Biomedical subjects

D Kühne

Publications and source records attributed to D Kühne.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Chronic encapsulated intracerebral hematoma]].

The purpose of this case report is to describe chronic encapsulated intracerebral hematoma (CEIH), a rare and not fully understood brain lesion. The differentiation from chronic cerebral hematoma, cerebral abscess, and intra-axial tumor is based on clinical and imaging criteria. The diagnosis is confirmed by histological analysis. In the English medical literature, we found 39 patients reported with this lesion. The key feature is the formation of a capsule between a hematoma and cerebral parenchyma. The reasons for this formation are not known. In our patient, an arteriovenous malformation was located outside but adjacent to the CEIH.

Adult↗

PubMed2000

[Diagnostic imaging in viral encephalitis].

The diagnostic procedure in viral encephalitis is based on the synopsis of clinical signs and symptoms, serological data, CSF analysis and diagnostic imaging findings. This article summarizes the findings of those viral encephalitides most frequently encountered in Western Europe. MRI is more sensitive than CT for the detection of inflammatory brain lesions due to the higher contrast resolution. The pattern of parenchymal damage is highly specific in only some viral encephalitides (e.g., the frequently hemorrhagic lesions of structures of the limbic system in herpes simplex virus type I encephalitis; the symmetric and confluent lesions of the frontal white matter of progressive diffuse leukoencephalopathy in AIDS). In the majority of viral encephalitides MRI demonstrates the location and extension of parenchymal damage. The specific diagnosis in terms of the causative agent is based on serological studies.

Brain↗

PubMed2000

[Septic-embolic and septic metastatic brain abscess].

The hematogenous spread of bacteria, fungi and protozoa may also reach the brain vessels, which happens mostly through septic emboli. From such an embolus a metastatic focal encephalitis and later a septic-embolic brain abscess may arise. The most frequently underlying infections that may cause septic emboli are bacterial endocarditis as well as bacterial infections of artificial heart valve prostheses. Congenital heart malformations with a right-to-left shunt also play here a certain role. Basically, however, all septic conditions and bacteriemias may cause septic-embolic brain abscesses. They occur frequently as multiple lesions. MRI is superior to CT in depicting the different stages of evolution from focal encephalitis, through the hardly encapsulated early abscess, to the formation of a membrane and later a dense fibrous capsule. The medical treatment of a brain abscess requires properly performed CT or MRI follow-up examinations in order to realize early enough a possible growing of such a lesion.

Brain↗

PubMed2000

[Clinical aspects and diagnostic imaging in sarcoidosis of the nervous system].

The central nervous system is frequently affected during the course of sarcoidosis. Many of these lesions remain without clinical correlates. Unenhanced and contrast enhanced CT and MRI play an important role during the diagnostic work-up of patients with sarcoidosis and suspected or proved CNS involvement. This article summarizes the most frequent manifestations of neurosarcoidosis and provides illustrative examples of MRI findings.

Brain↗

PubMed2000

Bypass-surgery and coil-embolisation in the treatment of cerebral giant aneurysms.

OBJECTIVE: Operative clipping is the most effective method in the treatment of cerebral giant aneurysms. But about 50% of all giant aneurysms are treatable this way. We want to report about eight patients with giant cerebral aneurysms, which were in our opinion "unclippable" without causing ischaemia in depending brain areas. METHODS: We describe eight cases of giant aneurysms of the pericallosal artery (n = 1) the middle cerebral artery (n = 3), the basilar tip (n = 3) and of the upper part of the basilar artery (n = 1). One patient with an aneurysm of the pericallosal artery was treated with an extra-intracranial saphenous vein bypass saphenous bypass, in three cases of middle cerebral artery aneurysms an extra-intracranial bypass was also done combined with a resection of the aneurysm. The four patients suffering from an aneurysm of the basilar artery got an extra intracranial bypass too followed by an occlusion of the aneurysm with GD-Coils. RESULTS: There was no peri-operative mortality and no severe peri- or postoperative complication. The neurological symptoms of all patients were unchanged after the operation. An angiographic control showed a complete obliteration of the aneurysm and a free running bypass in all cases. CONCLUSION: Bypass surgery and combined bypass surgery and coil embolisation are effective methods in the treatment of giant cerebral aneurysms, which can not be treated by clipping alone.

Anastomosis, Surgical↗

PubMed2000

Practicality and accuracy of prehospital rapid venous blood glucose determination.

Blood glucose testing plays an important role in emergency medicine. Although the use of visual reagent test strips is widely established in this setting, the accuracy of reflectometric blood glucose determinations under emergency conditions has rarely been investigated. In a prospective study, 522 of a total of 3,217 patients undergoing emergency blood glucose testing had parallel blood glucose measurements performed using a specific enzymatic method. These 522 patients (aged 61.4 years, 54% men, 90 cases of severe hypoglycemia) had an intravenous access placed at the scene of the emergency. Venous whole blood from the introducer needle of the access was applied to the test strip and the glucose measured with a GlucoTouch reflectometer (LifeScan, Inc.). A blood sample from the intravenous access was then immediately collected in a monovette for subsequent glucose determination in a chemical laboratory (hexokinase method) within 20 to 40 minutes. The emergency glucose measurements (mean: 7.3 mmol/L [95% confidence interval [CI] 6.9 to 7.7]; range: 0.55 to 27.7) correlated well with the reference laboratory results (Pearson's r = .98; linear regression analysis: slope 1.0, axial intercept 1.74). Error grid analysis also showed good agreement between corresponding measurements: zone A 96.7%, B 2.5%, C 0% and D 0.8%. The mean difference using the Bland-Altman method was 0.14 mmoVL; 2 SD 1.8 mmol/L; minimum -7.0 mmol/L; maximum 4.4 mmol/L. The accuracy of the rapid venous blood glucose determination by constantly changing emergency teams was high. Especially in 90 hypoglycemic patients, there were no deviations from the reference method that could have led to clinically relevant wrong decisions. The method of collecting whole blood directly from the venous access is simple and robust, and is independent of the hemodynamic status of the patient.

Blood Glucose↗

PubMed2000

Combined endovascular-microsurgical treatment of tentorial-incisural dural arteriovenous malformations. Report of five cases.

Dural arteriovenous malformations of the tentorial edge are rare lesions with an unfavorable clinical course if left untreated. As yet no optimum treatment has been established. We retrospectively evaluated the results of our therapy concept, which consists of endovascular embolization followed by microsurgical obliteration, and compared the results to the relevant literature in order to clarify which therapeutic regimen seems to be optimum at the present time. In all of our five patients the lesion was completely obliterated, as proven by angiography, with favorable clinical results and low morbidity. Several other clinical series confirm our results, so we conclude that combined endovascular therapy and microsurgery is the optimum treatment for these lesions.

Aged↗

PubMed2000

Progressive spontaneous herniation of the thoracic spinal cord: case report.

OBJECTIVE AND IMPORTANCE: We report one case of spontaneous thoracic spinal cord herniation. To our knowledge, this is the first case involving radiological documentation of the development of herniation. Clinical features and surgical techniques are also presented. CLINICAL PRESENTATION: We describe the case of a 51-year-old female patient who experienced progressive Brown-Sequard syndrome for 2 years. Three magnetic resonance imaging examinations were performed; they revealed the progressive development of anterolateral spinal cord herniation at the level of T6 during those 2 years. INTERVENTION: After laminectomy at T6, the herniated myelon was microsurgically removed and the neurological symptoms improved. CONCLUSION: We present the possible causes, the proposed pathophysiological mechanisms, and the clinical and radiological development of this rare entity, with a review of the literature published to date. We propose that a preexisting weakness of the ventral dural fibers, combined with abnormal adhesion of the spinal cord to the anterior dural sleeve, leads to progressive herniation throughout life. Microsurgical treatment may halt the exacerbation of the neurological symptoms.

Brown-Sequard Syndrome↗

PubMed2000

Torquability of microcatheter guidewires: the resulting torsional moment.

Guidewires for microcatheters used for the subselective catheterization of small vessels must meet high quality requirements in regard to handling, steerability, radiopacity and physical properties. The aim of this paper is to classify one of the factors that determine the physical and mechanical parameters of a number of existing microcatheter guidewires. A torsion-testing equipment for guidewires was devised. Nitinol wires were tested and compared with the austenitic stainless steel variants. 13 different commercial wires were tested. Tensile strength, shear modulus and wire diameter are the determining factors of the torsional rigidity of guidewires. By interpreting the measured torsional momentums various statements concerning the torsional rigidity of different wires can be made. The properties of guidewires are characteristic features of a system and friction and flexible strength examinations have to be carried out to design new variants of wires to meet the requirements of interventional physicians.

Algorithms↗

PubMed2000

Intracranial vertebrobasilar stenosis: angioplasty and follow-up.

BACKGROUND AND PURPOSE: When medication fails to improve symptoms of atherosclerotic stenosis of the intracranial vertebral and basilar arteries, percutaneous transluminal angioplasty (PTA) is considered. However, because investigators disagree on the usefulness of this procedure, we conducted a retrospective study to evaluate the indications, efficacy, and safety of PTA. METHODS: Twenty patients underwent PTA of the vertebral (n = 14) or basilar (n = 6) artery, 18 for neurologic signs and symptoms of arterial stenosis that recurred or progressed despite pharmacotherapy and two prophylactically. Neurologic examinations were performed before and after the procedure and arterial patency was evaluated at follow-up by digital subtraction angiography and/or MR angiography. Imaging follow-up was available for 14 (70%) of the 20 patients, neurologic follow-up for 15 (75%). RESULTS: The stenosis was successfully dilated in all patients, and on follow-up neuroradiologic examinations, vessel patency could be seen in 12 (86%) of 14 patients. Only one (7%) of 15 patients who returned for a follow-up neurologic examination had new symptoms (caused by occlusion of the vertebral artery 4 months after the procedure). One patient had a reversible neurologic deficit and one had hemiparesis after PTA. No patient died as a result of PTA. CONCLUSION: In our study, PTA of intracranial vertebrobasilar arteries was associated with a low mortality and morbidity rate and with a high degree of patency. This technique may therefore be regarded as an effective means of improving the patency of stenotic arteries. In selective cases, it might be considered for use prophylactically.

Aged↗

PubMed1999

[Pseudoaneurysm of the extracranial internal carotid artery. Treatment by stent and coil implantation].

Pseudoaneurysms of the extracranial internal carotid artery (ICA) can be caused by external injury or may be due to spontaneous dissection. Pseudoaneurysms bear an increased risk of arterio-arterial embolism. Treatment of pseudoaneurysms is influenced by the location and the type of injury, associated injuries, collaterals to the ipsilateral hemisphere, neurological signs and symptoms, growth of the lesion and patient age. Potential treatment regimen include conservative and medical approaches with anticoagulation and antiplatelet therapy, extra-intracranial bypass, resection of the pseudoaneurysm with vessel reconstruction, ligation or endovascular balloon occlusion of the ICA. Pseudoaneurysms of the ICA adjacent to the skull base require a major surgical procedure. If there are contra-indications for vessel occlusion conservative or medical treatment used to be the only therapeutic alternatives. We report the treatment of two patients with extracranial ICA pseudoaneurysms after blunt injury with stent placement (in one case combined with coil embolization) as a further treatment option.

Adult↗

PubMed1999

Accuracy of intravascular microcatheter pressure measurements: an experimental study.

Intravascular pressure measurements are considered useful for the monitoring and assessment of endovascular treatment effects in intracranial vascular malformations. Experimental data on the accuracy of these measurements are limited. A flow phantom with defined intraluminal pressures and pulsatility flow waveforms was used in this study. Microcatheters commercially available for neuroendovascular procedures (length 140-155 cm), with different outer (0.5-0.83 mm) and inner (0.3-0.53 mm) diameters, were introduced into the phantom in the direction of flow. In a static experiment, pressure values from 0 to 75 mmHg were applied, and in the dynamic part of the experiment mean pressure values from 25 to 65 mmHg, with a pulsatile amplitude from 70 to 170 mmHg were employed. In the static experiment, there was a linear relationship between the pressure values obtained through the microcatheters and the local transducer of the flow phantom. The pulsatile experiments showed increased damping of the pressure waveforms with decreasing inner diameter of the microcatheters. However, the mean pressure values remained accurate. This experimental study has shown that mean pressure values can be accurately measured through microcatheters from 0.3-0.5 mm inner diameter and more than 140 cm in length. In vivo pressure measurements during interventional procedures are therefore reproducible and can be used for monitoring of embolization effects in patients.

Blood Flow Velocity↗

PubMed1998

[Clinical application of transcranial color-coded duplex ultrasound for detection of intracranial aneurysms].

We investigated 88 Patients with a total of 102 angiographically diagnosed intracranial aneurysms by means of transcranial colour coded Duplex sonography (TCCD) during a time period of 15 months. Both the size and the localization of the aneurysms were determined. Seventy aneurysms (77%) with a diameter of 16 +/- 8 mm (6-55 mm) were detectable, with excellent visualization in 36 (42%), moderate visualization in 34 (40%), and no sufficient visualization in 16 (16%) aneurysms, respectively. In another 16 cases (16%) there was no sufficient vone window. Thrombotic material inside the aneurysm was detectable in 16/20 cases (75%), visualization of coil embolized aneurysms in 12/25 patients (48%). TCCD allows the follow up of cerebral aneurysms, with the detection of thrombosis and treatment effects after embolization. The method is not valid for the detection of intracranial aneurysms.

Adolescent↗

PubMed1998

Toxic spongiform leucoencephalopathy after inhaling heroin vapour.

This is a report of clinical, CT and MRI findings in a patient with toxic spongiform leucoencephalopathy after heroin ingestion. The disease is observed in drug addicts who inhale pre-heated heroin. The clinical onset, which usually occurs some days or even longer after the last heroin consumption, is characterized by a cerebellar syndrome. The cerebellar hemispheres, the cerebellar and cerebral peduncles and the pyramidal tract may be affected. Spongiform demyelination is the morphological substrate of the lesions, which are not contrast enhancing, hypodense on CT and hyperintense on T2-weighted MRI. The frequently perfect symmetry of the affection of functional systems points to a toxic and/or metabolic pathophysiological mechanism.

Administration, Inhalation↗

PubMed1998

Endovascular therapy of brain AVMs prior to radiosurgery.

The purposes of this study were to determine the safety and efficacy of embolization of brain AVMs prior to radiosurgery and to evaluate the total obliteration rate achieved. The brain AVMs of 64 patients were subselectively embolized mainly with NBCA, platinum microcoils and/or PVA. The aim of embolization was the reduction of the target volume and/or the elimination of vascular structures bearing an increased risk of hemorrhage. Presenting symptoms were intracranial hemorrhage in 33 patients, a seizure disorder in 21 patients, and headache in 6 patients. Four AVMs had been detected as an incidental finding. The initial AVM volume was in the range of 0.5 to 84 cc (mean 17 cc). Grading of the AVMs according to the Spetzler-Martin scale showed the following distribution: grade I, 3x; II, 13x; III, 11x; IV, 17x; V, 4x; VI, 16x. A total of 300 endovascular procedures including 47 subselective catheterizations without and 253 with embolization were performed. A size reduction of the AVMs between 10% and 95% (mean 63%, median 70%) was achieved. Neurological symptoms due to treatment complications were transient in 12 patients, of minor clinical significance but permanent in 4 patients. Following radiosurgery, one patient died due to recurrent intracerebral hemorrhage. Three patients are doing well but refused final follow-up angiography. A total of 30 patients is currently within the latency interval after radiosurgery. Radiosurgery failed to obliterate the embolized AVMs in 16 patients. Angiography confirmed complete nidus obliteration in 14 patients. The endovascular treatment of brain AVMs prior to radiosurgery proved safe and effective and may be considered in either high grade or incidental AVMs. AVM obliteration after embolization and radiosurgery is less frequently achieved than after stereotactic irradiation of primarily small AVMs.

Adolescent↗

PubMed1998

Giant basilar artery aneurysms encorporating the posterior cerebral artery: bypass surgery and coil occlusion--two case reports.

Giant aneurysms of the basilar artery are rare. With a diameter of 25 mm or more they are often partially thrombosed and show atheromatous plaques. There are some problems in the treatment especially when the aneurysm is broadbased with bulbous origin encorporating the origin of the posterior cerebral artery (PCA). In many of these cases neither operative clipping alone nor coil embolization alone will be practical without causing an ischemia in the depending brain areas. We will report about two patients with giant aneurysms of the basilar artery involving the origin of the PCA and a combined surgical and interventional neuroradiological approach. Preoperatively both patients showed only mild neurological symptoms (slight left hemiparesis, incomplete hemianopsia). We anastomosed the superficial temporal artery as an extracranial-intracranial bypass end-to-side to the PCA followed by clipping the PCA out of the aneurysm. Next day embolization of the aneurysm with Guglielmi ditachable coils was done. Both patients recovered without complications. An angiographic control showed no more filling of the aneurysm and a free running bypass feeding the PCA. In our opinion this combined approach is an effective method to treat giant aneurysms of the basilar artery which involve the origin of the PCA when clipping alone is impossible.

Adult↗

PubMed1998

Detection of microemboli distal to cerebral aneurysms before and after therapeutic embolization.

PURPOSE: Recently developed interventional radiologic techniques, such as embolization with platinum coils, may induce thrombus formation within an aneurysm. The aim of the present study was to investigate the frequency of microemboli distal to untreated and treated cerebral aneurysms. METHODS: Among a total of 110 patients treated with platinum coil embolization, 35 patients (27 women and eight men, aged 50+/-10 years) who were at high risk of ischemic complications underwent emboli detection with a transcranial Doppler sonographic monitoring system. All patients were studied before and after coil embolization. The aneurysms were located at the internal carotid artery (n=14), the basilar artery (n=10), the middle cerebral artery (n=7), or the vertebral artery (n=4). Twenty-nine (85%) of 35 patients were monitored within 6 hours of the completion of treatment. RESULTS: Microemboli distal to the aneurysm were not detected in any of the patients before treatment. Microemboli were detected in 11 patients (31%) after embolization (mean, 16+/-21 per hour; range, 1-74 per hour). Microemboli were detected in five (71%) of seven patients in whom ischemic complications occurred after treatment, but in only six (21%) of 28 asymptomatic patients. This difference was statistically significant. The rate of occurrence of emboli in patients with ischemic complications (23+/-30 emboli per hour) was higher than in asymptomatic patients (10+/-7 emboli per hour), but this difference was not statistically significant. CONCLUSION: Microemboli were detected significantly more often in patients who suffered from cerebral ischemia after coil embolization of an intracranial aneurysm. This observation supports the definition of a high-risk group of patients with incomplete embolization or with a large-diameter, broad-neck aneurysm. The early detection of microemboli after treatment may be an indicator for excessive intraaneurysmal thrombus formation and could influence the decision for prophylactic treatment with heparin or aspirin.

Aneurysm↗

PubMed1996

[Acute epigastric pain after travel to the tropics. Emergency admission of a 28-year-old stewardess].

A 28-year-old stewardess was admitted to hospital with violent cramp-like pain in the right upper abdomen, which was accompanied by a single episode of watery pasty diarrhea. Over the next few days her symptoms persisted, she developed a high fever, and her general state of health deteriorated. Ultrasonography repeated on the fourth day then revealed a small space-consuming lesion in the right lobe of the liver. While the laboratory investigations initially remained negative, the suspected amebic abscess and colitis were subsequently also confirmed serologically.

Abdomen, Acute↗