Does the postural variable affect the determination of balance compensation level in vestibular schwannoma patients?

AbstractThe aim of this study was the determination of the incidence of symptoms of audio-vestibular dysfunction and of abnormalities on audio-vestibular testing in patients found to have a unilateral meningioma of the cerebello-pontine angle (CPA). The case notes of 25 patients diagnosed with unilateral, sporadic and histologically proven CPA meningioma were retrospectively reviewed. The age range of this series was 31–71 years, with a mean age of 50 years. Two patients were male (eight per cent) and 23 were female (92 per cent). The mean length of history was 44.7 months. The distribution of tumour size was skewed toward larger tumours, with 15 cases (60 per cent) having tumours with a maximum diameter greater than 3.5 cm on imaging. Pure tone audiometry was normal in five cases (20 per cent), and no patients exhibited the high frequency sensorineural hearing loss that is characteristic of vestibular schwannoma. Speech audiometry was normal in 50 per cent of cases. Caloric testing was abnormal in 77 per cent of the 18 cases tested, whilst auditory brainstem responses (ABR) were abnormal in 100 per cent of the 18 cases who had sufficient hearing for this test to be possible. The presence of normal audiometry in patients with a proven CPA lesion indicates that, if in a protocol for investigation, asymmetry of hearing is mandatory then some pathology will be missed. Any suspicion of a CPA lesion warrants investigation even in the absence of hearing loss.The investigation of choice for the identification of CPA lesions has become magnetic resonance imaging (MRI). If this technique is not available then this study indicates that ABR is a suitable and sensitive investigation. It should be borne in mind however that the data in this study has been derived from a series of predominantly large tumours, and the sensitivity of ABR to smaller CPA meningiomata may fall, as is the case for vestibular schwannoma.

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Galactic orbits of stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900105340 ◽

1966 ◽

Vol 25 ◽

pp. 93-97

Author(s):

Richard Woolley

Keyword(s):

Globular Cluster ◽

Potential Field ◽

High Velocity ◽

Velocity Vector ◽

Variable Stars ◽

The Sun ◽

Proper Motions ◽

Rr Lyrae ◽

The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

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Distance to SN 1987A and the LMC

Symposium - International Astronomical Union ◽

10.1017/s0074180900118959 ◽

1999 ◽

Vol 190 ◽

pp. 549-554

Author(s):

Nino Panagia

Keyword(s):

Angular Size ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Light Curves ◽

Distance Modulus ◽

Absolute Size ◽

Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

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International determination of the total motion of the pole

Symposium - International Astronomical Union ◽

10.1017/s0074180900177824 ◽

1961 ◽

Vol 13 ◽

pp. 29-41

Author(s):

Wm. Markowitz

Keyword(s):

Secular Motion ◽

The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

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Time and Latitude in South Africa

International Astronomical Union Colloquium ◽

10.1017/s0252921100026816 ◽

1972 ◽

Vol 1 ◽

pp. 27-38

Author(s):

J. Hers

Keyword(s):

South Africa ◽

Cape Town ◽

Astronomical Observations ◽

Royal Observatory ◽

The Republic ◽

Astronomical Determination ◽

Limited Accuracy ◽

Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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Large-scale Motion of Solar Filaments

International Astronomical Union Colloquium ◽

10.1017/s0252921100064502 ◽

2000 ◽

Vol 179 ◽

pp. 205-208

Author(s):

Pavel Ambrož ◽

Alfred Schroll

Keyword(s):

Magnetic Flux ◽

Proper Motion ◽

Time Scale ◽

Large Scale ◽

Accuracy Of Measurements ◽

Solar Filaments ◽

General Movement ◽

Scale Motion ◽

Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

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