitation of the cerebello-thalamo-cortical pathway as a neuromodulation target to promote rehabilitation.Significance Statement:Cerebral infarct due to stroke can lead to lasting reduction in cerebellar metabolism resulting in poor rehabilitative outcomes. Thorough investigation of the cerebellar electrophysiology as well as cortico-cerebellar connectivity in humans that could provide key insights to facilitate development of novel neuromodulatory technologies, has been lacking. As a part of the first in-human phase-I trial investigating deep brain stimulation of the cerebellar dentate nucleus (DN) for chronic, post-stroke motor rehabilitation, we collected invasive recordings from DN and scalp EEG while stroke patients performed a motor task. Our data indicate strong coupling between ipsilesional sensorimotor cortex and DN in the low-ß band across all impairment levels encouraging the exploration of electrical stimulation of the DN.

Effects of flexible scheduling and virtual visits on burnout for clinicians.

OBJECTIVE: Burnout is a healthcare quality problem, linked to negative impacts in patient care and healthcare providers. The pandemic prompted clinicians to adapt virtual practices and adopt more flexible, autonomous schedules. However, the impact of flexible scheduling and autonomy on provider burnout is unknown. The study aim was to evaluate the effect of flexible schedules versus standard schedules, and the amount of digital care, on burnout. METHODS: This was a prospective survey study at two time points 6 months apart. Providers from Rheumatology, Neurology, and Pediatrics completed surveys at baseline, between 6/22/2020-9/8/2020, and six months later, between 12/20/20-3/12/21. The primary outcome was the Mini-Z work life survey which measured burnout in 2 different groups: flexible schedules (FS) and standard schedules (SS) during the height of the pandemic. RESULTS: The study included 149 providers, 47 with FS and 102 with SS, who completed the survey at baseline and 6 months later. At baseline providers reported high job satisfaction (85.9%) and low burnout (29.7%), which remained consistent at 6 months. Compared to those with SS, clinicians with FS participated in a greater number of telemedicine activities at baseline, but did not differ significantly in degree of burnout (25.5% FS, 31.7% SS, p=0.45). Participants in the FS group were significantly more likely to indicate improvement in control over workload and experience reduced work-related stress compared to those in the SS group. There was no association between amount of telemedicine visits and burnout. Predictors of burnout at 6 months included Rheumatology providers and those in the 20-39 year old age group. DISCUSSION: Schedule flexibility does not appear to influence overall burnout; however it does impact variables associated with burnout such as control over workload and perceived job stress. CONCLUSIONS: Participants reported overall job satisfaction, and FS did not impact overall burnout. FS was more likely to indicate improvement in control over workload and experienced reduced work-related stress compared to SS. In addition, burnout was more likely in the 20-39 year old age group, suggesting that special focus should be paid to this age group.

Effects of preparation with the Self-Adjusting File, TRUShape and XP-endo Shaper systems, and a supplementary step with XP-endo Finisher R on filling material removal during retreatment of mandibular molar canals.

AIM: To compare the effects of three instrumentation systems, and a supplementary approach with a finishing instrument, on filling material removal during retreatment of mandibular molar canals. METHODS: Sixty mesial canals from mandibular molars (Vertucci's type IV anatomy) were instrumented, filled and subjected to retreatment. After initial removal of the root canal filling material using the D-RaCe system, the canals were randomly distributed into three groups (n = 20) according to the instrument system used for preparation: the Self-Adjusting File (SAF), TRUShape or XP-endo Shaper. The filling material volume in the apical 5 mm of the canals was assessed by means of micro-computed tomography (micro-CT) before and after retreatment. All specimens with residual filling material were subjected to a supplementary approach with the XP-endo Finisher R instrument and another micro-CT scan was taken. Data on the volumes of filling material and incidence of total removal were compared between groups by the general linear model for paired data and the Fisher's exact test. The effects of the refinement step were evaluated by the Wilcoxon Signed Ranks test. RESULTS: The amount of removed material was 92.4%, 96.9% and 96.9% for the SAF, TRUShape and XP-endo Shaper, respectively. There were no significant differences between them (P > 0.05). Canals were completely cleaned of filling material in 70% of the specimens for XP-endo Shaper, 55% for SAF and 30% for TRUShape; the difference between XP-endo Shaper and TRUShape was significant (P = 0.03). The supplementary step with the XP-endo Finisher R instrument was associated with additional filling material removal of 38% (P < 0.001). Six more canals were rendered free of filling material after using this finishing instrument. CONCLUSIONS: The tested systems were equally effective in removing the mass of filling material from the apical 5 mm of molar canals. The supplementary step with the XP-endo Finisher R instrument enhanced filling material removal.

Models to Tailor Brain Stimulation Therapies in Stroke.

A great challenge facing stroke rehabilitation is the lack of information on how to derive targeted therapies. As such, techniques once considered promising, such as brain stimulation, have demonstrated mixed efficacy across heterogeneous samples in clinical studies. Here, we explain reasons, citing its one-type-suits-all approach as the primary cause of variable efficacy. We present evidence supporting the role of alternate substrates, which can be targeted instead in patients with greater damage and deficit. Building on this groundwork, this review will also discuss different frameworks on how to tailor brain stimulation therapies. To the best of our knowledge, our report is the first instance that enumerates and compares across theoretical models from upper limb recovery and conditions like aphasia and depression. Here, we explain how different models capture heterogeneity across patients and how they can be used to predict which patients would best respond to what treatments to develop targeted, individualized brain stimulation therapies. Our intent is to weigh pros and cons of testing each type of model so brain stimulation is successfully tailored to maximize upper limb recovery in stroke.

A magnetoencephalography study of multi-modal processing of pain anticipation in primary sensory cortices.

Pain anticipation plays a critical role in pain chronification and results in disability due to pain avoidance. It is important to understand how different sensory modalities (auditory, visual or tactile) may influence pain anticipation as different strategies could be applied to mitigate anticipatory phenomena and chronification. In this study, using a countdown paradigm, we evaluated with magnetoencephalography the neural networks associated with pain anticipation elicited by different sensory modalities in normal volunteers. When encountered with well-established cues that signaled pain, visual and somatosensory cortices engaged the pain neuromatrix areas early during the countdown process, whereas the auditory cortex displayed delayed processing. In addition, during pain anticipation, the visual cortex displayed independent processing capabilities after learning the contextual meaning of cues from associative and limbic areas. Interestingly, cross-modal activation was also evident and strong when visual and tactile cues signaled upcoming pain. Dorsolateral prefrontal cortex and mid-cingulate cortex showed significant activity during pain anticipation regardless of modality. Our results show pain anticipation is processed with great time efficiency by a highly specialized and hierarchical network. The highest degree of higher-order processing is modulated by context (pain) rather than content (modality) and rests within the associative limbic regions, corroborating their intrinsic role in chronification.

Comparing two deep brain stimulation leads to one in refractory tremor.

A sizable proportion of medication refractory tremor patients may not respond satisfactorily to deep brain stimulation (DBS) to the ventralis intermedialis nucleus of the thalamus (Vim). Implanting a second DBS lead ipsilaterally to the first one is thought to be beneficial based on scarce and unblinded data. This article aims to report a double-blind assessment of five patients with a second DBS lead for refractory tremor. Tremor was assessed by two blinded movement disorder specialists using a videotaped tremor rating scale (TRS) evaluation of each patient in four conditions: both leads OFF, Vim ON/2nd lead OFF, Vim OFF/2nd lead ON, and both leads ON. Paired t-test was used to determine if double stimulation was different than stimulation of Vim alone or than stimulation of the 2nd lead alone. Each hypothesis was tested with the total TRS as well as the contralateral upper limb score and the contralateral hemibody score. Tremor was secondary to multiple sclerosis in two patients and to essential tremor in three. The second lead was in the ventralis oralis anterior nucleus of the thalamus in three patients and in the prelemniscal radiations in two patients. There was improvement with the 2nd lead or double ON in four patients compared to stimulating the Vim alone. However, when taken as a group, the results were not statistically significant. These results were constant with the three different ratings used. The lack of overall statistically significant improvement might be secondary to the small size and the heterogeneity of our sample. However, four patients had 17 to 60 % tremor improvement after the implant of the 2nd lead on double-blinded evaluation. We report objective improvement after addition of a second DBS lead in patients with tremor refractory to Vim DBS. Larger studies are needed to confirm these results.

Deep brain stimulation of the ventral internal capsule/ventral striatum for obsessive-compulsive disorder: worldwide experience.

Psychiatric neurosurgery teams in the United States and Europe have studied deep brain stimulation (DBS) of the ventral anterior limb of the internal capsule and adjacent ventral striatum (VC/VS) for severe and highly treatment-resistant obsessive-compulsive disorder. Four groups have collaborated most closely, in small-scale studies, over the past 8 years. First to begin was Leuven/Antwerp, followed by Butler Hospital/Brown Medical School, the Cleveland Clinic and most recently the University of Florida. These centers used comparable patient selection criteria and surgical targeting. Targeting, but not selection, evolved during this period. Here, we present combined long-term results of those studies, which reveal clinically significant symptom reductions and functional improvement in about two-thirds of patients. DBS was well tolerated overall and adverse effects were overwhelmingly transient. Results generally improved for patients implanted more recently, suggesting a 'learning curve' both within and across centers. This is well known from the development of DBS for movement disorders. The main factor accounting for these gains appears to be the refinement of the implantation site. Initially, an anterior-posterior location based on anterior capsulotomy lesions was used. In an attempt to improve results, more posterior sites were investigated resulting in the current target, at the junction of the anterior capsule, anterior commissure and posterior ventral striatum. Clinical results suggest that neural networks relevant to therapeutic improvement might be modulated more effectively at a more posterior target. Taken together, these data show that the procedure can be successfully implemented by dedicated interdisciplinary teams, and support its therapeutic promise.

Guidelines for neurosurgical trauma in Brazil.

This chapter emphasizes some aspects of the Brazilian Guidelines for the Assessment of Head Injury Patients, written based on the experience of the Emergency Service, Neurosurgical Division of the University of São Paulo Medical School Hospital, and sponsored by the Brazilian Society of Neurosurgery. These guidelines approach the management of head-injury patients from their initial assessment in the Emergency Room until the final suggested clinical or surgical management. The Brazilian Guidelines represents our efforts to provide the basis for a common unified data collection system, which may allow cooperative studies in the future.

Functional recovery after combined cerebral and cerebellar hemispherectomy in the rat.

The cerebellum seems to be one of the structures responsible for early neurological improvement after cerebral hemispherectomy and its consequent deficits. Considered as an accessory brain, the cerebellum may constitute a neurobiological substrate for the recovery of such extensive cortical and subcortical lesions. It may compensate for the injury by structural remodeling and plasticity. The authors observed that, indeed, rats submitted to contralateral hemicerebellectomy before cerebral hemispherectomy do not recover as well as those submitted to hemicerebellectomy 2 weeks after cerebral hemispherectomy.

Intravascular papillary endothelial hyperplasia causing cauda equina compression: case report.

OBJECTIVE AND IMPORTANCE: Intravascular papillary endothelial hyperplasia (Masson's vegetant hemangioendothelioma) is a rare condition affecting the neuraxis. In the literature, only one case of this lesion involving the vertebral canal with spinal cord compression has been reported. We present a case of cauda equina compression due to this abnormality. CLINICAL PRESENTATION: A 17-year-old boy was admitted at our hospital with pain, numbness, paresis of the left lower extremity, and bladder dysfunction of approximately 1 month's duration. Computed tomography and magnetic resonance imaging of the spine revealed a tumor within the spinal canal at the T12-L1 level. INTERVENTION: The patient underwent a T12-L1 laminectomy. An epidural red nodular tumor was visualized and totally resected. The findings of the pathological examination were compatible with intravascular papillary endothelial hyperplasia. At follow-up examination 1 month after the operation, the patient had complete resolution of the pain, and the motor deficit and bladder dysfunction had improved significantly. CONCLUSION: This rare benign vascular lesion may be clinically and histopathologically mistaken for an angiosarcoma. Because the intravascular papillary endothelial hyperplasia can be cured by complete surgical resection, it is important to distinguish between these two lesions to avoid inappropriate aggressive treatment.

Evaluation of the effectiveness of sodium hypochlorite used with three irrigation methods in the elimination of Enterococcus faecalis from the root canal, in vitro.

The effectiveness of 4.0% sodium hypochlorite (NaOCl) used with three irrigation methods in the elimination of Enterococcus faecalis from the root canal was tested in vitro. Root canals contaminated with E. faecalis were treated as follows: (i) irrigation with 2 mL of NaOCl solution and agitation with hand files; (ii) irrigation with 2 mL of NaOCl solution and ultrasonic agitation; (iii) irrigation with NaOCl alternated with hydrogen peroxide. Contaminated canals irrigated with sterile saline solution served as the control. Paper points used to sample bacteria from the root canals were transferred to tubes containing 5 mL of brain heart infusion (BHI) broth. Tubes were incubated and the appearance of broth turbidity was indicative of bacteria remaining in the root canal. There were no statistically significant differences between the experimental groups. However, NaOCl applied by the three methods tested, was significantly more effective than the saline solution (control group) in disinfecting the root canal.

Subluxacao recorrente da articulacao interfalangeana proximal do 5o. artelho. / Recurrent subluxation of the proximal interphalangeal joint of the 5th toe

Os autores apresentam tres casos de "subluxacao recorrente da articulacao interfalangena proximal do 5o. artelho". Todos foram vistos inicialmente em Servicos de Urgencia Especializados. Ainda nao encontramos mencao na literatura de patologia que descrevemos. O tratamento cirurgico instituido nos tres casos apresentou resultados uniformemente excelentes