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 10,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aim of the current study was to investigate the influence of intracranial hypertension on the resolution of vasogenic brain edema following intracerebral hemorrhage. An intracerebral hematoma was induced by 500 microliters of blood injected into the left frontal lobe of rabbits (n = 25). Na(+)-fluorescein (MW376) and Texas-Red-albumin (MW67.000) were administered intravenously as edema markers. By using a closed cranial window for superfusion of the brain surface and a ventriculo-cisternal perfusion the clearance of both fluorescence markers was measured in the CSF-effluates up to 8 hours using spectrophotometry. ICP was adjusted between 2-6 mmHg (low pressure, n = 10), 8-12 mmHg (moderate pressure, n = 10) or 14-20 mmHg (high pressure, n = 5). In all groups Na(+)-fluorescein started to accumulate at 60 min after induction of the hematoma in the subarachnoid space, while at 90 min in the ventricular system. In the low intracranial pressure group Na(+)-fluorescein (mean +/- SEM) in the ventricular system amounted to 1.47 +/- 0.42 nmol as compared to 1.34 +/- 0.41 nmol in the moderate, or 0.38 +/- 0.11 nmol in the high intracranial pressure group. In the subarachnoid space the marker reached 1.96 +/- 0.57 nmol, 4.15 +/- 1.28 nmol, or 0.96 +/- 0.32 nmol, respectively. In conclusion, the data demonstrate that vasogenic edema induced by an intracerebral hematoma is cleared into both CSF compartments, albeit with delay into the ventricular system. Edema resorption occurred earlier and to a higher extent into the subarachnoid space as compared to the ventricular system. Further, edema resorption is influenced by the actual intracranial pressure, with marked inhibition by a high intracranial pressure.
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PMID:Intracranial hypertension influences the resolution of vasogenic brain edema following intracerebral hemorrhage. 1145 77

The international The simultaneous measurement of the resistance and compliance during a single investigation minimizes the patients exertion. In contrast to the classical method it is not necessary that the ICP reaches a plateau. Our mathematical method diverges with t he description of a pressure dependent slope of the function for the resistance from the static examination models. We proved our mathematical method by the use of a dynamic infusion test in 10 H-Tx rats without hydrocephalus and five hydrocephalic H-Tx rats. For that we are able to take the non linearity of the CSF resorption into consideration.
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PMID:The ICP-dependency of resistance to cerebrospinal fluid outflow: a new mathematical method for CSF-parameter calculation in a model with H-TX rats. 1174 20

Since Lundberg first described slow oscillations as so called B-waves during ICP-monitoring, similar oscillations have been found in various physiological systems. Thus, the detection of slow waves in intracranial CSF- and blood-flow with MR-techniques seemed very likely. We examined the interventricular CSF-flow and cerebral blood flow of 11 healthy volunteers with dynamic echo-planar imaging by simultaneous registration of respiration and peripheral pulse. The spectral analysis was restricted to slow waves, which were divided into B-waves (0.008-0.05 Hz), Mayer- or C-waves (0.05-0.15 Hz) and respiration-related waves (0.15-0.6 Hz). In the CSF, the integrated amplitude of B-waves accounted for 18.2%, Mayer- or C-waves for 26.9% and respiration-related waves for 55.0%. Proportional values were recorded in the artery and peripheral pulse. In the venous sinus, a higher percentage of B- and Mayer-/C-waves and a lower percentage of respiration related waves were found. In conclusion, with MR-EPI technique, slow rhythmic oscillations in the cerebral blood- and CSF-flow can be analysed non-invasively and independently from the cardiac cycle. The comparable distribution of slow waves in the pulse, arteries and CSF may reflect an origin in autoregulation, whereas divergent patterns like in the incompressible venous sinus may be of a passive origin.
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PMID:Slow rhythmic oscillations in intracranial CSF and blood flow: registered by MRI. 1216 86

Decompressive craniectomy sometimes causes neurological deficits known as 'the syndrome of the sinking skin flap' or 'the symptom of the trephined'. These disorders can be corrected with cranioplasty, but there is no consensus on appropriate treatments. We report a case of successful correction of traumatic hydrocephalus following craniotomy. A 50-year-old man was admitted to our hospital with disturbance of consciousness after a head injury. Decompressive craniectomy was performed for a right acute subdural hematoma. His consciousness recovered after the operation, but then deteriorated gradually and left hemiparesis occurred. CT scan revealed midline shift from right to left. These symptoms and CT findings were not improved after cranioplasty, but were improved with removal of the CSF from the adhered subarachnoid space. The diagnosis was traumatic hydrocephalus, and a cisternoperitoneal shunt was subsequently placed. We report this case to emphasize the necessity for study of CSF circulation, as well as the importance of examination of CBF and ICP after craniectomy.
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PMID:[A case of the traumatic hydrocephalus after large craniectomy for acute subdural hematoma]. 1261 57

The objective was to study the displacement of the cerebrospinal fluid pressure-volume curve during the descent relative to the ascent of intracranial pressure recorded during the cerebrospinal fluid constant rate infusion test. This phenomenon can be interpreted as the hysteresis of the pressure-volume curve. The cerebrospinal fluid dynamics were tested in fifty-eight patients with clinical symptoms of hydrocephalus. After finished infusion, ICP was recorded until it returned to steady state level. Pressure-volume curves were plotted separately for ascending and descending phases of the test. The parameters of CSF compensation were estimated on the basis of mathematical mono-exponential model of CSF circulation. The pressure-volume curve post-infusion was visibly shifted upward in 69% of tests. Those who demonstrated the upward shift of the pressure-volume curve had greater an elastance coefficient of the cerebrospinal space (with shift: E1 = 0.26 +/- 0.14; without shift: E1 = 0.17 +/- 0.06; p < 0.05). Magnitude of the shift was positively correlated with pulse amplitude of ICP (r = -0.763; p < 0.0001). The accuracy of clinical examination of the pressure-volume compensatory reserve, which take into account both compression and decompression phase of the study, may be affected by this phenomenon.
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PMID:Hysteresis of the cerebrospinal pressure-volume curve in hydrocephalus. 1475

The international accepted calculation methods concerning the cerebrospinal fluid dynamics proceed from a pressure independent resistance to cerebrospinal fluid outflow. In a new model we focus our attention on the pressure dependency of resistance. In our calculation model we are monitoring the complete pressure course p(t) over the time t during and after the infusion. The comparison of the pressure rise On(p) during the infusion and the descent Off(p) after the infusion in the same pressure level allows to construct all formulas for the compliance C(p) and resistance R(p). The simultaneous measurement of the resistance and complications during a single investigation allows minimizing the patient's exertion. In contrast to the classical methods it is not necessary that the ICP reach a plateau. Our mathematical method diverges with the description of a pressure dependent slope of the function for the resistance from the static examination models. We proved our mathematical method by the use of a dynamic infusion test in ten H-Tx rats without hydrocephalus and five hydrocephalic H-Tx rats. For that we are able to take the non-linearity of the CSF resorption into consideration.
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PMID:The ICP-dependency of resistance to cerebrospinal fluid outflow: a new mathematical method for CSF-parameter calculation in a model with H-Tx rats. 1475 2

The method for the continuous assessment of cerebral autoregulation using slow waves of MCA blood flow velocity (FV) and cerebral perfusion pressure (CPP) or arterial pressure (ABP) has been introduced seven years ago. We intend to review its clinical applications in various scenarios. Moving correlation coefficient (3-6 min window), named Mx, is calculated between low-pass filtered (0.05 Hz) signals of FV and CPP or ABP (when ICP is not measured directly). Data from ventilated 243 head injuries and 15 patients after poor grade subarachnoid haemorrhage, 38 patients with Carotid Artery stenosis, 35 patients with hydrocephalus and fourteen healthy volunteers is presented. Good agreement between the leg-cuff test and Mx has been confirmed in healthy volunteers (r = 0.81). Mx also correlated significantly with the static rate of autoregulation and transient hyperaemic response test. Autoregulation was disturbed (p < 0.021) by vasospasm after SAH and worse in patients with hydrocephalus in whom CSF circulation was normal (p < 0.02). In head injury, Mx indicated disturbed autoregulation with low CPP (< 55 mmHg) and too high CPP (> 95 mmHg). Mx strongly discriminated between patients with favourable and unfavourable outcome (p < 0.00002). This method can be used in many clinical scenarios for continuous monitoring of cerebral autoregulation, predicting outcome and optimising treatment strategies.
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PMID:Continuous assessment of cerebral autoregulation: clinical and laboratory experience. 1475 10

Endoscopic third ventriculostomy is considered a safe technique for the treatment of obstructive hydrocephalus. However, the literature contains several reports of complications related to this procedure. We describe a case of chronic subdural hematoma (CSDH) after ETV, which required surgical evacuation, in a 69-year-old male patient completely asymptomatic up to the control MRI four weeks after the operation. We believe this unusual complication could result from the ICP changes caused by ETV. In our opinion, successful ETV gives a boost to CSF absorption, and overdrainage may evolve also in endoscopic treatment of obstructive hydrocephalus. This situation could be the starting point of the subdural collection. We review the literature and discuss the causes that may lead to CSDH after ETV procedure.
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PMID:Overdrainage after endoscopic third ventriculostomy: an unusual case of chronic subdural hematoma--case report and review of the literature. 1496 3

Recent studies on normal pressure hydrocephalus (NPH) have pointed to a possible link between the disturbance in CSF circulation and cerebrovascular factors. We investigated the quantitative relationship between the resistance to CSF outflow (Rcsf) and vasogenic waves of ICP in patients with normal pressure hydrocephalus. Forty-five patients with NPH were investigated by an infusion study. The magnitudes of vasogenic ICP components: pulse, respiratory and slow vasogenic waves were assessed, and compared with Rcsf. Both baseline respiratory and slow waves of ICP were positively correlated with Rcsf. The respiratory wave at baseline was a single independent predictor of Rcsf (r = 0.66, p < 0.0002). All vasogenic components increased significantly during the infusion test. The magnitude of the increase was positively correlated with Rcsf. The vasogenic ICP waves, notably the respiratory wave of ICP, correlate with the resistance to CSF outflow.
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PMID:Link between vasogenic waves of intracranial pressure and cerebrospinal fluid outflow resistance in normal pressure hydrocephalus. 1504 Jul 16

The aim of the present study was to report on the utility of continuous Pcsf monitoring in establishing the diagnosis of idiopathic intracranial hypertension without papilledema (IIHWOP) in chronic daily headache (CDH) patients. We report a series of patients (n = 10) with refractory headaches and suspected IIHWOP referred to us for continuous Pcsf monitoring between 1991 and 2000. Pcsf was measured via a lumbar catheter and analysed for mean, peak, highest pulse amplitude and abnormal waveforms. A 1-2 day trial of continuous controlled CSF drainage (10 cc/ h) followed Pcsf monitoring. Response to CSF drainage was defined as improvement in headache symptoms. Patients with abnormal waveforms underwent a ventriculoperitoneal (VPS) or lumboperitoneal (LPS) shunt insertion. All patients had normal resting Pcsf (8 +/- 1 mmHg) defined as ICP < 15 mmHg. During sleep, all patients had B-waves and 90% had plateau waves or near plateau waves. All patients underwent either a VPS or LPS procedure. All reported improvement of their headache after surgery. Demonstration of pathological Pcsf patterns by continuous Pcsf monitoring was essential in confirming the diagnosis of IIHWOP, and provided objective evidence to support the decision for shunt surgery. Increased Pcsf was seen mostly during sleep and was intermittent, suggesting that Pcsf elevation may be missed by a single spot-check LP measurement. The similarity between IIHWOP and CDH suggests that continuous Pcsf monitoring in CDH patients may have an important diagnostic role that should be further investigated.
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PMID:Utility of CSF pressure monitoring to identify idiopathic intracranial hypertension without papilledema in patients with chronic daily headache. 1515 60


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