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Biomedical subjects

Z Czernicki

Publications and source records attributed to Z Czernicki.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

[Computerized infusion test. I. The method].

Biophysical aspects and the method of the Computerized Infusion Test (CIT) developed in the Neurosurgical Clinic of the Medical Research Center, Polish Academy of Sciences, are presented. The CIT is a development of classical methods of estimating the cerebrospinal fluid outflow resistance. It is based on a clinically tested mathematical model of the intracranial pressure-volume compensating mechanisms. The CIT enables the etrapolation of the infusion curve in cases when it is impossible to reach the upper steady during the constant infusion test because of the ICP exceeding values estimated as being critical.

Computers↗
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[Computerized infusion test. II. Clinical use].

In 39 patients with intracranial lesions the resorption resistance was measured using an own computerized infusion test. A high usefulness of this test was demonstrated in the diagnosis of hydrocephalus and for establishing indications to ventriculocardiac valve implantation. In patients after craniocerebral injuries a rise was observed of the resorption resistance immediately after trauma in cases with subarachnoid haemorrhage. Later on, this resistance decreased gradually reaching a stable value after 1-2 years. Data obtained in the infusion test make possible establishing of optimal intracranial pressure and choice of an appropriate valve. The determination can be performed intraoperatively.

Brain Injuries↗
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[Cerebral blood changes during neuropsychological tests administered by Doppler sonography. Preliminary report].

The preliminary studies on cerebral blood flow changes during neuropsychologic tests were carried out using transcranial Doppler sonography (TCD). The procedure with the standardized cerebral activation in order to obtain the control brain activity level was elaborated and tested. Blood flow velocity changes were measured during two groups of tests: linguistic with left dominant hemisphere and visual-spatial with right dominant hemisphere. Similar dynamics of blood flow changes was observed with all kinds of brain activation with the maximum velocity increase of 15-20%. The velocity measured in the dominant hemisphere was about 8-10% above the contralateral side. TCD seems to be complementary to the neuropsychologic tests useful especially in diagnosis of different types of dementia.

Brain↗
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[Diagnosis of brain stem ischemia by transcranial Doppler ultrasonography].

Intracranial pressure (ICP) was elevated in cats by intrathecal infusions. Middle cerebral artery and basilar artery were studied using Transcranial Doppler (TCD) during the infusion followed by systemic arterial pressure increase (Cushing response). Cushing response was symptomatic for brain stem ischaemia. The earliest TCD changes concerned the basilar artery. The most informative data for the diagnosis were pulsatility index increase and diastolic velocity decrease.

Animals↗
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[Application of transcranial Doppler ultrasonography in the assessment of cerebrovascular reactivity studies and cerebral vascular reserve estimation in patients with focal brain injury].

Cerebrovascular reactivity and cerebrovascular reserve were studied using transcranial Doppler sonography (TCD). Investigations were carried out in acute cases--8 patients with severe head injury within 5 days after trauma and in chronic cases with brain tissue defect (12 patients), and in cases with cerebral circulation insufficiency (15 patients). In acute cases the pCO2 cerebrovascular response was studied and in chronic cases cerebrovascular reserve was estimated using acetazolamide. TCD was found suitable for local vascular reactivity disturbances determination independently in three intracranial compartments--both hemispheres and infratentorial space. In patients with local brain tissue defect cerebrovascular reserve remained within normal range. In cerebral circulation insufficiency vascular reserve disturbances were limited to one compartment in cases with local vascular lesion they were found in all three compartments in cases with generalized atheromatosis.

Acetazolamide↗
PubMedDate not supplied

[Application of physiological loadings in evaluation of intracranial volume-pressure relations. II. Clinical studies].

The effects of physiological loadings (venous pressure increase, postural changes, pCO2 increase) on intracranial volume-pressure relations were studied. The standardized increase of venous outflow pressure was found to be a good test for the evaluation of CSF outflow routes. Standardized venous outflow pressure increase in Queckenstedt test seems to be especially useful.

Adult↗
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[Intracranial volume reserve assessment based on ICP pulse wave analysis].

ICP waves were analysed in the situation of expanding intracranial mass. The aim of the study was to determine how big the intracranial added volume has to be in order to produce significant changes of harmonic disturbances index (HFC) of ICP pulse waves. The diagnostic value of HFC and other parameters was compared. The following other parameters were studied: intracranial pressure (ICP), CSF outflow resistance (R), volume pressure response (VPR) and visual evoked potentials (VEP). It was found that ICP wave analysis very clearly reflects the intracranial volume-pressure relation changes.

Animals↗
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[Evaluation of intracranial volume compensation analyzing changes of harmonic components of intracranial pressure pulse wave].

Intracranial pressure (ICP) pulse wave was analysed during infusion tests performed in hospital (hydrocephalus) and in cats. Pulse wave changes were evaluated calculating the high frequency centroid index (HFC) in the HFC, found to be a very valuable parameter in intracranial volume-pressure situation evaluation. The HFC decrease occurred much earlier than the rise of ICP in both clinical and experimental studies. Thus the HCF index should be very usefull in clinical evaluation of intracranial volume-pressure relation disturbances.

Adolescent↗
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[Three-phase infusion test].

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.

Animals↗
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[Hazards of uncontrolled administration of dehydrating agents].

A 38-year-old male patient was admitted to a neurosurgical hospital department because of hemiparesis and speech disturbances which had developed during an acute febrile disease. In view of supposed brain tumour the patient had been given prior to admission to the neurosurgical department high doses of dehydrating agents which resulted in high grade dehydration of the patient. During 10 days it was possible to achieve compensation of water and electrolyte disturbances and simultaneously hemiparesis regressed and function of speech improved. Angiography ruled out presence of brain tumour. The patient had no neurological disturbances during follow-up examination 6 months after discharge from the hospital. In the case the cerebral distrubances were due probably to venous thrombosis and intensive dehydrating therapy had contributed considerably to the severe condition of the patient.

Adult↗
PubMedDate not supplied

[Statistical analysis of cerebrospinal fluid acid-base equilibrium and cerebrospinal fluid lactate concentration in cases of brain tumors, cerebrocranial injuries and meningoencephalitis].

A statistical analysis of CSF lactate concentration and CSF pH and PCO2 was performed. The values were obtained from 211 samples taken from 76 neurosurgical patients. The values of pH and pCO2 were classified in three groups corresponding to the following three ranges of lactate concentration: below 15 mg%, 15-30 mg%, over 30 mg%. The mean values and standard deviations were calculated: suitable tests: F, t (Student), C (Cochran and Cox) were used. It was established, that statistically significant changes of CSF acid-base balance were present at lactate levels over 30 mg%. Next, the patients with lactate concentrations over 30 mg% were analysed. They were divided into three groups according to etiology: inflammatory changes, injuries, tumours. It was shown, that the CSF acid-base balance in patients with brain tumours is less disturbed then in patients with inflammatory changes or brain injury.

Acid-Base Equilibrium↗
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[Multi-stage method for the diagnosis of low-pressure hydrocephalus].

Multistage method of low-pressure hydrocephalus diagnosis, elaborated in our department, is discussed. The method consists of four stages: I Clinical and neuropsychological examinations, standard computerized tomography. II Somatosensory evoked potentials. III Determination of water concentration and distribution in fluid compartments of the brain by utilising new mathematical formula. IV Three-phase complementary test. The application of this method allows to eliminate many false diagnoses and may contribute to lower costs of treatment.

Body Fluid Compartments↗
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[Effect of deep hyperventilation on lactate concentration in cerebrospinal fluid and brain tissue].

Deep hyperventilation (HV)--pCO2 less than 15 mm Hg--was applied in rabbits with normal intracranial pressure (ICP) and in cats with experimental brain oedema developed after epidural balloon compression. In animals with normal ICP there was an increase of CSF and tissue lactate concentration as soon as after 45 min. of HV. The lactate concentration was increasing all the time during HV. The resumption of normoventilation (2 h) after 10 h of HV was sufficient to bring the lactate level down near normality. Electron microscope studies showed only slight ultrastructural changes without destruction, even after 10 h HV. In animals with increased ICP, brain oedema was the main factor raising the lactate level, while the effect of HV was negligible.

Animals↗
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[Hyperventilation and mannitol administration during surgery in patients with space-occupying intracranial lesions].

The aim of this work was to evaluate the effect of hyperventilation and mannitol on brain volume during neurosurgical operations. The material comprises 30 cases of supratentorial tumours. pO2, pCO2, pH and lactate concentration were determined in the arterial blood and in 7 cases also in the CSF. It was established that hyperventilation sometimes fails to decrease ICP; it was observed that hyperventilation was more effective in decreasing brain volume of the pCO2 level decreased by 14,6 mm Hg on the average. The joint use of hyperventilation and hypertonic mannitol was found to be more effective. Neither of the above methods was effective in the case of cystic tumors.

Adolescent↗
PubMedDate not supplied

[The usefulness of intraoperative high-frequency doppler flowmetry in surgeries for intracranial aneurysms].

The flowmeter enables estimation of blood flow velocity changes in small calibre arteries. The authors examined blood flow velocity patterns in the vessels during aneurysm operations and blood flow velocity and its disturbances inside aneurysm. Evaluation technique, technical data of the flowmeter use are described and the characteristics of the blood flow velocity picture in cerebral arteries obtained by this method is presented. The presented method enables a very precise estimation of blood flow velocity and detection of changes in flow patterns. The method may become very helpful in identification of the vessels in other types of cerebral surgery.

Equipment Design↗
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[Cerebrospinal fluid lactates following craniocerebral injuries].

CSF lactate concentration was determined in 37 patients after craniocerebral injury. In 26 cases the lactate concentration was raised above the normal value (15 mg/100 ml) and in 11 cases it was above 30 mg/100 ml. All fatal cases were in the group with lactate level above 30 mg/100 ml. The study confirms the fact that CSF lactate concentration is related to the severity of cerebral tissue damage and has a prognostic significance.

Brain Injuries↗