Tremor was measured from the index finger during low force, position holding in 18 control subjects and 18 battery workers with low level exposure to mercury. All workers were asymptomatic on clinical neurological examination. No differences were found in average tremor amplitudes between the groups, but statistically significant abnormalities in tremor frequency distribution existed. Tremor po...

Pysiological tremor was measured in 14 pairs of monozygotic twins, 14 pairs of dizygotic twins, and 14 pairs of control subjects matched for age and sex. Postural finger tremor was measured in each pair using a sub-miniature accelerometer and subjecting the amplified signals to power spectral analysis. Significant genetical influences were found for the proportion of tremore at frequencies near...

Blood concentrations of harmane, a tremor-producing neurotoxin, are elevated in essential tremor (ET). Harmane is also a comutagen. Using a case-control design, we compared the prevalence of cancer in ET cases vs. controls, and determined whether blood harmane concentrations are elevated among ET cases with cancer. 66/267 (24.7%) ET cases vs. 55/331 (16.6%) controls had cancer (adjusted OR 1.52...

BACKGROUND The aim of this study was to analyze the different forms of leg tremors exhibited while standing in patients with Parkinson disease (PD), and to determine if the type of leg tremor exhibited is indicative of prognosis or treatment response in PD patients. METHODS We studied the clinical characteristics of five PD patients (all women; mean age, 59 years, range, 53-64 years) with uni...

BACKGROUND Tremors are among the most common movement disorders. As there can be considerable variability in the manner in which clinicians assess tremor, objective quantitative tools such as electromyography, accelerometry, and computerized, spiral analysis can be very useful in establishing a clinical diagnosis and in research settings. METHODS In this review, we discuss the various methods...

The objective of the study was to investigate the presence of the phase-locking between a pair of physiological tremor signals from two closely located neurons in the thalamotomy area of a human brain. Most frequently used current methods detect both phase and amplitude correlations between tremor signals based on the stationary assumption of the signals. The correlation analysis method utilize...

Observations on wrist tremor have been made in the horizontal plane using a tremorograph of new design. A small tap to the hand gave rise to a decrementing series of oscillations at about 9 Hz; as these effects were seen in relaxed and in anaesthetised subjects they were not due to neural reflexes. With the fingers partially extended the spontaneous tremor increased markedly and taps again gave...

Aging is characterized by a general decline in physiological and behavioral function that has been widely interpreted within the context of the loss of complexity hypothesis. In this paper, we examine the relation between aging, neuromuscular function and physiological-behavioral complexity in the arm-hand effector system, specifically with reference to physiological tremor and isometric force ...

Patients with essential tremor (ET) may develop Parkinson's disease (PD); however, few studies have examined the clinical features of this combination syndrome. Fifty-three patients with ET-PD were studied and compared to 53 PD and 150 ET patients. Although the latency from onset of ET to PD was brief (<5 years) in 38.5%, in a sizable proportion (30.8%), it was very long (>20 years). The gender...

BACKGROUND Embarrassment is a commonly described feature of essential tremor (ET) but has not been the focus of clinical research. OBJECTIVE To estimate the prevalence, identify susceptible patient groups, and quantify the therapeutic correlates of reported embarrassment. METHODS A total of 106 ET cases from a population-based sample and 349 ET cases from a clinical sample were asked, "Does...