Intermittent Tremor Research Articles

Analysis of the intermittent volcanic tremor observed at Mt. Etna, Sicily during March-May 1987

Volcanic activity at the summit craters of Mt. Etna includes phreatic eruptions which jeopardize tourists and other people who sporadically approach the top of the volcano. To date no appreciable precursors of this kind of activity are known. Solely intermittent volcanic tremor might be considered a short-term seismic forerunner. The pattern of volcanic tremor amplitude at Mt. Etna during springtime 1987 was investigated and revealed significant periodicities before both phreatic explosions occurring at the summit craters during that time span. Results are in agreement with a boiling mechanism as the source of intermittent volcanic tremor, even if the lack of data on the ground water table in the upper part of the volcano did not allow the formulation of quantitative models.

EMG analysis of harmaline-induced tremor in normal and three strains of mutant mice with Purkinje cell degeneration and the role of the inferior olive

1. The effects of intraperitoneal injections of 10 mg/kg harmaline were tested in normal mice and three strains of cerebellar mutant mice with Purkinje cell degeneration. Ten normal (wild-type) mice (+/+), as well as five lurcher (lc/+), six nervous (nr/nr), and eight Purkinje cell degeneration (pcd/pcd) mutants were implanted with chronic electromyogram (EMG) electrodes in the hamstring and quadriceps muscle groups of the right hindlimb. 2. EMGs were recorded in each of the mice during spontaneous activity before and after intraperitoneal injections of 0.3 ml harmaline (10 mg/kg). Spectral analysis was used to quantify the amplitude and frequency of tremor found in the EMGs after harmaline administration. Normal mice responded to harmaline with strong, continuous 11- to 14-Hz tremor. Mutants from the pcd/pcd strain also reacted with continuous tremor, but of lower amplitude and frequency. In contrast, nr/nr mutants exhibited intermittent paroxysmal tremor lasting for only a few seconds, and lc/+ mutants showed no evidence of tremor whatsoever. 3. In order to detect covert tremor that was possibly not revealed by focal intramuscular EMG recordings, several mutant and normal mice were also tested on a suspended platform to which an accelerometer was attached. The results confirmed the findings from EMG recordings. 4. An incidental observation made during the course of this study was that harmaline tremor disappeared from the normal mouse during swimming and reappeared when the animal was withdrawn from the water. 5. Although Purkinje cells appeared to increase both the depth of modulation and the frequency of tremor, the inhibitory action of the cerebellar cortex does not seem to be essential for the generation of tremor. 6. Parasagittal cerebellar sections of the normal, wild-type mice and the three strains of cerebellar mutant mice of various ages were stained with cresyl violet and examined for Purkinje cell degeneration. Purkinje cell degeneration was found to be complete in the pcd/pcd and lc/+ strains. Although an initial examination of parasagittal sections of the nr/nr strain failed to find any surviving Purkinje cells, further examination of sections cut in the coronal plane revealed small clusters of Purkinje cells in the vermal area of the posterior lobe. 7. The retrograde transport of wheat-germ-agglutinin-conjugated horseradish peroxidase (WGA-HRP) pressure-injected into the cerebellar cortex was used to study the olivocerebellar projections in the wild-type mice and the three strains of cerebellar mutant mice.(ABSTRACT TRUNCATED AT 400 WORDS)

A probable case of hypoparathyroidism in a cat

ABSTRACTIdiopathic hypoparathyroidism was suspected in a young female cat. The relevant historical and clinical findings were: anorexia, intermittent muscle tremors, hindlimb ataxia, behavioural changes and cataracts. Salient laboratory findings were: hypocalcaemia, hyperphosphataemia and normal renal function (normal serum urea and creatinine concentrations with hypersthenuria). No evidence of intestinal malabsorption, pancreatitis or nutritional secondary hyperparathyroidism was found. Treatment with oral synthetic vitamin D (1,25 dihydroxycholecalciferol) and intravenous and oral calcium supplements was successful in correcting the hypocalcaemia and abolishing the clinical signs.

A Simple Tremor Model Induced by Pentobarbitone in Guinea Pig

We have recently reported that a combined application of chlorpromazine and pentobarbitone induced intermittently occurring tremor bursts in guinea pigs (Tan et al., in press). This was a chance discovery. It will be shown in the present work that chlorpromazine is not essential for this postural tremor; only pentobarbitone in low dosages produced intermittent tremor bursts in guinea pigs lying in a supine position. Chlorpromazine alone was not effective in producing tremor. The pentobarbitone-induced tremors were attenuated by the i.v. application of biperiden or lioresal. These results indicate that these tremors would be produced by the basal ganglia as in Parkinsonism.

Volcanic tremors associated with the July, 1989 volcanic activity off eastern Izu peninsulla. Analysis of data by JMA network.

On June 30, 1989, an earthquake swarm started off the east coast of the Izu Peninsula in Japan. During the activity, volcanic tremors were observed from July 11 and submarine volcanic eruptions were visually observed on July 13. In this paper, some characteristics of the volcanic tremors are investigated by analyzing the data obtained by the permanent seismic network of the Japan Meteorological Agency (JMA). The volcanic tremors occurred when the earthquake swarm activity was on the decline. The spectra of these tremors are composed of low-frequency waves (about 1Hz) and high-frequency waves (more than 3Hz). The ratio of the amplitudes of the former to those of the latter increased from July 11 to July 12, and more low-frequency waves are observed in July 13. Four isolated events which were observed from 19h 03m to 19h 05m of July 13 simultaneously with a continuous low-frequency tremor (about 1Hz) show similar spectra with those of the continuous tremor during the submarine eruptions. Hence, the continuous tremor during the submarine eruptions seems to include a lot of such events. The high-frequency waves in the tremors were predominant while explosive sounds and water domes were frequently observed, and seem to be P-waves associated with explosions at the sea bottom. The low-frequency tremors are classified into continuous tremors (about 1Hz) and surface waves associated with the explosions. As the result of particle motion diagrams at the KMT station, the low-frequency tremors associated with the explosions seem to be composed of both Rayleigh waves and Love waves and the continuous tremors seem to be composed of only Love waves. After the eruptions, intermittent volcanic tremors with small amplitude were observed until July 21. Very little high-frequency waves are found in these tremors. The predominant frequency of the tremors was about 1Hz until July 16, changing to about 1.5Hz from July 17.

Public Administration in the First Decade of Bangladesh: Some Observations on Developments and Trends

In 1981 Bangladesh completed its first decade as an independent nation. It had been a turbulent period characterized by intermittent political tremors, recurring economic crises, and widespread social changes. The ramifications of these multifaceted phenomena had deep impact upon the administrative dimensions of the state with consequent implications for the society and its people. The purpose of this article is to analyze the major developments and trends in public administration that were perceptible during the first decade of independent Bangladesh. First, it looks at developments that occurred during the first three years (1972-74) of the parliamentary regime, and second, it identifies important trends during the remaining years (1975-81) of the decade that saw the operation of presidential systems of

Normal copper metabolism in quaking mice

Copper levels and the activities of two copper dependent enzymes, ceruloplasmin and cytochrome c oxidase, were determined in tissues from quaking mice (qk/qk) and their littermate controls (+/?). Quaking mice were identified visually by their intermittent tremors and biochemically by a three-fold decrease in brain 2′,3′-cyclic nucleotide 3′-phosphohydrolase (CNP) activity. When compared to their littermates adult quaking mice have normal tissue copper concentrations. Brain cytochrome oxidase activity is not reduced. Perinatal copper metabolism was equivalent in brains of 10, 15, 18 and 22 day old quaking mice and their littermates. Mothers (+/qk), supplemented throughout gestation and lactation with copper sulfate (208 ppm Cu), still produced tremorous mice. These offspring have elevated brain and liver Cu levels but not ceruloplasmin or CNP activities when compared to quaking mice from dams supplemented with sodium sulfate. It is suggested that quaking mice have normal copper metabolism.

Toxigenic fungi associated with stored corn.

A total of 246 fungal isolates were obtained from 25 moldy corn samples collected in central Iowa. Either water or ether extracts of all corn samples except one exhibited some degree of toxicity in mice and/or ducklings. At least one toxigenic isolate was obtained from each corn sample. Extracts of cultures of 99 of the fungal isolates, involving 13 genera, produced death in one or more of the assay animals. The majority of the toxigenic isolates belonged to the generaAspergillus andPenicillium. Three isolates ofTrichothecium roseum were highly toxic to ducklings and mice. The ducklings exhibited a flaccid paralysis shortly after receiving an oral dose of extracts of these three isolates. Death frequently occurred following a second oral dose given 24 hr later. Mice given intraperitoneal injections of extracts ofT. roseum first exhibited lethargy and intermittent tremors, then hyperemotivity, roughening of the hair coat, abdominal respirations, incoordination, dyspnea and clonic convulsions with death occurring usually within 10 to 20 min.

ENCEPHALITIS WITH TUMOR OF THE BRAIN

The differential diagnosis of encephalitis, cerebral thrombosis and tumor of the brain sometimes offers considerable difficulty, which is increased when two of the conditions are coincident. In the case reported below all three were present. Another reason for reporting this case is the finding of an organism in the blood stream during life and in the brain after death—an organism that Evans and I have isolated from several cases of epidemic encephalitis. We believe that it was the cause of the idiopathic paralysis agitans in this patient. REPORT OF CASE Clinical History. —S. K. H., aged 56, a public school teacher, always high strung and a hard worker, had had an intermittent rhythmic tremor of the right hand since the summer of 1925. At various times also she had had neuritic pains in the arms, for which nine teeth had been extracted in October, 1925. This operation was