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PubMed2006

A supermicrosurgical flap model in the rat: a free true abdominal perforator flap with a short pedicle.

BACKGROUND: Perforator flaps have recently gained considerable popularity in reconstructive surgery, and their importance and advantages over conventional flaps have been widely accepted. Given the improvements in microsurgical techniques, researchers have encouraged the search for further perforator flap sources, such as a perforator flap with a short pedicle only. The purpose of this study was to describe a true perforator flap model with a short vascular pedicle in the abdominal region in the rat. METHODS: Twenty-six adult Sprague-Dawley rats weighing 400 to 500 g were used. In 10 rats, the perforator vascular anatomy of the abdominal region was determined by anatomic dissection. In the remaining 16 rats, a true abdominal perforator-based flap was created based on a short segment of deep epigastric vessels. In eight rats, the flap was transferred to the groin region as a free flap, and anastomosis was performed between the artery and vein of the flap and the superficial inferior epigastric artery and vein of the recipient site. In addition, in two of these flaps, the long thoracic vein of the flap was anastomosed to the femoral vein. In the remaining eight rats, the flap was transferred to the groin region, but in this group anastomosis was not performed. The latter group was designated as the control group. RESULTS: The skin islands of seven free perforator flaps survived completely, and the one remaining flap was determined to be necrotic. All the flaps in the control group underwent complete necrosis. CONCLUSIONS: Not only is the free abdominal perforator flap a reliable and true perforator flap model for future physiological, biological, and pharmacological studies, it is also an excellent self-controlled supermicrosurgical training model for learning proper techniques, meticulous intramuscular dissection of true perforator flaps, and anastomosis of small-caliber vessels.

Anastomosis, Surgical↗

PubMed2005

How effective are simulated molecular-level experiments for teaching diffusion and osmosis?

Diffusion and osmosis are central concepts in biology, both at the cellular and organ levels. They are presented several times throughout most introductory biology textbooks (e.g., Freeman, 2002), yet both processes are often difficult for students to understand (Odom, 1995; Zuckerman, 1994; Sanger et al., 2001; and results herein). Students have deep-rooted misconceptions about how diffusion and osmosis work, especially at the molecular level. We hypothesized that this might be in part due to the inability to see and explore these processes at the molecular level. In order to investigate this, we developed new software, OsmoBeaker, which allows students to perform inquiry-based experiments at the molecular level. Here we show that these simulated laboratories do indeed teach diffusion and osmosis and help overcome some, but not all, student misconceptions.

Biology↗

PubMedDate not supplied

The cerebellum's role in reading: a functional MR imaging study.

BACKGROUND AND PURPOSE: Long considered to have a role limited largely to motor-related functions, the cerebellum has recently been implicated as being involved in both perceptual and cognitive processes. Our purpose was to determine whether cerebellar activation occurs during cognitive tasks that differentially engage the component processes of word identification in reading. METHODS: Forty-two neurologically normal adults underwent functional MR imaging of the cerebellum with a gradient-echo echo-planar technique while performing tasks designed to study the cognitive processing used in reading. A standard levels-of-processing paradigm was used. Participants were asked to determine whether pairs of words were written in the same case (orthographic processing), whether pairs of words and non-words rhymed with each other, respectively (phonologic assembly), and whether pairs of words belonged to the same category (semantic processing). Composite maps were generated from a general linear model based on a randomization of statistical parametric maps. RESULTS: During phonologic assembly, cerebellar activation was observed in the middle and posterior aspects of the posterior superior fissure and adjacent simple lobule and semilunar lobule bilaterally and in posterior aspects of the simple lobule, superior semilunar lobule, and inferior semilunar lobule bilaterally. Semantic processing, however, resulted in activation in the deep nuclear region on the right and in the inferior vermis, in addition to posterior areas active in phonologic assembly, including the simple, superior semilunar, and inferior semilunar lobules. CONCLUSION: The cerebellum is engaged during reading and differentially activates in response to phonologic and semantic tasks. These results indicate that the cerebellum contributes to the cognitive processes integral to reading.

Adult↗

PubMed1987

The use of therapeutic touch in the management of pain.

Nursing by definition is in part nurturing. It is the care of human beings--people who should be viewed and treated as a unified whole, people who interact with the environment and those around them on many levels. Nursing as a profession offers a unique service to those who are ill and in pain. That service takes form in many ways, among them a deep caring for the patients. The caring component in nursing is one of the most valuable intangibles, and TT is one of the most basic of the caring skills. TT provides the patient with extra care and puts the "art" back in nursing. But TT is also something much more than that. TT is a very personal act of caring, of giving to another person. To the patient with pain, TT affirms that you care and that you are acknowledging their pain. That, in and of itself, can be a source of great comfort to someone with pain. The management of pain is a complex and inexact science at best. The pain experience is a complex and often frustrating one. Patients look to various members of the health care profession for assistance and affirmation of their pain. But there are no "magic bullets" in the treatment of pain; even TT is not a universally effective therapy. There is a great deal to learn about pain, about the treatment of pain, and about TT. The challenge now is to continue the research to better understand pain, to understand the human response to pain, and to explain the phenomenon of TT, one modality in the treatment of pain. In implementing this research effort, it is important to recognize that objective scientific information is a necessary but insufficient component in understanding pain. Subjective information, the pain experience, is just as necessary for fully understanding the problem of pain. Until research provides better approaches, the treatment of the patient with pain, regardless of modality, demands multiple approaches, a commitment to keep trying, engaging the patient in the treatment plan, and moving at the patient's pace, not that of the care giver or health care team.

Acute Disease↗

PubMed2003

Learning root debridement with curettes and power-driven instruments. Part II: Clinical results following mechanical, nonsurgical therapy.

BACKGROUND, AIMS: In a manikin study we recently assessed how effectively student operators were able to learn scaling with curettes (GRA) and power-driven instruments (PP). Calculating the debrided root area effectiveness was low in both groups without systematic training or without a motivational program. After 10 weeks (20 h) of training, operators reached a high effectiveness of 84.7% (GRA) and 81.6% (PP). The purpose of the present study was to evaluate the clinical outcome of nonsurgical treatment as performed by these student operators. METHODS: In a clinical trial, 19 students trained in the use of Gracey curettes for 10 weeks (=20 h) (GRA10) and Periopolisher system for 1 week (=2 h) (PP1), and 20 students trained in the use of Gracey curettes for 1 week (GRA1) and the Periopolisher for 10 weeks (PP10) treated one patient each in a split-mouth design. At baseline and 6 months, we recorded probing depth (PD), probing attachment level (PAL) and bleeding on probing (BOP) by computer-assisted probing. Statistical analysis was carried out for moderate (category B) and deep sites (category C). Groups were compared using Student's t-tests (p<0.05). RESULTS: Category B sites showed a PD reduction of 1.2/1.0 mm (GRA10/GRA1) and 1.1 mm (PP10/PP1). PAL gain was 0.5/0.3 mm (GRA10/GRA1) and 0.4/0.2 mm (PP10/PP1). In category C sites, PD reduction was 2.1/2.3 mm (GRA10/GRA1) and 2.0 mm (PP10/PP1) with a PAL gain of 0.6/0.9 mm (GRA10/GRA1) and 0.4 mm (PP10/PP1). BOP was significantly lower in all groups. CONCLUSION: The results show that student operators who had received a systematical training on manikins and had attained different effectiveness results were able to treat periodontally diseased patients successfully using both Gracey and Periopolisher instruments.

Dental High-Speed Equipment↗

PubMed2001

Understanding human impact on the Baltic ecosystem: changing views in recent decades.

Grave environmental problems, including contamination of biota by organochlorines and heavy metals, and increasing deep-water oxygen deficiency, were discovered in the Baltic Sea in the late 1960s. Toxic pollutants, including the newly discovered PCB, were initially seen as the main threat to the Baltic ecosystem, and the impaired reproduction found in Baltic seals and white-tailed eagles implied a threat also to human fish eaters. Countermeasures gradually gave results, and today the struggle to limit toxic pollution of the Baltic is an international environmental success story. Calculations showed that Baltic deep-water oxygen consumption must have increased, and that the Baltic nutrient load had grown about fourfold for nitrogen and 8 times for phosphorus. Evidence of increased organic production at all trophic levels in the ecosystem gradually accumulated. Phosphorus was first thought to limit Baltic primary production, but measurements soon showed that nitrogen is generally limiting in the open Baltic proper, except for nitrogen-fixing cyanobacteria. Today, the debate is concerned with whether phosphorus, by limiting nitrogen-fixers, can control open-sea ecosystem production, even where phytoplankton is clearly nitrogen limited. The Baltic lesson teaches us that our views of newly discovered environmental problems undergo repeated changes, and that it may take decades for scientists to agree on their causes. Once society decides on countermeasures, it may take decades for them to become effective, and for nature to recover. Thus, environmental management decisions can hardly wait for scientific certainty. We should therefore view environmental management decisions as experiments, to be monitored, learned from, and then modified as needed.

Animals↗

PubMed2005

A study of hospital discharges for venous thromboembolism in the south of Spain. An analysis of 19,170 cases from a regional database from 1998 to 2001.

BACKGROUND: Our objective was to learn about the incidence of hospitalization for venous thromboembolism (VTE) in the public health care system in Andalusia and to define the profile of the patients, with special reference to the Department of Internal Medicine. METHODS: We analyzed the discharged data set of 32 hospitals in the Andalusian Health Care Service between 1998 and 2001, identifying the cases in whom the diagnosis was VTE. The age, sex, length of stay, outcome, number of diagnoses, diagnosis-related group (DRG), and coded procedures were studied. RESULTS: During the period studied, there were 2,228,894 discharges, 19,170 of which involved VTE. In 8494 of these, VTE was the cause of the admission. Some 3961 patients (46.6%) were admitted for pulmonary embolism (PE); 45% were discharged from internal medicine, 41% from pneumology, and 14% from other departments. The average patient age was 65, the length of stay 13.8 days, and the global in-hospital mortality rate 13%. Some 4533 cases (53.4%) were admitted due to deep vein thrombosis (DVT): 38.5% to internal medicine, 21.30% to general surgery, 12.35% to angiology, and the remainder to other departments. The length of stay was 10.6 days with an in-hospital mortality rate of 2.20%. In 7721 cases, VTE was the secondary diagnosis (after excluding 2955 cases of superficial thrombophlebitis of the upper limbs); 74% was associated with a medical DRG. CONCLUSIONS: VTE is a frequent pathology in our hospitals. It shows a great variability in clinical practice although there are differences between patients treated by different specialists. VTE as secondary diagnosis was more frequent in medical inpatients.

Journal Article↗

PubMed2004

Facial expression recognition and subthalamic nucleus stimulation.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor signs in Parkinson's disease. However, clinical studies suggest that DBS of the STN may also affect cognitive and emotional functions. OBJECTIVE: To study the impact of STN stimulation in Parkinson's disease on perception of facial expressions. RESULTS: There was a selective reduction in recognition of angry faces, but not other expressions, during STN stimulation. CONCLUSIONS: The findings may have important implications for social adjustment in these patients.

Adult↗

PubMed1980

On the nature of the visual-cliff-avoidance response in human infants.

22 infants 6.7--12.3 months old were tested on a visual-cliff apparatus both crawling and in a walker. Experience with the walker ranged from 0.5 to 4.5 months; experience crawling from 0.1 to 4.8 months. A multivariate analysis of latencies to full support and to reach the mother showed a significant interaction between cliff side and type of locomotion. Latencies on the deep side were longer when crawling than when in the walker. Age and experience factors were examined as predictors of avoidance and nonavoidance behavior in the crawling condition. Stepwise discriminant analyses chose "age when first crawled" as the best predictor of avoidance behavior. While experience crawling was a significant predictor when entered into the analysis first, greater experience crawling predicted nonavoidance behavior. Further analysis suggests that the effect of experience was not independent of age when first crawled. These results argue for a maturation-based explanation of cliff avoidance and against an explanation in terms of reafferent information produced by experience locomoting.

Avoidance Learning↗

PubMed2004

Technique and considerations when using external fixation as a standard treatment of femoral fractures in children.

Femoral fractures in children can be treated effectively and with a low complication rate by using external fixation. However, as with most treatment modalities there is a learning curve to be considered. The aim of this paper is to report "tricks" and different considerations that we have learned to be of value based on experience gained during a prospective and consecutive study of 98 femoral fractures in children aged 3-15 years. Our experience is based on the use of a unilateral fixator with the option to apply axial dynamisation. Traction prior to operation is not needed if the child is operated on within 24h. During surgery a traction table will prevent significant malrotation and facilitate reduction prior to insertion of the pins. Four 4 or 5mm pins are sufficient for adequate stability in children. Transverse skin incisions are preferable for pin insertion as the scars become smaller and the soft tissue irritation during activity is less when compared with longitudinal incisions. Unrestricted weight-bearing can be allowed. A nihilistic approach to pin site care with daily showers is as effective as more aggressive treatment with local antiseptics. Pin infections can occur but are mild and can be treated locally or with a short period of antibiotics taken orally. Pin-loosening and deep infections are very uncommon. By using external fixation, malunion, overgrowth or delayed union can almost be avoided completely. Re-fractures are rare and occur only after significant trauma. Treatment time is relatively short. No physiotherapy or further protection of the leg is necessary during or after healing.

Adolescent↗

PubMed1997

[Intraoperative EEG monitoring using a neural network].

OBJECTIVE: To introduce a new EEG parameter for monitoring a patient's cerebral status during anaesthesia. METHOD: EEG epochs (channel C3 P3, duration 30 see per epoch) yield patterns used as the training input of a self-organising neural network (neural gas algorithm). Each pattern contains spectral components. An additional "suppression parameter" reflects the proportion of flat curves during an EEG epoch and reduces the shortcomings of spectral analysis. The enhanced pattern vector enables the recognition of burst-suppression periods representing depressed cerebral activity during anaesthesia. Following training with 25549 EEG epochs ¿recorded in 196 consenting patients in the period beginning 5 minutes before induction of anaesthesia to extubation¿ the network knows 125 basic patterns (neural clusters). The neural clusters are responsible for different stages of anaesthesia: some neurons are activated by EEG epochs of awake patients, others are stimulated by deep stages. The homogeneity of the EEG epochs of cluster is checked. The portion of the EEG epochs not recognised by the network (7.5%) contains heterogeneous and sporadic patterns (mainly outlines caused by artefacts). RESULTS: In comparison with commonly used variables of anaesthesiological EEG monitoring (spectral edge or median frequency) neural discriminant analysis achieves better discrimination between awake and deeply anaesthetised stages (reclassification of 96% vs. 70%). On the basis of 56 complete sequences of patterns (from the beginning of the infusion of anaesthetics to the occurrence of burst suppression) a trend value of between 0.0 and 100.0 is assigned to each neural cluster. In contrast to existing methods, induction of anaesthesia causes a strictly linear increase in the electroencephalographic trend. CONCLUSIONS: Detailed neural cluster and discriminant analysis on the basis of the model described leads to an improved EEG parameter which better reflects the hypnotic effects of anaesthetic agents and arousal reactions caused by pain stimuli. Misclassifications of awake and anaesthetised stages are reduced. The neural network learns to recognize the complex changes in EEG patterns during induction of anaesthesia with different agents.

Adult↗

PubMedDate not supplied

[Ukhtomskiĭ and the nature of the human "ego"].

A. Ukhtomskiĭ is one of those Russian naturalists of the beginning of the 20th century (K. Tsiolkovskiĭ, V. Vernadskiĭ, K. Timiriazev, I. Pavlov), whose scientific work is characterized by a combination of the valuable contribution to a specific field of science and deep philosophical conceptualizations. Ukhtomskiĭ enriched modern neurophysiology by the ideas on dominant--a stable focus of enhanced excitability, determining the organism reactions to the environmental stimuli. Unlike artificial experimental models, natural dominant--vector of the goal-directed behaviour--represents the needs of immediate satisfaction, dominating at the present moment. Formation of needs hierarchy, characteristic of the given personality, occurs during the process of people communication. Namely, another man serves to the subject a mirror, looking into which he realizes himself as a human being (K. Marx). By his teaching on the dominant, Ukhtomskiĭ has revealed the dual nature of the personality's self-consciousness in the process of its perception of the surrounding people. He showed that involuntary projection of its dominating vital and social needs (motives, intentions) to the image of another man makes the latter only the "double" of the observer, which does not promote the development and enrichment of personality. Actually productive is only the perception which is motivated by the ideal need of learning another personality, sincere interest in him, what makes another person a "well-deserved colocutor", a source of new knowledge about people and himself. The ideas of Ukhtomskiĭ on the nature of human "self" are close to ideological searchings of L. Tolstoĭ and F. Dostoevskiĭ.(ABSTRACT TRUNCATED AT 250 WORDS)

Ego↗

PubMedDate not supplied

Mini-open approach to the spine for anterior lumbar interbody fusion: description of the procedure, results and complications.

BACKGROUND CONTEXT: Since the introduction of threaded devices in the mid-1990s, anterior lumbar interbody fusion (ALIF) has become a staple in the armamentarium of the spine surgeon. The procedure, however, is heavily dependent on the ability of the approach surgeon to provide exposure quickly and safely in view of a reported incidence of vascular injury as high as 15% and 2.3% incidence of retrograde ejaculation. PURPOSE: This study describes a mini-open approach to the lumbar spine and discusses the results and the complications seen. STUDY DESIGN/SETTING: The study was designed to evaluate patients for possible complications of the approach while they were in the hospital undergoing ALIF. They were also followed for 6 months after the operation. PATIENT SAMPLE: A total of 686 approaches to the lumbar spine performed on 684 patients between August 1997 and December 2000 were reviewed concurrently and retrospectively. OUTCOME MEASURES: All complications of the approach were reported. These included vascular injury, retrograde ejaculation, deep vein thrombosis (DVT), pulmonary emboli, infection, wound disruption/hernia, ileus, hematoma, myocardial infarction, stroke, peripheral ischemia, rectus muscle paralysis, aborted cases and death. METHODS: The patients were observed in the perioperative period and for 6 months postoperatively to determine the occurrence of complications related to the approach. The data collected included age, weight, gender, levels approached, time of completion of the approach, size of incision and complications. RESULTS: There were six arterial injuries (0.8%), six venous injuries (0.8%) and one instance of retrograde ejaculation (0.1%). In addition, there were seven cases that developed DVT (two ileofemoral and five calf-popliteal, 1.0%), four cases of ileus lasting more than 3 days (0.6%), three wound infections above the fascia (0.4%), two hernias and two compartment syndromes. There was one myocardial infarction and one death. No rectus muscle paralysis occurred. CONCLUSIONS: This experience suggests that a well-planned small incision that preserves the musculature can be performed quickly and safely to allow the spine surgeon adequate access to the anterior lumbar spine. The learning curve, however, can be high even for experienced surgeons.

Adult↗

PubMed2003

Quality of life philosophy II: what is a human being?

The human being is a complex matter and many believe that just trying to understand life and what it means to be human is a futile undertaking. We believe that we have to try to understand life and get a grip on the many faces of life, because it can be of great value to us to learn to recognize the fundamental principles of how life is lived to the fullest. Learning to recognize the good and evil forces of life helps us to make use of the good ones. To be human is to balance between hundreds of extremes. Sometimes we have to avoid these extremes, but at other times it seems we should pursue them, to better understand life. With our roots in medicine, we believe in the importance of love for better health. The secret of the heart is when reason and feelings meet and we become whole. Where reason is balanced perfectly by feelings and where mind and body come together in perfect unity, a whole new quality emerges, a quality that is neither feeling nor reason, but something deeper and more complete. In this paper, we outline only enough biology to clarify what the fundamental inner conflicts are about. The insight into these conflicts gives us the key to a great deal of the problems of life. To imagine pleasures greater than sensual pleasures seems impossible to most people. What could such a joy possibly be? But somewhere deep in life exists the finest sweetness, the greatest quality in life, the pure joy of being alive that emerges when we are fully present and life is in balance. This deep joy of life is what we call experiencing the meaning of life.

Adaptation, Psychological↗

PubMedDate not supplied

The molecular biology of brain and mind development.

The recent dramatic development of molecular neurobiology has focused almost entirely on biological events in individual brain cells, and it seems that many of the goals of such work will soon be attained. Yet, when we attain those goals, we will still have to ask how this information will enable us to understand the properties of brain cell collectivities and their presumptive roles in higher brain functions. Even general ideas about those functions are not yet well defined. Therefore, it seems worthwhile to start studying correlations of the molecular events to these higher functions to help delineate the molecular aspects that need study. It is readily appreciated that we cannot tell what other animal species see, hear, taste, smell and feel when touching something, though we can foresee the time when we will be able to detail the biochemical and biophysical consequences of all inputs to those senses. Thus, however deep our understanding of the biology of those species, we are unable to establish relations between their biological responses to inputs and their presumptive mental perceptions. Even though humans can use language to talk about those perceptions, we cannot even verify whether someone else's perceptions are the same as our own, as with the old question of whether two individuals see the same thing when viewing something blue. Questions about still higher mental functions of human brains are even less accessible to analysis and can be approached at best, by using correlations. In this article are a number of such questions and their current correlation-level answers.

Aging↗

PubMed1990

Intracortical processes regulating the integration of sensory information.

The mechanisms that link sensory inputs in spatially separated regions of cortex can be elucidated by analyzing the mechanisms that generate receptive field properties in cortical neurons under conditions that mimic the waking state; a state when learning, memory and the modification of synaptic strength can be most readily demonstrated. Important advances in understanding receptive field mechanisms in sensory cortex have arisen from studying the precise relationship between the mystacial vibrissae or "whiskers" and their neural representation in separate cortical domains or "barrels". The anatomical precision of whisker projections to barrels permits a unique delineation of thalamocortical and intracortical components of cortical cell responses based on latency and security of response to peripheral receptor stimulation. When recorded in awake animals or even under very light anesthesia, cortical neurons show two components to their response to whisker movement. Neurons in layer IV of a whisker's primary projection zone respond with short latency (7-10 msec) and a high response magnitude (two or more action potentials (spikes) per stimulus). This "Center Receptive Field" (CRF) for layer IV cells is generated in large part by sensory fiber inputs from the thalamus. The CRF is restricted to 1.4 whiskers on average and is the only response detectable when cortical responses are depressed by deep anesthesia. In the "waking state" the same neuron often will respond to deflection of 4-6 surrounding whiskers, but only at longer latency (15-40 msec) and with fewer spikes per stimulus. These more labile responses form an excitatory surround receptive field (SRF). Sensory information that is transduced by individual whiskers and that generates the SRF of a cortical neuron achieves this added response complexity through intracortical mechanisms. The control of the mechanisms that determine the dissemination of sensory information within cortex include: (1) regulating the level of GABAergic inhibition; and (2) potentiation or depression of the response level generated by repeated sensory experience. State-dependent "modulatory" inputs to cortex, such as the noradrenergic and cholinergic fiber system, could regulate the degree of horizontal spread of a sensory input, in part through global changes in the level of inhibition and/or regulating the amplitude of cortical responses, thereby determining the level of associative interactions between sensory inputs.

Animals↗

PubMed2006

Valproic acid prevents brain injury in a canine model of hypothermic circulatory arrest: a promising new approach to neuroprotection during cardiac surgery.

BACKGROUND: The anticonvulsant valproic acid (sodium valproate, Depacon) acts as a neuroprotectant in rodents, but has never been tested in larger animals. We used valproate in our canine model of hypothermic circulatory arrest to evaluate its neuroprotective benefit in complex cardiac surgical cases. METHODS: Thirteen dogs pretreated with valproate before 2 hours of hypothermic circulatory arrest survived for 24 hours (n = 7) or 72 hours (n = 6). Thirteen control animals (placebo only) also survived for 24 hours (n = 7) or 72 hours (n = 6) after hypothermic circulatory arrest. Blinded clinical neurologic evaluation was performed daily until sacrifice using the Pittsburgh Canine Neurologic Scoring System. Brains were harvested for blinded histopathologic analysis by a neuropathologist to determine the extent of apoptosis and necrosis in 11 brain regions (Total Brain Cell Death Score: 0 = normal, 99 = extensive neuronal death in all regions). Quantification of N-acetyl-aspartate, an established marker for brain injury, was performed with mass spectrometry. RESULTS: Valproate dogs scored significantly better than control animals on clinical neurologic evaluation. Histopathologic examination revealed that valproate animals demonstrated less neuronal damage (by Total Brain Cell Death Score) than control animals at both 24 hours (16.4 versus 11.4; p = 0.03) and 72 hours (21.7 versus 17.7; p = 0.07). At 72 hours, the entorhinal cortex, an area involved with learning and memory, was significantly protected in valproate dogs (p < 0.05). Furthermore, the cortex, hippocampus, and cerebellum demonstrated preservation of near-normal N-acetyl-aspartate levels after valproate pretreatment. CONCLUSIONS: These data demonstrate clinical, histologic, and biochemical improvements in dogs pretreated with valproate before hypothermic circulatory arrest. This commonly used drug may offer a promising new approach to neuroprotection during cardiac surgery.

Animals↗

PubMed2000

Neuropsychological consequences of chronic bilateral stimulation of the subthalamic nucleus in Parkinson's disease.

The aim of this study was to examine possible neuropsychological changes in patients with advanced idiopathic Parkinson's disease treated with bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN). Eleven patients (age = 67 +/- 8 years, years with Parkinson's disease = 15 +/- 3, verbal IQ = 114 +/- 12) were evaluated (in their best 'on state') with tests assessing processes reliant on the functional integrity of frontal striatal circuitry, prior to the procedure (n = 11), at 3-6 months (n = 11) and at 9-12 months (n =10) post-operatively. Six of these patients were older than 69 years. Despite clinical motor benefits at 3-6 months post-operative, significant declines were noted in working memory, speed of mental processing, bimanual motor speed and co-ordination, set switching, phonemic fluency, long-term consolidation of verbal material and the encoding of visuospatial material. Declines were more consistently observed in patients who were older than 69 years, leading to a mental state comparable with progressive supranuclear palsy. 'Frontal' behavioural dyscontrol without the benefit of insight was also reported by half (three of six) of the caregivers of the elderly subgroup. At 9-12 months postoperative, only learning based on multiple trials had recovered. Tasks reliant on the integrity of frontal striatal circuitry either did not recover or gradually worsened over time. Bilateral STN DBS can have a negative impact on various aspects of frontal executive functioning, especially in patients older than 69 years. Future studies will evaluate a larger group of patients and examine the possible reversibility of these effects by turning the DBS off.

Affect↗