Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2002
Multicenter Study Comparative StudyMulti-centre assessment of the Spiegelberg compliance monitor: interim results.
Analyses of a multi-centre database of 71 patients at risk of raised ICP showed that in head injured patients (n = 19) and tumour patients (n = 13) clear inverse relationships of ICP vs compliance exist. SAH patients (n = 5) appear to exhibit a biphasic relationship between ICP and compliance, however greater numbers of patients need to be recruited to this group. Patients with hydrocephalus (n = 34) show an initial decrease in compliance while ICP is less than 20 mmHg, thereafter compliance does not show a dependence upon ICP. ⋯ Preliminary time-series analyses of the ICP and compliance data is revealing evidence that the cumulative time compliance is in a low compliance state (< 0.5 ml/mmHg), as a proportion of total monitoring time, increases more rapidly than the cumulative time ICP is greater than 25 mmHg. Before trials testing compliance thresholds can be designed, we need to consider not just the absolute threshold, but the duration of time spent below threshold. A survey may be required to identify a consensus of what is the minimum duration of raised ICP above 25 mmHg needed to instigate treatment.
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Acta Neurochir. Suppl. · Jan 2002
Review Case ReportsDeep brain stimulation of the globus pallidus internus (GPI) for torsion dystonia--a report of two cases.
Generalized dystonia is known as a type of movement disorder in which pharmacotherapeutic options are very limited. Deep Brain Stimulation (DBS) is well established for Parkinson's disease (PD) and tremor dominant movement disorders. We report on two cases of generalized dystonia which were successfully treated by chronic high frequency stimulation in the Globus pallidus internus (GPI). ⋯ The medication was continuously reduced. At the 24 month follow-up the effect of stimulation remained unchanged. However high stimulation parameters are required to maintain an optimal effect (mean 3.5 V, 400 microseconds, 145 Hz).
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Induced blood pressure elevation has become a popular treatment for intracranial hypertension. However, there remains a concern that in some patients blood pressure elevation will further elevate ICP. This study was conducted to test the hypothesis that increasing MAP decreases ICP. ⋯ In patients with lower GCS and high SjvO2 an increase in MAP resulted in an increase in ICP. We concluded that in the majority of studies increasing MAP was followed by an increase in ICP. CPP therapy has a selective indication in patients with high GCS, low SjvO2 and increased ICP.
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This investigation analyzed 22 xenon CT cerebral blood flow (CBF) studies from 18 severely head-injured patients (Glasgow motor score < 6) who underwent xenon CT scanning while brain tissue oxygen tension (PbtO2) was being monitored. CBF was determined both in a localized region of interest around the actual or estimated location of the tip of the PbtO2 probe and in the entire corresponding CT slice. ⋯ Very low values were significantly less common for global CBF than for rCBF. Further investigation is necessary to determine how probe placement near contused areas vs. in normal tissue affects our understanding of the relationship between rCBF, global CBF, PbtO2, and cerebral oxygen consumption.
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Acta Neurochir. Suppl. · Jan 2002
Continuous cerebral compliance monitoring in severe head injury: its relationship with intracranial pressure and cerebral perfusion pressure.
Cerebral Compliance describes the ability of cranial content to accommodate volume variations. Intracranial vascular compartment is thought to be one of the most important determinants of Compliance. Cerebral perfusion pressure (CPP) has a significant influence upon the calibre of cerebral vessels and consequently, upon blood volume. ⋯ At CPP > or = 60 mmHg Compliance decreased with CPP (R2 = 0.83). In the range of low CPP vasoparalysis is impending. However, when ICP is pathological, at high CPP our results may express vasodilatation instead of expected vasoconstriction from normal autoregulation.