Miracle-dz/UniFAR-FTUs huggingface dataset:
The Prognosis of Acute Low Back Pain in Primary Care in the United States: A 2-Year Prospective Cohort Study

Study Design. Prospective cohort study. Objective. To assess the prognosis of patients presenting with acute low back pain (LBP) in a primary care setting in the United States. Summary of Background Data. Practice guidelines for acute LBP based on return-to-work outcomes underestimate the development of chronic pain in the primary care setting. Because of differences in inclusion criteria, chronic pain definitions, and national health systems, prognostic cohort studies have reported a wide range of results limiting interpretation and generalization. Current data from carefully designed prognostic studies of acute LBP are lacking for the US primary care system. Methods. Members of a large health service organization were enrolled after seeking medical care for acute LBP, with or without sciatica, of up to 30 days duration, with no episode in the past 12 months and no history of spine surgery. We conducted phone interviews at baseline, 6 months, and 2 years. Based on receiver operating characteristic analyses, a combination of global perceived recovery with pain intensity was used as primary outcome for chronic pain. Recurrence and multiple secondary outcomes were assessed to allow for comparison with other studies. Results. Six hundred five patients had an average pain intensity of 5.6 (numeric rating scale = 0–10) and disability of 15.8 (Roland-Morris scale = 0–24). Eight percent had declared sick leave between pain onset and baseline interview. Thirteen percent of 521 patients (86% follow-up) experienced chronic pain at 6 months and 19% of 443 patients at 2 years. At 6 months, 54% had experienced at least 1 LBP recurrence, and 47% in the subsequent 18 months. Conclusion. The prognosis of strictly defined acute LBP, with or without sciatica, is less favorable than commonly stated in practice guidelines based on failure to return to work. Broad initiatives to develop new means for the primary and secondary prevention of recurrent and chronic LBP are urgently needed.
AGE-RELATED CHANGES IN THE NEURAL CORRELATES OF DEGRADED AND NONDEGRADED FACE PROCESSING

In order to explore the neural correlates of age-related changes in visual perception of faces, positron emission tomographic scans were obtained on young and old adults while they were engaged in tasks of nondegraded and degraded face matching. Old adults were less accurate than were young adults across all face matching conditions, although the age difference was greatly reduced when degraded performance was adjusted for nondegraded performance. The interaction of age and degree of degradation on performance measures was not significant. Brain activity patterns during nondegraded face matching were similar in the two groups with some differences in parietal and prestriate cortices (greater activity in young adults) and in prefrontal cortex, thalamus, and hippocampus (greater activity in old adults). Increases in activity related to increasing degradation of the faces were seen mainly in prefrontal cortices in both age groups. Despite this similarity in the brain response to face degradation, there were striking differences between groups in the correlations between brain activity and degraded task performance. Different regions of extrastriate cortex were positively correlated with behavioural measures in the two groups (fusiform gyrus in the young adults and posterior occipital regions in old adults). In addition two areas where older adults showed greater activity during nondegraded face matching, thalamus and hippocampus, also showed positive correlations with behaviour during the degraded tasks in this group, but not in the young group. Thus, although the elderly are not more vulnerable to the effects of increasing face degradation, the brain systems involved in carrying out these visual discriminations in young and old adults are not the same. These results are consistent with the idea of functional plasticity in face processing over the life span.
LOCALISED FACE PROCESSING BY THE HUMAN PREFRONTAL CORTEX: FACE-SELECTIVE INTRACEREBRAL POTENTIALS AND POST-LESION DEFICITS

The patient described in the companion paper by Vignal, Chauvel, and Halgren (this issue) was studied with event related potentials (ERPs) recorded directly within the brain substance, as well as with neuropsychological tests before and after therapeutic cortectomy. Large ERPs were evoked in the prefrontal cortex to faces, as compared to sensory controls and words. The largest such ERPs were highly localised to the same right anterior inferior prefrontal site where direct electrical stimulation resulted in face hallucinations. Face-selective ERPs were also evoked in the right prefrontal sites that had shown projected activity during face hallucinations, and near the right anterior superior temporal sulcus. Selective responses began about 150msec after face onset. Words, but not faces or sensory controls, evoked large ERPs in distinct locations, mainly in the left hemisphere. A successful surgical therapy was performed by removing the cortex surrounding the right prefrontal site where face-selective responses were recorded and where face hallucinations were evoked by stimulation. This cortectomy resulted in a severe deficit in the recognition of emotional facial expressions, especially fear. No change was noted, however, in the recall of emotional words, or other tasks. The current results provide strong support for the early, specific, and sustained involvement of a multi-focal network in the right inferior fronto-temporal cortex in face-processing.
The “living things” impairment and the nature of semantic memory organisation: An experimental study using PI-release and semantic cues

The present paper evaluated categorical and featural proposals of memory organisation, for explaining the living/nonliving things dissociation observed in semantic memory. The experimental study used the Release from Proactive Interference (PI-release) paradigm. Normal subjects were tested with this task using word vs. picture stimuli in a standard taxonomical PI-release condition (i.e., nonliving to living things) and in a cue condition with attributes that run opposite to the taxonomical shift. Experiments 1 and 2 cued functional attributes (means of transportation; dangerousness), and experiments 3 and 4 cued perceptual attributes (size; number of legs). The overall pattern of PI-release emphasizes the role of functional attributes and the role of structural processing to semantic processing. Implications for the different proposals presented, including possible alternative accounts of the results, are also discussed.
A role for the habenula in the regulation of locomotor activity cycles

Although much is known about the regulation of the circadian rest–activity cycle by the hypothalamic suprachiasmatic nucleus in nocturnal rodents, little is known about the neural substrates that regulate the temporal organization of nocturnal activity within the active phase. In this report, data are presented in Syrian hamsters to implicate the habenula – believed to be involved in motivation, reward and motor control – as a candidate site for such a role. First, by examining hamsters during the day and night and by introducing a ‘novel’ running wheel in order to induce daytime motor activity, we showed that immunoreactive c‐Fos expression in the lateral and medial habenula is related to motor activity/arousal. Second, by transecting the habenula’s major efferent pathway (fasciculus retroflexus), we showed that the interruption of habenula neural output alters the daily amount of motor activity, lengthens the period of the circadian rest–activity rhythm and disrupts the species‐typical pattern of nocturnal motor activity, measured as either wheel‐running behavior or general locomotor activity. Instead of the usual pattern of night‐time locomotion, characterized by a prolonged bout of elevated activity in the early night followed by shorter sporadic bouts or the cessation of activity altogether, lesioned animals exhibited a more homogeneous, undifferentiated temporal profile extending across the night. These data suggest a previously unrecognized function of the habenula whereby it regulates the temporal pattern of activity occurring within a circadian rest–activity window set by the suprachiasmatic nucleus.
The emergence of jargon in progressive fluent dysgraphia: The widening gap between target and response

This paper presents a long-term follow-up study of a dysgraphic patient reported in an earlier paper (Graham, Patterson, & Hodges, 1997). FM developed “jargon dysgraphia”: In writing to dictation, she fluently produced well-formed written output consisting of pronounceable neologisms which, over time, bore a progressively weaker resemblance to the target words (e.g., scribe → SCRIPE, January 1992; → SRIME, November, 1994; → BRINCE, August, 1996; → MEATH, November, 1997). Although this spelling disorder has been (rarely) reported in patients with stable brain lesions, this is the first time that it has been documented in the context of progressive disease, a situation that provided a unique opportunity to document its characteristics at different stages. Longitudinal results from a spelling-to-dictation task showed that FM was, for a time, able to activate at least partial orthographic information, even after her overall accuracy (assessed in terms of the number of words spelled completely correctly) had reached the floor. For example, her error responses were correlated in length with the targets, and contained a larger than chance number of letters that overlapped between target and response. Ultimately, FM's spelling responses had no detectable similarity with the targets, although they remained word-like in that they were pronounceable and contained few illegal letter combinations.
Neuronal basis for evaluating selected action in the primate striatum

Humans and animals optimize their behavior by evaluating outcomes of individual actions and predicting how much reward the actions will yield. While the estimated values of actions guide choice behavior, the choices are also governed by other behavioral norms, such as rules and strategies. Values, rules and strategies are represented in neuronal activity, and the striatum is one of the best qualified brain loci where these signals meet. To understand the role of the striatum in value‐ and strategy‐based decision‐making, we recorded striatal neurons in macaque monkeys performing a behavioral task in which they searched for a reward target by trial‐and‐error among three alternatives, earned a reward for a target choice, and then earned additional rewards for choosing the same target. This task allowed us to examine whether and how values of targets and strategy, which were defined as negative‐then‐search and positive‐then‐repeat (or win‐stay‐lose‐switch), are represented in the striatum. Large subsets of striatal neurons encoded positive and negative outcome feedbacks of individual decisions and actions. Once monkeys made a choice, signals related to chosen actions, their values and search‐ or repeat‐type actions increased and persisted until the outcome feedback appeared. Subsets of neurons exhibited a tonic increase in activity after the search‐ and repeat‐choices following negative and positive feedback in the last trials as the task strategy monkeys adapted. These activity profiles as a heterogeneous representation of decision variables may underlie a part of the process for reinforcement‐ and strategy‐based evaluation of selected actions in the striatum.
The Biomechanical Effect of Pedicle Screws' Insertion Angle and Position on the Superior Adjacent Segment in 1 Segment Lumbar Fusion

Study Design. A finite element analysis. Objective. To investigate the association between the position of an inserted pedicle screw and the corresponding facet contact force or intradiscal pressure. Summary of Background Data. Although superior facet joint violation by pedicle screws is not an uncommon occurrence in instrumented lumbar fusion surgery, its actual biomechanical significance is not well understood. Furthermore, the association between the position of the pedicle screw and the stress on the corresponding disc/facet joint has yet to be investigated. Methods. According to the positions of pedicle screws in L4 of the L4–L5 lumbar fusion, 4 L4–L5 fusion models were simulated. These models included the violation of both L3–L4 superior facet joints by pedicle screws (facet joint violation [FV] model), the nonencroachment of both L3–L4 superior facet joints by pedicle screws (facet joint preservation [FP] model), and the removal state of pedicle screws in the FV model (removal of violated pedicle screws [rFV] model). The facet joint contact [FC] model represented the scenario in which the pedicle screws did not encroach upon either facet joint but were inserted close to the L3–L4 facet joint surface. Moreover, the uninstrumented fusion [UF] model represented the uninstrumented L4–L5 fusion. In each scenario, the intradiscal pressures and facet contact forces at the L2–L3 and L3–L4 segments were analyzed under extension and torsion moments. Results. The FV model yielded the greatest increases in facet contact force and intradiscal pressure at the L3–L4 segment under extension and torsion moments. Following the FV model, the increases in intradiscal pressure and facet contact force were the second highest in the FC model followed by the FP model. Furthermore, the rFV model represented prominent reductions of previously increased facet contact force and intradiscal pressure at the L3–L4 segment. Conclusion. In models of 1-segment lumbar fusion surgery, the positions of pedicle screws were closely linked with corresponding disc stresses and facet contact forces. However, even in cases of facet violation by pedicle screws, removal of the pedicle screw after fusion completion can reduce facet contract forces and disc stresses under both extension and torsional moments.
Within-object and between-object coding deficits in drawing production

We examine how perceptual grouping influenced drawing errors in two patients with constructional apraxia. The patients copied simple geometric stimuli, formed from right-angled elements of variable size arranged as the corners of a square. Grouping was systematically manipulated by altering the closure between these local parts. The patients also made perceptual judgments about similar figures. Despite relatively intact perceptual discrimination of the stimuli, both patients produced errors in drawings relative to controls. When local elements were arranged as a square, patient ECR produced some shape errors but showed a marked tendency to complete across gaps between elements. In contrast, patient RA made no such completion errors but placed the elements so that they were poorly spatially located. When grouping was reduced, ECR completed fewer gaps and RA showed improved spatial localization. These symptoms suggest impairments of perceptuomotor representations of object relations. ECR's deficit appeared to be in between-object coding—she often failed to separate the individual elements when they formed a strong perceptual whole. In contrast, RA's deficit appeared to be in within-object coding—spatial localization of elements was impaired when they shared strong grouping cues. His performance only improved when the strength of the grouping between the elements was reduced. These findings demonstrate the coding of different forms of spatial relation in the perceptual-motor domain.
An Analysis of Causes of Readmission After Spine Surgery

Study Design. Retrospective review of medical records. Objective. We reviewed all early readmissions after elective spine surgery at a single orthopedic specialty hospital to analyze the causes of unplanned readmissions. Summary of Background Data. Recent advances in techniques and instrumentation have made more complex spinal surgeries possible, although sometimes with more complications. Early readmission rate is being used as a marker to evaluate quality of care. There is little data available regarding the causes of early readmissions after spine surgery. Methods. Using the hospital's administrative database of patient records from 2007 to 2009, all patients who underwent spine surgery and were readmitted to the hospital within 30 days were identified and broadly categorized as planned (a staged or rescheduled procedure or a direct transfer) or unplanned. Unplanned readmissions were defined to have occurred as a result of either a surgical or a nonsurgical complication. Analysis was focused on 12 common spine procedures based on the principle procedure International Classification of Diseases, Ninth Revision, Clinical Modification code for the patient's initial admission. The readmission rate was calculated for each procedure. Results. A total of 156 early readmissions were identified, of which 141 were unplanned. Of the unplanned readmissions, the most common causes were infection or a concern for an infection (45 patients, 32% of unplanned readmissions), nonsurgical complications (31 patients, 22% of readmissions), complications requiring surgical revision (21 patients, 15% of readmissions), and wound drainage (12 patients, 9% of readmissions). Fifty-seven percent of unplanned readmissions required a return to the operating room (76% of infections or concern for infection). The average length of stay for the unplanned readmissions was 6.5 days. When using the 12 most common procedures based on the International Classification of Diseases, Ninth Revision, Clinical Modification, the early readmission rate was 3.8% (141 early readmissions in 3673 procedures). Conclusion. Infection, medical complications after surgery, and surgical complications requiring revision of implants are the primary causes of unplanned early readmissions and spine surgery. Further studies are necessary to identify patients and procedures most associated with readmission.
Severe developmental letter-processing impairment: A treatment case study

We report the case of ET, a 7-year-old child with a severe developmental letter-processing impairment. Detailed assessment revealed multiple impairments of the letter-processing system affecting abstract visual letter representation, semantics, and connections between the phonological processing modules and the orthographic buffer. Treatment methods focused on letter sounding through development of abstract visual representation and semantic representation of letters. Treatment resulted in dramatic and enduring improvements in cross-case matching, letter/number categorization, and letter sounding. Cognitive neuropsychological reading research has largely focused on word processing, with a relative neglect of single-letter processing. The current study investigated letter processing in greater detail than has been usual and outlines a broad theoretical framework for letter processing. ET's assessment and treatment data are used to support and question predictions from the framework. A number of theoretical implications are discussed with reference to ET's data and that of other reported cases of impaired single-letter processing. Finally, the paucity of investigation of letter processing in children is highlighted, particularly with regard to integrity of abstract letter representation in developmental dyslexia.
Fluoxetine rescues impaired hippocampal neurogenesis in a transgenic A53T synuclein mouse model

The accumulation of alpha‐synuclein in Lewy bodies and Lewy neurites of different neuronal populations is one of the neuropathological hallmarks in Parkinson disease (PD). Overexpression of human wildtype or mutant alpha‐synuclein affects the generation of new neurons in the adult dentate gyrus (DG) of the hippocampus in models of PD. Hippocampal dysfunction with reduced neurogenesis plays an important role in the pathogenesis of depression, an important non‐motor symptom in PD. Moreover, effective antidepressant treatment is still an unmet need in PD. The present study explored if impaired hippocampal neurogenesis in the A53T transgenic animal model of PD may be restored by chronic oral application of the selective serotonin reuptake inhibitor (SSRI) fluoxetine. First, we determined the expression pattern of transgenic mutant A53T synuclein in developing DG neurons and showed early expression of the transgene linked to a severely impaired neurogenesis. After chronic fluoxetine treatment we observed an increased adult neurogenesis in the hippocampus of more than threefold in treated A53T mice compared with controls. The pro‐neurogenic effect of chronic fluoxetine application is predominantly related to an increased proliferation of neural precursor cells in the DG, and to a lesser extent by induction of differentiation into mature neurons. Analysis of the underlying mechanisms revealed an induction of brain‐derived and glial cell‐derived neurotrophic factor levels as a result of fluoxetine treatment. This study underlines the large potential of SSRI‐dependent mechanisms to stimulate adult hippocampal neurogenesis in alpha‐synuclein models and may lead to novel means to improve neuropsychiatric symptoms in PD.
Impact of Unilateral Corrective Tethering on the Histology of the Growth Plate in an Established Porcine Model for Thoracic Scoliosis

Study Design. Histological growth plate analysis. Objective. To evaluate the histological effects on vertebral growth plates following corrective mechanical tethering in the porcine scoliosis model. Summary of Background Data. Theoretically, growth modulation allows progressive vertebral correction in the setting of scoliosis (Hueter-Volkmann principle). Methods. This IACUC-approved study divided 9 immature Yorkshire pigs into 2 groups: deforming tether release (TR, n = 4) group and anterior corrective (AC, n = 5) tether group. Once 50° coronal Cobb was demonstrated, TR had release of the deforming tether, whereas AC had release of the deforming tether and additional placement of a corrective tether. After 20 weeks of observation, pigs were killed, spines were removed, and apical samples were prepared for histological study. Growth plate analysis included the following histological parameters: proliferative zone height, hypertrophic zone height, and cell heights within the hypertrophic zone. Student t test was used to evaluate differences within and between groups. Results. No significant differences were found within the release group on the concave versus convex side in terms of proliferative zone height, hypertrophic zone height, and cell heights in the hypertrophic zone. In the anterior correction group, the proliferative zone height was significantly smaller on the concave side than on the convex side (P < 0.01); no significant differences were found in AC on the concave versus convex side in terms of hypertrophic zone height and cell heights in the hypertrophic zone. No significant differences were found in any parameters between TR and AC on either the concave or the convex side. Conclusion. No significant decrease in any of the measured parameters was observed in the anterior correction group compared with the tether release group. These histological findings are consistent with preservation of growth potential.