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1.
Neurology ; 96(23): e2874-e2884, 2021 06 08.
Article in English | MEDLINE | ID: mdl-33910940

ABSTRACT

OBJECTIVES: To test for cerebellar involvement in motor and nonmotor impairments in Parkinson disease (PD) and to determine patterns of metabolic correlations with supratentorial brain structures, we correlated clinical motor, cognitive, and psychiatric scales with cerebellar metabolism. METHODS: We included 90 patients with PD. Motor, cognitive, and psychiatric domains were assessed, and resting-state 18FDG-PET metabolic imaging was performed. The motor, cognitive, and psychiatric scores were entered separately into a principal component analysis. We looked for correlations between these 3 principal components and cerebellar metabolism. Furthermore, we extracted the mean glucose metabolism value for each significant cerebellar cluster and looked for patterns of cerebrum-cerebellum metabolic correlations. RESULTS: Severity of impairment was correlated with increased metabolism in the anterior lobes and vermis (motor domain); the right crus I, crus II, and declive (cognitive domain); and the right crus I and crus II (psychiatric domain). No results survived multiple testing corrections regarding the psychiatric domain. Moreover, we found distributed and overlapping, but not identical, patterns of metabolic correlations for motor and cognitive domains. Specific supratentorial structures (cortical structures, basal ganglia, and thalamus) were strongly correlated with each of the cerebellar clusters. CONCLUSIONS: These results confirm the role of the cerebellum in nonmotor domains of PD, with differential but overlapping patterns of metabolic correlations suggesting the involvement of cerebello-thalamo-striatal-cortical loops.


Subject(s)
Behavioral Symptoms , Cerebellum , Cognitive Dysfunction , Nerve Net , Parkinson Disease , Adult , Aged , Basal Ganglia/diagnostic imaging , Basal Ganglia/metabolism , Basal Ganglia/physiopathology , Behavioral Symptoms/diagnostic imaging , Behavioral Symptoms/etiology , Behavioral Symptoms/metabolism , Behavioral Symptoms/physiopathology , Cerebellum/diagnostic imaging , Cerebellum/metabolism , Cerebellum/physiopathology , Cerebral Cortex/diagnostic imaging , Cerebral Cortex/metabolism , Cerebral Cortex/physiopathology , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/etiology , Cognitive Dysfunction/metabolism , Cognitive Dysfunction/physiopathology , Female , Fluorodeoxyglucose F18 , Humans , Male , Middle Aged , Nerve Net/diagnostic imaging , Nerve Net/metabolism , Nerve Net/physiopathology , Parkinson Disease/complications , Parkinson Disease/diagnostic imaging , Parkinson Disease/metabolism , Parkinson Disease/physiopathology , Positron-Emission Tomography , Principal Component Analysis , Thalamus/diagnostic imaging , Thalamus/metabolism , Thalamus/physiopathology
2.
J Pers ; 89(3): 468-482, 2021 05.
Article in English | MEDLINE | ID: mdl-32936956

ABSTRACT

OBJECTIVE: When confronted with major threats, people often experience decline in well-being. The central purpose of this study was to identify mechanisms underlying change of well-being in times of threat, using the example of the COVID-19 pandemic, with a focus on appraisals of the pandemic and affective states, stress, as well as mindfulness in daily life. METHOD: We conducted a study across 3.5 weeks, including pretest, posttest, and a diary phase in-between. We worked with a sample of 460 adults, pre- and post-test information, as well as 7,189 observations from the diary phase. RESULTS: Results showed that deterioration in mental health symptoms across the duration of the study was associated with (a) change towards less fortunate appraisals of the pandemic and (b), more negative affect and less mindfulness in daily life. Furthermore, appraisals of the pandemic at pretest predicted experiences in daily life, with more negative appraisals of the pandemic predicting more negative affect and stressor occurrence as well as less mindfulness. CONCLUSIONS: These findings speak to the dynamic nature of well-being and appraisals in times of threat, and highlight the role of experiences in daily life in changes in well-being.


Subject(s)
Behavioral Symptoms/physiopathology , Behavioral Symptoms/psychology , COVID-19 , Health Knowledge, Attitudes, Practice , Life Change Events , Mindfulness , Personal Satisfaction , Adult , Affective Symptoms/physiopathology , Affective Symptoms/psychology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Stress, Psychological/physiopathology , Stress, Psychological/psychology
3.
Neuropsychopharmacol Rep ; 40(1): 10-15, 2020 03.
Article in English | MEDLINE | ID: mdl-32037737

ABSTRACT

We examined whether symptoms of dementia are improved by olfactory nerve stimulation in Alzheimer type dementia patients. First, a stick-type olfactory identification ability test was performed in patients with Alzheimer type dementia, to select patients without olfactory dysfunctions. Then, these patients were randomly assigned into the intervention (n = 19) and the control groups (n = 17). To evaluate the effects of olfactory nerve stimulation, we exposed the intervention group to a disinfecting ethanol with added aroma extracts from ceder and the control group to the ethanol without the added aroma extracts. Each group underwent the intervention for 8 weeks, cognitive and behavioral functions were evaluated before and after treatments using the Neuropsychiatric Inventory (NPI), the Japanese version of Zarit Caregiver Burden interview (J-ZBI), and the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog). A significant improvement was observed in the NPI score and J-ZBI in the intervention group compared to the control group at 4 and 8 weeks. On the other hand, there was no significant difference in the score of ADAS-cog. Exposure to cedar fragrance improved behavioral and psychological symptoms of dementia (BPSD) in Alzheimer type dementia and may reduce the burden of nursing care. In addition to its effectiveness, the procedure is simple and minimally invasive and would be a valuable non-pharmaceutical treatment.


Subject(s)
Alzheimer Disease/therapy , Aromatherapy/methods , Behavioral Symptoms/therapy , Oils, Volatile/administration & dosage , Olfactory Nerve , Olfactory Perception , Administration, Inhalation , Aged , Aged, 80 and over , Alzheimer Disease/complications , Alzheimer Disease/physiopathology , Alzheimer Disease/psychology , Behavioral Symptoms/etiology , Behavioral Symptoms/physiopathology , Behavioral Symptoms/psychology , Ethanol/administration & dosage , Female , Humans , Male , Olfactory Nerve/drug effects , Olfactory Perception/drug effects , Solvents/administration & dosage
4.
Lancet Psychiatry ; 7(3): 282-290, 2020 03.
Article in English | MEDLINE | ID: mdl-31982031

ABSTRACT

Individuals with chronic pain are at an elevated risk of suicide, yet psychosocial factors that might be involved in increasing or decreasing vulnerability for suicidal ideation and behaviour have received little attention. Extant literature on the topic of suicide in individuals with chronic pain incorporates only a few of the wide array of known vulnerability and protective factors. This Review focuses on transdiagnostic psychological processes, (ie, those of relevance for both chronic pain and suicide). We reviewed a selection of published literature on chronic pain and suicide, concentrating on previously unexplored and underexplored lines of research, including future orientation, mental imagery, and psychological flexibility. A greater degree of crosspollination between the fields of chronic pain and suicide research is required to progress our understanding of why some people with chronic pain become suicidal and others do not.


Subject(s)
Behavioral Symptoms/physiopathology , Chronic Pain/psychology , Suicidal Ideation , Suicide Prevention , Suicide , Humans , Psychology , Suicide/psychology
5.
Int Rev Psychiatry ; 32(1): 89-95, 2020 02.
Article in English | MEDLINE | ID: mdl-31587599

ABSTRACT

It has long been established that fighting sports such as boxing and mixed martial arts can lead to head injury. Prior work from this group on the Professional Fighters Brain Health Study found that exposure to repetitive head impacts is associated with lower brain volumes and decreased processing speed in fighters. Current and previously licensed professional fighters were recruited, divided into active and retired cohorts, and matched with a control group that had no prior experience in sports with likely head trauma. This study examined the relationship between age of first exposure (AFE) to fighting sports and brain structure (MRI regional volume), cognitive performance (CNS Vital Signs, iComet C3), and clinical neuropsychiatric symptoms (PHQ-9, Barratt Impulsiveness Scale). Brain MRI data showed significant correlations between earlier AFE and smaller bilateral hippocampal and posterior corpus callosum volumes for both retired and active fighters. Earlier AFE in active fighters was correlated with decreased processing speed and decreased psychomotor speed. Retired fighters showed a correlation between earlier AFE and higher measures of depression and impulsivity. Overall, the results help to inform clinicians, governing bodies, parents, and athletes of the risks associated with beginning to compete in fighting sports at a young age.


Subject(s)
Athletic Injuries , Behavioral Symptoms , Boxing/injuries , Brain Injuries , Cognitive Dysfunction , Corpus Callosum , Depression , Hippocampus , Martial Arts/injuries , Adult , Age Factors , Athletic Injuries/complications , Athletic Injuries/pathology , Athletic Injuries/physiopathology , Behavioral Symptoms/etiology , Behavioral Symptoms/pathology , Behavioral Symptoms/physiopathology , Brain Injuries/complications , Brain Injuries/pathology , Brain Injuries/physiopathology , Cognitive Dysfunction/etiology , Cognitive Dysfunction/pathology , Cognitive Dysfunction/physiopathology , Corpus Callosum/pathology , Depression/etiology , Depression/pathology , Depression/physiopathology , Hippocampus/pathology , Humans , Impulsive Behavior/physiology , Male , Middle Aged , Retirement
6.
J Huntingtons Dis ; 8(4): 375-391, 2019.
Article in English | MEDLINE | ID: mdl-31594240

ABSTRACT

Huntington's disease (HD) is a fatal genetic neurodegenerative disorder. It has mainly been considered a movement disorder with cognitive symptoms and these features have been associated with pathology of the striatum and cerebral cortex. Importantly, individuals with the mutant huntingtin gene suffer from a spectrum of non-motor features often decades before the motor disorder manifests. These symptoms and signs include a range of psychiatric symptoms, sleep problems and metabolic changes with weight loss particularly in later stages. A higher body mass index at diagnosis is associated with slower disease progression. The common psychiatric symptom of apathy progresses with the disease. The fact that non-motor features are present early in the disease and that they show an association to disease progression suggest that unravelling the underlying neurobiological mechanisms may uncover novel targets for early disease intervention and better symptomatic treatment. The hypothalamus and the limbic system are important brain regions that regulate emotion, social cognition, sleep and metabolism. A number of studies using neuroimaging, postmortem human tissue and genetic manipulation in animal models of the disease has collectively shown that the hypothalamus and the limbic system are affected in HD. These findings include the loss of neuropeptide-expressing neurons such as orexin (hypocretin), oxytocin, vasopressin, somatostatin and VIP, and increased levels of SIRT1 in distinct nuclei of the hypothalamus. This review provides a summary of the results obtained so far and highlights the potential importance of these changes for the understanding of non-motor features in HD.


Subject(s)
Behavioral Symptoms , Huntington Disease , Hypothalamus , Metabolic Diseases , Animals , Behavioral Symptoms/etiology , Behavioral Symptoms/physiopathology , Humans , Huntington Disease/complications , Huntington Disease/metabolism , Huntington Disease/pathology , Hypothalamus/metabolism , Hypothalamus/pathology , Metabolic Diseases/etiology , Metabolic Diseases/metabolism
7.
J Dev Behav Pediatr ; 40(8): 589-596, 2019.
Article in English | MEDLINE | ID: mdl-31166250

ABSTRACT

OBJECTIVE: Research suggests that adolescents seeking gender-affirming hormone therapy experience elevated rates of depression, anxiety, and difficulties with peer relationships. Less is known regarding more specific aspects of mental health and psychosocial functioning. Furthermore, few studies have explored variations in mental health and psychosocial functioning by age, gender, degree of physical dysphoria, and informant type (adolescent, mother, and father). METHOD: Participants are adolescents (n = 149) and parents/guardians (n = 247) who presented to a multidisciplinary gender clinic in Dallas, TX for an initial assessment before initiation of gender-affirming hormone therapy. Adolescents completed the Youth Self-Report (YSR) and the Body Image Scale (a measure of physical dysphoria), and parents/guardians completed the Child Behavior Checklist (CBCL). RESULTS: Approximately half of participants reported clinically significant difficulties with internalizing symptoms and psychosocial functioning (particularly engagement in activities), with approximately one-third indicating significant difficulties with depression, anxiety, obsessive compulsive, and posttraumatic stress symptoms. Parents reported fewer symptoms than adolescents across several subscales, but differences were generally small. By contrast, gender differences were found across all internalizing subscales and were generally large. Age and body dissatisfaction were not independently associated with broadband measures but, in combination with gender, were strongly associated with variance in YSR and CBCL reports of internalizing symptoms. CONCLUSION: Elevated rates of depression, anxiety, and competency difficulties were broadly consistent with the previous literature and demonstrate the need for investment in the clinical training and infrastructure to provide comprehensive care to this population. Differences in mental health and psychosocial functioning by gender and clinic location appear to be less straightforward.


Subject(s)
Adolescent Behavior/physiology , Behavioral Symptoms/physiopathology , Gender Dysphoria/psychology , Hormone Replacement Therapy , Sex Reassignment Procedures , Social Skills , Stress Disorders, Post-Traumatic/physiopathology , Transgender Persons/psychology , Adolescent , Behavioral Symptoms/epidemiology , Child , Female , Gender Dysphoria/drug therapy , Gender Dysphoria/epidemiology , Hormone Replacement Therapy/statistics & numerical data , Humans , Male , Sex Reassignment Procedures/statistics & numerical data , Stress Disorders, Post-Traumatic/epidemiology , Texas/epidemiology , Transgender Persons/statistics & numerical data
8.
Curr Opin Psychol ; 28: 285-293, 2019 08.
Article in English | MEDLINE | ID: mdl-31059966

ABSTRACT

Distress is commonly characterized by prolonged internal suffering that can range from self-focused processing of negative emotions and stressors, to highly intensely aversive and prolonged emotional states, thereby, worsening or complicating emotional and physical conditions. Decentering represents a metacognitive capacity thought to reflect three interrelated processes: meta-awareness, disidentification from internal experience, and reduced reactivity to thought content-which is reliably increased with mindfulness-based interventions. In this essay, we seek to link the clinical presentation of distress disorders to known or hypothesized disruptions in neural networks that underlie emotion, cognition, and goal directed behavior, and offer a neurobehavioral account for how and why treatments imbued with mindfulness meditation might ameliorate these conditions, in part through increases in decentering.


Subject(s)
Behavioral Symptoms/therapy , Metacognition , Mindfulness , Nerve Net , Psychological Distress , Behavioral Symptoms/physiopathology , Humans , Metacognition/physiology , Nerve Net/physiopathology
9.
Sci Rep ; 8(1): 13977, 2018 09 18.
Article in English | MEDLINE | ID: mdl-30228354

ABSTRACT

The aim of this study was to assess the risk factors associated with the behavioral development among 24-month-old children in rural northwestern China. A total of 657 children whose mothers had participated in a double-blinded, randomized, controlled trial of antenatal micronutrient supplementation in western China were followed until 24 months of age. Their mental, psychomotor, and behavioral development were assessed by the Bayley Scales of Infant Development. Multivariate logistic regression models were used to examine the factors associated with infant behavioral development. Six behavioral factors of infants were presented: activity, social adaptability, reactivity, endurance, concentration, and motor coordination. Further analysis demonstrated that maternal malnutrition, exposure to risk factors during pregnancy, and adverse birth outcomes negatively affected the behavioral development of children at 24 months, which is a common co-occurrence with cognitive and emotional problems. These results suggest that strategies to improve infant behavioral development should consider the maternal pregnancy status.


Subject(s)
Behavioral Symptoms/physiopathology , Child Development , Developmental Disabilities/prevention & control , Dietary Supplements , Micronutrients/administration & dosage , Mothers/psychology , China/epidemiology , Developmental Disabilities/epidemiology , Double-Blind Method , Female , Follow-Up Studies , Humans , Infant , Male , Nutritional Status , Pregnancy , Randomized Controlled Trials as Topic , Rural Population
10.
Philos Trans R Soc Lond B Biol Sci ; 369(1644): 20130183, 2014.
Article in English | MEDLINE | ID: mdl-24778378

ABSTRACT

Autism spectrum disorder (ASD) is a neurodevelopmental condition exhibiting impairments in behaviour, social and communication skills. These deficits may arise from aberrant functional connections that impact synchronization and effective neural communication. Neurofeedback training (NFT), based on operant conditioning of the electroencephalogram (EEG), has shown promise in addressing abnormalities in functional and structural connectivity. We tested the efficacy of NFT in reducing symptoms in children with ASD by targeting training to the mirror neuron system (MNS) via modulation of EEG mu rhythms. The human MNS has provided a neurobiological substrate for understanding concepts in social cognition relevant to behavioural and cognitive deficits observed in ASD. Furthermore, mu rhythms resemble MNS phenomenology supporting the argument that they are linked to perception and action. Thirty hours of NFT on ASD and typically developing (TD) children were assessed. Both groups completed an eyes-open/-closed EEG session as well as a mu suppression index assessment before and after training. Parents filled out pre- and post-behavioural questionnaires. The results showed improvements in ASD subjects but not in TDs. This suggests that induction of neuroplastic changes via NFT can normalize dysfunctional mirroring networks in children with autism, but the benefits are different for TD brains.


Subject(s)
Autistic Disorder/physiopathology , Autistic Disorder/therapy , Cognition/physiology , Mirror Neurons/physiology , Neurofeedback/methods , Social Perception , Adolescent , Behavioral Symptoms/physiopathology , Child , Conditioning, Operant/physiology , Electroencephalography , Female , Humans , Male , Parents , Surveys and Questionnaires
11.
PLoS One ; 8(6): e64578, 2014.
Article in English | MEDLINE | ID: mdl-23755128

ABSTRACT

A novel approach based on diffusion tractography was used here to characterise the cortico-thalamic connectivity in two patients, both presenting with an isolated bilateral infarct in the thalamus, but exhibiting partially different cognitive and behavioural profiles. Both patients (G.P. and R.F.) had a pervasive deficit in episodic memory, but only one of them (R.F.) suffered also from a dysexecutive syndrome. Both patients had an MRI scan at 3T, including a T1-weighted volume. Their lesions were manually segmented. T1-volumes were normalised to standard space, and the same transformations were applied to the lesion masks. Nineteen healthy controls underwent a diffusion-tensor imaging (DTI) scan. Their DTI data were normalised to standard space and averaged. An atlas of Brodmann areas was used to parcellate the prefrontal cortex. Probabilistic tractography was used to assess the probability of connection between each voxel of the thalamus and a set of prefrontal areas. The resulting map of corticothalamic connections was superimposed onto the patients' lesion masks, to assess whether the location of the thalamic lesions in R.F. (but not in G. P.) implied connections with prefrontal areas involved in dysexecutive syndromes. In G.P., the lesion fell within areas of the thalamus poorly connected with prefrontal areas, showing only a modest probability of connection with the anterior cingulate cortex (ACC). Conversely, R.F.'s lesion fell within thalamic areas extensively connected with the ACC bilaterally, with the right dorsolateral prefrontal cortex, and with the left supplementary motor area. Despite a similar, bilateral involvement of the thalamus, the use of connectivity-based segmentation clarified that R.F.'s lesions only were located within nuclei highly connected with the prefrontal cortical areas, thus explaining the patient's frontal syndrome. This study confirms that DTI tractography is a useful tool to examine in vivo the effect of focal lesions on interconnectivity brain patterns.


Subject(s)
Behavioral Symptoms/physiopathology , Cerebral Infarction/physiopathology , Cognition , Magnetic Resonance Imaging , Nerve Net/physiopathology , Thalamic Diseases/physiopathology , Thalamus/pathology , Thalamus/physiopathology , Adult , Brain Mapping , Cerebral Infarction/pathology , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Thalamic Diseases/pathology
12.
Am J Psychiatry ; 170(9): 1011-9, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24030612

ABSTRACT

OBJECTIVE: The neural correlates of stimulus-driven processes, such as response preparation, have been posited to be associated with the onset of attention deficit hyperactivity disorder (ADHD) while being distinct from the neural mechanisms associated with recovery. The authors tested this hypothesis in adults with remitted and persistent ADHD. METHOD: Thirty-eight young adults who were diagnosed with combined-type ADHD in childhood (probands) and 32 carefully matched comparison subjects were followed longitudinally and scanned with functional MRI while performing an event-related cued reaction time task. Probands were characterized as individuals with persistent or remitted ADHD. Differences in thalamo-cortical activation and functional connectivity during response preparation between comparison subjects and probands and between individuals with persistent ADHD and those with remitted ADHD were assessed by contrasting neural activation and functional connectivity during cue or noncue events. RESULTS: Probands exhibited less cue-related activation than comparison subjects in the thalamus, anterior cingulate cortex, supplementary motor area, inferior parietal lobe, and dorsolateral prefrontal cortex despite similar overall patterns of activation. There were no differences in activation between individuals in the remitted ADHD group and those in the persistent ADHD group in any hypothesized regions. However, cue-related functional connectivity between the right thalamus and brainstem was greater in comparison subjects relative to probands, and cue-related connectivity was greater between the right thalamus and prefrontal regions in individuals with remitted ADHD relative to those with persistent ADHD. CONCLUSIONS: Decreased thalamo-cortical activation during response preparation was present in adults diagnosed with ADHD in childhood regardless of symptom remission in adulthood, and may be partly driven by less functional coordination between the brainstem and thalamus. Greater functional integration of the thalamo-cortical network might parallel symptom recovery.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Cerebral Cortex , Thalamus , Adult , Age of Onset , Asymptomatic Diseases , Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit Disorder with Hyperactivity/physiopathology , Attention Deficit Disorder with Hyperactivity/psychology , Behavioral Symptoms/diagnosis , Behavioral Symptoms/physiopathology , Brain Mapping/methods , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Female , Humans , Magnetic Resonance Imaging/methods , Male , Neural Pathways/physiopathology , Neuropsychological Tests , Psychiatric Status Rating Scales , Reaction Time , Task Performance and Analysis , Thalamus/pathology , Thalamus/physiopathology
13.
Depress Anxiety ; 29(11): 948-57, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22581482

ABSTRACT

BACKGROUND: The behavioral symptoms of Generalized Anxiety Disorder (GAD) are not well characterized. This study examines behavioral symptoms in patients with GAD compared to healthy participants, their change during behavioral therapy, and their role for predicting short- and long-term outcome. METHODS: Secondary data analysis of 56 patients with DSM-IV GAD from a randomized controlled trial testing worry exposure (n = 29) and applied relaxation (n = 27), compared to 33 demographically matched healthy participants. Participants reported on attempts to control or prevent worry, specifically cognitive and behavioral avoidance, safety behavior, and reassurance, along with other GAD symptoms. The Hamilton Anxiety Scale served as immediate (post therapy) and the Penn State Worry Questionnaire as immediate and long-term (6-/12-month follow-up) treatment outcome measure. RESULTS: GAD patients engage significantly more in attempts to control or prevent worry as reflected in cognitive and behavioral avoidance, safety behavior, and reassurance seeking than healthy comparison participants. Behavior therapy significantly reduces these behavioral strategies without substantial indication of differential effects of treatment type. However, only patients remitting from GAD reach the low symptom level of healthy participants. The initial level of behavioral symptoms is irrelevant for immediate treatment success, but higher degrees of cognitive and behavioral avoidance and safety behavior at the end of treatment predict worse long-term outcome. CONCLUSIONS: Behavioral symptoms appear to be relevant features in GAD that improve with successful treatment. Further research is warranted to examine whether inclusion of behavioral symptoms in the definition of GAD would have beneficial effects on diagnostic recognition and treatment.


Subject(s)
Anxiety Disorders , Behavioral Symptoms/physiopathology , Adult , Anxiety Disorders/complications , Anxiety Disorders/physiopathology , Anxiety Disorders/therapy , Behavioral Symptoms/etiology , Behavioral Symptoms/therapy , Case-Control Studies , Cognitive Behavioral Therapy , Female , Humans , Male , Middle Aged , Randomized Controlled Trials as Topic , Relaxation Therapy , Treatment Outcome
14.
Brain Res ; 853(1): 68-73, 2000 Jan 17.
Article in English | MEDLINE | ID: mdl-10627309

ABSTRACT

Cerebral hypoxia is a major component of immediate and secondary cell damage caused by ischemia. Hyperbaric oxygen (HBO) is a potent means to increase the amount of oxygen dissolved in blood plasma. The effectiveness of HBO in clinical and experimental cerebral ischemia, however, is controversial. We sought to determine whether treatment with HBO initiated early after focal cerebral ischemia-onset protects the brain when experimental conditions such as brain temperature are controlled. Male Wistar rats (n=57) underwent reversible filament occlusion of the right middle cerebral artery (MCA) for 75 min. Animals were awakened after filament introduction and assessed for presence of forelimb paresis. Rats then underwent a 60-min course of either 100% O(2) at 1.0 atmosphere absolute (ata; control group), HBO 1.5 ata, or HBO 2.5 ata in a customized HBO chamber allowing physiological monitoring and pericranial temperature control. The filament was then removed. Seven days after ischemia, rat behavior was scored from 3-18 (18=normal) and brains were removed for histological analysis of infarct volume. Rats treated with HBO 2.5 ata had better mean+/-standard deviation (S.D.) behavioral scores (14+/-2; p<0.05) than control (10+/-3) or HBO 1.5-ata-treated animals (11+/-3). Similarly, total infarct volumes (mean+/-S.D.) were smaller in animals receiving HBO at 2.5 ata (76+/-65 mm(3); p<0.05) compared to control (129+/-83 mm(3)) and HBO 1.5-ata (119+/-68 mm(3))-treated groups. Cortical infarction occurred less frequently in HBO 2. 5-ata-treated than in control animals (44% vs. 71%; p<0.05). We conclude that HBO can improve outcome after temporary focal ischemia when treatment is started early after ischemia-onset but HBO dose appears important. Potential mechanisms include enhanced oxygen supply to marginally perfused cells.


Subject(s)
Behavioral Symptoms/physiopathology , Hyperbaric Oxygenation , Ischemic Attack, Transient/therapy , Animals , Behavior, Animal/drug effects , Blood Gas Analysis , Cerebral Cortex/drug effects , Cerebral Cortex/pathology , Dose-Response Relationship, Drug , Infarction, Middle Cerebral Artery/physiopathology , Ischemic Attack, Transient/physiopathology , Male , Oxygen/administration & dosage , Rats , Rats, Wistar
15.
Dement Geriatr Cogn Disord ; 10(5): 330-4, 1999.
Article in English | MEDLINE | ID: mdl-10473933

ABSTRACT

Delirium has been considered a syndrome of generalized dysfunction of higher cortical functions due to its breadth of symptoms and associated diffuse slowing on electroencephalogram. Advances in neuropsychiatry have revealed differences between brain regions, including the hemispheres, which may underlie the constellation of symptoms among different psychiatric disorders. For example, different neural pathways are involved in major depression and obsessive-compulsive disorder, including lateralization to one or the other hemisphere. In this article the author proposes that delirium, too, involves particular neural pathways and that lateralization to the right may be relevant. Structural and functional neuroimaging reports and recent neuropsychological studies support this lateralization. Prefrontal cortices, anterior and right thalamus, and right basilar mesial temporoparietal cortex may play a significant role in subserving delirium symptoms and may be the 'final common pathway' for delirium from a variety of etiologies. The final common pathway may be responsible for certain 'core symptoms' (disorientation, cognitive deficits, sleep-wake cycle disturbance, disorganized thinking, and language abnormalities), while other symptoms (delusions, hallucinations, illusions, and affective lability) may occur depending on the etiology causing delirium. An imbalance in the cholinergic and dopaminergic neurotransmitter systems is most commonly implicated in causing delirium, and could both account for delirium symptoms and be consistent with the neuroanatomical pathways being implicated.


Subject(s)
Delirium/etiology , Attention/physiology , Behavioral Symptoms/physiopathology , Brain/pathology , Brain/physiopathology , Cholinergic Fibers/physiology , Delirium/pathology , Delirium/physiopathology , Dopamine/physiology , Humans , Neural Pathways/anatomy & histology , Neural Pathways/physiopathology , Prefrontal Cortex/anatomy & histology , Prefrontal Cortex/physiopathology , Thalamus/anatomy & histology , Thalamus/physiopathology
16.
Schizophr Bull ; 24(2): 267-83, 1998.
Article in English | MEDLINE | ID: mdl-9613625

ABSTRACT

The absence of an animal model that accurately approximates schizophrenia limits current research into the pathophysiology of this disorder. Obviously, the cognitive disturbances associated with schizophrenia are difficult to evaluate in laboratory animals. Nonetheless, animal studies have provided insight into the anatomy and physiology of the brain systems that have been implicated in schizophrenia. These studies also suggest how brain systems may be involved in information processing in normal and pathological conditions. Thus, a careful assessment of the properties and functions of the brain regions suggested to be involved in schizophrenic symptoms has been a primary objective in several laboratories. In this review, we discuss the interactions among the brain regions implicated in schizophrenia--the ventral striatum, prefrontal cortex, hippocampus, and dopamine systems--and provide an integrative model linking altered function in these regions with specific clusters of symptoms of schizophrenia.


Subject(s)
Behavioral Symptoms/physiopathology , Brain/physiopathology , Neurobehavioral Manifestations/physiology , Schizophrenia/physiopathology , Animals , Antipsychotic Agents/pharmacology , Basal Ganglia/drug effects , Basal Ganglia/physiology , Brain/drug effects , Disease Models, Animal , Dopamine/physiology , Dopamine Agents/pharmacology , Hippocampus/physiology , Humans , Models, Neurological , Neural Pathways/anatomy & histology , Neural Pathways/drug effects , Neural Pathways/physiology , Nucleus Accumbens/drug effects , Nucleus Accumbens/physiology , Prefrontal Cortex/physiology , Schizophrenia/drug therapy , Schizophrenia/etiology , Thalamus/physiology
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