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  • 1990-1994  (2)
  • 1945-1949
  • 1910-1914
  • 1890-1899
  • Distal shunt failure  (1)
  • Dorsal terminal nucleus (DTN)  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Effects of lesions of the nucleus of the optic tract on optokinetic nystagmus and after-nystagmus in the monkey (1990)
    Springer
    Experimental brain research 79 (1990), S. 225-239 
    Details
    ISSN: 1432-1106
    Keywords: Optokinetic nystagmus (OKN) ; Optokinetic after-nystagmus (OKAN) ; Velocity storage ; Nucleus of the optic tract (NOT) ; Dorsal terminal nucleus (DTN) ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The nucleus of the optic tract (NOT) and the dorsal terminal nucleus (DTN) of the accessory optic system were lesioned electrolytically or with kainic acid in rhesus monkeys. When lesions involved NOT and DTN, peak velocities of optokinetic nystagmus (OKN) with slow phases toward the side of the lesion were reduced, and optokinetic after-nystagmus (OKAN) was reduced or abolished. The jump in slow phase eye velocity at the onset of OKN was smaller in most animals, but was not lost. Initially, there was spontaneous nystagmus with contralateral slow phases. OKN and OKAN with contralateral slow phases were unaffected. 2. Damage to adjacent regions had no effect on OKN or OKAN with two exceptions: 1. A vascular lesion in the MRF, medial to NOT and adjacent to the central gray matter, caused a transient loss of the initial jump in OKN. The slow rise in slow phase velocity was prolonged, but the gain of OKAN was unaffected. There was no effect after a kainic acid lesion in this region in another animal. 2. Lesions of the fiber tract in the pulvinar that inputs to the brachium of the superior colliculus caused a transient reduction in the buildup and peak velocity of OKN and OKAN. 3. In terms of a previous model (Cohen et al. 1977; Waespe et al. 1983), the findings suggest that the indirect pathway that activates the velocity storage integrator in the vestibular system to produce the slow rise in ipsilateral OKN and OKAN, lies in NOT and DTN. Activity for the rapid rise in OKN, carried in the direct pathway, is probably transmitted to the pontine nuclei and flocculus via an anatomically separate fiber path-way that lies in the MRF. A fiber tract in the pulvinar that inputs to the brachium of the superior colliculus appears to carry activity related to retinal slip from the visual cortex to NOT and DTN.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00608231
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Time-related patterns of ventricular shunt failure (1994)
    Springer
    Child's nervous system 10 (1994), S. 524-528 
    Details
    ISSN: 1433-0350
    Keywords: Proximal shunt failure ; Distal shunt failure ; Time to shunt failure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Proximal obstruction is reported to be the most common cause of ventriculoperitoneal (VP) shunt failure, suggesting that imperfect ventricular catheter placement and inadequate valve mechanisms are major causes. This study retrospectively examined patterns of shunt failure in 128 consecutive patients with symptoms of shunt malfunction over a 2-year period. Factors analyzed included site of failure, time from shunt placement or last revision to failure, age of patient at time of failure, infections, and primary etiology of the hydrocephalus. One hundred of these patients required revisions; 14 revisions were due to infections. In this series there was a higher incidence of distal (43%) than of proximal (35%) failure. The difference was not statistically significant when the overall series was considered; however, when factoring time to failure as a variable, marked differences were noted regardless of the underlying cause of hydrocephalus or the age of the patient. Of the 49 patients needing a shunt revision or replacement within 2 years of the previous operation, 50% had proximal malfunction, 14% distal, and 10% had malfunctions attributable directly to the valve itself. Also, 12 of the 14 infections occurred during this time interval. In sharp contrast, of the 51 patients having shunt failure from 2 to more than 12 years after the previous procedure, 72% had distal malfunction, 21% proximal, and only 6% had a faulty valve or infection. This difference between time to failure for proximal versus distal failures was statistically significant (P〈0.00001 for both Student's t-test and non-parametric Mann-Whitney U-test). It is concluded that these data are valuable for interpreting outcome studies of novel valve systems and ventricular catheter placement techniques, by defining a time frame during which these modifications can be reliably evaluated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335075
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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