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Query: UMLS:C0268318 (ICP)
 10,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new CSF circulation diagnostic procedure is presented. The method is called three-phase infusion test. In phase I the CSF absorption mechanisms were tested within ICP range below 20 mmHg and then the infusion rate of 0.06 ml/min was applied. In phase II the high infusion rate (0.3 ml/min) was used and high ICP increase occurred. This part of the study provided data concerning the ability of alternative CSF outflow routes. In phase III again low infusion rate (0.06 ml/min) was applied. The obtained CSF outflow data in phase III were significantly lower than in phase I. This is the so called persistent outflow facilitation phenomenon. The method described, covering different mechanisms of CSF absorption, enables the complex evaluation of CSF outflow sufficiency.
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PMID:[Three-phase infusion test]. 808 66

Significant morbidity from ventricle shunt overdrainage at 6-7 years after initial shunt placement for hydrocephalus is increasingly recognized as due to excessive gravity-flow of shunted CSF when upright. Shunts are designed primarily to control high ICP. Shunts should also mimic normal upright ICP. Normal upright ICP is -65 mm of water (vertex reference), indicating that a level of zero ICP exists at 65 mm below the brain vertex, with negative ICP above and positive ICP below that level. This normal zero ICP level must be maintained by CSF shunts to mimic normal upright ICP. This will prevent and correct CSF shunt overdrainage. The zero ICP shunt (ZIPS) by design controls this zero level with a zero pressure device (ZPD; siphon control device) installed at the normal vertical level of zero ICP (cm/mm) below the vertex (65 mm). The shunt thus prevents excessive gravity-induced CSF shunt flow. Successful use of ZIPS in 56 patients is reported (low ICP group: n = 42; high ICP group: n = 14). Follow-up is up to 4.5 years. Results show that: (1) adjustability of ZPD level can achieve the desired clinical results; (2) the level of ZPD installed correlates within 4 mm of upright ICP attained; (3) the optimal level of ZPD installation to produce normal upright ICP is 65 mm below the vertex; (4) CT ventricle size, both slit ventricles and large ventricles, may or may not normalize when normal upright ICP is attained in this group of complex, previously shunted patients.
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PMID:Hydrocephalus: the zero ICP ventricle shunt (ZIPS) to control gravity shunt flow. A clinical study in 56 patients. 819 62

Hydrocephalic patients with years of ventricle shunts may be disabled by shunt overdrainage. Gravity-induced upright CSF shunt flow produces this overdrainage with abnormally low, upright ICP. Consequently, the concept of a normal level of zero ICP, which ventricle shunts must mimic, was developed. For 4.5 years, this concept has been applied in hydrocephalus patients by using a Siphon Control Device as a Zero Pressure Device in ventricle shunts. The results in 56 patients, including 42 overdrainage problems, were assessed by clinical grading, ICP record analyses, and computed tomographic (CT) ventricle size comparisons. All patients ultimately achieved satisfactory clinical results. This occurred in 80% of the patients on the first insertion. Adjustment of the vertical level of the Zero Pressure Device was necessary in 20%. The optimum clinical result correlated with an upright ICP of -66 mm of H2O. This postoperative ICP correlated within 4 mm of the Zero Pressure Device placement below vertex. Ventricle size correlated poorly with clinical grade and normal ICP. Only 73% of slit ventricles enlarged by 16.5 months. The need to mimic normal upright ICP by maintaining a normal level of zero upright ICP in shunted patients is supported by these results.
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PMID:Shunted hydrocephalus: normal upright ICP by CSF gravity-flow control. A clinical study in young adults. 845 85

The feline infusion model of brain edema was used to evaluate the pathophysiological effects of 0.6 ml infusions of autologous serum protein (66%), human serum protein (66%), human glioma cyst fluid and a tissue culture medium (TCM) on the structure and function of the forebrain white matter. These infusions increased local white matter water content by between 10.8 and 12.5 ml/100 g brain and were associated with moderate increases in ICP and CSF outflow resistance and a significant decrease in lumped craniospinal compliance. Cortical somatosensory potentials, motor evoked potentials, EEG and local cerebral blood flow (rCBF) at normocapnia were generally unchanged by the various infusions. All infusates except the 66% autologous serum protein infusion impaired rCBF CO2 reactivity. Histologically all infusates caused marked extracellular edema. The autologous serum protein infusion caused no additional histological changes whereas the glioma cyst infusates caused profound endothelial and astrocytic swelling, focal endothelial necrosis, basement membrane disruption, perivascular microglial reaction and pavementation and perivascular migration of polymorphonuclear leukocytes. Similar but less marked changes were seen after infusion of human serum protein whilst the TCM produced only minimal changes. The intensity and extent of Evans Blue extravasation into the forebrain white matter was greatest with glioma cyst infusates and with all infusions reflected the extent to microvascular changes. These studies show that products derived from gliomas cause additional damage to the blood-brain-barrier than that caused by non-autologous serum proteins. These results add further support for the existence of glioma derived permeability factors (GDPF), but suggest neither serum proteins nor glioma derived compounds in the white matter interstitium significantly influence local electrophysiological function. Some limitations of the infusion edema model when using non-autologous infusions and difficulties quantitating brain dysfunction are emphasised.
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PMID:Neuropathological and neurophysiological effects of interstitial white matter autologous and non-autologous protein containing solutions: further evidence for a glioma derived permeability factor. 846 May 70

Standardized volume-pressure craniospinal system loadings based on physiological loadings were developed in order to study the CSF outflow route efficiency and to evaluate the intracranial volume-pressure relations. The study was carried out on 10 cats. Standardized abdominal compression was applied in order to produce a central venous pressure increased and subsequently ICP increase to the level of 20 and 30 mmHg for 2 minutes. The abdominal compression test seems to be useful in the CSF outflow route evaluation. The orthostatic changes were studied in control animals and in cats with an epidural balloon. The animal body was evaluated to an angle of 50 degrees and 80 degrees with the head directed upwards and downwards. This test was found suitable for the intracranial volume reserve estimation. Similar application, especially in experimental conditions can be found in the hypercapnia test. PaCO2 concentration was increased by means of respiration with a gas mixture containing 5% CO2. A steady increase of ICP of 9 +/- 1 mmHg was obtained. Vascular dilatation resulted in an intracranial volume loading. The ICP response in subjects with normal CO2 response can be related to the intracranial volume reserve. The studies performed show the usefulness of the standardized volume-pressure loadings. The loadings applied are more physiological than lumbar infusion tests used so far.
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PMID:Evaluation of craniospinal system condition using standardized volume-pressure loadings. 874 65

Identical twins who both presented with progressively enlarging heads in their first year of life are reported. Neuroimaging demonstrated morphological similarities in the cerebral cortex. The CSF space, including ventricular system, and subarachnoid space were dilated, suggesting external hydrocephalus. Cerebral blood flow velocity in the anterior cerebral artery monitored by Doppler sonogram indicated the two had similar flow patterns and velocities. Simultaneous recording of ICP waves and intracranial biomechanical properties, that is, pressure buffering capacity (pressure volume index: PVI) and CSF outflow resistance (Ro) measured by the bolus saline injection technique, objectively indicated that all these biomechanical factors were also quite similar in the twins. These results indicate that identical twins with external hydrocephalus have very similar intracranial environments, both anatomically and biomechanically.
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PMID:Anatomical and biomechanical similarity in intracranial environment in identical twins with external hydrocephalus. 945 84

The presence of lactic acidosis in the cerebral spinal fluid of 50 patients with severe head injury was studied. The GCS scores of these patients were < or = 8. The patients were divided into two groups. We treated 25 patients with a dose of 4 to 5 ml/kg of THAM infused intravenously 2 to 3 times for daily administration. Other 25 patients who were not treated with THAM served as a control group. In each case, a ventricular pressure monitoring device was installed. The ICP was the contineously recorded. In addition, laboratory study, including lactate, pH, HCO-3 and BE in CSF was performed. THAM infusion was associated with improved survival, decreased ICP as compared to that in the control group. We believe that THAM treatment may significantly improve the prognosis of presence of lactic acidosis as a result of severe head injury.
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PMID:[Therapeutic effect of THAM on lactic acidosis of severe brain injury]. 959 80

Seven patients between the ages of 3 and 24 years were admitted to our hospital in the last 28 years who had a histological diagnosis of medullomyoblastoma. These patients presented with classic symptoms of a posterior fossa midline mass associated with evidence of raised ICP. A CT scan in each patient revealed a uniformly high-attenuating tumour in the posterior fossa with gross hydrocephalus. In all seven patients a ventriculoperitoneal shunt was placed prior to definitive surgery. Radical tumour excision was carried out in all cases 3-5 days after CSF diversion. The histological diagnosis was made on H&E-stained slides. In two cases each, the tumour tissue was subjected to electron microscopy and immunohistochemical studies. Six of the seven patients survived the operation. One patient died 21 days after surgery as a result of shunt block and shunt infection. All surviving patients received cranial and spinal radiation 2-4 weeks after surgery, and also chemotherapy. The cranial radiation dose ranged from 4500 to 5000 rad, while the spinal radiation dose was limited to 1500 rad. Patients were followed up carefully. Three patients died within 6 months, and the remaining three between 2.5 and 3 years after surgery. None of the patients in our study survived longer than 3 years. One patient had developed paraplegia. This study highlights the details of an uncommon entity and reports the largest collection of such cases in the literature.
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PMID:Medullomyoblastoma. A rare cerebellar tumour in children. 972 81

It is suggested that reduced intracranial compliance may be present even when measured ICP is normal and may precede clinical deterioration. Our findings reflect a decompensation of hydrodynamic parameters more pronounced 4-7 postictal days, when compliance is reduced not only in patients with poor clinical condition, but also in patients with Hunt-Hess grade I-III. Increased CSF outflow resistance in the first few days is not surprising; it is thought to be due to the blockage of flow of CSF through the basal subarachnoid cisterns and clogging of the arachnoid villi with erythrocytes and fibrin. Enlargement of ventricles seen on CT scan at the same time suggests the development of acute hydrocephalus. During the first days after SAH, our data reflects evidence of ventricular enlargement in patients presenting with both poor and better clinical condition. We conclude that the monitoring of ICP and dynamic measuring of CSF hydrodynamic parameters is important for longer than the generally accepted few days for selected cases after SAH.
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PMID:The possible role of CSF hydrodynamic parameters following in management of SAH patients. 977 30

Using ICP measurements and the bolus injection technique dynamic parameters of the cerebrospinal fluid system as there are pressure-volume-index (PVI) and resistance to CSF outflow (Rout) were investigated in a new model of diffuse closed head injury (CHI) in the rat. It was found that in the absence of brain oedema and ICP alterations an increase in PVI and Rout was present in the early (4h) period following head injury. This may be indicative for a reduction in cerebral blood flow and cerebral blood volume, both shown previously to occur after CHI. Furthermore an early impairment of CSF absorption mechanisms is evident. To answer the question, whether bolus injection techniques are advisable for clinical routine and whether results might have a predictive value, further investigations covering longer observation intervals and in the presence of secondary insults to the brain are necessary.
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PMID:CSF dynamics in a rodent model of closed head injury. 977 13


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