PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Models, Neurological”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Autism as impairment in the formation and use of meaning: an attempt to integrate a functional and a neurological model.

Neurological approaches and functional approaches to impairments in autism provide different perspectives on the disorder. This study attempted an integration of the two approaches, based specifically on the role of the mesolimbic/neostriatal system in imparting adaptive meaning to percepts and problems that autistic persons have in making adaptive use of meaning.

Autistic Disorder↗

Postulating that our neurological models for musculoskeletal support, movement, and emotional expression come from archetypal forms in early organisms.

The ability for humans, in principle, to almost effortlessly support themselves against gravity, to move with grace, and to express themselves in subtle and beautiful ways is amazing, given the number of moveable joints, variety of obstacles and intentions, and possible emotions to express. The actual mechanics are obviously astonishing but the models for these activities, in origin, must be simple. The basic hypotheses concerning these models are the following: The neurological model for the control of our musculoskeletal system is a simple support system from early organisms. This model involves a complementary relationship between the dorsal and ventral surfaces. There are three functionally distinct parts of the body, though not visually observable. These parts, named here "the director, motor, and rudder segments," are functionally distinct in optimal posture and movement. Healthy balance, posture, and movement result from their relatively independent yet coordinated actions. Forms of locomotion used by early organisms: peristalsis, lateral undulation, and dorsal-ventral undulation are present in us yet. Four frozen phases of the dorsal-ventral wave, for example, constitute four distinct postural and personality styles. I present these hypotheses together in this short paper as an introduction to a new illustration-dependent way to conceive some of our psychophysical realities. The hypotheses came from efforts to develop mental imagery to assist students in learning the Alexander technique (AT). In addition, a little known theory concerning four basic emotions and personality types, called the Fusion Theory, provided an initial concept of personality types. Four fixed postural patterns that I observed in teaching AT linked well to this personality typology. There is research that supports the use of mental imagery to affect change in body use, mostly in the sports and dance fields, but none exists addressing the specific imagery derived from these hypotheses. If these theories were confirmed, several areas could stand to benefit. Through imagery, some concepts involving musculoskeletal health could become more accessible to health-conscious and suffering individuals and give them a new way to become more connected to and responsible for their postural and mental health. Kinesiology, neurology, and psychology could develop a closer connection if research found that some aspects of posture, movement, and emotion all developed from allied origins. Specific benefits could come to the study of facial and body expression, understanding the physical basis of emotion and attitude, and understanding the experience of qualia in general.

Animals↗

[A neurologic model of early infantile autism].

Based on the abnormalities in sleep-wakefulness cycle of early infantile autism, the author discussed its pathophysiology focusing on its main lesion in the raphe nuclei. These neurons, located in the midline portion of the brainstem send their axons to various neurons of the upper and lower nervous systems, including the locus coeruleus and the dopamine neurons of the tegmentum, the former having a broad innervation and the latter a restricted area in the central nervous system. These monoaminergic neurons modulate the functions of the involved neurons and regulate their functional and structural maturation in the early developmental course. The early lesion of the raphe nuclei causes poor adaptation to environment which develops as abnormal circadian oscillation and pervasive lack of responsiveness. Combined hypofunction of the locus ceruleus, particularly of its dorsal bundle, results in the failure of extinction of acquired memory in mice which relates clinically to the excellent memory and resistance to change peculiar interests and attachments in humans. From early childhood, the disturbance of dopaminergic neurons becomes apparent clinically, and causes hyperkinesia and stereotyped activities. With the other two monoaminergic neurons, dopaminergic neurons cause occasional aggressiveness or self-mutilation. The latter behaviors are like those of pampered children and are simulated to "muricide" and "friendliness" observed in rats with these monoaminergic lesions. The particular language disturbance with echolalia is due to the right hemispheric dominance, which might have been caused by a delayed functional lateralization of the hemisphere resulting also from the delayed development of the circadian oscillation in infancy. The motor disturbances consisting of hypotonia and impaired locomotion might be due to decreased tonic innervations of the locus ceruleus and the raphe nuclei to the spinal locomotion center. CT examination of symptomatic autism showed the amygdala as one of the causative nuclei for the autistic behavior.

Animals↗

Forgiveness: a neurological model.

A definition of "forgiveness" is chosen that emphasizes its biological and neurological components, namely the cessation of emotions connected with memories of a hurtful act. An experience of forgiveness is analyzed into seven steps and each is associated with a neurological source. The cornerstone hypothesis is that, before forgiveness takes place, memories periodically arouse fear stemming from the amygdala. This fear drives a pattern of anger and fight-or-flight readiness. Under appropriate circumstances the frontal cortex interrupts the pattern and quells the fear response in the amygdala. The resultant relaxation of muscular tension signals the cortex that forgiveness has occurred. In addition, the memory pathway from the rhinal cortex and hippocampus to the amygdala is inhibited. Finally, a tangible act confirms that the memories no longer stimulate the amygdala and the pattern of anger and stress do not recur. The relationship of the neurological model with other theoretical models is presented and some avenues for experimental testing of the model are mentioned.

Amygdala↗

Functional-imaging studies of the 19th Century neurological model of language.

This paper will consider the consistencies and disparities between the classic 19(th) Century model of language and the results of functional neuro-imaging studies on auditory and visual word repetition. The functional imaging studies show that, as predicted by the 19(th) Century neurologists, auditory and visual word repetition engage perisylvian regions in the left posterior superior temporal and posterior inferior frontal cortices. More specifically, the roles that Wernicke and Broca assigned to these regions lie respectively in the upper banks of the left posterior superior temporal sulcus and the left anterior insula/frontal operculum. In addition, a region in the left posterior inferior temporal cortex is activated for word retrieval and provides a second route to reading, emphasised by 20(th) Century cognitive models of language. There is no firm evidence as yet to link the function of a visual word form area to a specific neural substrate. The angular gyrus, previously linked to the visual word form system, is shown to be part of a distributed semantic system that can be accessed by objects and faces as well as speech. Overall, functional neuroimaging demonstrates that the 19(th) Century neurological model of language is remarkably insightful.

Aphasia, Broca↗

Toward a neurologic model of competency: Cognitive predictors of capacity to consent in Alzheimer's disease using three different legal standards.

OBJECTIVE: To identify cognitive predictors of competency performance and status in Alzheimer's disease (AD) using three differentially stringent legal standards for capacity to consent. DESIGN: Univariate and multivariate analyses of independent neuropsychological test measures with three dependent measures of competency to consent to treatment. SETTING: University medical center. SUBJECTS: 15 normal older controls and 29 patients with probably AD (15 mild and 14 moderate). MAIN OUTCOME MEASURES: Subjects were administered a batter of neuropsychological measures theoretically linked to competency function, as well as two clinical vignettes testing capacity to consent to medical treatment under five legal standards (LSs). The present study focused on three differentially stringent LSs: the capacity simply to "evidence a treatment of choice" (LS1), which is a minimal standard; the capacity to "appreciate the consequences" of a treatment of choice (LS3), a moderately stringent standard; and the capacity to "understand the treatment situation and choices" (LS5), the most stringent standard. Control subject and AD patient neuropsychological test scores were correlated with scores on the three LSs. The resulting univariate correlates were than analyzed using stepwise regression and discriminant function to identify key multivariate predictors of competency performance and status under each LS. RESULTS: No neuropsychological measures predicted control group performance on the LSs. For the AD group, a measure of simple auditory comprehension predicted LS1 performance (r(2)=0.44, p < 0.0001), a word fluency measure predicted LS3 performance (r(2)=0.58, p < 0.0001), and measures of conceptualization and confrontation naming together predicted LS5 performance (r(2)=0.81, p < 0.0001). Under discriminant function analysis, confrontation naming was the best single predictor of LS1 competency status for all subjects, correctly classifying 96% of cases (42/44). Measures of visumotor tracking and confrontation naming were the best single predictors, respectively, of competency status under LS3 (91% [39/43]) and LS5 (98% [43/44]). CONCLUSIONS: Multiple cognitive functions are associated with loss of competency in AD. Deficits in conceptualization, semantic memory, and probably verbal recall are associated with the declining capacity of mild AD patients to understand a treatment situation and choices (LS5); executive dysfunction with the declining capacity of mild to moderate AD patients to identify the consequences of treatment choice (LS3); and receptive aphasia and severe dysnomia with the declining capacity of advanced AD patients to evidence a simple treatment choice (LS1). The results offer insight into the relationship between different legal thresholds of competency and the progressive cognitive changes characteristic of AD, and represent an initial step toward a neurologic model of competency.

Alzheimer Disease↗

A neurological model for childhood autism.

We analyze the behavioral and motor disturbances in childhood autism. On the basis of analogy to signs and conditions seen in adult neurology, we propose that the syndrome results from dysfunction in a system of bilateral neural structures that includes the ring of mesolimbic cortex located in the mesial frontal and temporal lobes, the neostriatum, and the anterior and medial nuclear groups of the thalamus. The mesolimbic cortex is cytoarchitectonically, angioarchitectonically, and neurochemically distinct and, along with the striatum, forms the entire target area of dopaminergic mesencephalic neurons. This raises the possibility that autism is related to neuromediator imbalance in those structures. Such dysfunction might be the result of macroscopic or microscopic changes in the target area or in structures functionally influencing them, consequent to a variety of causes such as perinatal viral infection, insult to the periventricular watershed area, or genetically determined neurochemical abnormalities.

Attention↗

Proton relaxation studies of water compartmentalization in a model neurological system.

Proton relaxation measurements from 18 crayfish abdominal nerve cords (a model of human CNS) are used to demonstrate that the transverse (though not the longitudinal) relaxation can be decomposed into four reproducible components that, in conjunction with optical and electron microscopy of the morphology, can be assigned to three water compartments within the cord and possibly to the mobile lipid protons. The assignments are extraaxonal water protons (32 +/- 9% and mean T2 = 600 +/- 200 ms), axonal water protons (59 +/- 12% and mean T2 = 200 +/- 30 ms), intramyelinic water protons (7 +/- 4% and mean T2 = 50 +/- 20 ms), and finally an unsubstantiated assignment of lipid protons (2.0 +/- 2.0% and mean T2 = 7 +/- 4 ms).

Algorithms↗

Severity-of-illness scoring systems and models: neurological and neurosurgical intensive care units.

Predicting the outcome of critically ill patients admitted to intensive care units (ICU) has undergone considerable evolution over the last two decades. Various general purpose severity-of-illness scoring systems, Acute Physiology and Chronic Health Evaluation score (APACHE II, APACHE III), Mortality Predicting Model (MPM II), and Simplified Acute Physiology Score (SAPS II), have been extensively validated for large groups of critical care patients with mixed diagnoses and found to correlate well with observed outcome in general. The general hypothesis underlying the use of severity-of-illness scoring systems is that clinical variables that can be assessed on ICU admission and subsequent days of stay in the ICU predict survival and other outcomes of critically ill patients. Variables included in severity-of-illness scoring systems measure specific clinical and physiological functions that are major determinants of mortality. These scoring systems may be used alone within a single disease category or any other independently defined patient group to perform relative risk stratification. Variation in death rates by disease reflects the nature of the underlying process. There is a need for using these scoring systems in specialized ICUs like neurological and neurosurgical ICU as they allow, in addition to predicting outcome, evaluation of new therapies, monitoring of resource utilization and quality assessment of intensive care units.

Critical Care↗