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Biomedical subjects

H Kourtopoulos

Publications and source records attributed to H Kourtopoulos.

At least 19 recordsLinked to original sources
PubMed2005

Transclival decompression of brainstem from a compressing coiled aneurysm of the midbasilar artery.

The authors present the case of a young woman, suffering from progressive tetraplegia, cranial nerve dysfunction, respiratory failure and lethargy due to radiographically demonstrated increased brainstem compression after coil embolization of an aneurysm of the midportion of the basilar artery. The patients condition improved dramatically after transclival decompression. The importance of understanding the effects of a rigid endovascular mass on adjacent neural structures is emphasized.

Adult↗
PubMed1997

Carbamazepine levels in the hair of patients under long-term treatment: a preliminary study.

Carbamazepine (CBZ) levels in the scalp hair of seventeen patients (ten male and seven female), aged from five to forty years old, receiving the drug systematically were determined after hair dissolution and solid-phase extraction procedures using both immunoassay (Abbott TDx) and gas chromatographic (GC) techniques. Carbamazepine levels in hair ranged from 13.9 to 66.3 micrograms/g (mean 26.6 micrograms/g, median 20.9 micrograms/g) according to GC measurements. The immunoassay technique gave slightly higher results (mean 28.0 micrograms/g, median 22.1 micrograms/g). The blood concentrations of carbamazepine, using immunoassay (Abbott TDx) technique, ranged from 2.9 to 10.7 micrograms/ml (mean 6.2 micrograms/ml, median 5.7 micrograms/ml). Our data indicate the possible use of hair testing as a marker of the dosage history of patients under long-term treatment with CBZ.

Adolescent↗
PubMed1994

Open thrombectomy combined with thrombolysis in massive intracranial sinus thrombosis.

A case of complete thrombosis of the superior sagittal sinus in a pregnant women with multiple haemorrhages and hydrocephalus is described. Due to acute onset and progressive neurological deterioration, the decision was taken to remove the clot surgically. A sinotomy was performed removing the thrombotic material followed by local infusion of tissue plasminogen activator (t-PA). The combination of surgical removal and thrombolysis was life-saving for this young patient.

Adolescent↗
PubMed1992

CT showing early ventricular dilatation after subarachnoidal hemorrhage.

We performed a retrospective analysis of 398 patients with subarachnoidal hemorrhage (SAH) confirmed by CT. On the first CT examination the temporal horns were enlarged in 84%, the frontal horns in 32%, and the third ventricle in 21% of the patients. The amount of blood in the basal cisterns was highly correlated to dilatation of the temporal horns. The temporal horns were enlarged even when small amounts of blood were found in the cisterns. The frontal and temporal horns were dilated only when moderate or large amounts of blood were present in the cisterns. In 24 patients no blood was seen in the basal cisterns on CT performed within 5 days of the hemorrhage; none of the 3 patients with aneurysms showed normal temporal horns while 18 without demonstrable aneurysms had normal, and 3 had moderately dilated, temporal horns. Because the temporal horns cannot usually be seen at CT of healthy individuals, dilatation could be a useful sign in the diagnosis of SAH.

Adult↗
PubMed1990

New microsurgical suction tubes.

A set of new suitable microsurgical suction tubes has been designed especially suitable for fragile and delicate tissues such as the nervous and vascular tissues in the brain and spinal cord. The set provides two different shafts and five different tubes for superficial of deep micro- as well as macro-operations. These new suction tubes have two major advantages compared to traditional suction tubes. Firstly: the perforated smooth suction-tip allows continuous suction without damage to the tissue and secondly: the tubes are quickly and easily exchanged from the suction shaft when necessary.

Equipment Design↗
PubMed1989

Microvascular decompression for trigeminal neuralgia.

An analysis of 57 patients with trigeminal neuralgia (TN) treated with microvascular decompression (MVD) is presented. Mean follow-up time was 3.1 years. Vascular compression of the trigeminal nerve root was noted in 54 cases. In the remaining 3 patients, adhesions were observed in two, whereas no obvious cause was found in one case. Among the patients with vascular compression, 43 (80%) became painfree immediately after surgery, and have remained so during the observation period. There was an indisputable relationship between the degree of observed vascular compression of the nerve and long-term complete pain relief. There was no mortality in association with the surgery. Major morbidity was seen in 3.6%, and partial facial sensory loss was seen in seven patients (12%). The implications of these findings are discussed.

Adult↗
PubMed1989

The use of ultrasonic aspirator, Sonocut, for removal of brain tumours. Analysis of 26 consecutive cases.

Since the introduction of the ultrasonic aspirator system in 1978, there have been several reports on its efficacy and safety in neurosurgery. During the last six months we have used in our department the swedish manufactured device Sonocut for removal of various tumours within the central nervous system. Its benefits and limitations are discussed. Evaluation of the histological appearance of tissues removed by the aspirator versus conventional technics is presented.

Adult↗
PubMed1989

Neurotoxicity of benzylpenicillin in experimental renal failure and Enterobacter cloacae meningitis.

The neurotoxic potential of benzylpenicillin administered as a continuous intravenous infusion was studied in rabbits with intact blood-CNS barriers, experimentally established Enterobacter cloacae meningitis and experimental renal failure, secondary to cephaloridine-induced acute tubular necrosis after iv administration. The concentrations of benzylpenicillin in serum, CSF and brain tissue fluid were assayed at the onset of epileptogenic electroencephalographic activity. The brain tissue concentrations of benzylpenicillin were consistently higher than those in CSF in both infected and uninfected animals. The highest brain tissue fluid concentrations of benzylpenicillin were found in rabbits with renal failure after cephaloridine pretreatment. The brain tissue fluid concentrations of benzylpenicillin rather than the CSF concentrations were decisive for neurotoxicity. Cephaloridine-induced uraemia, but not the combination of uraemia and meningitis, resulted in a significantly increased tolerance of high intracerebral concentrations of benzylpenicillin before EEG-changes were precipitated.

Acute Kidney Injury↗
PubMed1989

Local anesthesia prevents hypertension following application of the Mayfield skull-pin head holder.

A marked hypertensive response is often seen when the Mayfield skull-pin device is applied to stabilize the head of the anesthetized patient for neurosurgery. In a prospective, blinded and randomized trial, 10 patients received an infiltration block of 0.5% mepivacaine with epinephrine 5 micrograms/ml (3 ml at each pin site) 1 min before the Mayfield holder was applied. Ten patients received normal saline and served as controls. All patients were under general anesthesia induced with sodium pentothal, fentanyl and pancuronium, and maintained with isoflurane in nitrous oxide/oxygen and increments of fentanyl. In the control group, there were significant increases in mean arterial pressure (mean increase 43%, P less than 0.001) and heart rate (15%, P less than 0.01) at 0.5, 1 and 2 min after application. In the mepivacaine group, no significant changes occurred. Infiltration of local anesthetic with epinephrine can thus safely protect against potentially dangerous increases in arterial pressure when the Mayfield holder is used.

Anesthesia, Local↗
PubMed1988

Stabilization of the unstable upper cervical spine in rheumatoid arthritis.

We present our clinical experience and the results of surgical treatment of 13 patients with rheumatoid involvement of the cervical spine, namely severe atlanto-axial dislocation. A posterior fusion was carried out using a bicortical H-shaped iliac crest bone graft and steel wire. Postoperatively all patients were immobilized for 8 weeks in a Halo cast. There were no postoperative complications and all patients showed a stable fusion confirmed by radiography. Complete pain relief was obtained in 9 patients, partial in 4.

Adult↗
PubMed1988

Neurotoxicity of benzylpenicillin: correlation to concentrations in serum, cerebrospinal fluid and brain tissue fluid in rabbits.

The neurotoxic potential of benzylpenicillin, administered as continuous intravenous infusion, was studied in rabbits. Thirteen animals were killed at the onset of epileptogenic EEG activity (seven) or convulsions (six). Benzylpenicillin levels were determined in serum, cerebrospinal fluid (CSF) and brain tissue fluid. High doses of benzylpenicillin were required to induce neurotoxicity; epileptogenic (EEG) changes were seen at serum levels of 510-960 mg/l and convulsions at 920-1902 mg/l. Neurotoxicity correlated well with levels of benzylpenicillin in brain tissue fluid, calculated as 10 x the concentration in whole brain tissue. The correlation of neurotoxic reactions to levels of benzylpenicillin in CSF was poor and the CSF levels were consistently lower than those in brain tissue fluid. The technique used was found to be a satisfactory, though laborious, way to study neurotoxicity of drugs.

Animals↗
PubMed1988

Neurotoxicity of benzylpenicillin in experimental Escherichia coli meningitis.

The neurotoxic potential of benzylpenicillin administered intravenously as a continuous infusion was studied in rabbits with experimental Escherichia coli meningitis. As controls a group of rabbits was injected with saline into the cisterna magna. The concentrations of benzylpenicillin in serum, CSF and brain tissue fluid were studied at onset of epileptogenic electroencephalographic activity (thirteen rabbits) or convulsions (ten rabbits), with a previously developed method for neurotoxicity studies. E. coli meningitis did not increase the neurotoxicity of benzylpenicillin, despite high concentrations of the drug in both CSF and brain tissue fluid. The intracisternal injection of saline in the control group produced slight pleocytosis in some rabbits indicating some degree of damage of the blood-CSF barrier.

Animals↗
PubMed1986

Fiber composition of the recurrent laryngeal nerve after experimental vagotomy and sympathectomy. A qualitative study by light and electron microscopy.

A qualitative study of the nerve fiber composition of the recurrent laryngeal nerve of the rat was performed by light and electron microscopy. Various surgical denervation procedures were employed to determine the origin of the variously sized myelinated fibers and the unmyelinated axons present within the nerve. After extracranial vagotomy all myelinated fibers degenerated, whereas some unmyelinated axons remained intact. Intracranial vagotomy on the other hand revealed that about 70% of the small (1.5-4.0 micron) myelinated fibers were unaffected, as were many unmyelinated axons. After sympathectomy, both kinds degenerated but normal unmyelinated axons could be found. Thus, the majority of the small myelinated fibers are afferent sensory fibers whose cell bodies are located in the vagal ganglia at the base of the skull. The medium and large myelinated fibers represent efferent neurons originating from the brain stem. The unmyelinated fibers emanate from at least three different sites, viz. the brain stem, the sensory vagal ganglia and finally the ganglia of the cervical sympathetic nerve trunk.

Animals↗