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)

Physiological and pharmacological studies of more than 150 patients with movement disorders are reported. Particular attention is paid to the differentiation of various types of tremor on the basis of rate, rhythm, and pattern of EMG activity in antagonistic muscles. The typical 'tremor-at-rest' of Parkinson's disease--3-7 Hz activity which alternates between antagonistic muscles--is suppressed, at least briefly, during voluntary activity, at which time typical 8--12 Hz 'physiological tremor' may be seen. Essential tremor and its familial or senile variants also have a characteristic EMG pattern during voluntary activity--5-8 Hz bursts of activity which are synchronous in antagonistic muscles. This type of tremor may also be present in patients with Parkinson's disease and in certain kinships with a Charcot-Marie-Tooth polyneuropathy. Other tremors in association with polyneuropathy ('neuropathic tremor') have different physiological characteristics. Myoclonus is of essentially two types ('positive' with EMG bursts and 'negative' with brief pauses in ongoing activity, as with asterixis) and may, at times, mimic tremor. Certain specific tremors respond predictably to specific pharmacological therapy.
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PMID:Physiological and pharmacological aids in the differential diagnosis of tremor. 0 92

This article focuses on the current knowledge about movement disorders associated with alcohol and drug abuse. Chronic alcohol use can produce a wide spectrum of movement disorders including tremor, withdrawal parkinsonism and dyskinesias, cerebellar ataxia, and asterixis. MPTP, a neurotoxin first reported to cause parkinsonism in a group of drug abusers, has provided important insights into the pathogenesis of Parkinson's disease. There is a growing body of literature providing evidence that dyskinesias such as tics and dystonia may be precipitated or exacerbated by cocaine. Amphetamines have been implicated in the production of stereotypies and exacerbation of tics.
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PMID:Movement disorders. 837 47

This is a proposal of the Movement Disorder Society for a clinical classification of tremors. The classification is based on the distinction between rest, postural, simple kinetic, and intention tremor (tremor during target-directed movements). Additional data from a medical history and the results of a neurologic examination can be combined into one of the following clinical syndromes defined in this statement: enhanced physiologic tremor, classical essential tremor (ET), primary orthostatic tremor, task- and position-specific tremors, dystonic tremor, tremor in Parkinson's disease (PD), cerebellar tremor, Holmes' tremor, palatal tremor, drug-induced and toxic tremor, tremor in peripheral neuropathies, or psychogenic tremor. Conditions such as asterixis, epilepsia partialis continua, clonus, and rhythmic myoclonus can be misinterpreted as tremor. The features distinguishing these conditions from tremor are described. Controversial issues are outlined in a comment section for each item and thus reflect the open questions that at present cannot be answered on a scientific basis. We hope that this statement provides a basis for better communication among clinicians working in the field and stimulates tremor research.
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PMID:Consensus statement of the Movement Disorder Society on Tremor. Ad Hoc Scientific Committee. 982 89

Whole-head MEG-systems and modern spatial-filter-based analysis tools recently provided new possibilities to analyze non-invasively cerebral networks of human tremor syndromes. We compared tremor syndromes in Parkinsonian patients with a typical resting tremor as well as in patients with hepatic encephalopathy (HE) with a postural tremor called "mini-asterixis". In 6 patients with idiopathic Parkinson's disease (PD) we found strong coherence between the electromyography (EMG) of forearm muscles and activity in the contralateral primary motor cortex (M1) at tremor frequency but also at double tremor frequency. Furthermore, significant coherences were observed between M1 and medial wall areas (CMA/SMA), lateral premotor cortex, diencephalon, SII cortex, posterior parietal cortex and the contralateral cerebellum at tremor and, stronger, at double tremor frequency. In contrast, in 6 patients with "mini-asterixis" and HE due to chronic liver cirrhosis excessive corticomuscular coherence occurred at the individual tremor frequency between EMG and M1 activity. Interestingly, thalamus-M1 coupling was significantly altered towards lower frequencies matching the individual frequency of the mini-asterixis. Cerebro-muscular or cerebro-cerebral coupling at double tremor frequency was not observed. Therefore, "mini-asterixis" reflects most likely a pathologically decelerated and augmented synchronized rhythmical motor cortical output. This could be due to functional alterations in the M1-basal-ganglia-thalamo-cortical loops in severe HE. In summary, tremor syndromes in PD as well as in patients with HE and "mini-asterixis" are characterized by pathological oscillatory activity within cerebral networks of motor areas. However, the present study shows different mechanisms of tremor generation in PD and HE patients.
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PMID:Pathological oscillatory coupling within the human motor system in different tremor syndromes as revealed by magnetoencephalography. 1601 24

An array of movement disorders is associated with ethanol, illicit drugs, and tobacco. Heavy ethanol users experience withdrawal tremor and, less often, withdrawal parkinsonism, chorea, and myoclonus. Asterixis is a feature of hepatic failure. On the other hand, ethanol can ameliorate essential tremor and myoclonus-dystonia. Among opioid drugs, meperidine can precipitate myoclonus. Severe parkinsonism affected users of a synthetic meperidine analog contaminated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Spongiform leukoencephalopathy, sometimes with chorea and myoclonus, occurred in inhalers of heroin vapor (chasing the dragon). Psychostimulants including cocaine acutely cause stereotypies and dyskinesias. Phencyclidine toxicity causes myoclonus. Tobacco use, on the other hand, protects against Parkinson's disease. Clinicians need to consider substance abuse in patients with unexplained movement disorders.
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PMID:Substance abuse and movement disorders. 2072 28