ISSN:
0942-0940
Keywords:
Intracranial pressure
;
supratentorial mass lesions
;
transtentorial herniation
;
pupillary change
;
auditory brain-stem responses
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary This study was carried out to investigate the effects of an expanding supratentorial mass on auditory brain-stem responses (ABRs). A balloon was inserted into the supratentorial epidural space of seven baboons (in two cases, in the right occipital area; in five cases, in the right temporal area). The balloons were inflated at a rate of 0.2 ml/minute to increase intracranial pressure (ICP). ICP (right frontal epidural pressure) and blood pressure (BP) were continuously recorded. Recordings of ABRs (vertex to mastoid on both sides) were made serially. Pupillary changes were also recorded. At 30mmHg ICP, the amplitude of wave V on the right side was observed to be significantly attenuated (p〈0.02). At 50 mm Hg ICP, the latency of wave V on the right side was significantly prolonged compared with that at 30mmHg ICP (p 〈 0.02). At 70mmHg ICP, significantly decreased amplitude of wave V on the left side was also observed (p〈0.02, from the control), associated with significant increased latency of wave IV on the right side (p〈0.01, from the control; p 〈0.05, from 50 mm Hg ICP). Finally, waves IV and V on both sides substantially disappeared at 100 mm Hg ICP. Anisocoria appeared in four animals at 30–50 mm Hg (mean ±SD; 45±8.7) ICP. The amplitude of wave V was significantly decreased in these circumstances (p〈0.05). Bilaterally fixed pupils occurred in five animals at 70–100 mm Hg (mean±SD; 76 ±12) ICP. wave IV latencies on both sides were significantly prolonged (p〈0.02 right; p〈0.05, left) and disappearance of wave V (four out of five on the right side, three out of five on the left side) was observed in these circumstances. These findings suggest that serial measurement of ABRs can be useful for evaluation of the progress of transtentorial herniation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01407457
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