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Biomedical subjects

Z Czernicki

Publications and source records attributed to Z Czernicki.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[Usefulness of somatosensory evoked potentials in the diagnosis of low-pressure hydrocephalus].

The study group comprised 35 patients in whom previous computed tomography had demonstrated significant dilatation of the ventricular system. On the basis of analysis of clinical manifestations and tomograms the patients were divided into two groups: 24 cases (group I) low-pressure hydrocephalus, 11 cases (group II) brain atrophy. For establishing of final diagnosis in both groups the resistance of cerebrospinal fluid outflow was determined (using continuous infusion at a rate of 2 ml/min) and somatosensory evoked potentials were produced by stimulation of median nerve. In patients with increased resistance to CSF resorption (low-pressure hydrocephalus) the conduction time in the N14-P15 segment involving brain stem structures was prolonged (in 17 out of 19 cases). In cases with not increased resistance no changes of evoked potentials were noted. It is thought that the so called posterior cranial fossa conduction time (N14-P15) may be a useful indicator for differential diagnosis of low-pressure hydrocephalus from brain atrophy.

Adult↗
PubMedDate not supplied

[Analysis of the correlations of volume-pressure parameters and visual evoked potentials during disturbances of intracranial volume compensation].

The experiment was carried out on 19 cats with changed intracranial volume-pressure relations by means of an epidural balloon which was inflated to 1.0 ml volume over 60 minutes. The intracranial pressure, the resistance to cerebrospinal fluid resorption, the volume-pressure responses and visual evoked potentials were determined at balloon volumes of 0.3 ml, 0.5 ml, 0.8 ml, 1.0 ml, 1.3 ml, 1.5 ml, 1.8 ml, 2.0 ml and 2.3 ml. It was demonstrated that intracranial pressure is of important informative value only after exhaustion of 63% of the intracranial volume reserve. This value of the volume-pressure responses and resistance to CSF resorption appeared after exhaustion of 28% of this reserve, and the visual evoked potentials were changed after exhaustion of 43% of the reserve. The correlation coefficient between these parameters was high during decompensation. At the time of compensation of the volume the correlation coefficient between the intracranial pressure and the remaining determined parameters was only 0.6.

Animals↗
PubMedDate not supplied

[Changes in the intracranial volume-pressure relations and visual evoked potentials produced by stabilized and compensated additional volume].

The experiment was carried out on 17 cats with intracranial volume-pressure relations changed by means of an epidural balloon of 1.0 ml volume (group I--12 cats) and 0.5 ml (group II--5 cats). The duration of compression exerted by the balloon was 360 min. The intracranial pressure, volume-pressure responses, resistance to cerebrospinal pressure resorption and visual evoked potentials were determined at intervals of 60 minutes. In group I pressure exerted by 1 ml balloon was followed by changes of volume-pressure relations and visual evoked potentials which increased with duration of the experiment. In group II the changes were noted only in the volume-pressure responses and resistance to CSF resorption at the time of balloon volume rise from 0 to 0.5 ml. Maintenance of this balloon volume in the cranial cavity caused no further changes of volume-pressure parameters or visual evoked potentials during 360 minutes of the experiment.

Animals↗
PubMedDate not supplied

[Occlusion of the superior sagittal sinus caused by meningioma, intracranial volume-pressure relations and brain edema].

Fifty-one cases of parasagittal meningiomas were analysed. In 37 cases the tumour was situated in the middle and posterior part of the falx. In 17 cases occlusion of the superior sagittal sinus was diagnosed and confirmed by angiography. No correlation was found between the extent of brain oedema and sinus occlusion and tumour size. However, extensive oedema was present in tumours of high malignancy. Occlusion of the sagittal sinus caused no increase of intracranial pressure or venous stasis. This suggests that sinus occlusion caused by meningioma is completely compensated and has no effect on the preoperative and postoperative course.

Adult↗
PubMedDate not supplied

[Changes in cerebral blood flow and microcirculation caused by cranio-cerebral injuries].

Posttraumatic cerebral blood flow (CBF) and cerebral microcirculation (CM) changes are discussed separately in acute and chronic stage. The acute changes depend mostly on adrenergic and cholinergic reactions and posttraumatic vasomotor disturbances. The mechanisms of posttraumatic brain swelling, CBF and metabolism coupling and uncoupling are described. Late posttraumatic circulatory changes are caused mainly by brain oedema. The important influence on CBF and CM has also the applied therapy including infusions, osmotherapy and hyperventilation.

Acute Disease↗
PubMedDate not supplied

[Disorders of intracranial volume-pressure relations].

The clinical aspects of volume-pressure relations and their disturbances are presented with description of acute and chronic changes after intracranial lesions and various physiological situations. The diagnostic methods which are applied for the assessment of intracranial volume-pressure relations are discussed. A method clinically useful is the numerical analysis of CT images, which is a direct methods, while the indirect methods include computer analysis of the ICP value, lumbar infusion tests and analysis of electrophysiological studies, especially evoked potentials. Further development of studies of volume-pressure relations for diagnostic purposes is foreseen.

Brain Edema↗
PubMedDate not supplied

[Circulatory and respiratory disorders caused by increased intracranial pressure].

In an experimental model the effect of increased intracranial pressure on respiration and circulation was studied. Infusions of varying volumes of fluid into the subarachnoid space over the convexity of the brain in the right parietal area were carried out, recording then changes in respiration and arterial blood pressure, heart rate and ECG, paying attention to arrhythmias and ischaemic myocardial changes. Intracranial pressure rise caused a sympathetic system response with increased arterial blood pressure, increased heart rate and various arrhythmias, even ventricular fibrillation. The observed ischaemic changes, even those suggesting electric gap presence, were reversible indicating absence of fixed structural changes.

Animals↗
PubMedDate not supplied

[Concentration of lactates, sodium and potassium in brain tissue obtained during neurosurgery].

In samples of brain tissue obtained during operations from 40 neurosurgical patients the concentrations of lactate, sodium and potassium were determined. A statistically significant fall of potassium concentration and increased sodium concentration was found in patients with lactate concentration exceeding 0.9 mg/g of fresh tissue. All patients with raised lactate level in the cerebrospinal fluid before the operation tolerated poorly the neurosurgical intervention. Examination of brain tissue in these cases showed changes compatible with advanced brain oedema.

Adolescent↗
PubMedDate not supplied

[Blood-brain barrier disorders and changes in intracranial pressure in cats with surgical brain wound following sudded brain decompression].

The condition of the blood-brain barrier and changes in intracranial pressure were studied in cats with surgical brain wounds and after sudded decompression. It was found that evident disturbances of the barrier function appeared only 48 hours after removal of brain tissue and were affecting mainly the white matter. Sudden decompression led to disturbances of blood-brain function when it was proceded by at least 2 hours of epidural compression. Changes developed in the cortex and basal ganglia. After 48 hours from tissue removal a significant rise of pressure was observed in the cisterna magna to a mean value of 11.5 mm Hg. Decompression caused a fall of cerebrospinal pressure, often below zero, and this was followed by a rise to values significantly exceeding the level before decompression.

Animals↗