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

Paralysis agitans may be mimicked by other disease processes and drugs which disturb the structural or functional integrity of the dopaminergic nigrostriatal system. In another group of patients, isolated symptoms or signs such as tremor or increased muscle tone are considered out of the context of the total clinical picture and may suggest parkinsonism.
 ...
PMID:Differential diagnosis of paralysis agitans. 26 20

The recording technique described makes possible the detailed analysis of hypertonia and tremor in Parkinson's disease, as well as the action of different drugs. It may contribute to the understanding of the physiopathological basis of these motor disturbances and the mode of action of anti-parkinsonian drugs. It also represents a reliable method of repeated observation, independent of subjective factors, in the evaluation of the long-term effectiveness of a medication. We were particularly concerned with the evaluation and comparison of the effect of different drugs in the course of a short study, involving the administration of a single dose of the medications used. In this way were studied: Apomorphine, given sub-cutaneously in non-emetic doses, which decreases in a constant and spectacular fashion both tremor and hypertonia ; Piribedil (1-3 mg IV) ; L-Dopa (100 mg IV) ; Ro-080576/007 F in a dose of one capsule containing 200 mg of L-Dopa and 50 mg of L-dopa-decarboxylase inhibitor. The effect of these various medications was invariable greater than that of a placebo and lasted much longer. With these doses, and under the special experimental conditions of this study, Piribedil was better tolerated and in general more active than L-dopa, in particular in relation to tremor. The action observed in the course of this short study prior to treatment might, to a certain extent, make it possible to predict the effect of long-term treatment.
 ...
PMID:[Polygraphic recording of tremor and of hypertonic phenomena. Application to the action of various drugs]. 110 46

The triad of rigidity, fever, and elevation of serum creatine phosphokinase (CPK) levels, labeled 'neuroleptic malignant syndrome' (NMS), is a dangerous complication of neuroleptic drug treatment. Amantadine was introduced for the pharmacological management of NMS because of its beneficial effects in Parkinson's disease which were attributed to direct or indirect dopaminomimetic properties of amantadine. While the dopaminomimetic effects of amantadine are weak under experimental conditions, recent studies have confirmed that amantadine is an antagonist at the N-methyl-D-aspartate (NMDA) type of glutamate receptor. Two lines of evidence suggest that amantadine or other NMDA receptor antagonists could be effective drugs for the reversal of NMS symptoms. First, glutamate antagonists restore the balance between glutamatergic and dopaminergic systems when dopaminergic transmission has been antagonized by neuroleptic drugs. Second, by virtue of their effects against rigor and spasticity, NMDA antagonists may reduce increased muscle tone and prevent rhabdomyolysis. In conclusion, NMS may be considered an iatrogenic excitatory aminoacid syndrome which is amenable to NMDA receptor antagonist therapy.
 ...
PMID:A rationale for NMDA receptor antagonist therapy of the neuroleptic malignant syndrome. 133 36

Two patients presenting Parkinson's disease underwent thalamotomy by a stereotactic procedure at San Fernando Clinic. These patients were selected using a strict protocol. The surgical procedures and the results have been described. Review of potential complications are also discussed. Thalamotomy by stereotactic surgery is a method that offer excellent results in patients presenting movement disorders. Specifically in Parkinson's disease, it has demonstrated a great effectiveness in abolishing tremor and in controlling hypertonia. Bradykinesia does not seem to respond to this procedure.
 ...
PMID:[Stereotaxic surgery in Parkinson's disease. A preliminary report of 2 cases]. 162 Aug 90

Studies of orofacial motor control in Parkinson's disease (PD) have demonstrated that these subjects may exhibit hypokinesia and bradykinesia, as well as increased muscle tone. Yet the relationship between aberrations of orofacial movement and muscle rigidity remains unclear. Measures of labial muscle rigidity and movement were made for 12 parkinsonian and 9 age-matched control subjects. Displacement amplitude, peak instantaneous velocity, and movement time were evaluated during repetitive syllable productions. The results showed that while mean parkinsonian displacement amplitudes and velocities were lower than the normal control subjects, there was no statistical relationship between labial rigidity and the degree of movement abnormality. It is concluded that while rigidity may play a part in the overall disability, it does not sufficiently explain the labial articulatory difficulties associated with parkinsonism. This is in agreement with the literature on limb rigidity and movement aberrations in PD, suggesting that rigidity and bradykinesia may represent independent pathophysiological phenomena.
 ...
PMID:Labial kinematics during speech in patients with parkinsonian rigidity. 365 93

An autopsy case of a 52-year-old man suffering from chronic manganese poisoning (CMP) is reported with determination of the manganese distribution in the brain. The patient had been working in a manganese ore crushing plant since 1965. In 1967 he began to complain of difficulties in walking and diminished libido. Later, he developed various neuropsychiatric symptoms including euphoria, emotional incontinence, masked face, monotonous speech, "cock-walk", increased muscle tone, weakness of upper and lower extremities, tremor of the eye lids, and exaggeration of knee jerks. The major neuropathological change was degeneration of the basal ganglia, in which the pallidum was severely affected. The pallidum disclosed a loss and degeneration of nerve cells, which was especially marked in the medial segment, a prominent decrease of myelinated fibers, and moderate astrocytic proliferation. The substantia nigra was intact. Distribution of manganese in the brain of the present case of CMP was determined using flameless atomic absorption spectrometry and compared with control cases and also a case of Parkinson's disease (PD). There was no significant difference between the control cases and the case of PD in average concentration of manganese and its distribution in the brain. The present case of CMP showed no elevation in average concentration of manganese in the brain. However, there were some changes in its distribution. Thus, the continuance of neurological disorders in CMP is not linked to an elevated manganese concentration itself in the brain. CMP appears to be different from PD in neuropathology and manganese behavior in brain.
 ...
PMID:Chronic manganese poisoning: a neuropathological study with determination of manganese distribution in the brain. 376 27

Clinical Neurophysiology brings about 2 major contributions in the study of Parkinson's disease: on the one hand, it makes it possible to measure the motor troubles; on the other, it enables their pathophysiological analysis. The 3 classical signs must be studied separately. Tremor can easily be recorded by electromyography. Moreover, its parkinsonian nature can be specified by studying the resetting of EMG bursts following electrical stimulation of the motor nerve. A pace maker has been demonstrated in the thalamus from where rhythmic messages are first sent to motor cortex and thereafter reverberated to spinal motoneurons. Rigidity can be assessed by sophisticated but not generalized methods. It is easier to evaluate it by long-loop responses evoked by proprioceptive or exteroceptive stimulations. These responses reflect activity in pathways relaying in supraspinal structures. Contrary to spasticity, rigidity is not basically due to dysfunctions in segmentary spinal circuits. It is more likely that it depends on hyperactive and hyperexcitable long loop pathways. This hypothesis is in agreement with well established facts showing that parkinsonian hypertonia vanishes after dorsal root section. Akinesia is complex semeiologically. It is made of various components some of which can be measured. Reaction times and movement times provide interesting data which however are not strictly correlated with the motor handicap. Motor programmes are assembled in normal delays but they are not "called upon" correctly, reflecting a disturbance in the motor planning. A lack of "energetization" of the motor cortex and the pyramidal tract is likely. A functional disconnection between the motor program/plan side and the execution side can be hypothesized to explain the 3 major signs; on the one hand, neural messages are not correctly transferred to the pyramidal system, on the other, spinoencephalospinal loops on the execution side become more active as they escape from the control normally exerted by the plan/program side where basal ganglia play a prominent role.
 ...
PMID:[Clinical neurophysiology in the evaluation and physiopathology of Parkinson's disease]. 383 95

Torque curves were recorded during passive and active ankle joint movements at three preset angular velocities (30, 60 and 120 degrees/s) with the subject in the supine position and 45 degrees hip and knee angles. Recordings were performed in normal subjects (n = 11), patients with clinical spasticity (n = 10) and patients with Parkinson's disease (n = 7). The torque curves recorded during passive dorsiflexion followed by plantar flexion showed a counterclockwise hysteresis loop with minimal area in the normal subjects and a large area in patients, especially at the highest velocity. The torque increase during dorsiflexion was proportional to the angular velocity in the patients with spasticity but not in the patients with Parkinson's disease. In the patients with spasticity, a good correlation was found between clinical assessment of hypertonia and measurements of torque during passive movements but not torque values during maximal voluntary dorsiflexion. A model for data reduction and estimation of instant slope values on different parts of the torque-angle curve is suggested. The use of ankle torque recordings for evaluation of treatment effects is exemplified.
 ...
PMID:Measurement of torque during passive and active ankle movements in patients with muscle hypertonia. A methodological study. 658 32

A 45-year-old woman with a history of probable perinatal craniocerebral trauma resulting in mild asymptomatic right hemiatrophy developed right leg weakness and hypotonia alternating with dystonia only after prolonged exertion at age 12. At age 27, she developed right-sided parkinsonism. Exertional paresis and dystonia and parkinsonism responded completely to levodopa; however, she developed a progressive reduction in the duration of action of levodopa over the first 4 years of treatment. Investigations including computed tomography, magnetic resonance imaging, [18F]fluorodopa, and [18F]fluorodeoxyglucose positron emission tomography scans suggested a static lesion involving the left substantia nigra. This unusual exertion-induced weakness and hypotonia alternating with hypertonia and dystonia has not been reported previously. The role of dopamine deficiency in dystonia and the role of levodopa in the development of fluctuations in Parkinson's disease are discussed. Review of the literature, including this patient, emphasizes the heterogeneity of the syndrome of hemiparkinsonism-hemiatrophy.
 ...
PMID:Hemiatrophy, juvenile-onset exertional alternating leg paresis, hypotonia, and hemidystonia and adult-onset hemiparkinsonism: the spectrum of hemiparkinsonism-hemiatrophy syndrome. 756 31

The aim of the present study was to localize the dopamine receptors involved in the regulation of muscle tone. A strategy was used whereby the effects on muscle tone of injecting the irreversible dopamine receptor antagonist N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) in discrete brain regions were assessed. Increases in muscle tone were measured as changes in electromyographic activity of the gastrocnemius and tibialis muscles of conscious, unrestrained rats. No increases in muscle tone were found after injections of EEDQ into the anterior and posterior striatum, which produced marked reductions in dopamine receptor concentration. The effects of muscle tone of injecting EEDQ into the substantia nigra pars reticulata were also assessed. Large increases in muscle tone were observed associated with inactivation of either D1 or D2 dopamine receptors in the substantia nigra. The increased muscle tone was not reduced by subcutaneous administration of apomorphine, despite the presence of a normal population of striatal dopamine receptors. These findings provide evidence that dopamine receptors in the substantia nigra play an important role in the regulation of muscle tone. Further, they challenge the hypothesis that the muscle rigidity of Parkinson disease results primarily from loss of striatal dopamine receptor stimulation.
 ...
PMID:Dopamine receptors in the substantia nigra are involved in the regulation of muscle tone. 787 37


1 2 3 4 Next >>