Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Basal ganglia disorders are a heterogeneous group of clinical syndromes with a common anatomic locus within the basal ganglia. To account for the variety of clinical manifestations associated with insults to various parts of the basal ganglia we propose a model in which specific types of basal ganglia disorders are associated with changes in the function of subpopulations of striatal projection neurons. This model is based on a synthesis of experimental animal and post-mortem human anatomic and neurochemical data. Hyperkinetic disorders, which are characterized by an excess of abnormal movements, are postulated to result from the selective impairment of striatal neurons projecting to the lateral globus pallidus. Hypokinetic disorders, such as Parkinson's disease, are hypothesized to result from a complex series of changes in the activity of striatal projection neuron subpopulations resulting in an increase in basal ganglia output. This model suggests that the activity of subpopulations of striatal projection neurons is differentially regulated by striatal afferents and that different striatal projection neuron subpopulations may mediate different aspects of motor control.
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PMID:The functional anatomy of basal ganglia disorders. 169 77

Stride parameters were established in 17 patients with idiopathic Parkinson's disease (PD; mean age 68.8 yrs.; Hoehn-Yahr stages 2 and 3) and in 33 healthy age-matched controls. Free-walking speed was lower in PD as were stride length and cadence. Impaired locomotor synergies in PD were reflected by a higher coefficient of variation of stride length; step width and its coefficient of variation (the latter related to postural imbalance in locomotion) were not changed. No stride parameter correlated with any total score of either the Hoehn-Yahr Scale, the Unified Parkinson's Disease Rating Scale Motor Examination ("UPDRS-III"), the Columbia Rating Scale (CURS) or the Webster Rating Scale. Stride length correlated with a CURS-Bradykinesia-Score, whereas gait velocity correlated with UPDRS-III-Axial-Motor-Score and with the CURS-Bradykinesia-Score. Hypokinesia of gait in moderately disabled PD patients is best assessed by combined analysis of stride parameters and locomotion-related subscores from conventional rating scales.
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PMID:Gait quantitation in Parkinson's disease--locomotor disability and correlation to clinical rating scales. 920 85

Hypokinesia, the inability to initiate or maintain movement, represents one of the most disabling aspects of Parkinson's disease (PD), and displays intriguing moment-to-moment variability from environmental stressors. Correlates of orofacial hypokinesia (characteristics of spontaneous eye blink and speech) were coded from videotaped interactions for PD patients in maritally distressed and nondistressed dyads. Significant changes occurred only for the patients in distressed relationships on the two strongest neurophysiologic measures of orofacial hypokinesia, rate and duration of spontaneous eye blink. Further analyses suggest two possible explanations for these temporal symptom changes. Distressed spouses may exacerbate symptoms by exposing the patient to negativity. Alternately, nondistressed spouses may compensate for the demands of the interactional task by assuming a greater share of the conversation relative to the patient's contribution. Results are linked to existing literature; the role of social and familial support in chronic illness is discussed.
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PMID:Symptom study in context: effects of marital quality on signs of Parkinson's disease during patient-spouse interaction. 959 94

Because in the literature bradykinesia and hypokinesia are frequently confounded, we assessed the relation between these two fundamental aspects of altered movement and the influence of disease severity on these measures in 41 patients with Parkinson's disease (PD) and 24 age-matched healthy controls. Bradykinesia was measured with a test microcomputer interfaced with a response-board. Hypokinesia was assessed by activity monitoring at home over a period of 5 successive days. For each subject the choice reaction time and measures reflecting bradykinesia (tap rate, movement time) and hypokinesia (movement index, duration of immobility periods) were calculated. Patients with PD had a normal choice reaction time and a significantly impaired execution of voluntary movement and reduced amount of movement over time. Bradykinesia was clearly present in the less affected patients with PD, and worsened as the disease severity increased. Hypokinesia, however, emerged prominently only in the more affected patients. There was a striking lack of relation between the measures that reflect bradykinesia and hypokinesia. The use of levodopa or dopamine agonists did not confound these findings. Our findings show the very different character and course of two tiers of altered movement in patients with PD and question the causative mechanisms of both motor features in PD. A more precise use of the terms brady- and hypokinesia is a prerequisite for future studies that attempt to provide insight in the causative mechanisms of both motor features.
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PMID:Bradykinesia and hypokinesia in Parkinson's disease: what's in a name? 966 Jan

Hypokinetic movement can be greatly improved in Parkinson's disease patients by the provision of external cues to guide movement. It has recently been reported, however, that movement performance in parkinsonian patients can be similarly improved in the absence of external cues by using attentional strategies, whereby patients are instructed to consciously attend to particular aspects of the movement which would normally be controlled automatically. To study the neurophysiological basis of such improvements in performance associated with the use of attentional strategies, movement-related cortical potentials were examined in Parkinson's disease and control subjects using a reaction time paradigm. One group of subjects were explicitly instructed to concentrate on internally timed responses to anticipate the presentation of a predictably timed go signal. Other subjects were given no such instruction regarding attentional strategies. Early-stage premovement activity of movement-related potentials was significantly increased in amplitude and reaction times were significantly faster for Parkinson's disease subjects when instructed to direct their attention toward internally generating responses rather than relying on external cues. It is therefore suggested that the use of attentional strategies may allow movement to be mediated by less automatic and more conscious attentional motor control processes which may be less impaired by basal ganglia dysfunction, and thereby improve movement performance in Parkinson's disease.
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PMID:Movement-related potentials in Parkinson's disease: external cues and attentional strategies. 991 46

Underactivity of the external segment of the globus pallidus is thought to contribute to the generation of parkinsonian hypokinetic symptoms in association with striatal dopaminergic dysfunction and overactivity of the subthalamus. These symptoms can be corrected by neurosurgical techniques aimed at normalizing subthalamic overactivity. The aim of the present study was to compare the amount of neurodegeneration and changes in the calcium-binding protein parvalbumin in the external segment of the globus pallidus in parkinsonian disorders. Cases with progressive supranuclear palsy were compared with cases with Parkinson's disease and control subjects. The number of neurones and neurofibrillary tangles was estimated using unbiased stereologic techniques. The external segment of the globus pallidus in Parkinson's disease was not significantly different from that in control subjects. In contrast, most patients with progressive supranuclear palsy had significant neurodegeneration of the external pallidum, particularly patients with significant degeneration of both the subthalamus and substantia nigra. These results suggest that the parkinsonian symptoms in progressive supranuclear palsy are caused by the degeneration of the external segment of the globus pallidus because such degeneration would increase thalamic inhibition through the basal ganglia output nuclei, particularly in patients with a loss of excitatory drive from the subthalamus.
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PMID:The external globus pallidus in patients with Parkinson's disease and progressive supranuclear palsy. 1043

Hypokinesis is the term used to refer to slow or reduced movement. Hypokinetic movement disorders are often referred to as parkinsonisms because they display clinical features of idiopathic Parkinson's disease (IPD). As a result, distinguishing other parkinsonian syndromes from IPD is difficult, and it is often not until post mortem that a misdiagnosis is realized. Conditions displaying features of parkinsonism are extensive. The more commonly encountered are IPD, multiple system atrophy, and progressive supranuclear palsy.
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PMID:Hypokinetic movement disorders. 1108 96

In Parkinson's disease, besides the dopaminergic neurodegeneration, locus coeruleus noradrenergic neurons degenerate as well. Noradrenergic neurons have potential anti-parkinsonian, neuromodulatory and neuroprotective properties. Presently, an animal model with dopaminergic lesion has been used as a standard model of Parkinson's disease. The behavioral effects of dopaminergic agents in a Parkinson's animal model with additional noradrenergic lesions has not been studied so far. Here, the behavioral effects of dopaminergic agents L-DOPA (15 mg/kg) and D-amphetamine (4 mg/kg) in two different pathophysiological conditions have been explored; One group involving only dopaminergic deficiency with 6-hydroxydopamine (6-OHDA) and the other group with both dopaminergic and noradrenergic deficiency with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4). DSP-4 specifically depleted noradrenaline from locus coeruleus terminal fields. 6-OHDA lesion depleted dopamine and its metabolites DOPAC, HVA and 3-MT in the regions of basal ganglia and it was potentiated by additional locus coeruleus denervation. Dopaminergic lesion produced catalepsy and hypoactivity. Hypoactivity in openfield was potentiated by additional noradrenergic denervation of locus coeruleus neurons. L-DOPA produced effective anticataleptic activity in group with both dopaminergic and noradrenergic lesions and D-amphetamine was found to be more effective in group only with dopaminergic lesions, indicating increased dopaminergic neurodegeneration after noradrenergic lesions. L-DOPA produced hyperactivity in dual neurodegenerated group indicating its differential activity in an animal model with noradrenergic and dopaminergic lesions. These findings indicate the neuroprotective and symptomatic role of noradrenergic neurons. It implicates the importance of noradrenergic pathophysiology in Parkinson's disease and its treatment and need for a more relevant animal model.
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PMID:Behavioral and neurochemical effects of noradrenergic depletions with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine in 6-hydroxydopamine-induced rat model of Parkinson's disease. 1508 35

We have examined whether degeneration of nigrostriatal dopaminergic neurons causes dysfunction of both the basal ganglia-thalamic and cerebello-thalamic pathways. Changes in the activity of thalamic neurons receiving input from the basal ganglia or the cerebellum were examined in two models of Parkinson's disease, 6-hydroxydopamine (6-OHDA)-lesioned rats and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys. Metabolic activity of the neurons was evaluated at the cellular level by quantitative in situ hybridization, using the expression of messenger RNA for subunit I of cytochrome oxidase (COI), encoded by the mitochondrial genome, as the marker. COI mRNA expression decreased significantly in thalamocortical neurons receiving input from the substantia nigra (-50.6%) or the cerebellum (-45%) in 6-OHDA-lesioned rats compared with controls. The decrease was observed in all thalamic neurons whether or not they were retrogradely labelled with a tracer injected into the motor cortex. Similarly, COI mRNA expression decreased in projection neurons and interneurons of the thalamus receiving input from the substantia nigra (-39 and -38%, respectively), the internal pallidum (-20 and -42.4%, respectively) and the cerebellum (-36.2 and -50%, respectively) of MPTP-treated monkeys compared with controls. These decreases in COI mRNA levels show that nigrostriatal denervation results in a decrease in the metabolic activity of thalamic neurons in the territories innervated by the substantia nigra, pallidum and cerebellum, which in turn is indicative of a decrease in their neuronal activity. The decrease did not concern the entire thalamus, however, since metabolic activity was unchanged in two thalamic nuclei considered to be limbic structures, the laterodorsal nucleus in 6-OHDA-lesioned rats and the anterior nucleus in MPTP-treated monkeys. Hypoactivity of both the basal ganglia-thalamic and cerebellar-thalamic pathways might therefore be implicated in the development of parkinsonian symptoms.
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PMID:Metabolic activity of cerebellar and basal ganglia-thalamic neurons is reduced in parkinsonism. 1714 69

In Parkinson disease patients who receive long-term antiparkinsonian medication, their original symptoms of rigidity, tremor and related motor disturbances markedly improve or disappear. However, the condition is still far from satisfactory in terms of maintaining independence in daily life activities even in these patients in whom the drug treatment is for improving motor disturbances. The reason is that they show abnormal behavior characterized by "spending the entire day in an idle state, which is perceived as laziness."This behavior is very annoying for the patient and the family. Despite the excellent effectiveness of drug treatment, this propensity toward idleness in mental and motor functions is not improved. Despite the denial of the depressive state and the absence of obvious cognitive disorder, such patients lack ambition and spend their time idly. However, although their motor function remains subliminal, such patients can carry out motor activities when the situation requires, but usually they do not have the drive to move. If we use the current nosological descriptions, the former is called "bradyphrenia" or psychic akinesia or slowness of thinking and the latter is called "akinesia". Akinesia is composed of two cardinal elements "bradykinesia" and "hypokinesia". Bradykinesia is the evaluation of quality of appeared motor behavior, and hypokinesia is the poverty of movement behavior. These two symptoms differ essentially. Hypokinesia is much more essential and is a cardinal element of akinesia. It indicates that the current drug treatment is ineffective for the improvement of hypokinesia and bradyphrenia. That is, these symptoms are a result of a dysfunction different from that causing residual motor symptoms or a result of other additional dysfunctions developing during the pathophysiological course of the disease. The dopamine (DA) system of the dorsal striatal pathway projecting from the substantia nigra pars compacta (A9) to the dorsal part of the striatum (motor striatum) functions in the control of speed and dexterity of movement. On the other hand, the DA system through the medial forebrain bundle projecting from the ventral tegmental area (VTA-A10) to the nucleus accumbens, ventral striatum (limbic striatum) and the cortex is associated with hypokinesia and bradyphrenia. This association can be confirmed by a long-term follow-up of Parkinson disease patients and experimental animal models lesioned in the ventral DA pathway (mesolimbic and mesocortical pathways).
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PMID:[Mesolimbic and mesocortical pathways in Parkinson disease]. 1788 76


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