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Biomedical subjects

A Perneczky

Publications and source records attributed to A Perneczky.

At least 73 records · Page 4Linked to original sources
PubMed1993

Intra-operative monitoring during syringo-endoscopy: results of median nerve stimulated somatosensory evoked potentials in nine patients.

Intra-operative SEP monitoring was performed in nine patients with cervical syringomyelia undergoing myelotomy and syringo-endoscopy. Several cortical and subcortical SEP components were evaluated. Pathological latency shifts of brain stem P14 were seen in two patients; other SEP components did not worsen nor recover intra-operatively. The clinical and pathophysiological significance of the data is briefly discussed.

Adult↗
PubMed1992

Neuroendoscopic technique for the operative treatment of septated syringomyelia.

The management of septated, chambered syringomyelia has until now been problematic because the usual operative methods cannot secure drainage of all chambers of the cavity. The development of a flexible neuroendoscope affords the possibility to perforate the septa under visual control which subdivide the cavity. We present our experiences with 11 cases of septated syringomyelia, which have been operated upon using a flexible neuroendoscope.

Endoscopes↗
PubMed1992

CT-guided stereotactic biopsy aided by Doppler ultrasonic vascular monitoring.

The use of a 20 MHz pulsed Doppler technique during stereotactic brain tumour biopsies is described. By means of a miniaturized ultrasonic probe the tissue planned for biopsy was investigated for vessel signals. Out of 41 patients, with this technique a flow-pulse curve in front of the biopsy cannula was registered in 14 cases. In 9 cases one pulse curve was determined and in 5 cases two or more flow curves were found, indicating the presence of arterial vessels. The depth of the vessels signal could be localized and this area avoided for biopsy sampling. In a series of 41 stereotactic biopsies carried out in this way there was no intra-operative haemorrhage or postoperative haematoma.

Adolescent↗
PubMed1992

Pterional trephination approach to tumors of the infratemporal fossa.

Tumors of the infratemporal fossa may extend superiorly into the middle cranial fossa and inferiorly into the retromaxillary space. Surgical removal commonly requires an interdisciplinary skull base team, which may have to approach the tumor from above and below in order to resect it. In an attempt to resect infratemporal fossa tumors of this magnitude with a single surgical approach, a pterional trephination (with or without removal of the zygomatic arch) was utilized in 13 cases to define its usefulness and limitations. In nine cases the histologic examination revealed a diagnosis of meningioma, in three, adenoid cystic carcinoma, and in one, undifferentiated carcinoma was found. Postoperative computed tomography was performed in all cases to assess the completeness of tumor resection. This article will detail the successful use of this single-stage approach to intra- or extradural lesions that originate in the infratemporal fossa.

Journal Article↗
PubMed1992

Suprasellar granular cell tumor.

A case of a suprasellar granular cell tumor, approximately 1.5 cm in diameter, in a 68-year-old woman is described. Diagnosis was established postoperatively by histopathological examination of the tumor tissue. The preoperative computed tomographic scan revealed a slightly hyperdense suprasellar mass with strong contrast enhancement. There was no evidence of calcification. The T1-weighted image on magnetic resonance imaging scan showed an isointense tumor with non-homogeneous enhancement after intravenous gadolinium diethylene-triamine-pentaacetic acid. In the proton-weighted image, the suprasellar mass presented a non-homogeneously enhanced signal. A non-homogeneous signal reduction was seen in the T2-weighted image.

Aged↗
PubMed1992

Occlusion of the pig superior sagittal sinus, bridging and cortical veins: multistep evolution of sinus-vein thrombosis.

Cerebral sinus-vein thrombosis may lead to severe hemodynamic changes, elevated intracranial pressure (ICP), and brain edema. It is supposed that progression of the thrombus from the sinus into bridging and cortical veins plays a key role in the development of these pathophysiological changes, but this hypothesis lacks experimental proof. The aim of this study, using a novel animal model of sinus-vein thrombosis, was to evaluate the effects of a standardized occlusion of the superior sagittal sinus and its bridging and cortical veins on hemodynamic alterations, on brain water content, and on ICP in domestic pigs. In 10 animals, the middle third of the superior sagittal sinus was occluded with a catheter-guided balloon. Five of these pigs received an additional injection of 1 ml fibrin glue into the superior sagittal sinus anterior to the inflated balloon, leading to an obstruction of bridging and cortical veins. In five control animals the balloon was inserted but not inflated. Five pigs underwent cerebral angiography. Four hours after occlusion, the brains were frozen in liquid nitrogen, and coronal slices were examined for Evans blue dye extravasation, regional water content, and histological changes. Occlusion of the superior sagittal sinus alone did not affect ICP or cerebral perfusion pressure (CPP). The additional injection of fibrin glue caused an obstruction of cortical and bridging veins as well as severe increases in mean (+/- standard deviation) ICP to 49.4 +/- 14.3 mm Hg, compared with 8.3 +/- 4.5 mm Hg in sham-treated controls and 7.1 +/- 3.9 mm Hg in animals with occlusion of the superior sagittal sinus alone. There was also a steep fall in the mean CPP to 34.2 +/- 19.6 mm Hg compared with 96.4 +/- 13.8 mm Hg in the control group. White-matter water content anterior to the occlusion site was elevated to 81.9 +/- 3.7 gm/100 gm frozen weight in the fibrin group as compared to 70.7 +/- 2.2 gm/100 gm in controls. Posterior to the occlusion site, water content did not differ among the three groups. Angiography demonstrated collateral flow via cortical and bridging veins in animals with occlusion of the superior sagittal sinus alone. Additional fibrin glue obstructed these collateral vessels. The data suggest a multistep process of pathophysiological alterations in patients with sinus-vein thrombosis and may explain why these patients present with a wide variety of symptoms: minor neurological deficits or headache might indicate thrombosis of the superior sagittal sinus and/or its bridging veins.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Evaluation of collateral flow capacity in patients with vascular or tumorous lesions of the skull base by Doppler sonography.

In 12 patients with vascular or tumorous lesions of the skull base, the collateral flow capacity was examined by transcranial Doppler sonography and carotid compression studies. In four patients no cross flow mechanism was found, in two patients the test remained unclear, and in six patients the examination suggested a good collateral flow capacity. However, for this application of Doppler sonography no borderlines have yet been defined and thus interpretation is difficult. Intraoperative Doppler sonography was used in five patients and proved to be helpful for localisation of the internal carotid artery within skull base tumors.

Adult↗
PubMed1991

Transsigmoid approach for tumors of the jugular foramen.

A transsigmoid approach is detailed for removal of tumors involving the jugular foramen. This approach was used in seven patients, eliminates the need for facial nerve transposition, and helps to preserve cochleovestibular function. The sigmoid sinus is packed and both the facial nerve and the labyrinth are identified. This approach provides excellent vision of the intradural and extradural course of the lower cranial nerves, rendering preservation of isolated nerves within the neural compartment feasible.

Journal Article↗
PubMed1991

Intrasellar cysticercosis mimicking a pituitary adenoma.

A case of a 50-year-old female with an intrasellar and suprasellar cysticercus cyst, which was pre-operatively misinterpreted as a macroadenoma of the adenohypophysis is described. Cranial computed tomography revealed a homogeneous hyperdense intrasellar and suprasellar lesion. In T1-weighted magnetic resonance images, a spotty hyperintense tumor of the sellar region was shown.

Adenoma↗
PubMed1990

Brain oedema and intracranial pressure in superior sagittal sinus balloon occlusion. An experimental study in pigs.

About 2/3 of all patients with thrombosis of the superior sagittal sinus (SSS) develop signs of increased ICP and/or brain oedema (BE). The time of onset and the spectrum of symptoms in SSS thrombosis vary extremely. This variability might be caused by differences in pathomechanism like BE and rise of ICP, parameters studied in the present contribution. 10 domestic pigs received a standardized occlusion of the SSS with two different balloon types (spherical and cylindrical). They were monitored for several systemic and intracranial pressures. After 4 hours of occlusion the brains were examined for BE (Evans blue, water content). They were compared with those of 4 sham-operated control animals. 4 animals underwent cerebral angiography. Within 4 hours ICP rose to 60 mm Hg in the group with the spherical balloon. Normal ICP of 5-10 mm Hg was seen in the group with the cylindrical balloon and in the sham-operated controls. The water content of the white matter was elevated in both occlusion groups differing significantly from the control group. Haemorrhagic infarction of the frontal parts of the cerebrum occurred in animals with concomitant obliteration of bridging and cortical veins. We conclude from our experiments that SSS occlusion may initiate a multitude of possible pathomechanisms depending on the involvement of bridging veins, cortical veins and inner brain veins.

Animals↗
PubMed1990

[Surgical accidents during repair of intracranial aneurysms].

The need to discuss incidents encountered during cerebral aneurysm surgery--as well as techniques and results--is increasingly accepted. Single incidents, however, do not allow for general conclusions; we wish to present 5 cases, analysis of which, we believe, is likely to elucidate the trouble of diagnosis and intraoperative decision making.

Adolescent↗
PubMed1989

Proliferation activity in pituitary adenomas: measurement by monoclonal antibody Ki-67.

The monoclonal antibody (MAb) Ki-67 detects a nuclear antigen expressed by proliferating cells during the entire cell cycle. In contrast to conventional histological techniques, the use of MAb Ki-67 on frozen sections or cytological smear preparations allows direct determination of the growth rate of tumors routinely. Sixty-two pituitary adenomas were investigated by use of the MAb Ki-67 in a two-step avidin-biotin-peroxidase complex technique. The proliferation activity ranged from 0.1 to 2.8%. There was no significant difference between the proliferation and hormonal state of the adenomas. Adenomas for which there was histological evidence of dural infiltration, however, showed a statistically significant higher proliferation activity (P less than 0.05) compared to noninvasive adenomas.

Adenoma↗
PubMed1988

Cavernous sinus surgery. Approach through the lateral wall.

The cavernous sinus is divided from the surgical point of view into three parts. The middle part consists of the lateral sinus wall, the cranial nerves III, IV, V, VI and the posterior siphonknee of the internal carotid artery. Lesions of this region, vascular as well as tumorous, can be exposed by approaching the lateral sinus wall. The surgical dissection through the sinus wall is based on some important anatomical details, which are described here. As a consequence a modified transcavernous approach will be introduced and demonstrated by 35 clinical cases.

Aged↗
PubMed1988

The paraclinoid carotid artery: anatomical aspects of a microneurosurgical approach.

The paraclinoid area is investigated anatomically for possible microneurosurgical approaches to the C3 segment of the internal carotid artery and to structures in the vicinity of the anterior siphon knee. Removal of the anterior clinoid process reveals a tight connective tissue ring that fixes the internal carotid artery to the surrounding osseous structures at the point of its transdural passage. Transection of this fibrous ring opens a microsurgical pathway to the carotid C3 segment. The artery is surrounded by a loose connective tissue layer that allows blunt preparation along the C3 segment, without compromising the cranial nerves and without damaging venous compartments of the cavernous sinus. This approach provides neurosurgical access to paraclinoidal aneurysms, to partly intracavernous aneurysms, and to carotid-ophthalmic aneurysms, allowing control of the proximal aneurysm neck and of the parent artery itself. In cases of tumors involving the medial sphenoid ridge, the apex of the orbit, or the cavernous sinus, the pericarotid connective tissue can serve as a guide layer for access along the internal carotid artery.

Adult↗
PubMed1986

Intraventricular aneurysm of the medial posterior choroid artery clipped via the contralateral transcallosal approach.

In lesions located in the lateral ventricle of the dominant hemisphere the contralateral transcallosal approach provides maximum protection of the dominant side as well as excellent visualization of the cella media of the contralateral lateral ventricle. We demonstrated this safe approach in a rare case with intraventricular aneurysm of the left medial choroid artery. The literature on aneurysms in the lateral ventricle is discussed.

Adolescent↗
PubMed1985

Problems of surgical technique for the treatment of supratentorial midline tumors in children.

In this presentation the authors describe briefly their thoughts on microsurgical management of certain typical brain tumors arising from within and adjacent to the third ventricle the surgical treatment of which has for many years been essentially conservative, not infrequently without histological verification of the type of the tumor or even of the presence of a real neoplasm.

Brain Neoplasms↗