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1.
Nat Med ; 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38997607

ABSTRACT

Recent advances in surgical neuromodulation have enabled chronic and continuous intracranial monitoring during everyday life. We used this opportunity to identify neural predictors of clinical state in 12 individuals with treatment-resistant obsessive-compulsive disorder (OCD) receiving deep brain stimulation (DBS) therapy ( NCT05915741 ). We developed our neurobehavioral models based on continuous neural recordings in the region of the ventral striatum in an initial cohort of five patients and tested and validated them in a held-out cohort of seven additional patients. Before DBS activation, in the most symptomatic state, theta/alpha (9 Hz) power evidenced a prominent circadian pattern and a high degree of predictability. In patients with persistent symptoms (non-responders), predictability of the neural data remained consistently high. On the other hand, in patients who improved symptomatically (responders), predictability of the neural data was significantly diminished. This neural feature accurately classified clinical status even in patients with limited duration recordings, indicating generalizability that could facilitate therapeutic decision-making.

2.
Adv Tech Stand Neurosurg ; 49: 291-306, 2024.
Article in English | MEDLINE | ID: mdl-38700689

ABSTRACT

Pediatric epilepsy has a worldwide prevalence of approximately 1% (Berg et al., Handb Clin Neurol 111:391-398, 2013) and is associated with not only lower quality of life but also long-term deficits in executive function, significant psychosocial stressors, poor cognitive outcomes, and developmental delays (Schraegle and Titus, Epilepsy Behav 62:20-26, 2016; Puka and Smith, Epilepsia 56:873-881, 2015). With approximately one-third of patients resistant to medical control, surgical intervention can offer a cure or palliation to decrease the disease burden and improve neurological development. Despite its potential, epilepsy surgery is drastically underutilized. Even today only 1% of the millions of epilepsy patients are referred annually for neurosurgical evaluation, and the average delay between diagnosis of Drug Resistant Epilepsy (DRE) and surgical intervention is approximately 20 years in adults and 5 years in children (Solli et al., Epilepsia 61:1352-1364, 2020). It is still estimated that only one-third of surgical candidates undergo operative intervention (Pestana Knight et al., Epilepsia 56:375, 2015). In contrast to the stable to declining rates of adult epilepsy surgery (Englot et al., Neurology 78:1200-1206, 2012; Neligan et al., Epilepsia 54:e62-e65, 2013), rates of pediatric surgery are rising (Pestana Knight et al., Epilepsia 56:375, 2015). Innovations in surgical approaches to epilepsy not only minimize potential complications but also expand the definition of a surgical candidate. In this chapter, three alternatives to classical resection are presented. First, laser ablation provides a minimally invasive approach to focal lesions. Next, both central and peripheral nervous system stimulation can interrupt seizure networks without creating permanent lesions. Lastly, focused ultrasound is discussed as a potential new avenue not only for ablation but also modulation of small, deep foci within seizure networks. A better understanding of the potential surgical options can guide patients and providers to explore all treatment avenues.


Subject(s)
Epilepsy , Neurosurgical Procedures , Child , Humans , Drug Resistant Epilepsy/surgery , Drug Resistant Epilepsy/diagnostic imaging , Epilepsy/surgery , Laser Therapy/methods , Neurosurgical Procedures/methods
4.
J Neurooncol ; 164(3): 525-533, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37707753

ABSTRACT

PURPOSE: Primary brain neoplasms are the most common solid tumors in pediatric patients and seizures are a common presenting symptom. Surgical intervention improves oncologic outcomes and seizure burden. A better understanding of factors that influence seizure outcomes in the surgical management of primary brain tumors of childhood can guide treatment approach thereby improving patient quality of life. METHODS: We performed a systematic analysis using articles queried from PubMed, EMBASE, and Cochrane published from January 1990 to August 2022 to determine predictors of seizure outcomes in pediatric patients undergoing resection of primary brain tumors. RESULTS: We identified 24 retrospective cohort studies, one prospective cohort study, and one mixed retrospective and prospective study for the systematic analysis. A total of 831 pediatric patients were available for analysis. 668 (80.4%) patients achieved seizure freedom after surgery. Complete tumor resection increased the likelihood of a seizure-free (Engel I) outcome compared to subtotal resection (OR 7.1, 95% CI 2.3-21.9). Rates of Engel I seizure outcomes did not significantly differ based on factors such as age at seizure onset, duration of epilepsy, gender, tumor laterality, or age at surgery, but trended towards significance for improved outcomes in temporal lobe tumors. CONCLUSION: Primary brain tumors in the pediatric population are commonly associated with seizures. Resection of these lesions reduces seizure burden and is associated with high rates of seizure freedom. Complete resection, compared to subtotal resection, significantly increases the likelihood of seizure-free outcomes.


Subject(s)
Brain Neoplasms , Supratentorial Neoplasms , Child , Humans , Retrospective Studies , Prospective Studies , Quality of Life , Electroencephalography , Treatment Outcome , Seizures/surgery , Seizures/complications , Supratentorial Neoplasms/complications , Brain Neoplasms/complications , Brain Neoplasms/surgery , Brain Neoplasms/pathology
6.
Neurosurgery ; 92(5): 1043-1051, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36700739

ABSTRACT

BACKGROUND: Vagus nerve stimulation (VNS) is a neuromodulatory procedure most extensively studied as an adjunct to medically refractory epilepsy. Despite widespread adoption and decades of clinical experience, clinical predictors of response to VNS remain unclear. OBJECTIVE: To evaluate a retrospective cohort of pediatric patients undergoing VNS at our institution to better understand who may benefit from VNS and identify factors which may predict response to VNS. METHODS: We conducted a retrospective cohort study examining pediatric patients undergoing VNS over nearly a 20-year span at a single institution. Presurgical evaluation, including demographics, clinical history, and diagnostic electroencephalogram, and imaging findings were examined. Primary outcomes included VNS response. RESULTS: Two hundred ninety-seven subjects were studied. The mean age at surgery was 10.1 (SD = 4.9, range = 0.8-25.3) years; length of follow-up was a mean of 4.6 years (SD = 3.5, median = 3.9 years, range 1 day-16.1 years). There was no association between demographic factors, epilepsy etiology, or genetic basis and VNS outcomes. There was an association between reduction in main seizure type with positive MRI finding. Of all MRI findings analyzed, brain atrophy was significantly associated with worse VNS outcomes, whereas dysplastic hippocampus and chronic periventricular leukomalacia findings were found to be associated with improved outcomes. Increased seizure semiology variability and seizure type were also associated with improved seizure outcomes. CONCLUSION: Predicting response to VNS remains difficult, leading to incompletely realized benefits and suboptimal resource utilization. Specific MRI findings and increased seizure semiology variability and type can help guide clinical decision making and patient counseling.


Subject(s)
Drug Resistant Epilepsy , Epilepsy , Vagus Nerve Stimulation , Humans , Child , Infant , Child, Preschool , Adolescent , Young Adult , Adult , Vagus Nerve Stimulation/methods , Retrospective Studies , Epilepsy/diagnosis , Epilepsy/therapy , Seizures , Electroencephalography , Drug Resistant Epilepsy/diagnosis , Drug Resistant Epilepsy/therapy , Vagus Nerve , Treatment Outcome
7.
Oncologist ; 28(4): 327-332, 2023 04 06.
Article in English | MEDLINE | ID: mdl-36715178

ABSTRACT

BACKGROUND: Limited data from small series have suggested that brain metastases from biliary tract cancers (BrM-BTC) affect ≤2% of patients with BTC. We sought to review our experience with patients with BrM-BTC and to identify associations of tumor-related molecular alterations with outcomes. MATERIALS AND METHODS: A retrospective review of patients with BTC seen at a tertiary referral center from 2005 to 2021 was performed; patients with BrM-BTC were identified, and clinical and molecular data were collected. RESULTS: Twenty-one of 823 patients with BTC (2.6%) developed BrM. For patients with BrM-BTC, median follow-up time was 27.9 months after primary BTC diagnosis and 3.1 months after BrM diagnosis. Median time from primary diagnosis to diagnosis of BrM was 14.4 [range, 1.1-66.0] months. Median overall survival (OS) from primary diagnosis was 31.5 [2.9-99.8] months and median OS from BrM diagnosis was 4.2 [0.2-33.8] months. Patients who underwent BrM-directed therapy trended toward longer OS following BrM diagnosis than patients receiving supportive care only (median 6.5 vs 0.8 months, P = .060). The BrM-BTC cohort was enriched for BRAF (30%), PIK3CA (25%), and GNAS (20%) mutations. patients with BrM-BTC with BRAF mutations trended toward longer OS following BrM diagnosis (median 13.1 vs 4.2 months, P = .131). CONCLUSION: This is the largest series of patients with BrM-BTC to date and provides molecular characterization of this rare subgroup of patients with BTC. Patients with BrM-BTC may be more likely to have BRAF mutations. With advances in targeted therapy for patients with BTC with actionable mutations, continued examination of shifting patterns of failure, with emphasis on BrM, is warranted.


Subject(s)
Bile Duct Neoplasms , Biliary Tract Neoplasms , Brain Neoplasms , Cholangiocarcinoma , Humans , Proto-Oncogene Proteins B-raf/genetics , Biliary Tract Neoplasms/genetics , Mutation , Brain Neoplasms/genetics , Retrospective Studies , Cholangiocarcinoma/pathology , Bile Duct Neoplasms/drug therapy
8.
J Neurosurg ; 138(4): 1117-1123, 2023 04 01.
Article in English | MEDLINE | ID: mdl-36087325

ABSTRACT

OBJECTIVE: Since the Accreditation Council for Graduate Medical Education (ACGME) implemented duty-hour restrictions in 2003, many residency programs have adopted a night float system to comply with time constraints. However, some surgical subspecialities have been concerned that use of a night float system deprives residents of operative experience. In this study, the authors describe their training program's transition to a night float system and its impact on resident operative experience. METHODS: The authors conducted a single-program study of resident surgical case volume before and after implementing the night float system at 3 of their 5 hospitals from 2014 to 2020. The authors obtained surgical case numbers from the ACGME case log database. RESULTS: Junior residents received a concentrated educational experience, whereas senior residents saw a significant decrease from 112 calls/year to 17. Logged cases significantly increased after implementation of the night float system (8846 vs 10,547, p = 0.04), whereas cases at non-night float hospitals remained the same. This increase was concurrent with an increase in hospital cases. This difference was mainly driven by senior resident cases (p = 0.010), as junior and chief residents did not show significant differences in logged cases (p > 0.40). Lead resident cases increased significantly after implementation of the night float system (6852 vs 8860, p = 0.04). When normalized for increased hospital cases, resident case increases were not statistically significant. CONCLUSIONS: Transitioning to a night float call system at the authors' institution increased overall resident operative cases, particularly for lead resident surgeons. Based on the results of this study, the authors recommend the use of a night float call system to consolidate night calls, which increases junior resident-level educational opportunities and senior resident cases.


Subject(s)
Internship and Residency , Neurosurgery , Humans , Neurosurgery/education , Neurosurgical Procedures , Education, Medical, Graduate , Hospitals , Workload , Personnel Staffing and Scheduling
9.
Front Pain Res (Lausanne) ; 3: 1028424, 2022.
Article in English | MEDLINE | ID: mdl-36387414

ABSTRACT

In end-stage cancer, oncologic pain refractory to medical management significantly reduces patients' quality of life. In recent years, ablative surgery has seen a resurgence in treating diffuse and focal cancer pain in terminal patients. The anterior cingulate gyrus has been a key focus as it plays a role in the cognitive and emotional processing of pain. While radiofrequency ablation of the dorsal anterior cingulate is well described for treating cancer pain, MRI-guided laser-induced thermal therapy (LITT) is novel. Our paper describes a patient treated with an MRI-guided LITT therapy of the anterior cingulate gyrus for intractable debilitating pain secondary to terminal metastatic cancer.

10.
Oper Neurosurg (Hagerstown) ; 23(3): 254-260, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35972090

ABSTRACT

BACKGROUND: A number of stereotactic platforms are available for performing deep brain stimulation (DBS) lead implantation. Robot-assisted stereotaxy has emerged more recently demonstrating comparable accuracy and shorter operating room times compared with conventional frame-based systems. OBJECTIVE: To compare the accuracy of our streamlined robotic DBS workflow with data in the literature from frame-based and frameless systems. METHODS: We retrospectively reviewed 126 consecutive DBS lead placement procedures using a robotic stereotactic platform. Indications included Parkinson disease (n = 94), essential tremor (n = 21), obsessive compulsive disorder (n = 7), and dystonia (n = 4). Procedures were performed using a stereotactic frame for fixation and the frame pins as skull fiducials for robot registration. We used intraoperative fluoroscopic computed tomography for registration and postplacement verification. RESULTS: The mean radial error for the target point was 1.06 mm (SD: 0.55 mm, range 0.04-2.80 mm) on intraoperative fluoroscopic computed tomography. The mean operative time for an asleep, bilateral implant without implantable pulse generator placement was 238 minutes (SD: 52 minutes), and skin-to-skin procedure time was 116 minutes (SD: 42 minutes). CONCLUSION: We describe a streamlined workflow for DBS lead placement using robot-assisted stereotaxy with a comparable accuracy profile. Obviating the need for checking and switching coordinates, as is standard for frame-based DBS, also reduces the chance for human error and facilitates training.


Subject(s)
Deep Brain Stimulation , Robotics , Deep Brain Stimulation/methods , Humans , Retrospective Studies , Stereotaxic Techniques , Workflow
11.
J Neurosurg Pediatr ; 29(6): 667-680, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35303699

ABSTRACT

OBJECTIVE: Drug-resistant epilepsy (DRE) affects many children. Vagus nerve stimulation (VNS) may improve seizure control; however, its role in children with genetic etiologies of epilepsy is not well described. The authors systematically reviewed the literature to examine the effectiveness of VNS in this cohort. METHODS: In January 2021, the authors performed a systematic review of the PubMed/MEDLINE, SCOPUS/Embase, Cochrane, and Web of Science databases to investigate the impact of VNS on seizure outcomes in children with genetic etiologies of epilepsy. Primary outcomes included seizure freedom rate, ≥ 90% seizure reduction rate, and ≥ 50% seizure reduction rate. Secondary outcomes were seizure severity and quality of life (QOL), including cognitive, functional, and behavioral outcomes. A random-effects meta-analysis was performed. RESULTS: The authors identified 125 articles, of which 47 with 216 nonduplicate patients were analyzed. Common diagnoses were Dravet syndrome (DS) (92/216 patients [42.6%]) and tuberous sclerosis complex (TSC) (63/216 [29.2%]). Seizure freedom was not reported in any patient with DS; the pooled proportion (95% CI) of patients with ≥ 50% seizure reduction was 41% (21%-58%). Secondary cognitive outcomes of VNS were variable in DS patients, but these patients demonstrated benefits in seizure duration and status epilepticus. In TSC patients, the pooled (95% CI) seizure freedom rate was 40% (12%-71%), ≥ 90% seizure reduction rate was 31% (8%-56%), and ≥ 50% reduction rate was 68% (48%-91%). Regarding the secondary outcomes of VNS in TSC patients, several studies reported decreased seizure severity and improved QOL outcomes. There was limited evidence regarding the use of VNS to treat patients with other genetic etiologies of epilepsy, such as mitochondrial disease, Rett syndrome, Doose syndrome, Landau-Kleffner syndrome, Aicardi syndrome, Angelman syndrome, ring chromosome 20 syndrome, and lissencephaly; variable responses were reported in a limited number of cases. CONCLUSIONS: The authors conducted a systematic review of VNS outcomes in children with genetic etiologies of DRE. Among the most studied conditions, patients with TSC had substantial seizure reduction and improvements in QOL, whereas those with DS had less robust seizure reduction. Increased testing, diagnosis, and long-term follow-up studies are necessary to better characterize VNS response in these children.


Subject(s)
Drug Resistant Epilepsy , Epilepsy , Vagus Nerve Stimulation , Child , Humans , Quality of Life , Drug Resistant Epilepsy/genetics , Drug Resistant Epilepsy/therapy , Epilepsy/genetics , Epilepsy/therapy , Seizures , Treatment Outcome , Vagus Nerve , Retrospective Studies
12.
Cell ; 183(2): 537-548.e12, 2020 10 15.
Article in English | MEDLINE | ID: mdl-33064989

ABSTRACT

Sequential activation of neurons has been observed during various behavioral and cognitive processes, but the underlying circuit mechanisms remain poorly understood. Here, we investigate premotor sequences in HVC (proper name) of the adult zebra finch forebrain that are central to the performance of the temporally precise courtship song. We use high-density silicon probes to measure song-related population activity, and we compare these observations with predictions from a range of network models. Our results support a circuit architecture in which heterogeneous delays between sequentially active neurons shape the spatiotemporal patterns of HVC premotor neuron activity. We gauge the impact of several delay sources, and we find the primary contributor to be slow conduction through axonal collaterals within HVC, which typically adds between 1 and 7.5 ms for each link within the sequence. Thus, local axonal "delay lines" can play an important role in determining the dynamical repertoire of neural circuits.


Subject(s)
Finches/physiology , Prosencephalon/physiology , Vocalization, Animal/physiology , Animal Communication , Animals , Axons , Male , Motor Cortex/physiology , Nerve Net/physiology , Neural Pathways/physiology , Neurons/physiology
13.
Neuron ; 98(6): 1133-1140.e3, 2018 06 27.
Article in English | MEDLINE | ID: mdl-29861283

ABSTRACT

A vast array of motor skills can be maintained throughout life. Do these behaviors require stability of individual neuron tuning or can the output of a given circuit remain constant despite fluctuations in single cells? This question is difficult to address due to the variability inherent in most motor actions studied in the laboratory. A notable exception, however, is the courtship song of the adult zebra finch, which is a learned, highly precise motor act mediated by orderly dynamics within premotor neurons of the forebrain. By longitudinally tracking the activity of excitatory projection neurons during singing using two-photon calcium imaging, we find that both the number and the precise timing of song-related spiking events remain nearly identical over the span of several weeks to months. These findings demonstrate that learned, complex behaviors can be stabilized by maintaining precise and invariant tuning at the level of single neurons.


Subject(s)
Courtship , Motor Skills/physiology , Neurons/physiology , Vocalization, Animal/physiology , Animals , Finches , Interneurons , Longitudinal Studies , Male , Motor Cortex/cytology , Motor Cortex/physiology , Optical Imaging , Prosencephalon/cytology , Prosencephalon/physiology
14.
Cortex ; 89: 111-119, 2017 04.
Article in English | MEDLINE | ID: mdl-28282570

ABSTRACT

The production and perception of music is preferentially mediated by cortical areas within the right hemisphere, but little is known about how these brain regions individually contribute to this process. In an experienced singer undergoing awake craniotomy, we demonstrated that direct electrical stimulation to a portion of the right posterior superior temporal gyrus (pSTG) selectively interrupted singing but not speaking. We then focally cooled this region to modulate its activity during vocalization. In contrast to similar manipulations in left hemisphere speech production regions, pSTG cooling did not elicit any changes in vocal timing or quality. However, this manipulation led to an increase in the pitch of speaking with no such change in singing. Further analysis revealed that all vocalizations exhibited a cooling-induced increase in the frequency of the first formant, raising the possibility that potential pitch offsets may have been actively avoided during singing. Our results suggest that the right pSTG plays a key role in vocal sensorimotor processing whose impact is dependent on the type of vocalization produced.


Subject(s)
Cold Temperature , Singing , Temporal Lobe/physiology , Voice/physiology , Adult , Craniotomy , Epilepsy/physiopathology , Epilepsy/surgery , Humans , Magnetic Resonance Imaging , Male , Temporal Lobe/surgery
15.
Neuron ; 90(4): 866-76, 2016 05 18.
Article in English | MEDLINE | ID: mdl-27196976

ABSTRACT

The zebra finch brain features a set of clearly defined and hierarchically arranged motor nuclei that are selectively responsible for producing singing behavior. One of these regions, a critical forebrain structure called HVC, contains premotor neurons that are active at precise time points during song production. However, the neural representation of this behavior at a population level remains elusive. We used two-photon microscopy to monitor ensemble activity during singing, integrating across multiple trials by adopting a Bayesian inference approach to more precisely estimate burst timing. Additionally, we examined spiking and motor-related synaptic inputs using intracellular recordings during singing. With both experimental approaches, we find that premotor events do not occur preferentially at the onsets or offsets of song syllables or at specific subsyllabic motor landmarks. These results strongly support the notion that HVC projection neurons collectively exhibit a temporal sequence during singing that is uncoupled from ongoing movements.


Subject(s)
Action Potentials/physiology , Behavior, Animal/physiology , Finches/physiology , Neurons/physiology , Prosencephalon/physiology , Vocalization, Animal/physiology , Animals , Electric Stimulation/methods , Electrophysiology/methods , Female , Male
16.
Neuron ; 89(6): 1187-1193, 2016 Mar 16.
Article in English | MEDLINE | ID: mdl-26924439

ABSTRACT

Spoken language is a central part of our everyday lives, but the precise roles that individual cortical regions play in the production of speech are often poorly understood. To address this issue, we focally lowered the temperature of distinct cortical regions in awake neurosurgical patients, and we relate this perturbation to changes in produced speech sequences. Using this method, we confirm that speech is highly lateralized, with the vast majority of behavioral effects seen on the left hemisphere. We then use this approach to demonstrate a clear functional dissociation between nearby cortical speech sites. Focal cooling of pars triangularis/pars opercularis (Broca's region) and the ventral portion of the precentral gyrus (speech motor cortex) resulted in the manipulation of speech timing and articulation, respectively. Our results support a class of models that have proposed distinct processing centers underlying motor sequencing and execution for speech.


Subject(s)
Brain Mapping , Broca Area/physiology , Functional Laterality/physiology , Motor Cortex/physiology , Speech , Adult , Aged , Biophysics , Brain Neoplasms/pathology , Brain Neoplasms/surgery , Cold Temperature , Electric Stimulation , Epilepsy/pathology , Epilepsy/surgery , Female , Humans , Male , Middle Aged , Sound Spectrography , Speech Articulation Tests , Time Factors , Wakefulness
17.
Med Teach ; 36(1): 25-31, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24083365

ABSTRACT

BACKGROUND: Consistent identification and prevention of failure for at-risk medical students is challenging, failing courses is costly to all stakeholders, and there is need for further research into duration, timing and structure of interventions to help students in difficulty. AIMS: To verify the value of a new exam two weeks into medical school as a predictor of failure, and explore the requirements for a preventative intervention. METHODS: Students who failed the two-week exam were invited to a series of large-group workshops and small-group follow-up meetings. Participants' subsequent exam performance was compared with non-participants. RESULTS: About 71% of students who performed poorly in the new exam subsequently failed a course. Attendance at the workshops made no difference to short- or long-term pass rates. Attendance at more than three follow-up small group sessions significantly improved pass rates two semesters later, and was influenced by teacher experience. CONCLUSIONS: Close similarity between predictor task and target task is important for accurate prediction of failure. Consideration should be given to dose effect and class size in the prevention of failure of at-risk students, and we recommend a systemic approach to intervention/remediation programmes, involving a whole semester of mandatory, weekly small group meetings with experienced teachers.


Subject(s)
Education, Medical, Undergraduate/standards , Remedial Teaching/standards , Students, Medical/psychology , Test Taking Skills/standards , Caribbean Region , Education, Medical, Undergraduate/methods , Education, Medical, Undergraduate/organization & administration , Educational Measurement/methods , Educational Measurement/standards , Humans , Remedial Teaching/methods , Remedial Teaching/organization & administration , Risk Assessment/methods , Schools, Medical , Test Taking Skills/methods , United States
18.
BMC Med Educ ; 13: 132, 2013 Sep 27.
Article in English | MEDLINE | ID: mdl-24070196

ABSTRACT

BACKGROUND: Previous work has shown that a programme that draws on a blend of theories makes a positive difference to outcomes for students who fail and repeat their first semester at medical school. Exploration of student and teacher perspectives revealed that remediation of struggling medical students can be achieved through a cognitive apprenticeship within a small community of inquiry. This community needs expert teachers capable of performing a unique combination of roles (facilitator, nurturing mentor, disciplinarian, diagnostician and role model), with high levels of teaching presence and practical wisdom. Yet, despite participants' convergent opinions on the elements of effective remediation, significant differences were found between outcomes of students working with experienced and inexperienced teachers. The current study explores the actual practice of teachers on this remediation course, aiming to exemplify elements of our theory of remediation and explore differences between teachers. METHODS: Since it is in the classroom context that the interactions that constitute the complex process of remediation emerge, this practice-based research has focused on direct observation of classroom teaching. Nineteen hours of small group sessions were recorded and transcribed. Drawing on ethnography and sociocultural discourse analysis, selected samples of talk-in-context demonstrate how the various elements of remediation play out in practice, highlighting aspects that are most effective, and identifying differences between experienced and novice teachers. RESULTS: Long-term student outcomes are strongly correlated to teacher experience (r, 0.81). Compared to inexperienced teachers, experienced teachers provide more challenging, disruptive facilitation, and take a dialogic stance that encourages more collaborative group dynamics. They are more expert at diagnosing cognitive errors, provide frequent metacognitive time-outs and make explicit links across the curriculum. CONCLUSIONS: Remediation is effective in small groups where dialogue is used for collaborative knowledge construction and social regulation. This requires facilitation by experienced teachers who attend to details of both content and process, and use timely interventions to foster curiosity and the will to learn. These teachers should actively challenge students' language use, logical inconsistencies and uncertainties, problematize their assumptions, and provide a metacognitive regulatory voice that can generate attitudinal shifts and nurture the development of independent critical thinkers.


Subject(s)
Education, Medical/methods , Remedial Teaching/methods , Students, Medical , Education, Medical/standards , Educational Measurement , Faculty, Medical , Humans , Risk Factors , Students, Medical/psychology
19.
Med Teach ; 34(11): e732-42, 2012.
Article in English | MEDLINE | ID: mdl-22658068

ABSTRACT

BACKGROUND: Previous work identified complex ingredients of a remediation programme for at-risk medical students: mandatory, stable, facilitated small groups promote both cognitive and affective developments, with improved self-regulation, metacognition and reflection resulting in significant performance gains. AIM: We explore the teachers' role in this intervention, aiming to expand and deepen understanding of remediation methods in medical education. METHODS: Extensive qualitative data from student surveys and in-depth teacher interviews, along with quantitative student performance data, produced a rich description of remediation processes. RESULTS: Remediation should support emotional needs and foster cognitive and metacognitive skills for self-regulation and critical thinking. Teachers of remediation need to motivate, critique, challenge and advise their learners, applying teaching and contextual expertise in a constructivist, student-centred environment that fosters curiosity and joy for learning. Teachers of remediation can mediate these processes through embodiment of five core roles: facilitator, nurturing mentor, disciplinarian, diagnostician and modeller of desired skills, attitudes and behaviours. CONCLUSION: Remediation of struggling medical students can be achieved through a cognitive apprenticeship within a small community of inquiry that motivates and challenges the students. This community needs teachers capable of performing a unique combination of roles that demands high levels of teaching presence and practical wisdom.


Subject(s)
Faculty, Medical/organization & administration , Professional Role , Students, Medical , Teaching/methods , Affect , Cognition , Humans , Risk Factors
20.
Eur J Obstet Gynecol Reprod Biol ; 156(2): 190-3, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21295396

ABSTRACT

OBJECTIVE: Estrogen receptor interacts in several types of cells with phosphatidyl-inositol 3-kinase/Akt pathway regulating cell survival and apoptosis. No data are available of the Akt/PKB signaling and its role in the endometrial homeostasis of the postmenopausal uterus. The aim of the present investigation was to study the Akt/protein kinase B signaling in tissue samples retrieved from postmenopausal endometrium of the human uterus with parallel observation of the changes of the expression and phosphorylation of ERalpha. STUDY DESIGN: Sixty disease-free postmenopausal women were enrolled in the study. Endometrial tissue samples were obtained from diagnostic curettage or direct from the uterus after hysterectomy done for benign uterine lesions other than endometrial disease. For comparison, the studied parameters were also analyzed in endometrial samples of women with regular menstrual cycles (n=16). In each individual tissue sample the expression and phosphorylation of ERalpha, Akt, and cyclin D1 was analyzed by Western blotting. RESULTS: The level of Akt protein did not show significant change, however, the activation of Akt proteins and the expression of ERalpha increased parallel with serum estrogen (E2) levels, suggesting the role of E2 in Akt activation and ERalpha expression. The level of pERalpha(Ser167) changed parallel with pAkt(Ser473) levels. Significant correlation was found between the changes of pERalpha and ERalpha (r=0.650399, p<0.005), and in that of pERalpha and pAkt (r=0.639643, p<0.007), respectively. The expression of cyclin D1 was increased in samples with elevated pAkt levels. CONCLUSION: The results are indicating that the postmenopausal endometrium responds to E2 by both genomic and nongenomic mechanism. The interaction between ERalpha and Akt plays crucial role in the regulation of proliferative activity in postmenopausal endometrium.


Subject(s)
Endometrium/enzymology , Estrogen Receptor alpha/metabolism , Postmenopause/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Female , Humans , Middle Aged , Phosphorylation
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