Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2012
Influence of isoflurane on neuronal death and outcome in a rat model of traumatic brain injury.
In the developing brain agents clinically used for the purpose of analgosedation can cause severe neurodegeneration. In patients with TBI analgosedation is a first-line treatment for intracranial hypertension. At the same time, damaged neuronal networks undergo conformational changes and use developmental mechanisms to restore brain function. ⋯ Along with histological findings neurological outcome was worst as indicated by a higher score in the experimental group with deep sedation (mean ± SEM 4 h, 13.9 ± 0.6, n = 14 and 20 ± 0.7, n = 15; 48 h, 8.1 ± 0.6, n = 14 and 13.3 ± 0.6, n = 15). Although blood pressure was lower with deep sedation, no frank hypotension occurred. In our experiments deep sedation with high doses of isoflurane caused neurodegeneration and worse outcome compared with regular sedation.
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From recent studies, it remains unclear whether CT angiography could be an alternative to other established ancillary tests for the diagnosis of brain death. We examined intracranial contrast enhancement in CT angiography after clinically established brain death and compared the results with EEG and TCD findings. ⋯ CT angiography is a promising method of evaluating intracranial circulatory arrest in brain death with a high spatial and temporal resolution, superior to all other established technical procedures. The examination is easily accessible in most hospitals, operator independent, minimally invasive and inexpensive. Therefore, CT angiography has the potential to enlarge the existing armamentarium of confirmatory brain death tests.
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Acta Neurochir. Suppl. · Jan 2012
How does moderate hypocapnia affect cerebral autoregulation in response to changes in perfusion pressure in TBI patients?
In traumatic brain injury, the hypocapnic effects on blood pressure autoregulation may vary from beneficial to detrimental. The consequences of moderate hypocapnia (HC) on the autoregulation of cerebral perfusion pressure (CPP) have not been monitored so far. Thirty head injured patients requiring sedation and mechanical ventilation were studied during normocapnia (5.1 ± 0.4 kPa) and moderate HC (4.4 ± 3.0 kPa). ⋯ Mx was adjusted to normal despite no significant change in CPP levels. Our study showed that short-term moderate HC may optimize the autoregulatory response to spontaneous CPP fluctuations with only a small CPP increase. Patients with impaired autoregulation seemed to benefit the most.
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Acta Neurochir. Suppl. · Jan 2012
Case ReportsWhat is the appropriate shunt system for normal pressure hydrocephalus?
Normal pressure hydrocephalus (NPH) represents a common disorder among older people with mild elevation of cerebrospinal fluid pressure and certain clinical manifestations. We present a patient with such a disorder in whom a programmable valve was implanted. ⋯ After evacuating the hematoma and by setting the valve pressure higher, the patient recovered without any symptomatology. We observed that only the higher pressure was the right one, although in two different pressure values the symptoms had subsided.
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Acta Neurochir. Suppl. · Jan 2012
Biography Historical ArticleModeling of CSF dynamics: legacy of Professor Anthony Marmarou.
The mathematical model of cerebrospinal fluid (CSF) pressure volume compensation, introduced by Anthony Marmarou in 1973 and modified in later studies, provides a theoretical basis for differential diagnosis in hydrocephalus. The Servo-Controlled Constant Pressure Test (Umea, Sweden) and Computerised Infusion Test (Cambridge, UK) are based on this model and are designed to compensate for inadequate accuracy of estimation of both the resistance to CSF outflow and elasticity of CSF pressure volume compensation. Dr. ⋯ Marmarou demonstrated that only around 30% of cases of elevated ICP in patients with TBI could be explained by changes in CSF circulation. The remaining 70% of cases should be attributable to vascular components, which have been proposed as equivalent to raised brain venous pressure. Professor Marmarou's work has had a direct impact in the field of contemporary clinical neurosciences, and many of his ideas are still being investigated actively today.